Global malaria control strategies highlight the need to increase early uptake of effective antimalarials for childhood fevers in endemic settings, based on a presumptive diagnosis of malaria in this age group. Many control programmes identify private medicine sellers as important targets to promote effective early treatment, based on reported widespread inadequate childhood fever treatment practices involving the retail sector. Data on adult use of over-the-counter (OTC) medicines is limited. This study aimed to assess childhood and adult patterns of OTC medicine use to inform national medicine retailer programmes in Kenya and other similar settings.Large-scale cluster randomized surveys of treatment seeking practices and malaria parasite prevalence were conducted for recent fevers in children under five years and recent acute illnesses in adults in three districts in Kenya with differing malaria endemicity.A total of 12, 445 households were visited and data collected on recent illnesses in 11, 505 children and 19, 914 adults. OTC medicines were the most popular first response to fever in children with fever  and adults with acute illnesses . 36.9%  adults and 22.7%  children using OTC medicines purchased antimalarials, with similar proportions in low and high endemicity districts. 1.9%  adults and 12.1%  children used multidose antimalarials appropriately. Although the majority of children and adults sought no further treatment, self-referral to a health facility within 72 hours of illness onset was the commonest pattern amongst those seeking further help.In these surveys, OTC medicines were popular first treatments for fever in children or acute illnesses in adults. The proportions using OTC antimalarials were similar in areas of high and low malaria endemicity. In all districts, adults were more likely to self-treat with OTC antimalarial medicines than febrile children were to receive them, and less likely to use them in recommended ways. Government health centres were the most common second resort for treatment and were often used within 72 hours. In view of these practices, more research is needed to assess the impact on the popularity of private medicine sellers of strengthened public sector policies on access to malaria treatment and insecticide-treated bed nets. Improved targeting of OTC antimalarials to high risk groups, better communication strategies regarding adult as well as children's dosages, and facilitating more rapid referral to trained health workers where needed are important challenges to private medicine seller programmes. Malaria continues to be a major cause of death and disability  and contSince 2001, the Kenya National Malaria Strategy (KNMS) has supported the implementation of programmes targeting private sellers of OTC medicines and their clients within district malaria control activities . Thirty-In this paper, we present data from household surveys of treatment seeking behaviour for recent childhood fevers and adult illnesses, and on malaria prevalence in well children under five years, in rural areas of three districts in Kenya. The data were collected during surveys conducted collaboratively by the Kenyan Medical Research Institute (KEMRI) Wellcome Trust Research Programme and the Division of Malaria Control (DOMC) in the Kenyan Ministry of Health (MOH) in 2002 and 2003 in districts with varying malaria transmission. The surveys aimed to inform the planning and evaluation of district-led training programmes for private medicine retailers and communities on malaria and its treatment. Data from the malaria parasite prevalence surveys are presented in this paper as markers for transmission pressure in the study sites, and for comparison with treatment-seeking behavior patterns. The findings are discussed with particular emphasis on adult OTC antimalarial use as an emerging challenge to programmes addressing this sector.The Kenya DOMC selected three districts for study, Busia, Makueni and Kwale Figure . Two disThis was a descriptive study based on cluster randomized cross sectional household surveys conducted during the peak malaria transmission season in each district. The methods used were surveys of reported treatment seeking behaviour for recent illness episodes in young children and adults, and malaria parasite prevalence surveys in a sub sample of well children using rapid diagnostic tests.In each study division, a list of National Census enumeration areas was used to construct a sampling frame and units for the household survey. Since some enumeration areas were much larger than others, to avoid weighting the chances of selection by population size, those with greater than 110 households were subdivided into smaller units prior to randomisation. In each district, a total of 4,000 households were identified in randomly selected enumeration areas (or subdivisions) of approximately 100 households. The sample size calculation was derived for planned future evaluations of the retailer training programmes, with a primary outcome of the proportion of childhood fevers treated with OTC antimalarials that included an adequate amount of the MOH recommended treatment. Since the future evaluations planned to include both intra and inter-district comparisons, sample sizes for the current household survey were calculated around comparisons of these proportions within districts, providing standard errors of 1.6% and 2.2% around estimations of 10% and 20% respectively (coefficient of variation 0.2) .Svy data commands in STATA version 8 . Proportions for key outcomes are presented with 95% confidence intervals. Chi-square tests of association were used to compare proportions across the districts and analysis of variance (ANOVA) models were used to compare means. Since one of the most common OTC antimalarial medicines in use, amodiaquine (AQ), has a three-day regime of administration, episodes where treatment was started within three days of the interview were excluded.Locally recruited and trained field workers collected detailed information on treatment seeking behaviour for children under five years of age with a recent fever and for adults present in the household at the time of interview with a recent acute illness, using a structured questionnaire. Recent episodes were defined as those occurring within a two-week period of the interview. In this survey, two target age groups were identified; children under five who present the greatest vulnerability to severe disease, and individuals over the age of fourteen years, as an adult group likely to make an autonomous decision on treatment seeking. To counteract the potential for reporting bias, a pre-tested questionnaire developed and validated from previous studies was used , and fieRandomly identified sub-samples of 971, 963 and 980 children from the household survey in Busia, Kwale and Makueni districts, respectively, were invited to participate in a cross sectional survey of malaria parasite and anaemia prevalence. The prevalence of anaemia was assessed during the baseline as a marker for programme impact in the future, and data on haemoglobin concentrations are not presented in this paper. The sample size was based on a conservative estimate of 50% prevalence for moderately severe anaemia , with a The Kenya National Scientific Steering and Ethical Committees and World Health Organization Ethics Review Committee granted approval for the study. The aim and purpose of all components of the study was discussed and agreed with local leaders. Verbal informed consent was sought for the household survey and information sheets including contact details were left in each home visited. Signed informed consent was obtained from parents or guardians for the malaria parasite prevalence survey. Reports on the findings of the surveys were sent to District Health Management Teams.12,445 households were visited to interview 11,505 caregivers of children under five years and 19,914 adults across all the districts. Table Table Given the high global burden of young childhood disease and deaths attributed to malaria ,2, earlyIn interpreting these results, it is important to consider limitations of the study methods. The data on treatment seeking behaviour were collected from reports concerning recent illness episodes. While standard practices were used to ensure that these were as accurate as possible , this type of data is always open to recall and reporting biases. In the household survey, for pragmatic reasons, histories were elicited for all children within a household who met inclusion criteria for age, including siblings. Theoretically, this may lead to clustering of data within households for which no allowance has been made in the analysis. Confidence intervals could therefore be wider than those stated here, although these are generally small given the size of these surveys. There is some evidence that intra-household clustering would have a negligible effect; a study in rural Tanzania found no difference in the outcome of an analysis of treatment seeking behaviour for all young children and for only one randomly selected child within that household . FinallyThe data presented here concur with earlier descriptions of the popularity of private medicine sellers as an early treatment option for childhood fevers, and the inappropriate ways in which OTC antimalarial medicines are generally used in young children ,23,30-33There is limited information on adult use of OTC antimalarial medicines. Several studies have addressed the frequency of OTC antimalarial use in adult populations in specific settings, but there is less information on the way that these medicines are used, or from large-scale surveys in areas of varying malaria endemicity. A study of OTC antimalarial use in a highland area of low seasonal malaria transmission in Kenya described a similar excess of adult over paediatric use  , as haveAdult over-use of antimalarials is an important phenomenon because of the potential for wastage of resources where adults have a lower risk of malaria than children. The extent of over-use is highlighted by the popularity of these medicines even in areas with low and seasonal malaria transmission. Adult over-use affects estimations of the volume of malaria medicines used in the private retail sector and therefore has an economic implication for governments and households, particularly in anticipation of, or following, the introduction of ACTs . There mFor both adults and children, there are clear differences in adherence to SP and AQ medicines, with adherence to SP being much higher than AQ. This finding is likely to be a result of the different regimes for administration, with SP medicines being given in a single dose in contrast to the 3-day AQ regimen. There is evidence that other multiple dose medicines, such as chloroquine, have commonly been used as single doses in the past, including in Kenya . AdherenA further pattern of interest emerging from the study concerns movement between private medicine sellers and trained health workers. Amongst the minority (14.4%), who sought further treatment after using OTC medicines, most carers (approximately 84%) chose to visit a trained health worker. Self referral to such a facility did not generally occur within 24 hours of onset of illness, as recommended by the Roll Back Malaria initiative , but theProgrammes for private medicine retailers in malaria control have been based on pragmatic principles, and these still obtain. The challenges of working with informal private providers have been well articulated at the policy level, including the size of the sector in many countries, lack of regulatory mechanisms and capacity, lack of organizational structures, multiplicity of brands, inadequate quality of OTC medicines, difficulties in diagnosing malaria clinically and commercial interests of retailers ,20,41,42The findings of this survey across three districts of differing malaria endemicity in Kenya confirm the common use of OTC medicines for fever in children and acute illnesses in adults, as well as the widespread inappropriate use of these medicines. They point to the frequent use of OTC antimalarial medicines in adults, irrespective of disease transmission rates, and the high risk that this will be accompanied by under dosing. A minority of OTC users subsequently seek further treatment through the formal sector, but many of these self-referrals occur within 72 hours of onset of illness even in rural situations. More research is needed to assess the impact on the popularity of private medicine sellers of free malaria treatment in public health facilities for children under five years and increased community coverage with treated bed nets. Improved targeting of OTC antimalarial medicines to high risk groups, better communication strategies on adult as well as children's dosages, and facilitating appropriate referral to trained health workers are important challenges to private medicine seller programmes.Timothy Abuya was involved in the design of the research, was primary supervisor of the survey work, analysed the data and prepared the first draft of the manuscript. Wilfred Mutemi was involved in the design of the research, supported the survey work and contributed to the writing of the manuscript. Karisa Baya was involved in the design of the research, was a major contributor to the survey work and contributed to the writing of the manuscript. Sam Ochola was involved in the design of the research, supported the survey work and contributed to the writing of the manuscript. Greg Fegan was involved in the design of the research, supervised the analysis of data and contributed to the writing of the manuscript. Vicki Marsh was responsible for the design of the research, planning and supervising survey work and contributed to the writing of the manuscript.


Beyond diagnosis, the logical utilization of RDTs is to monitor treatment outcome.Malaria presents a diagnostic challenge in most tropical countries. Rapid detection of the malaria parasite and early treatment of infection still remain the most important goals of disease management. Therefore, performance characteristics of the new indigenous ParaHIT A finger prick blood sample was collected from each clinically suspected case of malaria to prepare blood smear and for testing with the RDT after taking informed consent. The blood smears were read by an experienced technician blinded to the RDT results and clinical status of the subjects. The figures for specificity, sensitivity, accuracy and predictive values were calculated using microscopy as gold standard.P. falciparum infection, the persistence of parasite antigen leading to false positives even after clearance of asexual parasitaemia has limited its utility as a prognostic tool.The prevalence of malaria infection estimated by RDT in parallel with microscopy provide evidence of the type of high, low or no transmission in the study area. Analysis revealed  that overall sensitivity, specificity and accuracy of the RDT were >90% in areas of different endemicity. While, RDT is useful to confirm the diagnosis of new symptomatic cases of suspected f test was easy to use, reliable and cheap. Thus this RDT is an appropriate test for the use in the field by paramedical staff when laboratory facilities are not available and thus likely to contribute greatly to an effective control of malaria in resource poor countries.The study showed that the ParaHIT  We conducted a study to assess if this RDT is reliable, simple and practical in varied epidemiological situation in hospital and field. Our objective was to determine whether this RDT could be widely applied as a diagnostic tool to effective management and control of malaria.Malaria presents a diagnostic challenge in most tropical countries  and diagf dipstick test  was evaluated as a diagnostic test in 4 districts of Central India  with different transmission potential namely Jabalpur , Dindori (high transmission area), Mandla  and Korea district in Chhattisgarh (meso-endemic). The performance of the ParaHIT f for detecting P. falciparum infections was evaluated against microscopical examination of thick blood smears in field / hospital during April-August 2004.The ParaHIT Shorea robusta). The inhabitants are barely clothed and live in extremely primitive conditions. Medical facilities are non-existent. Anopheles culicifacies and An. fluviatilis, are two efficient vectors in the area. Seasonal transmission of P. vivax and P. falciparum are common. Chloroquine resistance against P. falciparum is prevalent. The villages are under indoor residual spray with synthetic pyrethroid (deltamethrin @20 mg/m2). All patients with fever or history of fever were screened for malaria in a mobile field clinic on a first come first serve basis.Dindori is highly malarious district contributing highest number of malaria cases (12%) in the state (6). The baiga tribe, living in an extremely difficult hilly terrain, with numerous hillocks (MSL. 980m). The population of 10 study villages ranged from 50–800. The villages are surrounded by reserved forests of Sal (2). Other characteristics (vectors and transmission pattern) are the same as in Dindori.District Korea is situated on the border of Madhya Pradesh in Chhattisgarh state. It also has dense forest and the terrain is undulating (MSL750m). The field clinic traveled 10 villages for screening malaria patients (gond ethnic tribe). The area is under 2 rounds of DDT spray . Transmission is seasonal and mainly due to The subjects of the hospital based study were the suspected cases of malaria who presented with fever or history of fever, at the malaria clinic run by the Malaria Research Centre (MRC) at Medicine department of Government Medical College hospital. This hospital is the largest medical facility in Jabalpur district (MSL 394m) and serves both as a general hospital for the local people and as a referral hospital for the adjoining districts.f test. There were four teams of MRC, Field Station Jabalpur, each consisting of two field workers and one Research Scientist. A one hour workshop, including training in blood collection from finger prick, performance and interpretation of rapid test was conducted at MRC laboratory. All the team members had attended the workshop in the use of the RDTs. All the samples were tested in field/hospital unsupervised. The thick blood smears were also examined in the field. The smears were checked by a microscopist blinded to the clinical status of the subjects and to the results of the diagnostic tests. Parasitaemia was determined from the thick films by counting the number of parasites against 200 leucocytes and assuming that each subject had 8000 leucocytes/μl.A finger-prick blood sample was collected from each case, after verbal informed consent was obtained. This sample was used to prepare thick and thin smears and for testing with the ParaHIT f test was performed as per manufacturer's instructions [P. falciparum were administered the standard oral dose of chloroquine (1500 mg chloroquine in 3 days) followed by primaquine (45 mg as a single dose). Children were given proportionally lower doses. Infants and pregnant women were not given primaquine.The ParaHIT ructions . The staP. falciparum gametocytes were detected and random sample of 20% of the remaining slides were checked blind by an independent trained laboratory technician at MRC laboratory.To check that HRP-2 antigenaemia was cleared by treatment, finger prick blood samples were collected on day 10 post-treatment and tested using the RDT in parallel with blood smears. To minimize variability, one microscopist examined all the smears and one technician interpreted all the results of the rapid tests. A quality control procedure was put in place. All discordant results (between the RDT and the slide), all slides where only The study protocol was approved by the ethics committee of the Malaria Research Centre (ICMR) Delhi.f were estimated using microscopy as gold standard [P. vivax and P. falciparum was treated as P. falciparum for the purpose of analysis.The data were recorded and analyzed using statistical software . Once all the samples had been tested, specificity, sensitivity, predictive values and accuracy to the ParaHIT standard ,8. BriefThe rates of fever and parasitaemia varied by study sites. The performance indices of RDT at each site is shown in Table 1.P. falciparum comprising 191, (40.9%) and P. vivax 14 (3.0%). The asexual parasite density ranged from 640–280,000 parasites/μl (GMPD 9840 ± 7.38parasites/μl). The RDT detected malaria infections in 171 (89.5%) of 191 patients. The sensitivity of the rapid test was 90.2%  and specificity 83%  compared to microscopy. The PPV and NPV were respectively 77%  and 93% .Two hundred five of 467 patient's (43.9%) had positive thick films, with th day, out of which 39 (41.5%) test were still positive post treatment. In 18 of the subjects (19%), the blood smears were also positive for P. falciparum. However, the RDT was positive only in 16 matching cases. 23 subjects were found false positive and 2 false negative with RDT. The sensitivity, specificity, PPV and NPV were respectively 84% , 69% , 41%  and 94.5% . The accuracy of test was 72.3% and J index 0.53 as compared to microscopy.In all 18 patients were positive by microscopy but negative by RDT and the parasitaemia in these patients ranged from 100–36,920 parasites/μl (GMPD 3715.35 ± 5.37). Only 94 cases were followed up on 10P. falciparum, 26 P. vivax and 1 mixed infection. The GMPD for P. falciparum was 323.59 ± 2.51 parasites/μl (range 80–7840 parasites/μl). The RDT detected malaria parasite in 57 subjects. The sensitivity and specificity of the test were 97%  and 95%  respectively with PPV 75%  and an NPV of 99.4% . When compared with microscopy, the accuracy of the test was 95.2% and J-index 0.92.Of the 440 individuals screened, microscopic examination of the thick film detected 64 P. vivax and 12 P. falciparum, of which 7 were cerebral malaria (CM) patients, comatose with various complications. All seven P. falciparum (CM) were also positive by RDT. However, results of the RDT were not used to guide treatment and antimalarial therapy was prescribed by the physician on the basis of clinical severity. The asexual parasitaemia ranged from 5000–100000 parasites/μl. The sensitivity of the test was 70%  with 93% specificity . The PPV and NPV were 33%  and 98.4%  respectively. The accuracy of the test was 92% and J-index 0.63 in comparison with gold standard.Of the 208 patients screened, only 19 were infected with malaria. 7 Only one hundred and two blood samples were screened by both the methods. Out of which only one was found RDT positive that too was smear negative.P. falciparum trophozoites. 60 out of 83 subjects claimed to have taken antimalarials drugs in the preceding days. P. falciparum gametocytes only were seen in 14 cases of which 9 were RDT positive. Out of 47 subjects with P. vivax infections as detected by microscopy, only 5 were found positive for P. falciparum by the RDT.Overall from 1217 subjects, 83 (6.8%) false positive were recorded. A prolonged re-examination of the slides from these 83 subjects, who were positive by the test, but apparently had negative slides, did not reveal the presence of Rapid, accurate diagnosis is necessary to effective management and control of malaria ,9,10. ThFrom a malaria transmission perspective in baigachak, the RDT can play a key role in rapid diagnosis and prompt treatment of malaria in high transmission areas . As RDT can be conducted immediately in the field clinic while the patient is present, the most important point for the villagers is the knowledge that they are infected with malaria parasite as well as dispersing any information for preventive measures of the disease. On the contrary, the delay in the results of microscopic diagnosis is a serious obstacles for the operation of a malaria control programme in remote areas where health staff operating the control programme have to visit several times to treat the positive subjects as per the results of microscopic examination.Of clinical concern is the persistence of parasite antigen leading to false positives even after the clinical symptoms of malaria has disappeared and the parasites have apparently been cleared from the host as recorded earlier from central India ,12 and wAn additional clinical concern is the occasional failure of rapid test to detect high parasite densities as recorded earlier . Pf HRP-In Mocha, an area free from malaria transmission, RDT may be useful to exclude the falciparum infection and indicate the need to give treatment for other causes of fever. RDT thus would improve the accuracy of the diagnosis and consequently decrease the use of antimalarials. In the medical college hospital the RDT also appeared useful although the test sensitivity was not high as in field clinics. However, RDT could facilitate the early diagnosis and an appropriate therapy in patients with cerebral malaria thereby reducing mortality as recorded earlier ,9. The vIn addition to good sensitivity and specificity, the criteria for the rapid test should also include affordability and user friendliness. The cost per test is Rs. 28 i.e. US$ 0.50, the cheapest available so far to the Ministry of Health and the institutes buying large numbers of test kits. Besides, where the number of people to be tested is very low in small villages in remote areas, where health-facility coverage is low, and the risk of contracting malaria is high, the test may be more cost effective than microscopy as the time factor may be in favour of the rapid test.Despite some limitations, a post study survey of all the personnel directly involved in the performance of the RDT were of opinion that the test was easy to use, decreased stress and potential delay in the diagnosis of falciparum malaria in field. If the present observations are validated in larger multicentre, clinical trial, the test may prove to be a useful alternative to microscopy, particularly in places where the facilities for microscopy are poor or non existent.RDTs in conjunction with microscopy should improve diagnosis of malaria. However, RDTs are more suited to investigators/health workers in situations where health services are deficient or absent. Therefore, it is reasonable to consider future use of the RDTs as an epidemiological tool for the rapid screening of malaria.The author(s) declare that they have no competing interests.Neeru Singh: Participated in design of the study and writing the manuscript.MM Shukla: Involved in rapid analysis in Medical College Hospital, Jabalpur.AK Mishra: Performed the rapid test in Korea district and help in analysis.SK Chand: Involved in data collection and analysis in Mocha, Mandla.Praveen Kumar Bharti: Performed the test in baigachak, Dindori.All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:


Malaria causes an acute systemic human disease that bears many similarities, both clinically and mechanistically, to those caused by bacteria, rickettsia, and viruses. Over the past few decades, a literature has emerged that argues for most of the pathology seen in all of these infectious diseases being explained by activation of the inflammatory system, with the balance between the pro and anti-inflammatory cytokines being tipped towards the onset of systemic inflammation. Although not often expressed in energy terms, there is, when reduced to biochemical essentials, wide agreement that infection with falciparum malaria is often fatal because mitochondria are unable to generate enough ATP to maintain normal cellular function. Most, however, would contend that this largely occurs because sequestered parasitized red cells prevent sufficient oxygen getting to where it is needed. This review considers the evidence that an equally or more important way ATP deficency arises in malaria, as well as these other infectious diseases, is an inability of mitochondria, through the effects of inflammatory cytokines on their function, to utilise available oxygen. This activity of these cytokines, plus their capacity to control the pathways through which oxygen supply to mitochondria are restricted (particularly through directing sequestration and driving anaemia), combine to make falciparum malaria primarily an inflammatory cytokine-driven disease. Plasmodium falciparum, arguably the pathogen that causes the most human suffering, has been hotly debated for many decades. Clearly, rational adjunct therapy depends on getting this right. For over twenty years the central debate has come from two apparently opposing camps. One champions the mechanical hypothesis, based on the concept of insufficient oxygen reaching vital organs, and the other the cytokine hypothesis, in which excessive release of pro-inflammatory cytokines are the primary driving force of disease and death. The former concept stresses the uniqueness of the pathophysiology of falciparum malaria compared to that of other severe systemic infectious diseases, whereas the latter sees malaria as having fundamentally the same basis as these other conditions, with the adhesive property of parasitized erythrocytes giving it no more than a distinctive flavour.The mechanism of the disease caused by Critical analysis of the mechanism of falciparum malarial disease would not have been possible without the seminal work of Peter Mitchell ,2, who iDespite advances in understanding diseases clinically very similar to falciparum malaria in terms of inflammatory cytokines, enthusiasm for the mechanical obstruction hypothesis seems at least as strong as ever -5. AlthoThere is now remarkably widespread acceptance that cytokines such as TNF and interleukin-1 (see "cytokine storm" in Google) are the essential mechanism of systemic disease caused by infectious agents. Indeed, one would be hard pressed to find an alternative explanation now current for the anorexia, tiredness, aching joints and muscles, fever and sleepiness that patients experience in any systemic infection, including both vivax and falciparum malaria. Neither is it disputed that exacerbated release of these same mediators is the best current line of investigation for the mechanism of severe and life-threatening illness, such as sepsis  and inflBabesia microti, was killed by the immune system in circulating red cells  + 8) give the PaCO2 from the HCO3 value. This has a parallel in the clear lung severe respiratory distress of falciparum malaria, with deep stressful breathing, first described in paediatric patients in coastal Kenya a decade ago. This hyperventilation predicted over three times the likelihood of a fatal outcome than did coma alone, and was recognized as a consequence of the underlying severe metabolic acidosis [The importance of hyperventilation in helping to get rid of the excess COn sepsis , and mecreviewed , if the acidosis ,291. LogThis need to breath heavily for an extended period demands much work of the muscles of the chest wall and diaphragm. Unfortunately, the pro-inflammatory cytokines that contribute to the acidosis also generate the inducible form of nitric oxide synthase (iNOS) in skeletal muscle in animal models of sepsis  and patiMore recently, the function of mitochondria in the diaphragm muscle of rats treated with bacterial endotoxin, which induces, in man as well as rat, the range of pro-inflammatory cytokines raised in both sepsis and malaria, has been examined in detail. A range of genes for proteins required for the mitochondrial electron transport chain are downregulated , resultiIn summary, lactate is an approximate, but workable, marker for metabolic acidosis, which in turn is a good marker for hypoxia, the primary pathophysiological lesion in these diseases. Whether arising from (a) poor supply of oxygen to mitochondria  or (b) reduced cellular utilisation of oxygen through mitochondrial dysfunction (in response to severe systemic inflammation) the outcome is essentially the same. The presence of inflammatory markers and the nature of the illness implies that mitochondrial dysfunction is the constant, and poor oxygen delivery the variable, in a synergistic whole.The literature on this disease reflects the fact that by far the most cases occur in children in tropical Africa, although comparisons with the clinical picture in Papua New Guinea, where children are said to experience a generally milder disease,  have beeCerebral malaria is certainly simpler to understand if one operates from the premise that, as Marsh and Snow so eloquently put it, severe malaria equals cerebral malaria equals cerebral microvascular sequestration . UnfortuCertainly coma can be a striking component of severe falciparum malaria, and sequestration plus accompanying microhaemorrhages a spectacular aspect of terminal brain histology. Yet, one without the other has commonly been reported, and a causal link questioned. An example from 60 years ago is by Kean and Smith , who colSequestering parasitized red cells are often an obvious histological feature, so some researchers ,8,302 coBabesia microti, the mouse form of which is functionally allied with several mouse malaria species, in that they cross-protect and cause similar pathology [B. microti infection can include altered mental status, adult respiratory distress syndrome, renal insufficiency, disseminated intravascular coagulation (DIC), gastrointestinal bleeding and multi-organ failure [B. microti does not sequester in mice, a recent opportunity was taken to see if it behaved differently in tissues from a patient infected with this parasite. Sequestration was not observed [Babesia bovis, widely regarded as a parallel for the vaso-occlusive model of falciparum malaria, did not produce parasites that generated more virulent infections in cattle [Human babesiosis is a haemoprotozoan tick-borne disease often associated with symptoms that are similar to falciparum malaria ,305. Speathology . Complic failure ,305. Theobserved . The impobserved ,309), imobserved , must ben cattle .As English and co-workers have noted, the low mortality when coma occurs in the absence of anaemia or markers of metabolic acidosis indicates that a localised cause of coma, such as cerebral vaso-occlusion, is very unlikely to be a sole cause of mortality without a systemic inflammatory input, and that coma in acidotic children might well have a different mechanism than in those with brain lesions only . NeverthIf cerebral sequestration proves not to become prominent until soon before death, might it, though present at autopsy, have been incidental to the fatal outcome? There is now increasing agreement ,314,315 2 was noted at the time [Functional evidence, in terms of reduced blood flow, has been sought for cerebral vascular occlusion being important in the pathogenesis of disease during falciparum malaria, both in Thai adults  and Afrithe time  to be cothe time , while athe time . In contthe time , but to The outcome of the recent study in African children referred to above  providesIntriguingly, these comatose malaria cases with no appreciable change in their brains nevertheless showed appreciable systemic evidence of inflammation, as demonstrated by the marked evidence of iNOS, MIF  and HO-1Plasmodium berghei ANKA, has used new experimental tools to address this question, and in a detailed and convincing study goes against conventional wisdom, disassociating cerebral pathology from sequestration [From the principles that form the stroke literature, individuals with appreciable cerebral sequestration are likely to be over-represented in fatal cases. Likewise, comatose patients who do not develop local brain changes, including overt sequestration, might well have a higher chance of survival, and are thus under-represented in the fatal comatose cases from which are drawn the histology samples that are the basis of the sequestration theory of cerebral malaria. Recent work on mouse cerebral malaria, caused by stration . This reTo understand cerebral functional impairment, including coma, in clinically defined cases of falciparum cerebral malaria that show minimal if any sequestration on brain sections ,71, it wProbably the most immediately relevant of these encephalopathies to a discussion on falciparum malaria  is the reduced consciousness sometimes seen in severe vivax malaria, caused by a parasite accepted not to sequester. For many years such reports were dismissed as undiagnosed double infections , but evidence from geographical areas where falciparum malaria was not present, plus new specific diagnostic techniques, have led to an acceptance of the concept. For instance, in 2002 Beg collected the records of 41 such cases , and a mper se, accounts for the outcome in individual patients, although the brain proves to be a sensitive indicator of severe generalised septic illness. More recently, Morita and co-workers [As in falciparum malaria, mental confusion and obtundation can be early signs of the sepsis syndrome, and altered mental status is associated with a higher mortality . The cli-workers , studyin-workers .Probably the best documented encephalopathy which closely parallels the changes that may occur in falciparum malaria is the form sometimes seen in severe influenza. It is most frequently reported in children in Japan and other Asian countries, and provides a close functional match indeed. As in malaria, the infectious agent is not neuroinvasive . SeizureIt is feasible, but to our knowledge not yet investigated, that increased inflammatory cytokines might cause some degree of poor brain microcirculation in influenza encephalopathy, as well as some local enhancement of inflammation, through inducing adhesion of platelets and monocytes. Were this so, it would be reasonable to regard such changes as pathology-enhancing accessories after the event was under way rather than prime instigators of it. In summary, influenza encephalopathy demonstrates that a syndrome inseparable from cerebral malaria can occur without invoking adherent parasitized red cells. The evidence suggests that the CM(A) group of paediatric malaria cases , and welPhenylalanine is an aromatic amino acid required, in controlled concentrations, for the normal synthesis of various monoamines essential for brain function. Several types of genetic defects of phenylalanine hydroxylase or tetrahydrobiopterin metabolism can elevate its plasma levels to pathological levels. If not corrected by a low phenylalanine diet from an early age, chronic excess of this amino acid can cause an encephalopathy associated with seizures, and in time retards brain development and causes various functional deficits . TransieEscherichia coli and Salmonella enteritidis) present. Certain tissues exhibited immunohistochemical evidence  of intense systemic inflammation. S. enteritidis is a pathogen known to alter brain function, causing a diffuse encephalopathy, including seizures as part of a systemic syndrome [As noted above, hyperphenylalanaemia warrants serious consideration as a contributor to the seizures observed in septic encephalopathy and cerebral malaria. So too does zinc chelation by S100 proteins. Our 2003 studies on tissue sections from East African children ,252 inclsyndrome . Currentsyndrome . S100B hsyndrome .Salmonella enteritidis sepsis  being a characteristic of childhood malaria more than of adult cases.There are real differences in the nature of the disease in children and adults. For example, severe anaemia is much more common for a given parasite density in young children than in older children and adults , and sei+/K+-ATPase inhibition thought to cause poor red cell deformability, and thus shorten erythrocyte life span, is higher in younger children [The cytokine theory of disease provides directions that could lead to an understanding, currently lacking, for these age differences. For instance, generation of nitric oxide, which has been instrumental in the Nachildren ,360. Addchildren , has an children . This hachildren ,363. Thechildren .In broad terms, the essential mechanism of death in falciparum malaria disease is agreed by many researchers: a functional tissue hypoxia that forces an unsustainable dependence on anaerobic metabolism. An unresolved key question is whether the tissue hypoxia arises (a) because insufficient oxygen reaches the mitochondria through either vascular occlusion from sequestered parasitized red cells acting alone, or in combination with anaemia or (b) because excessive release of inflammatory cytokines, induced by malarial toxin(s), render mitochondria unable to use oxygen to generate energy from oxidative phosphorylation. Although wearing contemporary clothes, this is the same dichotomy that was present a hundred years ago. Current basic literature suggests that inflammatory cytokines are very much the dominant partner, having amongst their powers the capacity to shut down bone marrow, make red cells prematurely poorly deformable, and channel sequestration towards certain sites, dictated by inate local thrombomodulin concentration Figure . Thus cy


Several studies conducted in areas of medium or low malaria transmission intensity have found associations between malaria immunity and plasma antibody levels to glutamate rich protein (GLURP). This study was conducted to analyse if a similar relationship could be documented in an area of intense malaria transmission.A six month longitudinal study was conducted in an area of holoendemic malaria transmission in north-eastern Tanzania, where the incidence of febrile malaria decreased sharply by the age of three years, and anaemia constituted a significant part of the malaria disease burden. Plasma antibodies to glutamate rich protein (GLURP) were analysed and related with protection against malaria morbidity in models correcting for the effect of age.P = 0.047]. Interestingly, there was an inverse relationship between the plasma anti-GLURP IgG1 and IgG3 levels and the levels of parasitaemia at enrolment. However, anti-GLURP IgG2 and IgG4 levels were not associated with reduction in parasite density. Similarly, antibody levels were not associated with haemoglobin levels or anaemia risk.The risk of febrile malaria episodes was reduced significantly in children with measurable anti-GLURP IgG1 antibodies at enrolment [adjusted odds ratio: 0.39 ; Cytophilic IgG1 and IgG3 antibodies against R0-GLURP may contribute to the control of parasite multiplication and reduction in febrile malaria incidence in children living in an area of intense malaria transmission. Plasmodium falciparum antigen, which has been studied extensively. It is a 220 kD protein expressed in the hepatic, asexual and sexual stages of the parasite life cycle ; and for IgG3 level, one log unit increase was associated with a reduction in P. falciparum density at enrolment by 983 parasites/μl . Although similar associations were observed in univariate analysis for non-cytophilic IgG subclasses such associations were not significant after adjusting for age , 11.5% (6/52), 11.4% (4/37) and 5.6% (1/18) for the age groups 0–4, 5–9, 10–14 and 15–19, respectively. Logistic regression models correcting for age indicated that the presence of a measurable R0-GLURP IgG1 was associated with a reduced risk of febrile malaria episodes  or IgG subclass (data not shown) R0-GLURP antibody response. Similarly, in linear regression models correcting for age and sex, there were no associations between plasma R0-GLURP IgG or IgG subclass levels and the haemoglobin level at enrolment (data not shown).In logistic regression models including age and sex, there were no statistically significant associations between the risk of anaemia and having a measurable IgG [AOR: 1.03 ; Studies in which observed clinical protection is linked to the level of malaria antibodies on an individual level have been used to identify vaccine targets ,6,15,22.The acquisition of IgG against GLURP was highly dependant on malaria transmission intensity. In the high transmission village antibody levels increased markedly after the age of two years, and in the three to four years old children a very high percentage had a detectable antibodies response. In the village with moderate transmission antibody acquisition was much slower and GLURP antibody response rates over 50% were only seen in the age groups older than 10 years.P. falciparum infection is anaemia occurring in infants and young children [In areas of high malaria transmission one of the major disease burdens attributable to children ,19,21. IP. falciparum parasite densities.In conclusion, this study conducted in an area of intense malaria transmission detected an association between protection against febrile malaria disease and presence of anti R0-GLURP antibodies and indicated that increasing levels of antibodies of the IgG1 and the IgG3 subclasses are associated with a reduction in JPAL carried out field surveys, performed ELISA, analysed data and drafted the manuscript. LSV carried out field surveys and in collaboration with JPAL, MA and MT contributed to the set up of the ELISA. BPM carried out field surveys and participated in data analysis. MT, AYK, MML and TGT conceived the design of the study. All authors amended and approved the final manuscript.


Malaria during first few months of life may be due to transplacental transfer of parasitized maternal erythrocytes. Although IgG and IgM antimalarial antibodies can be detected in maternal blood, only IgG antibodies are present in the infant's blood. These antibodies can delay and modify the onset of clinical manifestations.Plasmodium vivax. While the mother had significant levels of immunoglobulin G (IgG), the infant was found negative for IgG and had low immunoglobulin M (IgM) levels. The mother had a history of febrile illness during pregnancy and her peripheral smear was also positive for P. vivax. Both were successfully treated with chloroquine in the dose of 25 mg/kg/day over three days.An infant is described who presented with irritability and feeding problems. Clinical examination and investigations revealed that the infant was afebrile, had jaundice, hepatosplenomegaly and haemolytic anaemia. Peripheral smear demonstrated The case emphasizes the importance of considering the diagnosis of malaria even in infants in low transmission area, who may not present with typical symptoms of malaria, such as fever, but have other clinical manifestations like jaundice and haemolytic anaemia. Plasmodium falciparum have been described, the role of other species especially Plasmodium vivax, which exists in good proportion in some countries, including India, is not known. In a study conducted in central India although 2.2% (4/182) women were placenta positive for P. vivax or mixed infection, but none of the infants developed parasitaemia up to 6 months of age [Congenital malaria can be acquired by transmission of parasites from mother to child during pregnancy or perinataly during labour . Congeniugh 2.2% /182 womeChildren with congenital malaria can present with fever, irritability, feeding problems, hepatosplenomegaly, anaemia and jaundice . A case The case demonstrates the need of considering congenital malaria as differential diagnosis even in low endemic areas, especially in countries where there is social practice of moving the pregnant woman to her native place, which may be endemic for malaria, for child birth.The infant weighing 2.4 kg was a full-term, normal hospital delivery born to non-consanguineous parents. There was no history of physiological jaundice or any other parental problem. The child was on exclusive breast feeding since birth. On physical examination, the infant was afebrile and showed marked pallor and icterus. There was no dehydration. Hepatosplenomegaly was present . There was no ascites and other systems were normal. The infant was, therefore, investigated for severe anaemia with jaundice and hepatosplenomegaly. Laboratory tests revealed anaemia (Hb 6 gm%) with normal WBC and platelet counts.P. vivax and were referred to the National Institute of Malaria Research, where the presence P. vivax trophozoites with a parasitaemia of 0.1% (5000/μl) was confirmed.The reticulocycte count was 8%. Peripheral smear demonstrated moderate anisocytosis, dimorphic red blood cells with predominate microcytosis and hypochromia. Serum bilirubin was 10 mg/dL (conjugated 4.6 and unconjugated 5.4), SGOT 92 IU units/l and SGPT 100 IU units/l and alkaline phosphatase was 23.6 KA. X-ray chest and ultrasound were normal except hepatosplenomegaly. Blood studies for Toxoplasma, Rubella, Cytomegalovirus and Herpes (TORCH) were negative. Haemoglobin chromatography was normal. Twenty-four hours after admission Hb decreased to 4.5 gm% and repeat peripheral smears were examined more intensively for haemolysis. Smears were found to be positive for Packed cells transfusion was given and the infant was treated successfully with chloroquine at a dose of 25 mg/kg over three days. He was discharged after four days and at time of discharge his Hb was 9 gm%. Follow up of patient was again done after 10 days, when he had no clinical jaundice, his spleen was 2 cm below costal margin and he was accepting feeds. Four weeks later liver functions, haemoglobin (10.5 gm%) and other investigations were normal.th month of pregnancy, suffered febrile illness in her native place, which has a low to moderate endemicity for malaria. Although exact history of intake of antimalarials is not clear, she improved gradually. During the present episode she had no fever, but her peripheral smear showed presence of scanty P. vivax trophozoites suggesting the possibility of congenital malaria in the infant.Since patient reported from an area of very low malaria transmission , the possibility of a new infection is remote. A directed history revealed that the mother had, during 7P. vivax-infected erythrocyte lysate (PvL). The mother's serum showed substantial amount of IgG antibody to both the antigens. While significant level of IgM to these antigens was found in her serum, the serum of the infant found negative for IgG with both the antigens, whereas a very low level of IgM antibody with PvL was detected.Other causes of haemolytic anaemia in infants were excluded and there was no ABO/RH incompatibility in parents and G6PD was normal. Antibody profile of both mother and child sera were also tested for IgG and IgM isotypes against PvMSP1 peptide and P. vivax has been described from Sri Lanka [Although malaria continues to be major public health problem in India and pregnant women have been described as vulnerable group, there have been very few epidemiological studies to determine disease burden in pregnancy and infants . As suchri Lanka , Italy [ri Lanka , Singapori Lanka  and Thairi Lanka .In the present case, which had atypical presentation with no fever, diagnostic work up was done to rule out the other causes for haemolytic anaemia, jaundice and hepatosplenomegaly. The presence of parasitaemia in the low transmission period in a non-endemic area led us to label the case as congenital malaria which was further substantiated by history of travel in mother. Thus the epidemiological and circumstantial evidence strongly supports transplacental route of infection.It has been reported that clinical symptoms are rarer in younger infants and absence of febrile episodes has been described . This haThe treatment with chloroquine was adequate since there is no exoerythrocytic life cycle in congenitally-acquired vivax infection. The report suggests differential diagnosis of congenital malaria should be considered in areas where it is least suspected due to low transmission of disease and also emphasizes importance of history of travel of mother. Emphasis should also be given to awareness regarding use of chemoprophylaxis and bed nets in community and adequate treatment for suspect malaria during antenatal period.SB and SM were responsible for clinical management of the patient admitted in their hospital. NV was involved in investigation for congenital malaria and writing the manuscript. SB carried out the immunoassays. AP was involved in revising the manuscript and giving final approval of the version.


The objective was to measure the efficacy of the vaccination regimen FFM ME-TRAP in preventing episodes of clinical malaria among children in a malaria endemic area. FFM ME-TRAP is sequential immunisation with two attenuated poxvirus vectors (FP9 and modified vaccinia virus Ankara), which both deliver the pre-erythrocytic malaria antigen construct multiple epitope–thrombospondin-related adhesion protein (ME-TRAP).The trial was randomised and double-blinded.The setting was a rural, malaria-endemic area of coastal Kenya.We vaccinated 405 healthy 1- to 6-year-old children.Participants were randomised to vaccination with either FFM ME-TRAP or control (rabies vaccine).Following antimalarial drug treatment children were seen weekly and whenever they were unwell during nine months of monitoring. The axillary temperature was measured, and blood films taken when febrile. The primary analysis was time to a parasitaemia of over 2,500 parasites/μl.p = 0.14 by log-rank). A group of 346 children were vaccinated according to protocol (ATP). Among these children, the hazard ratio was 1.3 . When multiple malaria episodes were included in the analyses, the incidence rate ratios were 1.6 (95% CI 1.1–2.3); p = 0.017 for ITT, and 1.4 (95% CI 0.9–2.1); p = 0.16 for ATP. Haemoglobin and parasitaemia in cross-sectional surveys at 3 and 9 mo did not differ by treatment group. Among children vaccinated with FFM ME-TRAP, there was no correlation between immunogenicity and malaria incidence.The regime was moderately immunogenic, but the magnitude of T cell responses was lower than in previous studies. In intention to treat (ITT) analysis, time to first episode was shorter in the FFM ME-TRAP group. The cumulative incidence of febrile malaria was 52/190 (27%) for FFM ME-TRAP and 40/197 (20%) among controls (hazard ratio = 1.52). This was not statistically significant  uses two different delivery methods to transmit the same antigen . The two-step vaccination is designed to achieve a greater immune response than with just one vaccination. One research group, based in Oxford in the UK, is using an antigen called “ME-TRAP,” which is delivered using first a strain of modified fowlpox virus , then a weakened vaccinia virus . Previous studies done in adult UK volunteers have been promising, achieving an immune response and some protection against malaria when volunteers were deliberately infected. However, this approach has not been tested in the group most in need of a vaccine—young African children. Therefore a field trial was conducted among 405 healthy children aged 1–6 years, in a region of Kenya with year-round malaria transmission. Children were randomized to receive either the sequence of vaccines delivering ME-TRAP or to receive a rabies vaccine . The children were followed up for nine months, and the primary aim of the trial was to compare the occurrence of clinical malaria  in the two groups.What this trial shows: In the 387 children receiving vaccine and having at least one follow-up visit the vaccine did produce an immune response; however, this immune response did not seem to be protective, as the occurrence of malaria was slightly higher in the group receiving the candidate vaccine—although this difference was not statistically significant. Safety data were also collected; the number and severity of adverse events were similar between volunteers receiving the rabies vaccine and those receiving the candidate malaria vaccine, and any serious events were not judged to be linked to the vaccines by the trial's data safety monitoring board.Strengths and limitations: The methods used in the trial were robust, using appropriate randomization procedures and blinding of participants and researchers. Outcome measures  were clinically relevant. In order to detect cases of malaria in vaccinated children, health workers visited children weekly, and children with a temperature over 37.5 °C were tested for parasites in the blood.  This process of active detection of malaria cases  enables a smaller sample size to be used in the trial, but it is not clear whether this approach is more or less specific at picking up malaria cases than are passive methods. The researchers aimed to ensure that their case detection methods were specific; for children with normal temperature, but reported by their parents as feverish, parasite tests were done only if subsequent temperature readings were high.Contribution to the evidence: Previous studies of ME-TRAP using the FP9 and MVA vectors have shown the candidate vaccine is safe and induces a strong immune response. The safety result was also supported by the findings of the current trial, conducted in young Kenyan children, but a 5-fold lower immune response was found compared to previous studies. The trial showed that this weak immune response was not effective at preventing clinical cases of malaria in this group of children, although it is not clear why the immune response was lower than expected. More than 1 million people die each year from malaria, and this number is likely to increase , field sPlasmodium falciparum-infected mosquitoes, some individuals were fully protected and vaccinees showed mean delays in time to parasitaemia, corresponding to a mean 92% reduction in malaria parasites completing pre-erythrocytic development ), and among those vaccinated according to protocol, 58/175 (33%) and 48/171 (28%), respectively .In a secondary analysis, as specified in the Report and Analysis Plan (Text S1), episodes were defined as fever with parasitaemia at any density. In the malaria vaccine group 69/190 children (36%) had at least one episode, and 54/197 (27%) in the controls (stratified log-rank test χp = 0.017). Among those vaccinated according to protocol, the incidence rate ratio was 1.4 . When these analyses were repeated using malaria definition of fever with any parasitaemia, the incidence rate ratios were 1.5 (95% CI 1.1–2.0), p = 0.013 for ITT and 1.4 (95% CI 0.96–1.9), p = 0.08 for ATP.Multiple episodes were modelled by Poisson regression, adjusted for the same covariates . There wOnly two episodes of malaria required hospital admission (one in each vaccination group), and neither of these met accepted criteria for severe malaria.p = 0.4 for ex vivo and p = 0.24 for cultured). There was no indication that immune response predicted susceptibility when multiple episodes were analyzed .The Report and Analysis Plan had considered the possibility that susceptibility might vary by T cell response to vaccination (either by ex vivo or cultured ELISPOT). Vaccinees were divided into tertiles according to the ex vivo or cultured ELISPOT responses measured one week after vaccination, and each tertile was compared with the control group . No cleaHowever, the arithmetic mean was only 228 spots per million on ex vivo ELISPOT in the highest tertile. Exploratory analysis  divided vaccinees into seven groups of 28 children per group (on average), according to ex vivo T cell response. The highest responders were at a mean of 325 spots per million, but still had more frequent episodes of malaria than the control group (hazard ratio 2.39 [95% CI 1.1–5.9]). The 27 highest responders by cultured ELISPOT were at mean response of 1,130 spots per million, and the hazard ratio was 1.76 (95% CI 0.78–4.0) compared with controls.n = 346) and 33% and 33% at 9 mo (n = 306). Mean haemoglobin was 11 g/dl (95% CI 10.8–11.1) before monitoring began (n = 362), and 10.1 at 3 mo (95% CI 9.8–10.5) in both the FFM ME-TRAP and control group (n = 354).Other endpoints were haemoglobin and parasitaemia detected at cross-sectional surveys at 3 and 9 mo. These variables were not different between vaccination groups. The prevalences of parasitaemia for FFM ME-TRAP and the control group were, respectively, 29% and 26% at 3 mo (p < 0.001), and greater in FFM ME-TRAP vaccinees than in children receiving control vaccinations (p < 0.001). Ex vivo T cell responses rose from 30 spots per million before vaccination (95% CI 21–40) to 107 spots per million (95% CI 88–127) after vaccination. Cultured responses rose from 123 spots at baseline (95% CI 104–142) to 407 (95% CI 349–464). Vaccine-induced responses for both ex vivo and cultured ELISPOT remained above the control group at 9 mo  .The vaccine was moderately immunogenic . T cell The vaccine was well tolerated. Ten serious adverse events occurred. Four occurred after rabies vaccination  and six after FFM ME-TRAP . The serious adverse events identified were not unexpected events given the study population, were not closely related to vaccination in timing, and were judged unlikely to be linked to vaccination by the investigators and the Data Safety Monitoring Board. Local cutaneous discolouration and blistering was frequent, but blistering with a diameter greater than 0.5 cm occurred at a rate of 1%–4% . No blisFFM ME-TRAP was safe when given to 1- to 6-year-old children in a malaria-endemic area. It was moderately immunogenic, but not as immunogenic as in malaria-naïve  or semi-Although the formal possibility exists that altered peptide ligand effects , transfoFFM ME-TRAP was only moderately immunogenic in this population, despite the strong immunogenicity observed previously. Stronger immunogenicity was seen in previous Phase 1 studies in adults and children in Kilifi. Arithmetic mean responses by ex vivo ELISPOT were 610 spots per million PBMCs in malaria-naïve adults  but 350 Different batches of FP9 ME-TRAP can be associated with different immunogenicity , and worActive case detection might produce a less specific endpoint by detecting milder and more self-limiting illness than would passive case detection. This problem can be countered by using a parasitaemia threshold to define malaria cases . It is cIs it nevertheless possible that a case definition with poor specificity obscured vaccine efficacy? This seems unlikely. Febrile malaria was identified in only five (6%) of 74 5- to 6-year-olds, compared with 19 (29%) of 65 1- to 2-year-olds, although fever and asymptomatic parasitaemia were common in both age groups. A study using passive case detection would probably require a 4-fold increase in sample size for similar power .It is unclear whether reductions in liver parasites similar to those seen in sporozoite challenge  might haCONSORT ChecklistClick here for additional data file.(48 KB DOC)Trial ProtocolClick here for additional data file.(135 KB PDF)Alternative Language Abstract S1(23 KB DOC)Click here for additional data file.Text S1(37 KB DOC)Click here for additional data file.


PLoS Medicine that shows that α+-thalassemia protects against severe but not mild malaria.Pasvol discusses a new study in +-thalassaemia protects against severe but not mild malariaA new study finds that α Ever since Haldane proposed in 1949 that thalassaemia might protect individuals against the scourge of malaria . However9/l relative to controls  [+-thalassaemia (in which one or two of the four α-globin genes are deleted) is exceedingly common throughout sub-Saharan Africa, an area of high malarial transmission. However, thus far, the effects of α+-thalassaemia on the clinical manifestations of malaria in this area have not been extensively studied. And the few studies that have been carried out on the relationship between α+-thalassaemia and malaria have not provided an all-encompassing and plausible cellular mechanism for protection.Why has investigation of the interaction between thalassaemias and malaria remained inconclusive despite our best efforts? For ß-thalassaemia, it is only in a limited part of West Africa that it continues to co-exist with malaria. Malaria has been eradicated from most other regions where ß-thalassaemia is common. The findings of Willcox et al. support a protective role for ß-thalassaemia, in which heterozygotes one-to-four years old appear to have a reduced risk of malaria, using an arbitrary density criterion of 1 × 10, 0.79) . By contThere are many gaps in our knowledge of whether thalassaemia might protect against malaria.+-thalassaemic cells [Malarial parasites can certainly invade and multiply within ac cells . They alc cells . So how c cells . Thalassc cells ; perhapsc cells . We justPLoS Medicine, have now cogently approached the conundrum of a+-thalassaemia and malaria in a structured and compelling fashion within an area of intensive malarial transmission in sub-Saharan Africa. They studied two cohorts of children: (1) a cohort with “mild disease”, recruited from an age-stratified population sample, which was monitored using weekly clinical surveillance for three years; and (2) a “birth cohort” of children born between 1992 and 1995 within a defined geographical area of the Kenyan coast in East Africa, whose admissions to hospital were recorded. Slide-positive parasitaemia (with or without symptoms), as well as parasite density, was clearly defined. Moreover, definitions of severe malaria—largely, coma, more than two seizures in 24 hours, parasitaemia greater than 20%, and severe malarial anaemia (haemoglobin concentration less than 50 g/l)—were carefully delineated.Notwithstanding this, Sammy Wambua, Thomas Williams, and colleagues,  in a new+-thalassaemia did not protect against parasitisation in asymptomatic individuals. Furthermore, α+-thalassaemia did not protect against symptomatic malaria, nor did it lead to a reduction in the density of parasites in peripheral blood. In the birth cohort, there was reduced admission to hospital of α+-thalassaemic children with malaria or severe malaria. An even more tantalizing finding was that thalassaemia provided no protection against cerebral malaria unless accompanied by anaemia—the protection by α+-thalassaemia appeared to be mainly confined to severe anaemia. α+-thalassaemia also appeared to protect against nonmalarial anaemia.In brief, the authors found that α+-thalassaemia. Protection by α+-thalassaemia against nonmalarial disease—including respiratory infection, gastroenteritis, and meningitis—has previously been documented [+-thalassaemia, both in steady state and during mild malarial attacks, this result was reversed in severe disease when the children with thalassaemia had relatively higher haemoglobin concentrations.The researchers also investigated other major nonmalarial diagnoses—such as upper and lower respiratory tract infections, gastroenteritis, and skin or helminthic infections—and found that the occurrence of lower respiratory tract infections in the mild disease cohort was lower in those with αumented . PerhapsCould thalassaemia, in reality, protect against nonmalarial anaemia as found in this study? The absence of malaria parasites in the blood of an individual with severe anaemia living in a highly endemic area for malaria might not be sufficient to exclude a diagnosis of malaria. Malarial infection leaves a wake of red cell destruction, which often continues long after parasites have disappeared or are microscopically undetectable. The question of whether thalassaemia protects against nonmalarial anaemia can only be addressed in a study carried out in a nonmalarious area where thalassaemia and equivalent socioeconomic deprivation occur. Such an area would be hard to find: the coexistence of deprivation and malaria go almost hand in hand .+-thalassaemia does not protect individuals against acquiring malarial infection, becoming symptomatic, or developing high parasite densities. However, the study also concludes that the risks of developing severe malaria, especially malarial anaemia, are reduced in people with α+-thalassaemia . How those with thalassaemia appear to be protected against developing severe anaemia with or without malaria and why they might be protected against lower respiratory tract infections remain unexplained. Perhaps answers to these questions might turn out to be more rewarding than they first appear.This extensive and well-executed study concludes that α


Recent resurgence of malaria in the highlands of Western Kenya has called for a more comprehensive understanding of the previously neglected complex highland vector ecology. Besides other drivers of malaria epidemiology, topography is likely to have a major effect on spatial vector and parasite distribution. The aim of this study was to determine the effects of topography on malaria spatial vector distribution and parasite prevalence.Anopheles gambiae complex were identified by PCR. Blood parasites were collected from children 6–13 years old and densities categorized by site of home location and age of the children.Indoor resting adult malaria vectors and blood parasites were collected in three villages along a 4 km transect originating from the valley bottom and ending at the hilltop for 13 months. Members of the An. gambiae s.s. and (99%) Anopheles funestus were collected in houses located at the edge of the valley bottom, whereas 1% of An. gambiae s.s. were collected at mid hill and at the hilltop respectively. No An. funestus were collected at the hilltop. Malaria prevalence was 68% at the valley bottom, 40.2% at mid hill and 26.7% at the hilltop. Children aged six years and living at the edge of the valley bottom had an annual geometric mean number of 66.1 trophozoites for every 200 white blood cells, while those living at mid-hill had a mean of 84.8, and those living at hilltop had 199.5 trophozoites.Ninety eight percent (98%) of Malaria transmission in this area is mainly confined to the valley bottom. Effective vector control could be targeted at the foci. However, the few vectors observed at mid-hill maintained a relatively high prevalence rate. The higher variability in blood parasite densities and their low correlation with age in children living at the hilltop suggests a lower stability of transmission than at the mid-hill and valley bottom. The prevalence of malaria in the highlands of Eastern Africa varies spatially and temporally as a result of seasonal weather changes, climate variability ,2 and toMalaria epidemics in the Western Kenya highlands have been recorded since the early 1940's ,7 and cuThe heterogeneity of transmission has important implications for vector and morbidity control. Understanding the spatial pattern of vector distribution provides opportunities for limited and thus more cost-effective control programs . For exaMany vector and parasite studies assume a random distribution of mosquitoes and malaria cases. While this may be largely true in the lowlands such an assumption is not true in the highlands. An assumption of random distribution would lead to erroneous sampling. Where distribution of events is contiguous in space and time it would be advisable to use stratified sampling procedures.This study was undertaken to determine the effects of topography on distributions of vectors and malaria infections in Kakamega district, Western Kenya.The study was carried out at Iguhu Location, 0° 17'N, 34° 74'E, at an elevation of 1,450–1,580 m above sea level in Kakamega district in Western Kenya  or Anopheles funestus, the only two vectors collected indoors in the area. Their gonotrophic status was also identified and recorded. A proportion of the An. gambiae s.l. females were analyzed by the polymerase chain reaction (PCR) method to determine the proportion of the sibling species of An. gambiae s.s. and Anopheles arabiensis in the sample [A short transect was established, originating from the bottom of the Yala River valley and terminating at Sigalaga village, 4 km uphill Figure . Nine hoe sample .The EIR was estimated from the fraction of freshly blood fed females collected in the houses . Houses ®). Each child was asked in which of the three villages his or her home was located. The parasite data were classified according to the location of the child's home.Two cohorts of 120 children aged 6–13 years old living in the three villages  and attending Iguhu and Makhokho primary schools were identified for monthly malaria parasite prevalence surveys during the study period. After explanation of the study's objectives, methodologies, risks, and benefits, informed consent to take part in the study was obtained from the children's parents. The study was approved by the Ethics Review Committee of the Kenya Medical Research Institute (KEMRI), Protocol KEMRI SSC# 469. The two cohorts were alternated for monthly infection prevalence surveys to avoid sampling fatigue. Sampling was performed using the finger-prick method to obtain thick and thin smears. Immediately after the finger prick, any child presenting with a fever, had his or her thick-blood smear stained in 10% Giemsa for 10 min in the field and examined for the presence of malaria parasites. If parasites were seen, the child was treated with an analgesic (Paracetamol) and an appropriate dose of pyrimethamine/sulfadoxine combination  were calculated and tested for differences among the village means by a single factor ANOVA. Because not all children were regularly tested for malaria the data were not suitable for repeated sampling ANOVA. Detailed examination of the parasite prevalence data indicated the presence of parasites particularly in children residing in the valley bottom were not independent events. This violates assumptions in most statistical tests. Data reported only refers to malaria infections as indicated by presence and number of parasites in blood. As other causes of fever were not assessed we do not include any clinical malaria cases in the analysis. Monthly variations in parasite densities for the different villages were indicated by the 95% confidence intervals.Age-specific blood parasite density of An. gambiae s.l. analysed by PCR all were found to be An. gambiae s.s. The majority of An. gambiae s.s. vectors (98.2%) were collected at the valley bottom while 0.8% and 1.0% were collected in houses at mid-hill and hilltop, respectively . There was a 15.9% reduction in prevalence for every 50 meter increase in altitude along the transect.Malaria prevalence is hyper-endemic at the valley bottom, meso-endemic at mid-hill, and close to hypo-endemic at the hilltop Table . This enP. malariae and P. ovale were less than 4% and do not seem to play a significant role of malaria in the study sites  were infected. This indicates a high efficiency of transmission by the vectors. Although the possibility that children at mid-hill acquired their infections at the valley bottom cannot be ruled out, this seems unlikely because children generally sleep at their homes. It is acknowledge, however, that vector sampling did not represent all the areas where the children were living. The implication of these results is that any vector control method will have to be highly effective because even very low vector densities can maintain a high level of prevalence.While vector control is necessary for malaria control, data from this study suggest that reduced transmission could result in the human population having less ability to suppress blood parasite density. Such a shift in the immune status could increase the risk of severe disease and greater mortality. It is critical that vector control programmes such as long-term use of insecticide impregnated bed nets be sustainable so that the risk of severe disease is reduced .An alternative approach to sustainable vector control is focused intermittent indoor residual spraying specifically designed to reduce the impacts of potential epidemics. This approach would require an efficient epidemic forecasting tool, which would identify the potential epidemic with sufficient lead time to allow time for indoor residual insecticide spraying .The El Niño climate variability phenomenon is characterized by positive temperature anomalies and above normal rainfall in the Western Kenya highlands – conditions associated with increased malaria transmission and indeed epidemics . The warAn. gambiaes.s. and that of An. funestus are 2 km and 1 km respectively [Data from this study have shed light on how limited indoor residual spraying could be effectively applied to control focally transmitted malaria. Assuming that the flight range of ectively  and thatectively .AKG, JMA were involved in the study design, data collection analysis and manuscript writing. PKO FKA, JIG were involved in the data collection, entry and manuscript writing. BAN carried out PCR analysis of the vectors. GY carried out a critical analysis of the data and the manuscript.


Plasmodium falciparum prevalence difference between two neighbouring communities (Moshie Zongo and Manhyia). The primary objective of this follow-up study was to determine whether this parasite rate difference was consistent over time. Secondary objectives were to compare prevalences of clinical malaria, anaemia, intestinal parasite infections, and malnutrition between these communities; and to identify potential risk factors for P. falciparum infection and anaemia.A survey in Kumasi, Ghana found a marked P. falciparum parasitaemia, clinical malaria, anaemia, anthropometric indices, and intestinal helminths was conducted in April-May 2005. Data collection included child and household demographics, mosquito avoidance practices, distance to nearest health facility, child's travel history, symptoms, and anti-malarial use. Risk factors for P. falciparum and anaemia (Hb < 11 g/dl) were identified using generalized linear mixed models.A cross-sectional house-to-house survey of P. falciparum, clinical malaria, anaemia, and stunting were significantly higher in Moshie Zongo  compared to Manhyia . Of 197 children tested for helminths, four were positive for Dicrocoelium dendriticum. Population attributable risks (PAR%) of anaemia were 16.5%  and 7.6% . Risk factors for P. falciparum infection were older age, rural travel, and lower socioeconomic status. Risk factors for anaemia were P. falciparum infection, Moshie Zongo residence, male sex, and younger age.In total, 296 children were tested from 184 households. Prevalences of P. falciparum infection compared to malnutrition, indicate the importance of malaria as a cause of anaemia in this urban population.Heterogeneities in malariometric indices between neighbouring Kumasi communities are consistent over time. The low helminth prevalence, and the twofold higher PAR% of anaemia attributable to  Although often considered a predominantly rural disease in Africa, malaria represents a leading cause of morbidity and mortality among many urban African populations . With anIn Africa, malaria transmission is generally lower in urban compared with rural areas ,6. This Plasmodium falciparum parasite rates of 32.7% and 3.8%, respectively. The primary objective of this study was to determine whether the previously observed marked difference in parasite rates between the two communities was maintained. The secondary objectives were to compare prevalences of clinical malaria, anaemia, intestinal helminths, and malnutrition between these communities, and to identify risk factors for P. falciparum infection and anaemia.A baseline survey of malaria in children aged 6 months to 5 years, conducted in 2002–3 in Kumasi, Ghana, found marked prevalence differences between communities . ProximiKumasi is the second-largest city in Ghana, with a population of 1.2 million . LocatedP. falciparum parasite rates between the two communities  and multiplied by 2 for a design effect. The study received ethical approval from the Liverpool School of Tropical Medicine and the Faculty of Medicine, Kwame Nkrumah University of Science and Technology, Kumasi.A cross-sectional house-to-house survey was carried out in Moshie Zongo and Manhyia during April and May 2005. Sampling was conducted between 14:00 and 19:00 and alternated on an approximately weekly basis between communities. Cluster starting points were identified based on proximity to specific landmarks , with the whole area of each community included to gain a geographically representative sample of the community. A house was defined as any housing structure where one or more families were residing. The first house was selected randomly in each cluster, followed by the selection of every fifth house until a minimum cluster target of 10 children was reached. Voluntary written consent was obtained from primary carers prior to data collection. All children in the target age range present at the time of sampling were eligible to participate. The location of each sampled house was recorded using a handheld GPS receiver. A minimum sample size of 108 children per community was calculated using EpiInfo v.3.2.2 , based on detection of a 25% difference in P. falciparum parasitaemia was determined using a Rapid Diagnostic Test (RDT) . Haemoglobin (Hb) concentrations were measured using a HemoCue system . Axillary temperature was measured by digital thermometer. Clinical malaria was defined as presence of P. falciparum, with a current axillary temperature of ≥ 37.5°C and/or a reported fever history during the previous 48 hours. Anthropometric measurements included height, weight, and mid-upper arm circumference (MUAC). Stool samples were collected at the time of the haematological and anthropometric sampling or the following day. Faecal samples were preserved in 10% formal saline. A volumetric dilution procedure was used to analyse the stool samples for intestinal helminths [Data about household demographics, assets and house construction, together with the carer's knowledge about malaria and use of mosquito avoidance methods, were collected by questionnaire. Age, sex, recent rural travel, symptom history, and recent anti-malarial use were recorded for each child. The presence of elminths .Socio-economic status (SES) was calculated for each household using World Bank asset scores for Ghana, based on ownership of a television, radio, refrigerator, car, motorcycle, bicycle, farm, electricity in house, ceiling, floor cover, and number of individuals/sleeping room . The antA list of all government hospitals and primary care clinics in the surrounding area was obtained from the Kumasi Metro Director of Health and verified by the Manhyia District Hospital Administrator . The location of each health facility was mapped using a GPS. Straight-line distance to the nearest health facility was used as a proxy for access to formal healthcare services and was calculated using ArcInfo v7.2.1 .P. falciparum infection and malnutrition were estimated as population attributable risk percentages (PAR%) with 95% confidence intervals (CI) [P. falciparum infection and Hb < 11 g/dl. Variables not highly predictive of outcome variables (p > 0.1) in unadjusted models were excluded from further modelling. For all models, household was included as a random effect. Final adjusted models included all variables significant at p < 0.05.Statistics were calculated using SPSS v11.5 (USA) and SAS v8.2 . The proportion of anaemia cases attributed to als (CI) . UnivariTable P. falciparum , clinical malaria , and anaemia  were higher, and mean Hb levels lower (p < 0.001), in Moshie Zongo compared to Manhyia. There were few cases of moderate to severe anaemia . More children from Moshie Zongo were stunted , had a reported history of diarrhoea , and had reportedly taken malaria medication in the previous two weeks . Fewer than 5% in either community had travelled recently to a rural area. Stools were examined for the first 197 children surveyed. With the exception of 4 children from neighbouring households in Manhyia who had Dicrocoelium dendriticum infections, no helminth eggs were found. As a consequence, stool samples were not collected from the remaining 99 children.A total of 296 children were tested, 148 in each community  and 50.0% in Moshie Zongo (25/50). The PAR% of anaemia attributable to P. falciparum infection was 16.5% (95%CI: 9.5–23.3), and to malnutrition was 7.6% (95%CI: 1.4–13.9).Significantly higher prevalence of el Table . The samP. falciparum infection included being older (OR = 1.28 per 1-year increase), recent rural travel (OR = 23.45), and lower SES (OR = 3.95 per 1-unit decrease). Significant risk factors for anaemia were P. falciparum infection (OR = 3.92), Moshie Zongo residence (OR = 3.76), male sex (OR = 2.16), and younger age (OR = 0.79 per 1-year increase).In adjusted models Table , risk faP. falciparum among children in Moshie Zongo compared to neighbouring communities is temporally stable and not an artefact of a single study period [P. falciparum rate in Moshie Zongo was higher than recently reported rates in other urban areas; Kampala [This study demonstrated that the higher prevalence of y period . The P.  Kampala , Coutono Kampala  and Dar  Kampala , though  Kampala . Parasit Kampala . Heterog Kampala . This st Kampala .P. falciparum prevalence has been similarly reported among other urban populations, including Dar es Salaam [P. falciparum prevalence has been recorded in rural areas of the surrounding Ashanti region [The finding that recent rural travel was associated with increased s Salaam , Abidjans Salaam , Lusaka s Salaam , and pres Salaam . Howeveri region  and Norti region . Urban ri region . PromotiTwo-thirds of the Moshie Zongo children sampled in our study were anaemic . Prevalence of severe anaemia was low in both communities. When restricted to children under 5 years, the anaemia prevalence in the present study was comparable to the previous Kumasi survey , and to P. falciparum infections, and P. falciparum infection was strongly associated with anaemia after adjustment for other factors. This suggests that P. falciparum infection is an important determinant of anaemia among these Kumasi children and that anaemia may represent a useful indicator for malaria control progress in these communities.Anaemia is often caused by a combination of malnutrition, helminth infections, infectious diseases, and haemoglobinopathies ,24. SignA. lumbricoides, and 1 T. trichiura). Kumasi is exposed to problems of crowding and sewage disposal, which are often associated with increased risk of helminth infections [In comparison with these Ghanaian study populations, a higher prevalence of stunting but similar prevalence of wasting was found among urban Zairian children . In thesfections . One expP. falciparum [P. falciparum, and that they provide results quickly (within 15 minutes) [The Paracheck-Pf RDTs used in this survey detect the presence ofHistidine Rich Protein 2 (HRP-2), a water soluble protein produced by asexual stages and young gametocytes of lciparum . The benminutes) . One limminutes) . SurveysP. falciparum infection and 36.7% of children with clinical malaria had reported taking an antimalarial within the previous 2 weeks. The proportion of P. falciparum cases with reported recent antimalarial use was higher in Moshie Zongo (28.6%) than Manhyia (15.8%). It is possible that some false positives were detected due to residual HRP-2, while recall bias may also have resulted in overestimation of reported antimalarial use. However, this evidence also suggests that treatments being used by some children may not be effective in clearing parasitaemia. Home treatment or reliance on informal drug shops as a primary treatment method for child malaria is reported among many urban populations [P. falciparum infection. As many urban caregivers in Ghana report treating all child fevers with antimalarials [P. falciparum infection in our study communities. Further investigation is needed to determine the quality of drugs being sold in these areas and to assess patterns of drug utilization by caregivers.Twenty-five percent (25.3%) of children with ulations ,33. In eulations . Poor quulations . In addialarials , this suP. falciparum prevalence, and as a consequence, this study may have more limited power to assess differences in other factors between the communities. No data were collected to differentiate clinics by ownership type, treatment costs, or the range of services provided by each clinic; however, all of the clinics operating in Moshie Zongo were private clinics, which could have different treatment fees than government facilities. Good access to health services and timely provision of effective drug treatment is a self-targeting intervention, yet the costs of treatment and prevention often preclude the poorest people from using them [In addition, this study highlights the vulnerability of the urban poor to the impact of malaria, as a strong association was found between SES and disease prevalence. Disaggregating the mechanisms through which poverty acts is challenging due to the complex interactions of factors . The SESing them . GreaterP. falciparum infection compared to malnutrition, indicate the importance of malaria as a cause of anaemia in this urban population. Further investigation is needed to determine if treatment-seeking behaviours in these two communities differ and to what extent behaviours are associated with availability of different types of health services.Heterogeneities in malariometric indices between neighbouring urban communities of Kumasi are consistent over time. The low prevalence of intestinal helminths, and the twofold higher PAR% of anaemia attributable to LAR helped to design the study, performed data collection, analysis and drafted the manuscript. SLK helped to design the study, performed data collection and analysis. EK helped to design the study and assisted with the analysis. AOA helped to design the study and supervised data collection. IB performed data collection. GB designed and supervised the study. MJD conceived of the study, and participated in its design and coordination. All authors read and approved the final manuscript.The author(s) declare that they have no competing interests.