There were no significant correlations between PWV and changes in BP or heart rate with standing (p > 0.05). Between EDS types, there were no differences in supine hemodynamics or PWV measures (p > 0.05). These data demonstrate that increased arterial elasticity is associated with lower BP in people with EDS which may contribute to orthostatic symptoms and potentially provides a quantitative clinical measure for future genotype-phenotype investigations.Ehlers-Danlos Syndromes (EDS) are a group of heritable disorders of connective tissue (HDCT) characterized by joint hypermobility, skin hyperextensibility, and tissue fragility. Orthostatic intolerance (OI) is highly prevalent in EDS however mechanisms linking OI to EDS remain poorly understood. We hypothesize that impaired blood pressure (BP) and heart rate control is associated with lower arterial stiffness in people with EDS. Orthostatic vital signs and arterial stiffness were assessed in a cohort of 60 people with EDS . Arterial elasticity was assessed by central and peripheral pulse wave velocity (PWV). Central PWV was lower in people with EDS compared to reference values in healthy subjects. In participants with EDS, central PWV was correlated to supine systolic BP (r = 0.387,  Ehlers-Danlos syndromes (EDS) are a collection of heritable disorders of connective tissue characterized by joint hypermobility, mild skin hyperextensibility, and tissue fragility . Common Pulse wave velocity (PWV) has emerged as the gold standard method for measuring stiffness of the arteries because of its reliability and reproducibility . PWV is While PWV is well accepted as a measure of arterial stiffness, it has been used far less often to measure arterial elasticity, which is the mathematical inverse of stiffness. More distensible arteries will stretch more as pulse waves travel, resulting in lower (slower) pulse wave velocity. Few studies have sought to identify people, including those with EDS, with suspected increased arterial elasticity and hence decreased PWV. One study evaluated PWV in nine people with comorbid hypermobile EDS and postural tachycardia syndrome (POTS) and found PWV measurements were not different compared to healthy controls . Two stuTherefore, the current study is the first assessment of PWV measurements in a large heterogeneous sample of people with EDS. We hypothesized that the collagen changes in EDS would confer an increased distensibility of the vasculature in all EDS types, and that this would contribute to orthostatic intolerance. In this study, we investigated central and peripheral arterial stiffness in people with EDS using the non-invasive measurement of pulse-wave velocity (PWV). We hypothesize that impaired blood pressure (BP) and heart rate control is associated with increased arterial elasticity in people with EDS.The National Institute on Aging (NIA) study Clinical and Molecular Manifestations of HDCT was designed to investigate the natural history of the most common HDCT. Emphasis was placed on the cardiovascular, musculoskeletal, and neurological complications of HDCT and the natural history of these complications. The original study protocol was designed to collect clinical and family history data, and to use this information to clarify the clinical distinctions between diagnoses. Consenting participants were initially classified based on diagnostic criteria in place at the time of their clinical visit at the NIA (2001–2013). Subjects contributing only biological samples were diagnosed either through a limited onsite evaluation or through review of submitted medical records. The HDCT NIA Dataset v. 2016 consented cohort includes 1009 participants with an average age of 39 ± 18 years . One hundred and ninety-four participants were 18 years or younger.The NIA study Clinical and Molecular Manifestations of HDCT began by assembling consented cohorts with a wide range of heritable HDCT, under an umbrella protocol . After the study was closed to enrollment, the Institutional Review Board approved the reorganization and migration of the data into a relational database repository and approved re-contacting participants to determine if they would be interested in participating in future research. The HDCT cohort data are provided in SAS datasets, PDF, Excel, MRI DICOM file formats and are now under the umbrella of protocol 11-AG-N079, Sample and Data Repository Protocol for NIA Studies. Participants were recruited from the pool of patients previously seen by the principal investigators and from patient support groups nationally. An authorized guardian provided consent for minor participants, with age-appropriate assent by the minor. In 2016, a signed Data Transfer Agreement between NIA and Penn State University resulted in transfer of a copy of the HDCT NIA Dataset v.2016 data repository to the Penn State University Clinical Translational Science Institute (PSU-CTSI). Datasets were accompanied by copies of original CRFs and SAS dataset codebook descriptions .Participants were stratified by EDS type including: classical, hypermobile, vascular, or other or unclassified according to the Villefranche nosology  as previThe analytic cohort for the present study was a subset of the EDS cohort from this NIA study of HDCT consisting of 60 participants who had both orthostatic BP recordings and PWV measurements. BP and heart rate were measured by brachial artery oscillometry in triplicate following 5 min in the supine, seated, and standing postures. Central arterial stiffness was measured by carotid to femoral PWV and peripheral stiffness by carotid to radial PWV.The methods used to assess PWV in this study were the same methods used in the Baltimore Longitudinal Study of Aging . In shorOrthostatic vital signs were measured by a brachial artery BP cuff on both arms. BP was measured supine then seated then during standing. Study participants stayed in each posture  for 5 min prior to BP recordings. BP was measured in triplicate in each position with one minute between recordings. If BP varied by 15 mmHg or heart rate by 10 beats/minute in one position, a fourth recording was measured. All BP and heart rate measurements on the left arm were averaged for each participant in each posture.n = 1455, Reference Values for Arterial Stiffness, 2010) [Descriptive statistics include demographic data and EDS type. Comparison of characteristics among types was performed using ANOVA with post-hoc Tukey-Kramer tests when justified. Pearson’s correlations were run between BP, heart rate, and PWV measurements for the entire cohort. We performed a stratified analysis of central PWV measurements by age in the EDS participants of all types and compared those values to age-matched reference values from a large cohort of healthy participants  .Overall our data set included 60  EDS participants age 13–70 years. There were no differences in age, height, weight, and body mass index between EDS participants of different types .Arterial elasticity did not differ by EDS type . Groupedp = 0.003). Post-hoc analysis showed that standing systolic BP was lower in participants with vascular EDS compared to those with hypermobile EDS (p = 0.021) and other/unspecified EDS (p = 0.002). Standing diastolic BP and heart rate also trended lower in the vascular EDS group  and seated (r = 0.399) systolic BPs and supine diastolic BP (r = 0.400). Peripheral PWV did not correlate to HR or orthostatic BP. Peripheral PWV was correlated to diastolic BP in the supine (r = 0.322), seated (r = 0.383), and standing (r = 0.323) postures. All significant correlations were positive indicating that lower PWV (more elasticity) is associated with lower BP in our cohort of EDS participants.Correlations of central and peripheral PWV to BP and heart rate are shown in This study used PWV to evaluate arterial stiffness in a diverse sample of people with different EDS types. This study provides three novel findings. We demonstrated that PWV is lower in people with EDS compared to reference values in the healthy population implying that their arteries are more elastic. We also found that lower PWV (indicating greater elasticity) is associated with lower systolic and diastolic BP in people with EDS. These findings may help explain the connection between EDS and impaired autonomic cardiovascular control. We also found no differences in PWV measurements among EDS types which suggests that the elasticity of the vasculature is similar among the diverse types of EDS.The clinical association between EDS and orthostatic intolerance was identified in 1999 by Rowe et al. who first hypothesized that the mechanism connecting these two disorders is an increased enhanced elasticity in the arteries of people with EDS, predisposing them to OI . Two decPWV has become the gold standard for assessing arterial structure because it is reproducible and aligns with more invasive measures. Its ease of use means it is available for testing in larger cohorts . PWV hasThree studies have previously measured PWV in people with EDS ,12,13. IThe issue of age-associated changes in vascular function in people with vascular EDS was addressed by Mirault et al. using ultrafast ultrasound imaging (a method used by this group to measure PWV). They reported that the age-associated increase in vascular stiffness was attenuated in the vascular EDS participants . We obseOverall, lower PWV is related to lower BP measurements but is not directly indicative of orthostatic tolerance in EDS. These findings are consistent with measurements in healthy subjects and in other patient populations in which PWV tracks similarly to BP . All sigWe did not see a difference in most orthostatic vital signs between EDS types. Systolic BP was slightly lower in vascular EDS which may reflect a difference in physiology or medications taken. Overall, there was a huge range in BP and heart rate responses to orthostasis which demonstrates inconsistent hemodynamic responses in this population and may reflect the presence of different types of OI. According to Roma, et al., about half of people with EDS have POTS (increase in heart rate of 30 beats/minute while standing) but others have orthostatic hypotension or hypertension [Strengths of this this study are the large sample size with a diverse EDS cohort including several EDS types, and the concomitant measurement of orthostatic vital signs and PWV. We compared central PWV measurements to published reference values in a large cohort. To our knowledge, there are no peripheral PWV reference values from large populations. The methods used in this study were consistent with study protocols used in the Baltimore Longitudinal Study of Aging .This study had several limitations. First, we did not include a contemporaneous control group in this study. However, we used reference values from a large cohort of healthy volunteers for comparison . Second,Overall, this is the first report of increased arterial elasticity in all types of EDS. The increased arterial elasticity was associated with lower supine and seated systolic and diastolic blood pressure in all types of EDS. We did not see differences in PWV in different types of EDS but standing systolic and diastolic blood pressure were lower in vascular EDS compared to the hypermobile and unspecified types. Our findings suggest that increased arterial elasticity may be related to impaired blood pressure control in EDS. Further studies are needed to determine whether this pathophysiological finding relates to orthostatic symptoms in people with EDS.


Malaria is a life-threatening disease associated with high morbidity and mortality. Helminths are among the most widespread infectious agents prevalent in tropical and subtropical regions of the developing world. Malaria and soil-transmitted helminthiasis (STHs) are coendemic and major public health problems in Ethiopia. The effects of helminth coinfection on malaria parasitemia remained poorly understood. Therefore, the objective of this study was to assess malaria parasitemia among malaria-monoinfected and malaria-soil-transmitted helminthiasis–coinfected febrile patients attending Sanja Hospital, Northwest Ethiopia. t-test, and one-way analysis of variance (ANOVA) were performed. A P value of <0.05 was considered as statistically significant.  A cross-sectional study with parallel groups was conducted to assess malaria parasitemia among malaria-monoinfected and malaria-soil-transmitted helminthiasis–coinfected febrile patients in Sanja Hospital from January to March 2019. Double population proportion formula was used for sample size calculation, and convenient sampling technique was used to select 134 study participants. Data were entered and analyzed by using the Statistical Package for Social Sciences (SPSS) version 20. Descriptive statistics, independent Ascaris lumbricoides 11 (16.4%) and Strongyloides stercoralis 2 (3%). The mean Plasmodium parasite density was significantly higher in malaria-STHs–coinfected patients than in patients infected with only Plasmodium parasite density was significantly higher in malaria-STHs–coinfected patients than in patients infected with only P value of <0.05 was considered as statistically significant. Plasmodium parasite density was significantly higher in malaria-STHs–coinfected patients than in patients infected with only F = 6.953, P value of <0.05 was considered as statistically significant.  From 134 malaria-positive study participants, 67 were malaria-monoinfected and 67 were malaria-STHs–coinfected patients. Out of 67 malaria STHs-coinfected patients, 54 (80.6%) were infected with hookworm followed by Plasmodium parasite density. The current study finding also revealed that increased worm burden of hookworm as expressed by egg intensity had significantly increased Plasmodium parasite density.Plasmodium parasite density was significantly higher in malaria-STHs–coinfected patients than in patients infected with only Plasmodium parasite density was significantly higher in malaria-STHs–coinfected patients than in patients infected with only  Infections with STHs, especially hookworm, were positively associated with  Plasmodium and transmitted by different species of female Anopheles mosquitoes. The five known species of Plasmodium parasites that cause malaria for humans are Plasmodium falciparum , Plasmodium vivax (P. vivax), Plasmodium ovale , Plasmodium malariae , and Plasmodium knowlesi (P. knowlesi) [Plasmodium parasites which cause malaria involve two hosts in their life cycle. During blood feeding, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host [Malaria is a disease caused by a protozoan parasite belonging to the genus nowlesi) . The Plaman host .Ascaris lumbricoides (A. lumbricoides), Trichuris trichiura (T. trichiura), and the hookworms Necator americanus and Ancylostoma duodenale [Human intestinal helminthiasis is most commonly caused by soil-transmitted helminths (STHs), namely, uodenale . Soil-truodenale . Transmiuodenale .Malaria and helminthiases are the two most common predominant infections affecting humans, overlapping in their epidemiological distributions and frequently coinfecting the same individuals . The occPlasmodium infection or increasing the risk. Helminths are believed to have greater generalized immunoregulatory consequences than their copathogens such as Plasmodium. During their lifetime, helminths do not simply ward off the immune attack but they regulate the host immune response to create niches that improve successful feeding and reproduction [Different immunological mechanisms induced by helminth infection have been emphasized as potentially protective against oduction .Plasmodium infection and skewed antiplasmodium antibody response towards the production of noncytophilic immunoglobulins  ineffective against malaria instead of cytophilic ones necessary for immunity of malaria (IgG1 and IgG3). This will lead to an increased incidence and severity of malaria. Another explanation for the observed interaction of malaria and STHs is that T cell with the regulatory function may be induced in helminthiasis-infected patients leading to suppression of Th1 cells and proinflammatory activity [Chronic helminth infection may enforce crossregulatory effects on the development of proinflammatory response to initial activity .There are a number of studies that assessed the magnitude of coinfection between malaria and STHs; however, there are no adequate reports which show the association of coinfection with the level of malaria parasitemia. Even though both malaria and STHs are common in Sanja town and the surrounding area due to the low land geographical nature of the area, there have been no studies conducted similarly to this study. Therefore, the present study was conducted to assess the association of STHs infection with malaria parasitemia in febrile patients attending Sanja Hospital, Northwest Ethiopia.An institutional-based comparative cross-sectional study was conducted to assess malaria parasitemia level among malaria-monoinfected and malaria-soil-transmitted helminthiasis–coinfected febrile patients attending Sanja Hospital, Northwest Ethiopia. Sanja is the capital of Tach Armachiho district which is surrounded by the Maho Stream and Sanja River. The town is located 65 km in the North of Gondar town and 792 km from Addis Ababa, northwest part of Ethiopia. Sanja has an altitude of 1800 m above sea level, with an annual rainfall range from 800 to 1800 mm, and the annual temperature range from 25°C to 42°C . An estin) was calculated by using a double population proportion formula with the assumptions of 95% confidence level, 5% of marginal error, 80% power (1 − β), and using prevalence of malaria, p1 = 16%  [p2 = 5%  [n is the required sample size.The required sample size (thiopia) , and prethiopia) . (1)n=2Therefore, the minimum required sample size was 122. By adding 10% for nonrespondent, we had the final sample size = 134 (67 for each group). Convenient sampling technique was used to select the study participants until the expected sample size was obtained.The sociodemographic characteristics were collected by trained data collectors and supervised by the principal investigator. All febrile patients suspected of having malaria in Sanja Hospital were the source population of this study. Before data collection, data collectors selected patients who fulfilled the inclusion criteria and taken consent or assent form. If the study participants were children, consent was taken from their parent or guardian. All laboratory confirmed malaria-positive patients who had the ability to give stool sample, and patients greater than 6 months of age were included in the study. Patients who had a history of antihelminthic treatment in the past four weeks prior to screening, had any parasitic infection other than STHs in addition to malaria, are pregnant or lactating mothers, and had the presence of any other known chronic infections were excluded from the study.Plasmodium infection and parasite quantification. The thin smear was used to identify the type of Plasmodium species. The number of parasite per microliter of blood was calculated as described in [μl of blood was calculated by dividing the number of asexual parasites by the number of WBCs counted and then multiplying by an assumed WBCs per μl of blood (standard number of WBC = 8000/μl). Thick and thin smears were prepared on a single slide for each acute febrile patient from capillary blood by finger prick using sterile lancet. Each blood smear was air dried and stained with Giemsa and examined under the oil immersion microscope objective. A hundred fields were examined before reporting a negative result. Thick smear was used to detect ribed in . It was ribed in . ParasitTwo qualified laboratory technologists had read all the slides independently, and the parasite densities were calculated by averaging the two counts.A. lumbricoides, 1–4999 EPG, 5000–49999 EPG, and ≥50000 EPG; T. trichiura, 1–999 EPG, 1000–9999 EPG, and ≥10000 EPG; and hookworm, 1-1999 EPG, 2000-3999 EPG, and ≥4000 EPG [Approximately 5 gm of fresh stool specimen was collected by using labeled screw-capped stool cup from each participant; then, wet mount and two Kato slides per sample were prepared for microscopic examination. Quantitative examination for STH was performed, and the average egg counts of the two Kato Katz slides were multiplied by 24 to obtain egg counts per gram of stools for each study participant . Egg cou4000 EPG .The questionnaire was pretested on patients from Tikl Dengay Health Center for its accuracy and consistency prior to the actual data collection, and appropriate one day training was given to data collectors about the objectivity and relevance of the study, confidentiality issues, study participants' rights, consenting, techniques of an interview, and laboratory test procedures and their quality control. Giemsa stain quality was checked by using the known positive and negative samples for every batch of prepared working solution. After the data collection process, the data were checked for completeness and any incomplete or misfiled questionnaires were checked again by the principal investigator. For quality purposes, 10% of Giemsa-stained and Kato Katz slides were reexamined by an experienced laboratory technologist who was blind for the first result , 18.t-test was used to show the mean differences of Plasmodium parasite density between Plasmodium-STH coinfected and those who were infected with Plasmodium parasites alone. One-way ANOVA was used to test mean differences of parasitemia with intensity level of STHs infection. P values less than 0.05 were considered as statistically significant.The data were checked before entering for analysis for its completeness. Then, data were entered into SPSS version 20.0 for analysis purposes. Before analysis, data were cleaned or checked for errors and missing observations. Descriptive statistics was used to give a clear picture of background variables like age and sex. The frequency distributions of independent variables were done. An independent Plasmodium parasites in which 242 (47.3%) were males and 270 (52.7%) were females. Among 512 malaria-positive patients who provided stool samples for STH detection, 134 study participants who fulfilled the inclusion criteria were included in the study. During blood smear examination, there were no discordant results, i.e., there were no differences between the two microscopists in species diagnosis, in parasite density of >50% discrepancy, or in the presence of parasites.A total of 2675 malaria-suspected patients visited Sanja Hospital from January to March 2019. From the total screened for malaria, 512 (19.1%) were found positive for Plasmodium-infected study participants, 72 (53.7%) were females. The mean (±SD) age of the study participants was 27 (±14) years and 25 (±14) years for malaria-monoinfected and malaria-STHs–coinfected patients, respectively. The majority, 92 (68.7%), of the study participants were from rural residences, 74 (55.2%) were farmers and 80 (59.7%) of them were unable to read and write. The predominant age group of the study participants was 15-45 years (73.1%)  .Plasmodium species parasite-infected and the other 67 were malaria-STHs–coinfected patients. The majority of the infection was due to P. falciparum 85 (63.4%) followed by P. vivax which is accounted for 38 (28.4%) of the cases and the remaining 11 (8.2%) were mixed infection with P. falciparum and P. vivax. The mean malaria parasitemia level in malaria-monoinfected and malaria-STHs–coinfected patients was 7543.12 and 11909.80, respectively. There was statistically significant differences in mean parasite density of Plasmodium among malaria-monoinfected and malaria-STHs–coinfected study participants. The mean parasitemia level was significantly higher in malaria-STHs–coinfected patients than in patients infected with only Plasmodium parasites (P = 0.027)  .A. lumbricoides 11 (16.4%) and S. stercoralis 2 (3%). Moreover, from malaria-STHs–coinfected study participants, Plasmodium parasite density was high in patients coinfected with hookworm followed by those coinfected with A. lumbricoides and S. stercoralis , i.e., the mean Plasmodium density in coinfection with hookworm, A. lumbricoides, and S. stercoralis was 15063.64, 11330.67, and 10200.00, respectively. However, the difference was not statistically significant  followed by nificant .Plasmodium and A. lumbricoides, 54.5% (6/11), 27.3% (3/11), and 18.2% (2/11) had light, moderate, and heavy infection with A. lumbricoides, respectively. As the intensity of hookworm infection increased, mean Plasmodium density was also increased in coinfected patients. The difference was statistically significant . Additionally, the study participants who had heavy hookworm infection had significantly higher Plasmodium densities as compared to lightly or moderately infected patients. However, the mean levels of Plasmodium density decrease as intensity increased in A. lumbricoides-infected cases even though the difference was not statistically significant  , 18.5% (10/54), and 14.8% (8/54) had light, moderate, and heavy hookworm infection, respectively, and out of 11 participants infected with = 0.552) .Plasmodium density had a heterogeneous association with different species of STHs in malaria-STHs–coinfected patients [Approximately 27% and 41% of the total population in Ethiopia live in high and low malaria transmission areas, respectively . Moreovepatients , 24.Plasmodium was higher in malaria-STHs–coinfected patients as compared with patients infected with Plasmodium parasite alone. This indicates that helminth infection increases some degree of risks for the development of malaria severity by increasing parasite density of the patients since high parasite density could be a potential factor for the development of severe malaria. This result is also in agreement with the previous studies conducted in Southern Ethiopia [P. falciparum density inclined to be higher among children infected with STHs than those which are not infected with STHs. This might be due to the fact that helminths modulate the host immune response both to themselves and to coexisting infections or to the downregulation of the immune system by helminths. Consequently, the Plasmodium parasite could enter into the host and multiply at a faster rate in patients coinfected with STHs [The present study showed that the mean parasitemia density of Ethiopia  and findEthiopia . Additioith STHs .Plasmodium parasites [Plasmodium antigen [Plasmodium species, and complex nature of helminth and Plasmodium interaction when they coexist in a host.The present findings appear to verify the hypothesis that clinical malaria can be intensified during concomitant infection of intestinal helminths and arasites . Helmint antigen . Worm in antigen . However antigen –31. The Plasmodium density level than coinfection with A. lumbricoides. This means that hookworm is associated with increased Plasmodium density which suggests a positive association between hookworm infection and occurrence of severe malaria. The finding is in agreement with the previous reports [A. lumbricoides infection showed less Plasmodium density level than coinfection with hookworm which associated with reducing malaria severity. This finding was comparable with the studies which showed the protective effect of A. lumbricoides to reduce the severity of malaria [The current study also demonstrated that malaria with hookworm coinfection showed higher  reports , 29. In  malaria , 32. ThiThe first hypothesis for the association of helminths with protection from severe malaria was that helminths led to an increase in IgE complexes that activated the CD23 and thus releases the anti-inflammatory IL10 and activated the inducible nitric oxide synthase, which led to the release of nitric oxide (NO) and reduced sequestration of parasitized red blood cells .The second hypothesis is that worms decrease cytophilic IgG1 and IgG3 antibodies, which are necessary for malaria immunity, whereas it increased the noncytophilic IgG2, IgG4, and IgM antibodies. Consequently, it leads to an increase of severity of malaria .Plasmodium densities compared to heavily infected patients. Moreover, the study participants who had heavy hookworm infection had significantly higher Plasmodium densities as compared to lightly or moderately infected patients. Thus, a positive association between worm burden as expressed by egg intensity and Plasmodium parasite density was observed, which suggests that with the time course of the infection, such patients with high density of both hookworm and Plasmodium will tend to develop severe form of clinical malaria by influencing the immune response during coinfection [A. lumbricoides was associated with higher Plasmodium parasitemia, while those with heavy A. lumbricoides infection were found to have lower parasitemia, suggesting a positive interaction between hookworm infection intensity with Plasmodium densities whereas negative association between A. lumbricoides intensity with Plasmodium densities.In the current study, study participants infected lightly with hookworm had significantly lower nfection . HoweverPlasmodium density changes could have arisen due to the differences in the study groups, immune status of the study participants, differences in infecting Plasmodium species, differences in residence country, or complex nature of helminth and Plasmodium interaction when they coexist in a host.This finding was comparable with the previous studies that were conducted in different parts of Ethiopia like Alaba Kulito and Gilgel Gibe which suggested that STH infections especially hookworm aggravate the severity of malaria , 29. HowPlasmodium parasite density. The current study finding also revealed that increased worm burden of hookworm as expressed by egg intensity was associated with increased Plasmodium density which could be a density-dependent risk factor for the development of severe malaria with the course of the disease.In the current study, infections with STHs were positively associated with


Rapid diagnostic tests (RDTs) are selected based on their performances. Here, we compared the diagnostic performance of different malaria RDTs. Pf/Pan, Meriline-Meriscreen Pf/Pv/Pan, Right Sign Malaria Pf/Pan, and Right Sign Malaria Pf RDTs at Melen Regional Hospital in Gabon.Febrile patients were tested for malaria using Vikia Malaria In total, 120 of 274 tested children (43.8%) had malaria. The sensitivity was > 95% for all RDTs, while the specificity was > 85% for two tests. One test generated invalid tests (8%). Based on their performances, all tests except one may be recommended for malaria diagnosis.  Pf/Pan and Right Sign Pf have never been evaluated. In the present study, we compared the performances of four different RDTs for malaria diagnosis, namely, VIKIA Malaria Pf/Pan, Meriline-Meriscreen Pf/Pv/Pan, Right Sign Malaria Pf/Pan, and Right Sign Malaria Pf kits. The comparison was carried out between these tests and previous data. Microscopy was used as the gold standard method.The World Health Organization (WHO) recommends the use of microscopic examination or rapid diagnostic tests (RDTs) for the biological diagnosis of malaria in febrile patients before the prescription of antimalarial drug treatmentThis cross-sectional study was performed between April and June 2016 at the Clinical and Operational Research Unit located at the Melen Regional Hospital (RHM), a sentinel site for malaria survey in Gabon. The patients examined in this study had a temperature - > 37.5°C or a history of fever 48 h prior to their visit. The following data were collected after obtaining the patients’ consent to participate in the study: body temperature, fever status, age, sex, and any intake of antimalarial drug before consultation.Blood (1 mL) samples were collected from each patient in an ethylenediaminetetraacetic acid (EDTA)-coated tube and subjected to malaria diagnosis using RDTs and microscopy by an experienced staff. The Lambaréné’s method was employed for microscopic examination, as previously described by Planche et alPf/Pan  kit that detects the histidine-rich protein-2 (HRP-2) antigen specific to Plasmodium falciparum and aldolase, an enzyme common to all Plasmodium species. Its sensitivity is known to range from 89.1%Three RDTs were in a cassette format. We first tested the VIKIA® Malaria Pf/Pv/Pan  kit. In this kit, the ‘Pan’ line is coated with an anti-Plasmodium lactate dehydrogenase (pLDH) antibody specific topLDH common to all Plasmodium species, the ‘Pv’ test line is coated with an anti-pLDH antibody specific for P. vivax, while the ‘Pf’ test line is coated with an anti-HRP2 antibody. This RDT exhibited a sensitivity of 100%, as reported by the manufacturer.We then tested the Meriline-Meriscreen Malaria Pf/Pan test  allows the detection of HRP2 and aldolase. This test, when used with clinical samples, has sensitivity values between 98.0% and 99.9%The Right Sign Malaria Pf/Pan, Meriline-Meriscreen Pf/Pv/Pan, Right Sign Malaria Pf/Pan, and Right Sign Malaria Pf kits were added into neighboring wells. Results were obtained after 10 to 25 min.According to the manufacturer instructions, 5 µL of whole blood samples were dispensed in wells, and three to five drops of the buffer from VIKIA Malaria P. falciparum-positive, P. vivax, P. ovale, or P. malariae-positive, and/or P. falciparum and Pan-positive samples were determined according to the type and number of colored bands. Results were not validated when no control line was displayed.The interpretation of these three tests was similar and carried out according to the manufacturer’s instructions. Negative, Pf test  captures the HRP2 antigen on the strip. Its sensitivity is >99.0%. Whole blood (10 µL) was added into a tube and mixed with three drops of buffer. The test strip was vertically inserted into the tube and the results were obtained after 10 min. Appearance of two colored bands (control line ‘C’ and test line ‘T’) indicated P. falciparum-positive result, while a single colored line on the control line ‘C’ corresponded to negative results. Results were invalid in the absence of any color on control line.The Right Sign Malaria RDTs were stored between 19°C and 25°C as per manufacturers’ instructions (5°C-30°C). The integrity of the desiccant was controlled in each box containing RDTs before use. The tests were performed by trained members and experienced laboratory technicians.Experienced technicians read blood smears and in case of discordance, slides were judged by a third reader. The two closest parasitemia were considered to determine the median parasite density. The study was performed at one of the five sentinel sites for malaria survey of the Gabonese Ministry of Health. The Department of Parasitology Mycology served as the reference laboratory for the Malaria National Control Program and has the approval of the health authorities to perform free malaria diagnoses for febrile patients to monitor malaria morbidity and evaluate RDTs at all sentinel sites. After information and appropriate explanations, the parents or legal guardians of all children willing to participate in the study signed an agreement before sampling. P. falciparum mono-infection, non-P. falciparum species infection, and mixed infection . Sensitivity (Se), specificity, negative predictive value, positive predictive value, false positivity, and false negativity were assessed and compared. A p-value less than 0.05 was considered significant.Data were recorded on a case report form (CRF) and entered in an Excel sheet. Statistical analysis was performed using StatView 5.0 . Microscopy was considered as the gold standard method. RDT results were categorized as negative, Overall, 274 patients were selected during the study period, among which 50.5% (n = 138) were male. The median age was 5 [1.5-9] years; 49.2% (n = 135) of the participants were less than 5 years old. Among all patients, 77.0% (n = 211) had fever on the day of consultation and the median temperature was 38.5°C (38-39.2°C). Less than one-third of all patients  consumed an antimalarial drug prior to their visit. P. falciparum was the only parasite species identified. In the infected patients, the median parasite density was 10,500  P/µL. Parasitemia levels ranged from 35 to 420,000 P/µL. The parasite density in 6 (5%) and 10 (8.3%) patients was less than 500 P/µL and between 500 and 1,000 P/µL, respectively, while 104 (86.7%) patients had more than 1,000 P/µL.Based on microscopy analysis, almost half of patients  had a positive blood smear (PBS). Pf/Pan kit, 51.8% ofcases (n = 142/274) using Right Sign Malaria Pf/Pan kit, and 51.1% ofpatients (n = 140/274) using Right Sign Malaria Pf test. The Meriline-Meriscreen Pf/Pv/Pan test detected 46.0% (n = 126/274) of infected individuals. Invalid results were observed with the Meriline-Meriscreen test  of thepatients using VIKIA Malaria een test . More than 95% of PBS were confirmed positive using the RDTs tested. The proportion of false-positive results varied between 14.1% and 17.5% depending on the RDTs. False-negative results were observed in less than 5% of febrile cases.Pf and Meriline-Meriscreen Pf/Pv/Pan tests. The specificity was above 80% . Samples (n = 3) with parasitemia below 200 P/µL were positive with all RDTs. Two samples with a parasite density of 2,800 and 4,900 P/µL were negative with all RDTs  and Meriline-Meriscreen Pf/Pv/Pan (97.2%) tests tended to be slightly higher than that of VIKIA Malaria Pf/Pan (96.7%) and Right Sign Malaria Pf/Pan (95.8%) tests. In other malaria endemic countries, RDTs targeting same antigens had lower sensitivity values. For instance, the sensitivity values for the detection of HRP2 and pLDH were 85.7% for Paracheck TM-Pf, 88.2% for SD Bioline Ag-Pf/Pan, and 90.2% for SD 05FK60PfIn the present study, we compared four malaria RDTs with light microscopy at a sentinel site to evaluate their performances. The sensitivity was above 95% and similar for all RDTs tested. These results are comparable to the previously obtained data in GabonThe different RDTs tested herein had relatively low specificity  in comparison to the RDTs detecting HRP2 and pLDH in Ethiopia (98.6%)Pf/Pan kit had the highest frequency of false-positive cases (17.5%). This observation may be related to the release of parasite antigens or undetectable asexual parasite density or gametocytemia by all tests. This proportion of false positive cases is high, given that this rate should be less than 10% for all the RDTs selectedThe proportion of false-positive cases was also similar between all kits and ranged from 14% to 17%, although the Right Sign Malaria Pf/Pan and Right Sign Malaria Pf tests have already been assessed for malaria diagnosis in Gabon under the trade name Acon®Pf/PanPf tests were similar to those reported 4 years ago. Right Sign Malaria P. falciparum was the only species detected by microscopy and RDTs; one patient was diagnosed with a non-P. falciparum infection using two RDTs. The WHO/RDT/FIND/CDC recommends a detection score of P. falciparum in at least 75% samples with a parasite density of 200 parasites/µLMeriline-Meriscreen is the only RDT that provided invalid results at a rate of 8.4%, raising concerns related to its storage and transportation. This rate should be less than 5%Our study has some limitations. Although microscopy remains the gold standard method, molecular techniques for DNA amplification exhibiting high sensitivity values for low parasitemia detection could have provided better estimates of the frequency of false-positive results. However, the procedure of blood smear examination and good quality control of slide reading may have reduced the risk of misdiagnosis.P. falciparum or mixed infections. The negative predictive value was above 97% for all tests. The use of these tests will undeniably help in the diagnosis of malaria in situations where microscope is unavailable, with an exception of Meriline-Meriscreen Pf/Pv/Pan test. This study also highlights the importance of regular RDT surveys before their deployment to identify the possible changes in their on-field accuracy. In conclusion, these RDTs exhibited very good sensitivity (above 95%) despite low specificity (lower than 90%) for the detection of


Plasmodium falciparum-infected red blood cells cause an inflammatory response that can interfere with maternal–fetal exchange, leading to poor growth. The type I interferon (IFN-I) pathway plays an immunomodulatory role in viral and bacterial infections, usually by suppressing inflammatory responses. However, its role in placental malaria is unknown. This study examines the cytokine responses in placental tissue from subsets of malaria-infected and uninfected women, and attempts to correlate them with particular birth outcomes.Maternal malarial infection leads to poor perinatal outcomes, including low birth weight from preterm delivery and/or fetal growth restriction, particularly in primigravidas. In placental malaria, 40 whole placental biopsy samples were obtained from pregnant women at least 16 years of age recruited to a larger prospective chemoprevention trial against malaria. These were patients at Tororo District Hospital in Uganda, an area of high malaria endemicity where approximately 40% of women have evidence of malaria infection at delivery. They were regularly followed at a local clinic and monitored for fever, with blood smears performed then and at time of delivery to diagnose malaria infection. Placenta biopsies were taken for histological diagnosis of placental malaria, as well as quantitative PCR analysis of genes in the IFN-I pathway . Parameters such as infant birth weight and gestational age were also recorded.Histological analysis revealed placental malaria in 18 samples, while 22 were found to be uninfected. RT-PCR analysis showed a four-fold increase in IFN-β and IL-10 expression in multigravidas with placental malaria when compared to gravidity-matched, uninfected controls. This effect was not observed in primigravidas. Interestingly, linear regression analysis showed a positive association between IFN-β levels and higher birth weights . This association was strongest in primigravidas with placental malaria .These results demonstrate differential regulation of the IFN-I pathway in placental malaria according to gravidity, with the greatest anti-inflammatory response seen in multigravidas. The association between IFN-β levels and higher birth weight also suggests a protective role for IFN-I against fetal growth restriction in placental malaria. Plasmodium falciparum-infected red blood cells (RBCs) cause an inflammatory response that can interfere with maternal–fetal interchange and lead to fetal growth restriction [Almost half of the world’s population is at risk for malarial infection, which led to 429,000 deaths in 2015 –10. In ptriction –16.Plasmodium, spread by the bite of infected Anopheles mosquitoes. Five species are known to infect humans and are endemic to particular regions across the globe [Plasmodium falciparum is considered the most pathogenic, causing systemic infection that can be fatal when spread to the brain. During pregnancy, P. falciparum can also sequester infected RBCs in the placental intervillous spaces [Malaria is caused by the protozoan parasite he globe . Plasmods spaces , 18. In s spaces , 12. Stus spaces . Howevers spaces . This grs spaces –15, 20. s spaces –16.Plasmodium parasites do not invade placental cells and therefore do not directly damage the integrity of this interface, they do trigger inflammatory changes that impair trophoblast migration into the placenta, which is necessary for maternal spiral arteries to transform and improve the blood supply [The growth of the developing fetus is dependent on the efficient delivery of maternal blood to the placenta. While d supply , 16. Thid supply , 21. Up d supply , 22. Mald supply .There have been numerous efforts made towards elucidating the nature of the immune response to malaria. It is believed that adaptive immunity plays a significant role in protecting the host from recurrent malarial infections, particularly in placental malaria, where subsequent pregnancies appear to show a reduced risk of infection and clinical sequelae compared to primagravida cases , 23, 24.This study sought to compare the cytokine expression in placental samples with histologic evidence of malaria infection versus uninfected tissue, to see if it corresponded to either an increased or suppressed inflammatory pattern. Whether this phenotype changed based on gravidity, an important risk factor for worse malaria outcomes in pregnancy, was also examined. Placental tissue was collected from 40 patients recruited into a large malaria chemoprevention trial at the Tororo District Hospital in Uganda , an areaThis is a nested prospective cohort of 300 pregnant women enrolled in a randomized controlled trial (RCT) in Tororo, Uganda for one of three chemoprophylactic regimens against malaria . Tororo Additional placenta biopsy specimens taken from all available RCT enrollees delivering from January to February 2015 were selected for this study for RT-PCR analysis.Whole placenta specimens were obtained within 30 min of delivery. As part of the parent study, 1 × 1 cm blocks were collected, fixed and processed as previously described  for histWhen comparing patient characteristics, P-values were calculated by two-tailed student’s t-tests or Fisher’s exact test. For comparisons of cytokine expression between uninfected and placental malaria cases, P-values were calculated by two-tailed student’s t-test with Bonferroni’s correction. Associations with gene expression levels and birth weight were analysed by linear regression. All statistical analysis was performed with Stata 13 or Prism 6.This study analysed placental tissue from a subgroup of 300 women enrolled in a chemoprophylactic trial against malaria, including all samples from the 40 who delivered between January and February of 2015. Those 40 patients were evenly distributed between the three treatment arms. Through histopathological examination, placental malaria was diagnosed in 18 samples (45%), and the remaining 22 placentas (55%) were characterized as “uninfected”. In all 18 cases of placental malaria, no parasites were visualized–only pigment was found as evidence of past infection. Active infection diagnosed by tissue histology was also rare in the larger cohort. All patients were provided with a long-lasting insecticidal net at the time of enrollment into the Uganda study, where compliance was noted to be >85% between all treatment groups. Patients were asked to report to the study clinic for any fevers, at which time blood smears were taken to evaluate for malaria infection. Interestingly, of the 22 women in the “uninfected placenta” group, 4 (18%) actually had symptomatic malaria during pregnancy. Furthermore, of the 18 women with placental malaria, only 8 (44%) had symptomatic malaria diagnosed during pregnancy. The remaining characteristics of these two groups are outlined in Table Data represent the mean and standard deviation or n (%). P values were calculated by two-tailed student’s t-tests or Fisher’s exact test.RNA extracted from whole placental biopsies was analysed by quantitative RT-PCR (qRT-PCR) for expression of six cytokines of interest in the type I  and type II  interferon pathways. This qRT-PCR analysis was performed in a blinded fashion . The results were then stratified according to whether the samples were “uninfected” or diagnosed with placental malaria, as well as maternal gravidity status.In multigravida samples, placental malaria was associated with elevated transcription levels of all six cytokines compared to uninfected controls Fig. . This diThe cytokine expression profiles of individual samples were plotted with the corresponding infant birth weight to look for possible relationships between the inflammatory response and clinical outcomes. Linear regression analysis of all samples combined showed a positive association between IFN-β levels and higher birth weights , the demographic group at highest risk of adverse outcomes from placental malaria.Studies have shown primigravidas to be more susceptible than multigravidas to complications during malaria infection, such as low birth weight from preterm delivery and/or fetal growth restriction , 23, 24.P. falciparum [The placenta represents a complex environment where the maternal immune defenses are intentionally suppressed to prevent rejection of the fetus. However, malaria infection of the placenta stimulates cell-mediated immune responses that trigger the local production of inflammatory cytokines such as IFN-γ, IL-2, and TNF, which are believed to account for the placental pathology and adverse pregnancy outcomes that are particularly noted in primigravida women –35. Pathlciparum , and lowlciparum . Unfortulciparum . IL-10 hlciparum –41. IL-1lciparum . The resWhen examining the transcription levels of a subset of cytokines in the IFN-I signaling pathway, a four-fold increase was found in IFN-β and IL-10 expression in multigravidas with placental malaria when compared to gravidity-matched, uninfected controls. Interestingly, this pattern was not seen in primigravid samples. As cases of placental malaria have better perinatal outcomes in multigravida pregnancies than in primigravida pregnancies, and placental inflammation is a mechanism for fetal growth restriction, it was hypothesized that the increased expression of these cytokines in multigravid women is responsible for this difference. Further supporting this finding, linear regression analysis of the cohort data showed a positive association between IFN-β levels in placental samples and higher birth weights in the corresponding infants. Of note, this association was strongest in primigravidas with placental malaria. One possibility is that their overall lower expression of IFN-β makes them more sensitive to its effects. The mechanism by which increased gravidity raises the expression of these cytokines in placental malaria remains unclear. However, these results demonstrate a differential regulation of the IFN-I pathway in placental malaria according to gravidity, with the greatest anti-inflammatory response seen in multigravidas. This association between IFN-β levels and higher birth weight may point to a protective role for IFN-I against fetal growth restriction in placental malaria.In placental malaria, the type I interferon pathway is differentially regulated in primigravidas compared to multigravidas. Upregulation of the type I interferon pathway in multigravid women suggests a gravidity-dependent anti-inflammatory response. The association between IFN-β levels and higher birth weight suggests a protective role for type I interferons against fetal growth restriction in placental malaria.


P. falciparum malaria. For this purpose, a clinical and parasitological follow-up on malaria was conducted among 656 infants in southern Benin. G3m allotypes  were determined by a serological method of hemagglutination inhibition. FcgRIIA 131R/H and FcgRIIIA 176F/V genotypes were determined using the TaqMan method and FcgRIIIB NA1/NA2 genotypes were assessed by polymerase chain reaction using allele-specific primers. Association analyses between the number of malaria infections during the follow-up and polymorphisms in IgG G3m allotypes and FcgR were studied independently by zero inflated binomial negative regression. The influence of combinations of G3m allotypes and FcgRIIA/FcgRIIIA/FcgRIIIB polymorphisms on the number of P. falciparum infections, and their potential interaction with environmental exposure to malaria was assessed by using the generalized multifactor dimensionality reduction (GMDR) method. Results showed that individual carriage of G3m24 single allotype and of G3m5,6,10,11,13,14,24 phenotype was independently associated with a high risk of malaria infection. A risk effect for G3m6 was observed only under high environmental exposure. FcgRIIIA 176VV single genotype and combined carriage of FcgRIIA 131RH/FcgRIIIA 176VV/FcgRIIIB NA1NA2, FcgRIIA 131HH/FcgRIIIA 176FF/FcgRIIIB NA1NA1, FcgRIIA 131HH/FcgRIIIA 176VV/FcgRIIIB NA2NA2 and FcgRIIA 131HH/FcgRIIIA 176VV/FcgRIIIB NA1NA2 genotypes were related to a high number of malaria infections. The risk was accentuated for FcgRIIIA 176VV when considering the influence of environmental exposure to malaria. Finally, the GMDR analysis including environmental exposure showed strengthened associations with a malaria risk when FcgRIIA/FcgRIIIA/FcgRIIIB genotypes were combined to G3m5,6,11,24 and G3m5,6,10,11,13,15,24 phenotypes or G3m10 and G3m13 single allotypes. Our results highlight the relevance of studying IgG heavy chain and FcgR polymorphisms, independently as well as in combination, in relation to the individual susceptibility to P. falciparum infection. The intensity of individual exposure to mosquito bites was demonstrated to impact the relationships found.The binding of immunoglobulin (Ig) to Fc gamma receptors (FcgR) at the immune cell surface is an important step to initiate immunological defense against malaria. However, polymorphisms in receptors and/or constant regions of the IgG heavy chains may modulate this binding. Here, we investigated whether polymorphisms located in FcgR and constant regions of the heavy chain of IgG are associated with susceptibility to  Malaria remains the most lethal parasitic disease in the world. According to the latest world malaria report in 2019, 228 million estimated cases of malaria occurred in 2018 while the estimated number of deaths remained a concern, 429 000 in 2017 and 405 000 in 2018  expressed at the surface of immune cells such as monocytes, macrophages, or neutrophils  of the heavy IgG chains. Allelic variations found in the CH1, CH2, and CH3 IgG chains can lead to variations in the amino acid sequences of IgG subclasses and therefore in their efficiency to bind to their receptors. These amino acid changes are responsible for antigenic determinants named human immunoglobulin Gm (gamma markers) allotypes. There are four allotypes for IgG1 in the CH1 and CH3 constant domains called G1m , one allotype for IgG2 in the CH2 constant domain called G2m23 and thirteen allotypes for IgG3 in the CH2 and CH3 constant domains called G3m  , 13. TheP. falciparum malaria, a preferential expression of G3m10, G3m11, and G3m14 allotypes associated with a risk of anemia  and 131H (Histidine) firstly described according to their IgG2 binding efficiency, which is more affine for the 131H variant . BindingFcgRIIIA receptor plays an important role in phagocytosis and degranulation and presents two allotypes variants consisting in either F  or V  in position 176, the 176V variant offering a better affinity for IgG1 .FcgRIIIB is a C-terminus linked glycosylphosphatidylinositol (GPI) receptor expressed at the surface of neutrophils and eosinophils. A strong affinity for IgG1 and IgG3 was described . The FcgVarious studies have investigated the relationships between polymorphisms in FcgRIIA, FcgRIIIA, and FcgRIIIB receptors and malaria immunity. Omi et al.  showed aP. falciparum malaria. More precisely, the relationships between FcgRIIA 131R/H, FcgRIIIA 176 F/V, FcgRIIIB NA1/NA2, Gm allotypes, and malaria phenotypes were determined in a cohort of Beninese infants.As presented above, the individual susceptibility to malaria has yet been related to polymorphisms located either in the constant domains of the IgG heavy chain or in several FcgR, considered independently. We can hypothesize that the anchoring of IgG on its cellular receptors can be favored according to the respective variants on both sides. For this purpose, the present study investigated the combination of polymorphisms at both IgG constant domains and FcgR with the aim to evaluate their joint impact on susceptibility to Plasmodium rapid diagnostic test (RDT) and a thick blood smear examination (TBS) by optical microscopy were performed.The study was conducted in three health centers from the district of Tori Bossito located in southwest Benin, where 656 infants were included at birth  and 567 A symptomatic malaria infection was defined by the combined presence of an axillary temperature >37.5°C and a positive RDT and/or a positive TBS. In this case, an antimalarial treatment was administered according to the national guidelines that were applied at the time of the study. It consisted in an artemisinin-based combination therapy (artemether and lumefantrine). TBS were also performed every month to detect asymptomatic malaria infections. In addition, mothers were invited to bring their infants to the health center, at any time, in case of fever (suspected by the mother) or clinical signs, whether or not they were related to malaria, and the same protocol was applied.® DNA blood Mini Kit (QIAGEN) according to the manufacturer’s instructions.Venous blood samples were collected quarterly for hematological and immunological measurements. Venous blood was centrifuged for plasma isolation, and genomic DNA extraction was performed from buffy coat using the QIAampAnopheles density. Altogether, these data allowed modeling, for each child included in the follow-up, an individual risk of exposure to Anopheles bites by means of a space- and time-dependent variable  and geographical data  were recorded. Throughout the study, every 6 weeks, human landing catches were performed in several points of the villages to evaluate spatial and temporal variations of variable .The Gm allotype determination was performed for 501 infants  for whom a sufficient quantity of plasma (200 µl) was available at 15 months of age. Indeed, plasma samples collected earlier in the follow-up  were not suitable for this determination due 1) to a possible presence of IgG from maternal origin bearing their own Gm allotypes and 2) to an insufficient quantity of infant neo-synthesized IgG.In order to guarantee a highly reliable result, Gm allotype determinations for infants were confirmed by means of their consistency (inheritance) with those of both biological parents. Thereby, Gm determinations of 71 infants were discarded due to the lack of either the paternal (n = 62) or the maternal sample (n = 9).From the 430 residual samples for whom trios of Gm determinations could be constituted, inconsistent determinations within the father-mother-child trio were observed for 23 cases (5.3%), leading to Gm data for 407 infants that were retained for further analysis.G1m  and G3m  allotypes were determined in plasma samples by a standard hemagglutination inhibition method . All infGenomic DNA was available for 369 out of the 407 infants for whom Gm data were retained. Among these 369 infants, 368 Gm data were available, while all were genotyped for FcgRIIA, 365 for FcgRIIIA and 353 for FcgRIIIB. However, multivariate models using the four complete FcgR polymorphisms and G3m phenotypes determinations were done on 350 infants.Single nucleotide polymorphisms (SNP) corresponding to FcgRIIA rs1801274 and FcgRIIIA rs396991 were genotyped by the Applied Biosystems TaqMan SNP Genotyping Assay using predesigned primer/probe sets (C_9077561_20 and C_25815666_10). PCR was performed using the 7900HT Real-time PCR System (Applied Biosystems) according to the following conditions: one cycle at 92°C for 10 min, 40 cycles at 92°C for 15 s, and 60°C for 60 s. The results were then analyzed using the SDS software.2, 1X buffer solution, 16 μM dNTPs, 2.8 µM sense and antisense primers and 0.5 unit of Taq polymerase. PCR reaction conditions included 1 cycle at 95°C for 5min, followed by 30 cycles at 95°C for 30 s, 55°C for 30 s, and 72°C for 45 s. For NA2, the 5’-CTTC AAT GGT ACA GCG TGC TT-3’ (forward) and 5’-CTG TAC TCT CCA CTG TCG TT-3’ (reverse) primers were used to amplify a DNA sequence of 169 pb. Genomic DNA (100 ng) was added to the reaction mixture containing 45 µM MgCl2, 1X buffer solution, 16 μM dNTPs, 1.39 µM sense and antisense primers, and 0.5 unit of Taq polymerase. PCR reaction conditions included one cycle at 95°C for 5min, followed by 30 cycles at 95°C for 30 s, 60°C for 30 s, and 72°C for 45 s. The products of 142 pb and 169 pb were revealed on a 2% agarose gel.Two different PCR were performed for the detection of FcgRIIIB NA1 and NA2 alleles, using allele-specific oligonucleotides described previously by Hans and Mehta . RegardiP. falciparum infections per individual during the follow-up. No discrimination was made between symptomatic and asymptomatic infections since the total of symptomatic infections was greater than that of asymptomatic infections (597 versus 200 out of 797 infections) and there were more infants presenting only symptomatic infections (n = 153) than infants presenting only asymptomatic infections (n = 14).The clinical phenotype of interest was the number of U-test was used for comparisons of demographic and clinical characteristics between groups. The genotypic frequencies of FcgRIIA 131R/H, FcgRIIIA 176F/V and FcgRIIIB NA1/NA2 were tested for Hardy-Weinberg equilibrium (HWE).The Chi-square test was used to examine differences between proportions and the Mann-Whitney versus high exposure, taking the median as the threshold value. Univariate analyzes on each of the covariates were made and only those with a P value < 0.20 in the univariate model were included in the final multivariate model.First, association analyses between the number of malaria infections during the 18-month follow-up and polymorphisms in FcgR and IgG G3m allotypes were studied by zero-inflated binomial negative regression with adjustment on covariates . Environmental exposure was categorized into low The statistical analysis was carried out using the Stata software version 13.P. falciparum infections during the follow-up, and their potential interaction with mosquito exposure, we performed multivariate analyses by using the generalized multifactor dimensionality reduction (GMDR) method  method . This noSince the GMDR software requires a complete dataset with no missing values for analysis, we removed individuals with missing genotype data for at least two polymorphisms and those with unknown number of antenatal visits (n = 21). The remaining missing data for FcgR polymorphisms were imputed using the R package MICE (Multivariate Imputation by Chained Equations) , a multiWe performed an exhaustive search of all possible genotype combinations of one to four polymorphisms among those studied , and model selection and evaluation was carried out using ten-fold cross-validation. Briefly, a GMDR model was developed using 9/10th of the data and a classification error was estimated from this training set. Then, cross-validation methods were used to estimate the prediction error of the selected GMDR model using 1/10th of the data as evaluation data. This procedure was repeated for each of the ten pieces of the data and the classification and prediction errors were averaged across all ten runs. Two parameters were used to evaluate the best models: (a) the testing balanced accuracy (TBA), which is a measure of the degree of accuracy to which the selected interaction correctly predicts the number of malaria infections in the testing sets , with 1.00 indicating perfect prediction, and (b) the cross-validation consistency (CVC), which indicates how many times a set of loci is identified across the cross-validation subsets.Besides TBA and CVC statistics, GMDR also provides a measure of the significance of the identified model, the signal test, a robust nonparametric test implemented in this extension to MDR . The modIn the first round of analysis, the environmental variable quantifying mosquito exposure at individual level was included as a covariate in the GMDR models as well as the following variables: mother and child ages, bednet use, and number of antenatal visits. In the second round of analysis, this environmental variable was tested for its interaction with the gene polymorphisms to detect gene-environment interactions (only four covariates in the GMDR models).A linear regression analysis was performed for the significant models found in the GMDR analysis to estimate the effect of the combinations on malaria infections.The University of Abomey-Calavi’s institutional review board and the IRD’s Consultative Ethics Committee approved the study protocol. All women in this study signed an informed consent before enrollment  with the possibility to withdraw at any time.As presented in P. falciparum infected and non-infected groups (P = 0.842).Infants belonged mostly to the Tori ethnic group and no difference appeared between ethnic groups regarding malaria infection (P = 0.156). There were almost as many girls as boys and infants distributed equally in P. falciparum infected group.Interestingly, infants from the non-infected group were younger (P < 0.001), had more bednet use (P = 0.023), and were less exposed to mosquitoes (P = 0.048) and their mothers were older (P = 0.001) than infants from the Nine G3m phenotypes were observed in the study population, among which six presented a frequency above 5% and were G3m5,10,11,13,14 , G3m5,6,10,11,13,14,24 , G3m5,6,10,11,13,14 , G3m5,10,11,13,14,15 , G3m5,6,11,24 , and G3m5,6,10,11,13,15,24  Figure 1Carriage of G3m allotypes both in single form and in combinations was analyzed through a zero-inflated binomial regression model in order to explain the number of malaria infections per infant during the follow-up. We introduced a term of interaction between the genetic and the environmental variables in the model in order to explore the potential effect of G3m allotypes varying according to the intensity of individual exposure to mosquito bites.The six most prevalent G3m phenotypes (frequency above 5%) were analyzed.Only G3m5,6,10,11,13,14,24 was associated with a greater risk of malaria infections . The FcgRIIIB NA1/NA2 genotype distribution revealed significant deviation from HWE expectations which was also observed by Munde et al.  P < 0.0Table 4.Association between FcgRIIA 131R/H, FcgRIIIA 176F/V, and FcgRIIIB NA1/NA2 polymorphisms and the number of malaria infections was determined using zero-inflated binomial regression models .We determined if individual FcgR polymorphisms were associated with malaria infections Table 5.Finally, we analyzed the influence of FcgRIIA/RIIIA/RIIIB genotype combinations on the occurrence of malaria infections. The distribution of these combinations is shown in Results confirmed the higher risk of infection associated with FcgRIIIA 176VV compared to 176FF when exposed to high levels of mosquito bites . A similar pattern, barely significant, was observed for infants carrying FcgRIIIB NA2NA2 compared to FcgRIIIB NA1NA1  Table 7.The analysis of the interaction between FcgRIIA/RIIIA/RIIIB combined genotypes and environmental exposure showed that infants carrying 131RH/176FV/NA1NA2 compared to 131RR/176FF/NA2NA2 have a trend towards a lower number of infections when exposed to low environmental risk levels . However, compared to the same reference, the carriage of 131HH/176FF/NA1NA1 was associated with a trend towards a higher risk of infection when exposed to low levels of exposure  Table 8.GMDR was used to screen the potential interactions among G3m and FcgR polymorphisms and to evaluate the impact of gene-exposure interaction on the risk of malaria infection.Among all possible one- to four-locus models evaluated by the GMDR method, none reached the cut-off significance level of 0.05 when mosquito exposure was included as a covariate in the GMDR models, along with mother and child age, bednet use, and number of antenatal visits (data not shown). In contrast, when the exposure variable was combined with G3m and FcgR polymorphisms to detect potential gene-environment interactions, several models displayed significant results Table 9.The five-factor interaction model combining G3m, FcgRIIA, FcgRIIIA, FcgRIIIB polymorphisms, and mosquito exposure was the best model identified, with the maximum prediction accuracy of 62.70%, the maximum CV consistency of 10/10, and a sign test P-value of 0.001.These results only hold for four G3m in single form and in combinations: G3m5,6,11,24, G3m5,6,10,11,13,15,24, G3m10, and G3m13. Models with lower prediction accuracies, though still significant, were obtained for G3m5,10,11,13,14,15 and G3m14 . These results suggest significant gene-gene interactions between G3m and FcgR polymorphisms that are only revealed in an environment of high exposure to mosquito bites. The four-factor model including the three FcgR polymorphisms and mosquito exposure was the second best prediction model with a prediction accuracy of 60.82%, a maximum CV consistency of 10/10, and a sign test P-value of 0.001. The two-factor model involving the FcgRIIA 131R/H polymorphism and mosquito exposure (TBA of 0.604) reached an almost identical prediction accuracy.We also conducted a linear regression analysis for the significant models associating G3m, FcgR and environmental exposure found in the GMDR analysis Table 8.P. falciparum infections during an 18 months clinical and parasitological follow-up of newborns. Second, the influence of combined IgG G3m allotypes and FcgRs polymorphisms was assessed. We identified an increased risk of P. falciparum infection in infants carrying particular FcgRIIA 131R/H – FcgRIIIA 176F/V – FcgRIIIB NA1/NA2 genotypes combined to G3m5,6,11,24 or G3m5,6,10,11,13,15,24 phenotypes or to G3m10 or G3m13 single allotypes. These observations were reinforced by the application of two complementary statistical approaches , allowing to take into account the individual risk of exposure to malaria. We studied the combined impact of FcgRIIA, FcgRIIIA, and FcgRIIIB polymorphisms and IgG G3m allotypes on malaria susceptibility in early life in Benin. First, we studied separately the influence of IgG G3m allotypes and of FcgRs polymorphisms on the number of P. falciparum when considered as a single allotype. The risk effect of some allotypes was accentuated when infants were highly exposed to mosquito bites. For example, the effect of G3m6 appeared only when the interaction with the exposure variable was considered. These results suggest that the G3m6 effect is accentuated in conditions of high mosquito exposure and the risk associated with G3m5,6,10,11,13,14,24 could be linked to the presence of both G3m6 and G3m24.No diversity was observed among infants for the G1m allotypes, since all infants were G1m1 and G1m17 positive; therefore, the analysis focused on the G3m diversity present on IgG3. Our results showed an increased risk of malaria infections associated with the carriage of the G3m5,6,10,11,13,14,24 phenotype. It should be pointed out that the presence of G3m24 in this combination could play an important role as it was also associated with a higher risk to be infected by P. falciparum. IgG3 antibodies were shown to be protective against malaria and they can act directly by limiting host cell invasion or indirectly via their Fc-mediated eﬀector functions . The absence in our study of relationship with malaria infection involving FcgRIIA/FcgRIIIA genotype combinations compared to FcgRIIA/FcgRIIIA/FcgRIIIB ones may reflect a particular synergy between FcgRIIA and FcgRIIIB receptors  when taking into account the interaction with the environmental variable of exposure to mosquito bites, according to the GMDR analysis. This is particularly interesting in view of the preceding results, indicative of a cumulative risk linked to the double carriage of G3m6 and G3m24 joined to either FcgRIIIA 176VV or FcgRIIIB NA2NA2. Moreover, linear regression of these interactions showed high regression coefficients (4.804 and 5.444). Thus, these interactions are at risk under conditions of high exposure to mosquito bites because of the cumulative presence of G3m6 and G3m24 in one hand and of the FcgRIIIA 176VV and FcgRIIIB NA2NA2 genotypes in another hand. The malaria risk under conditions of low exposure involving G3m10 - FcgRIIA 131HH/FcgRIIIA 176FF/FcgRIIIB NA1NA1 and G3m13 - FcgRIIA 131HH/FcgRIIIA 176FF/FcgRIIIB NA1NA1 is interesting to note since at the individual level, G3m10 and G3m13 did not show any significant association. Thus, this result could reflect the fact that the effect found is only due to the influence of the FcgR association. Moreover, the linear regression showed that the FcgR associations concerned were defined at risk in the previous results.P. falciparum cycle life probably participate to the control of the parasite growth. Functional assays will clarify the mechanisms and antigens involved in malaria protection. These answers can probably also vary depending immune system cells. For example, FcgRIIIB is present on neutrophils and not monocytes, natural killers react more with FcgRIIIA compared to FcgRIIA, while monocytes and macrophages present both FcgRIIA and FcgRIIIA.The efficacy of IgG3 response can be explained by FcgR affinity but also by the nature of targeted antigens. High concentrations of AMA1, MSP1, MSP2-FC27, MSP3, GLURP-R2-specific IgG3 were found in infants able to control asymptomatic infections . Of courThis study showed the importance of polymorphisms in both FcgR and IgG in the modulation of the risk of malaria infections in Beninese infants. It would then be interesting to look at the CNV (Copy Number Variations) of these polymorphisms and their influence on risk or protection against malaria. CNV are polymorphisms represented by DNA segments that differ among individuals due to suppression, insertion, inversion, duplication, or complex recombination . Recent P. falciparum malaria as one or the other, or both, may influence the individual susceptibility to infection. Understanding the functional diversity within IgG subclasses may shed light on associations found with infectious diseases or auto-immune diseases and potentially initiate new strategies to improve therapeutic antibodies.In summary, the current study demonstrates that some combined G3m-FcgR polymorphisms are associated with a malaria risk and that this risk is even more pronounced in case of high mosquito exposure. The results highlight the relevance of studying combined IgG heavy chain/FcgR polymorphisms in relation to https://osf.io/), with accession number gmr4s.The data presented in the study are deposited in the Open Science Framework repository  Santé Environnement Santé Travail . The Université de Paris awarded a PhD scholarship to AF.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Plasmodium vivax rarely develops severe complications when compared to severe falciparum malaria. However, severe vivax malaria also needs urgent, intensive care and treatment as severe falciparum malaria. This systematic review aimed to explore pooled prevalence of severe vivax malaria and to identify factors related to poor outcome of patients who developed severe manifestation.P. vivax malaria in three databases including MEDLINE, Web of Science (ISI), and Scopus until October, 22 2019. The pooled prevalence of severe vivax malaria was achieved using STATA and RevMan 5 Software. Factors related to poor outcome of patients with severe vivax malaria were analyzed using SPSS 11.5 Software.The systematic review conducted by two reviewers independently through searching of research publications related to severe P. vivax compared to those with P. falciparum . In addition, thrombocytopenia, anemia, hepatitis, and severe thrombocytopenia were the most common minor complications. Analysis of cases indicated that convulsion, respiratory distress, renal failure, jaundice, anuria/oliguria, and complication during treatment impacted on longer hospital stays compared to other severe complications . Respiratory distress was frequently found after first treatment with anti-malarial drugs . Renal failure was frequently found before treatment with anti-malarial drugs . Mean days of fever and higher pulse rates at presentation were predictors of poor outcome among patients with severe vivax malaria .Among 2615 research publications retrieved from three databases, 49 articles reporting on 42,325 severity cases were selected for calculating pooled prevalence. Seventy-six patients from case reports, case series, letter to editors, and research communications were collected to identify factors related to poor outcome of patients with severe vivax malaria. The results showed that severe anemia, jaundice, respiratory distress, impaired consciousness, and renal failure were the most common major manifestations of severe malaria guided by the World Health Organization (WHO) criterion. The meta-analysis indicated that severe malaria was less frequent in patient with P. vivax malaria guided by the WHO criterion. Severe anemia was found less frequently in patients with P. vivax than those with P. falciparum. Renal failure, jaundice, anuria/oliguria, and complication during treatment along with, mean days of fever and higher pulse rates at presentation might be predictors of poor outcome of patients with severe vivax malaria.Severe anemia was the most common major manifestation of  Plasmodium spp. infection among humans were estimated at 228 million cases of malaria occurring worldwide in 2018, especially in the African Region (213 million or 93%), followed by the South-East Asia Region (3.4%) and the Eastern Mediterranean Region (2.1%) with an estimated 405,000 deaths  AND “complications”[All Fields]. EndNote Version X7  was used to manage references retrieved in this study.This systematic review and meta-analysis was reported according to the PRISMA statement guidelines . The seaP. vivax with no related topic/no complication, studies not about malaria prevalence, malaria studies but not on P. vivax infection, co-infection with other agents/with underlying diseases, reviews, and co-infection of other species of Plasmodium spp., which were excluded after screening the titles and abstracts. Only articles reporting on severe P. vivax mono-infection were selected. Studies were additionally excluded following full-text review if they reported incomplete prevalence on severe vivax complications.All studies in the English language which reported prevalence, incidence, and individual case reports of severe vivax malaria infection were included. Exclusion criteria included any studies that reported animal studies, clinical drug trial/drug studies, experimental/investigation studies, placental/maternal malaria, P. vivax found in blood film examination, Rapid diagnostic test (RDT) used in the study, time point of severity sign, complication after treatment, number of anti-malarial drugs given, discharged days, improving days, and days of parasite clearance.Two independent reviewers (Manas Kotepui and Kwuntida Uthaisar Kotepui) were responsible for searching and selecting articles associated with the inclusion criteria. First, Endnote X7 Software  was used to manage the references retrieved from three databases. Duplicate references among the three databases were excluded. The references were then being screened for their title and abstract. Screened articles were examined for full text evaluation. Any discrepancy between two reviewers were consulted with two independent reviewers (Giovanni De Jesus Milanez and Frederick Ramirez Masangkay) to determine whether articles can be included in the study. The articles that passed the inclusion and exclusion criteria were encoded into an Excel Spreadsheets . Each article contained these data: author, year of publication, severity sign, age, gender, country of infection, fever, days of fever, signs and symptoms at presentation, pulse, respiratory rate, systolic blood pressure, diastolic blood pressure, spleen and liver abnormality, hemoglobin, leukocyte count, platelet count, stage of Criteria of severe vivax malaria was defined by the WHO Guidelines including impaired consciousness, convulsion, prostration, pulmonary edema, acute renal failure, severe anemia, bleeding, jaundice, acidosis, hyperparasitemia, respiratory distress, and hypoglycemia with no parasite density threshold . Those cThe pooled prevalence and 95% CI of complications among severe vivax malaria was undertaken to perform a meta-analysis with STATA Software Version 16 . The pooled prevalence was calculated following a previous research  by usingP. vivax and P. falciparum was assessed using Cochrane Q (Chisquare) with Odds ratio, Moran’s I2 (Inconsistency), and subgroup analyses using RevMan 5 Software  [P. vivax and those with P. falciparum.The prevalence of severe complications between don, UK) . A rando. Qualitative demographic data  were analyzed using the frequency, percentage, and Chi-squared test with 95%CI. Differences among quantitative variables such as age, temperature, systolic blood pressure, diastolic blood pressure, pulse rate, days of fever, hemoglobin, leukocyte count, and platelet count between two groups were analyzed by an independent sample T test or Mann Whitney U test upon the distribution of the data.In order to identify factors related to poor outcome of severe vivax malaria, individual patient’s data from all case reports, case series, letter to editors, and correspondences were input to SPSS 11.5 Statistical Software All 3229 research articles were retrieved from three databases . After deleting duplicate references, the titles and abstracts of 2615 articles were screened. Out of 849 articles that were selected for full-text screening, 123 articles were included for further review. Out of these 123 articles, 49 articles reporting prevalence of severe vivax malaria for calculating pooled prevalence were further selected and included for pooled analysis. In addition, out of 203 individual patient reports , 76 individual cases reporting on the prevalence of severity signs were selected based on the criteria for severe vivax malaria and used to identify factors related to poor outcome of severe vivax malaria in our study , following by 2012 , 2014 , and 2016 . Most of the study’ participants were from India , Pakistan , and Indonesia .Characteristics of the 49 studies included in this study are listed in Table Characteristics of the 76 studies with individual patient’ reports were listed in Table Among 49 studies reporting on 42,325 severity cases, 21 reported impaired consciousness, 1 prostration, 8 convulsion, 4 acidosis, 22 respiratory distress, 8 severe anemia, 28 renal failure, 19 jaundice, 3 pulmonary edema, 8 bleeding, 6 shock, and 2 studies reported hyperparasitemia. The prevalence of severe complications of each study is shown in Fig. Among these studies, the pooled prevalence of the five most commonly reported major complications were: severe anemia 0.02% , jaundice 0.01% , respiratory distress 0.01% , impaired consciousness 0.01% , and acute renal failure 0.01%   . Considering each included study, none of these studies reported a difference in thrombocytopenia among P. vivax and P. falciparum.There were 6 articles selected for comparing the prevalence of thrombocytpenia between patients with P-value = 0.001, 95% CI = 0.14 (0.04–0.46)). Patients who developed convulsion had poor response (Discharged > 7 days) when compared to other complications ). Patients who developed respiratory distress had poor response (Discharged > 7 days) when compared to other complications ). Patients who developed renal failure had poor response (Discharged > 7 days) when compared to other complications ). Patients who developed jaundice had poor response (Discharged > 7 days) when compared to other complications ). Patients who developed urine (anuria/oliguria) had poor response (Discharged > 7 days) when compared to other complications ). Patients who developed splenomegaly at presentation had well response (Discharged ≤7 days) when compared to other complications ). Patients who developed complications after the first anti-malarial drugs had poor response (Discharged > 7 days) when compared to other complications ). The results also showed that patients who developed complications after the first drug regimen significantly required a second drug regimen ) . Among 22 patients present with respiratory distress, 8 (36.4%) patients developed respiratory distress before treatment, 9 (40.9%) patients developed respiratory distress after treatment with anti-malarial drugs, and 5 (22.7%) patients developed respiratory distress before and after treatment. Among 28 patients present with renal failure, 22 (78.6%) patients developed renal failure before treatment, 1 (3.6%) patient developed renal failure before treatment, and 5 (17.9%) patients developed renal failure before and after treatment . Among 8 patients developed bleeding, 2 (25%) developed bleeding before treatment, 2 (25%) patients developed bleeding before treatment, and 4 (50%) patients developed bleeding before and after treatment . Among 12 patients present with headache, 4 (33.3%) patients developed complications before treatment, 6 (28%) patients developed complications after treatment, and 2 (16.7%) patients developed complications before and after treatment . Among 7 patients present with rash, 4 (57.1%) patients developed complications before treatment, no patients developed complications before treatment, and 3 (42.9%) patients developed complications before and after treatment . Among 19 patients with urine output abnormality, 15 (78.9%) patients developed complications before treatment, no patients developed complications before treatment, and 4 (21.1%) patients developed complications before and after treatment .The association between patient characteristics and time point of severe manifestation is demonstrated in Table P-value = 0.04). The results also showed that patients with poor response had more mean pulse rate (mean = 114.9) than those with well response . Multivariate regression analysis demonstrated no association between patients with poor response and mean pulse rate after the multivariate regression analysis was performed by using age as a covariate .Differences in patient characteristics and days of response are demonstrated in Table P. vivax infections. Plasmodium species remained tagged with the term ‘benign’ in the last century. However, in recent years which peaked in 2013, a number of studies conducted in India [P. vivax infections and severe manifestations, so that the number of publications on severe vivax and death were recognized than in previous centuries. The geographic distribution and the incidence of severe manifestations of vivax malaria were very specific and frequently found in some areas of the world. About half of these studies came from India  and also from other countries including Brazil, Colombia, Ethiopia, Indonesia, Korea, Malaysia, and Pakistan. This is very interesting because no prevalence of severe vivax malaria has been reported in other endemic regions such as Thailand, Cambodia, Lao, Burma, and Vietnam. However, a few case reports of severe vivax malaria have been found in Thailand [This analysis showed a large increase in publication on severe vivax malaria from year 1998–2013 with a maximum number of publications found in year 2013 . The numbers of publication were continuously decreased from year 2014–2018. That fluctuation seems likely due to underreporting or low number of severe vivax cases found in the last century, and only few data to support the dangers of in India –37, Sudain India , Ethiopiin India , Korea [in India , Brazil in India , and Pakin India  suggeste3) was the most common severe manifestation of severe vivax malaria at the beginning of year 2014 [P. vivax malaria carries a well-known risk of splenic rupture, considered greater than for falciparum malaria thereby increasing the risk of severe malaria in vivax malarial patients [P. vivax compared to those with P. falciparum. It is believed that this is due to P. falciparum with a higher parasitemia causing a rapid drop in the hemoglobin level resulting in severe anemia [P. vivax infection was due to the accumulation of smaller hemoglobin decrements with each recurrent infection [The highest number of severity cases (629 cases) was found at Rumah Sakit Mitra Masyarakat (RSMM) hospital during 2004–2007 in India . The pooear 2014 . This miear 2014 . The sevear 2014 , 46. A ppatients . Our mete anemia . Moreovenfection .P. vivax and P. falciparum infection were the most common malaria-associated hematological complications [P. vivax had severe to very severe thrombocytopenia [P. vivax had a 2.8 -fold higher risk of developing severe thrombocytopenia than those with severe P. falciparum malaria [In this study, minor complications of severe malaria which were not based on the WHO criteria were also demonstrated. The results indicated that thrombocytopenia and severe thrombocytopenia was the most common minor complications. Thrombocytopenia in patients with ications . Howeverications , and plaications  which leications . Our resytopenia . Moreove malaria .P. vivax resulted in initial worsening of airflow obstruction and gas transfer, which took 6 hours to 8 days after the initiation of anti-malarial treatment [P. vivax infection may lead to poor outcome and increased mortality in P. vivax malaria. For renal failure, treatment of malaria-associated kidney diseases required a long-term duration due to management of appropriate antimalarial drugs, hydroelectrolytic disturbance corrections, fluid replacement, and dialysis [P. vivax malaria can cause renal failure more commonly than P. falciparum malaria, where renal ischemia was the dominant pathogenic mechanism [Analysis from the case reports showed that patients who developed impaired consciousness and splenomegaly had well response (Discharged ≤ 7 days) whereas patients who developed convulsion, respiratory distress, renal failure, urine (anuria/oliguria), jaundice, and complications after being treated with the first anti-malarial drugs had poor response (Discharged > 7 days). A previous study demonstrated splenomegaly and altered consciousness were more frequent in cases of severe vivax malaria and suggested that these symptoms could indicate a poor prognosis of malaria . For resreatment . Patientreatment . The resreatment , 57. It dialysis . A previdialysis . In our echanism .P. vivax with IV artesunate rapidly reduced parasitemia levels; however, patients underwent post-treatment hemolysis with the higher doses of IV artesunate [According to the WHO criteria, jaundice is one of the cardinal manifestations of severe malaria in adults . This sttesunate . This poP-value = 0.04). Fever in malaria is believed to be associated with release of toxins and antigenic substances, which induce the release of cytokines by white blood cells. Our study results indicated poor prognosis of patients who had more days of fever before presentation. During treatment, fever in severe malaria usually resolves by Day 4 to 5 and needs prompt investigations in case of a prolonged fever after severe malaria [This study also showed that patients with poor response had more mean days of fever before presentation (mean = 6.05) than those with well response (mean = 4.78,  malaria . To our P. vivax infection is associated with rare and serious cardiovascular complications [The results of the present study also showed that patients with poor response had a greater mean pulse rate than those with well response. We thought it could be cardiovascular involvement related to the previous studies, indicating that ications . AlthougThe present study had a main limitation in that we could not retrieve all full-text and non-English articles that passed our inclusion criteria.P. vivax malaria. Severe anemia was found less frequently in patients with P. vivax than those with P. falciparum. Renal failure, jaundice, anuria/oliguria, and complication during treatment along with mean days of fever and higher pulse rates at presentation might be predictors of poor outcome of patients with severe vivax malaria.Severe anemia was the most common major manifestation of Additional file 1. Data set 1.Additional file 2. Data set 2.Additional file 3. Data set 3.