herpes simplex virus ( hsv ) is a neurotropic virus that has a large linear , double - stranded dna genome protected by a capsid with icosahedral symmetry surrounded by an envelope consisting of a lipid bilayer with embedded glycoproteins , having yet a proteinaceous region between the capsid and envelope called tegument .
the hsv belongs to the family of herpesviridae , subfamily alphaherpesvirinae , and genus simplex virus [ 2 , 3 ] .
it is a virus that has a very complex life cycle and stands out as one of the most common pathogens in the etiology of sexually transmitted diseases worldwide .
hsv infects the mucosa of the mouth , eyes , and the human anogenital tract .
after primary infection , the virus replicates productively within mucosal epithelial cells and enters sensory neurons via nerve termini . the virus is then transported to neuronal cell bodies where latency is established .
the virus can remain in this latent state indefinitely but can be reactivated at any time during the lifetime of the host [ 4 , 5 ] . during latent infection ,
no infectious virus is produced from infected cells , symptoms are absent in the host , and the transmission does not occur .
however , reactivation can occur only in some cells , in the absence of symptoms , enabling the transmission of the virus .
this seemingly benign strategy has critical importance to the survival of the virus , where the infected cell continues throughout the life of the host , providing a reservoir for periodic reactivation .
hsv is presented in the form of two distinct serotypes : herpes simplex type 1 ( hsv-1 ) and type 2 ( hsv-2 ) , which are closely related but contain sufficient differences to enable type identification .
hsv-1 is usually transmitted during childhood by nonsexual contact , typically found in orofacial lesions , with latency in the trigeminal ganglia .
hsv-2 is the cause of most genital herpes and is almost always sexually transmitted , with latency in the lumbosacral ganglia .
however , in the last decades , hsv-1 has been pointed out by several studies as a main causative agent of genital herpes , especially in college students [ 7 , 8 ] .
regardless of which serotype of hsv is acquired , the infections remain intermittent throughout the host 's lifetime , in symptomatic or subclinical form with or without periodic reactivations . the extent and frequency of recurrent genital herpes are highly type - specific , with hsv-2 reactivation outpacing hsv-1 by three to one .
thus , although an increase in genital infections attributable to hsv-1 has been well recognized in recent years , the situation regarding recurrence has apparently remained unaltered , with hsv-2 being the dominant agent .
when there is a reactivation , the virus is excreted on the mucosal surfaces , allowing its transmission to susceptible individuals .
most hsv-1 and hsv-2 infections are subclinical . however , when the infection is symptomatic , the clinical manifestations of hsv-2 are typically characterized by recurrent , painful , vesicular , and ulcerative lesions , located in the genital and anal areas .
in contrast , symptomatic hsv-1 infections are usually manifested as recurrent orolabial and facial lesions . both hsv-1 and hsv-2 can cause genital herpes with greatest incidence among women of reproductive age , with risk of maternal transmission of the virus to the fetus and neonate .
the acquisition of genital herpes during pregnancy has been associated with spontaneous abortion , intrauterine growth restriction , prematurity , and congenital and neonatal herpes .
vertical transmission from an infected mother to her baby can cause severe disease resulting in sequelae or death of the infant .
most neonatal infections result from exposure to hsv in the genital tract during passage through the birth canal , although they can also be transmitted to the fetus during the intrauterine phase .
the risk of disease in the newborn is significantly higher when the mother acquires genital infection for the first time with hsv-1 or hsv-2 during pregnancy .
recurrent infections are rarely associated with disseminated neonatal disease in the newborn of immune - competent mothers .
in fact , the pregnant women who acquire genital herpes as a primary infection in the latter half of pregnancy , rather than prior to pregnancy , are at the greatest risk of transmitting the virus to their newborn [ 2 , 3 ] .
neonatal herpes has three major categories : skin , eye , and mouth disease ( sem ) , central nervous system infection ( cns ) , and disseminated infection ( di ) .
it has been observed that sem in itself is rarely fatal , but , without antiviral therapy , most cases progress to cns or di .
clinically , cns disease typically presents with nonspecific symptoms such as lethargy , poor feeding , irritability , vomiting , and seizures .
the disseminated infection is manifested in various combinations such as hepatitis , acute adrenal insufficiency , myocarditis , and consumption coagulopathy . in brazil
, there is a major lack of studies on the prevalence of genital infection by herpes simplex virus .
furthermore , the diagnosis of genital infection with these pathogens is not included among the mandatory prenatal examinations .
thus , there is no official data available on infection during pregnancy nor on the likely consequences of such infections in newborns . in this study
we evaluated the prevalence for herpes simplex virus types 1 and 2 genital infection among pregnant and nonpregnant women , its association with the presence of cervical abnormalities detected by colposcopy and cytology , sociodemographic characteristics , and reproductive activity .
this study included 236 sexually active women , 106 ( 44.9% ) of whom were pregnant and 130 ( 55.1% ) nonpregnant , enrolled among those who attended the health service by spontaneous demand for cervical screening programme or to prenatal care , and agreed to participate in the study .
the participants were residents in natal , rio grande do norte state , brazil , who sought gynecological care at two primary health care units from may 2010 until september 2011 and who agreed to participate in the research .
study subjects were asked to fill in an anonymous questionnaire in order to identify different demographic and behavioral risk factors that may have implied their exposure to hsv-1 and hsv-2 .
the patient 's ethnicity was identified based on self - reports according to the criterion of the brazilian institute of geography and statistics ( ibge ) , which classifies ethnicity into five categories : white , black , mulatto , asian , and native . in this study ,
the black , mulatto , asian , and native categories were combined into a nonwhite category .
data on sexual behavior included the age at the first sexual intercourse and the number of sexual partners during the lifetime .
the study was approved by the ethics committee for medical research of the federal university of rio grande do norte ( protocol 030/10cep / ufrn ) and the written informed consent has been obtained from each subject . all women participating in this study underwent a clinical examination followed by a visual inspection of the vulva , vaginal walls , and cervix by colposcopy , with only two gynecologists , to detect possible abnormalities of these structures . during the examination , a solution of 5% acetic acid was applied initially and the first visual analysis was performed . after washing to remove the acetic acid , lugol solution of i2 ( 1% ) in equilibrium with ki ( 2% ) in distilled water was applied , and the second inspection was done .
the colposcopy was considered with alteration , when at least one of the abnormal features ( acetowhite lesions , punctuation , mosaics , inflammatory punctuation , congestion , and ulceration ) in a localized area in the transformation zone was found .
two specimens containing exfoliated uterine cervical cells were collected from each patient using a cervical brush .
one of these specimens was used to obtain a smear on a slide that was stained by the papanicolaou method and analyzed by cytopathological examination , based on the bethesda system .
we considered as normal cytology , or cytology without alterations , the samples that presented no pathological alteration or only inflammatory changes .
cytology with alterations were the samples in which we detected the presence of atypical squamous cells of undetermined significance ( asc - us ) , squamous intraepithelial lesions of low grade ( lsil ) or squamous intraepithelial lesions of high - grade ( hsil ) .
the other cervical specimen was conditioned in a tube containing a preserving solution ( pbs + vancomycin + nystatin ) and sent to a laboratory where it was processed for dna extraction .
the tubes containing the cervical specimens were submitted to rigorous agitation before removal of the brush and were centrifuged at 300  g per 10  min .
the supernatant was removed and the resulting pellet was processed for dna extraction using qiamp dna mini kit ( qiagen , hilden , germany ) following the manufacturer 's recommendations . around 30  ng of the dna samples was submitted to a polymerase chain reaction ( pcr ) to amplify a 110  bp fragment of the human -globin gene , using the primers pco3+/pco4 +   to analyze the quality of target dna and the absence of pcr inhibitors .
the products of pcr were submitted to electrophoresis on 8% polyacrylamide gel , followed by silver staining .
the positive samples for -globin were analyzed for the presence of dna from hsv-1 and hsv-2 in separated reactions by pcrs specific for each type .
each reaction was composed of a master mix ( promega , madison , wi , usa ) , 10  mm of each primer , and 2.5  mm of dna sample , to a final volume of 25  l . the pair primers hsv-1a ( 5-ccctgtctcgcgcgagccac-3 ) and hsv-1b ( 5-tcagccacccatacgcgtaa-3 ) , which amplify a fragment of 142  bp ,
were used to detect the presence of hsv-1 , while the primers hsv-2 ( a ) ( 5-ggacgaggcgccaaagcacacg-3 ) and hsv-2 ( b ) ( 5-tccgtccagtcgtttatcttcac-3 ) , which generate a product 270  bp , were used to detect the presence of hsv-2 .
the conditions for both reactions were as follows : incubation at 50c for 2  min and denaturation of dna at 95c for 5  min , followed by 40 cycles of 94c for 1  min , 45  s at 58c for annealing , an extension step at 72c for 30  s , and a final extension step at 72c for 10  min .
the products of pcrs underwent vertical electrophoresis on polyacrylamide gel at 8% and subsequent visualization by silver staining .
statistical analysis of the results was performed using the chi - square test , while difference in proportion and associations between risk factors and hsv infection were analyzed by calculating the odds ratio ( or ) and their respective confidence intervals ( 95% ci ) .
the analysis of individual questionnaires revealed that the profile of the segment of the population studied was characterized by being composed of women aged 1472 years , mean 30.3  10.8 years .
most of them were less than 30 years of age , were of nonwhite ethnicity , were married or living in a stable relationship with her partner , had elementary education or less , had family income ( monthly minimum wage ) up to one minimum wage ( approximately us$ 300.00 ) , had their first sexual intercourse and the first pregnancy at age 18 or less , had more than one sexual partner in their lifetime , was not pregnant at the time of the survey , and had at least one pregnancy .
the presence of any of the serotypes of hsv alone or both together was detected in 95 women , revealing an overall prevalence of 40.3% of genital infection in the studied population ( 23.7% hsv-1 alone , 11.9% hsv-2 alone , and 4.7% the two serotypes together ) .
the presence of at least one of the serotypes of hsv was detected in 36/106 ( 34.0% ) pregnant women and in 59/130 ( 45.4% ) nonpregnant women .
we observed a significant higher prevalence rate of hsv-1 infection among non - pregnant women ( 30.0% ) , when compared to pregnant women ( 16.0% ) ( p = 0.0001 ) .
hsv-2 alone was found in 13/106 ( 12.3% ) pregnant women and in 15/130 ( 11.5% ) nonpregnant women .
the coinfection by the two serotypes of hsv , in the same patient , was detected in 5.7% of pregnant and 4.7% of nonpregnant women ( table 1 ) .
most of the participants in this study underwent morphological examinations by colposcopy ( 92.8% ) and cytology ( 96.6% ) to detect the presence of changes of the uterine cervix .
the colposcopic examination was carried out on 90/106 ( 84.9% ) pregnant women and in 129/130 ( 99.2% ) nonpregnant women . in the group of pregnant women ,
the colposcopic examination showed that 38/90 ( 42.2% ) had visible abnormalities of the uterine cervix . among nonpregnant women ,
the colposcopic examination showed that 45/129 ( 34.9% ) had cervical changes ( table 2 ) .
cytological examination was performed on 100/106 ( 94.3% ) pregnant women and in 128/130 ( 98.5% ) nonpregnant women ( table 3 ) .
the cytological alterations were more prevalent in pregnant ( 41/100 ) than nonpregnant ( 22/128 ) women ( p = 0.0001 ) .
we also analyzed the correlation between the presence of genital infection by any of the two serotypes of hsv and morphological findings detected by colposcopy and cytological examinations .
there was not any significant difference in the prevalence rates for hsv-1 between the groups with or without colposcopic abnormalities , in both pregnant and nonpregnant women .
however , the prevalences of hsv-2 were significantly higher in women with colposcopy abnormalities in both pregnant and nonpregnant women , compared to those with normal colposcopy ( table 2 ) .
similar results were found for women with or without cytological abnormalities ( table 3 ) .
analysis of the association between genital infection by hsv-1 and hsv-2 , each individually , and the considered variables revealed the absence of association between genital infection with hsv-1 and all variables tested ( table 4 ) .
the genital tract infection by hsv-2 was found to be associated with morphological alterations detected by colposcopy or cytology , ethnicity , marital status , and number of lifetime sexual partners . the nonwhite and single women and those who had multiple partners presented a greater risk of acquiring genital hsv-2 infection ( table 5 ) .
it has been shown that the prevalence of genital tract infection by hsv-1 and hsv-2 varies substantially in the different geographic regions , including those within the same country . in this study , we found an overall prevalence rate of 40.3% .
the found prevalence rate was almost three times higher than that reported for united states women ( 14.0% ) .
it was also higher than that described in a similar previous study involving women of natal , brazil ( 28.4% ) . considering each serotype of the hsv individually , hsv-1 was more prevalent than hsv-2 , in the segment of the population studied , presenting coherence with the results reported in other studies , such as those reported for women of the united states , for women of israel , and for women of natal .
this could be explained by changes in attitudes , behavior , and the sexual practices among adolescents , including oral - genital sexual contact .
furthermore , the use of condoms for vaginal intercourse could have reduced the exposure to genital infection by hsv-2 , contributing to an increasing proportion of cases of hsv-1 , compared with hsv-2 as cause of genital herpes infection .
hsv-1 was detected in 23.7% of women surveyed , presenting a prevalence rate almost equal to that found in a previous study for natal residents women ( 23.0% ) , but slightly smaller than the prevalence rate reported for women of the united states ( 32.0% ) .
hsv-2 was detected in 11.9% of the study participants , representing double the prevalence rate of 5.4% reported by pereira et al . in 2012 , but close to that described for american women ( 16.2% ) .
still the prevalence rate described in this study was very similar to that reported for women of israel ( 13.3% ) , while it was less than the estimated prevalence for women of south america   ( varying between 20.0% and 40.0% ) .
coinfection by the two serotypes of hsv was detected in 4.7% of the women surveyed , which was above that in previous research conducted by pereira et al .
hsv-1 was more prevalent among nonpregnant women , whereas hsv-2 presented similar prevalence among pregnant and nonpregnant women .
the prevalence of genital hsv-1 infection found in the nonpregnant women was higher than that described for women of the united states ( 14.0% ) .
regarding pregnant women , hsv-1 was found with a prevalence rate very similar to that reported in a previous study in natal 's women ( 23.0% ) .
the prevalence rate of hsv-2 was practically equal to that described for women in korea   ( 17.0% ) but was less than that reported for united states ' women , approximately 22.0% .
the prevalence rates found in nonpregnant women participating in this study for both hsv-1 and hsv-2 were higher than those described for women in the united states , which were 4.4% and 9.4% , respectively .
pregnant women had higher percentages of abnormal results in both colposcopic and cytological examinations , when compared to nonpregnant women .
we observed in this study a higher proportion of women infected with hsv-2 among those who had abnormal colposcopy and/or cytology , in both groups of pregnant and nonpregnant women .
this suggests that hsv-2 has a higher ability to cause lesions in the genital tract .
this result is consistent with the literature data reporting that the extent and frequency of symptomatic recurrent genital herpes is highly type - specific , with hsv-2 reactivations being much more frequent , outpacing hsv-1 by three to one .
furthermore , it was shown that genital hsv-1 recurs infrequently and the rate of recurrences decreases rapidly over time , with a median recurrence rate declining by about 50% from the first to the second year of infection .
when we evaluated the existence or lack of association between genital hsv-1 infection and sociodemographic variables and sexual activity , it was found that there was no association between the variables tested and genital hsv-1 infection among women of this study , corroborating with the results obtained in a previous study conducted in natal .
however , a significant association was observed between the variables of ethnicity , marital status , and number of sexual partners over a lifetime and the occurrence of genital infection by hsv-2 .
no association was observed with chronological age , education , and age at first sexual intercourse .
these results are consistent with those obtained for israel women , regarding education , age of first intercourse , and number of sexual partners . with regard to ethnicity ,
, the morphological alterations may not have been caused exclusively by hsv , once that there are other pathogens that cause cervical lesions , such as hpv , that were not analyzed in this study .
besides , the studied population is limited to women attended in two primary health care units and may not be representative of the female population of natal .
the analysis of a larger number of patients would allow obtaining more conclusive results . in conclusion ,
results of the current study show a high prevalence rate of both hsv-1 and hsv-2 in the studied population .
the significant proportion of pregnant women infected by hsv-2 that presented morphological alterations in the uterine cervix suggests the importance of including the colposcopy or cytology exams as part of routine prenatal care .
 
 objective . to evaluate the prevalence of hsv-1 and hsv-2 in pregnant and nonpregnant women , testing the correlation between dna of the viruses with colposcopic and/or cytological changes , and 
 evaluate association with sociodemographic characteristics and sexual activity . 
 methods . included in this study were 106 pregnant and 130 nonpregnant women treated at primary health care units of natal , brazil , in the period 2010 - 2011 . 
 the patients were examined by colposcopy , and two cervical specimens were collected : one for cytology examination and another for analysis by pcr for detection of hsv-1 and hsv-2 . 
 results . 
 hsv-1 alone was detected in 16.0% of pregnant and 30.0% of nonpregnant women . 
 for hsv-2 , these rates were 12.3% and 15.5% , respectively . 
 hsv-2 had a higher correlation with cytology and/or colposcopy changes than hsv-1 did . 
 genital hsv-1 infection was not associated with any of the variables tested , whereas hsv-2 infection was associated with ethnicity , marital status , and number of sexual partners . 
 conclusions . 
 the prevalence of hsv-1 was higher than that observed for hsv-2 in both pregnant and nonpregnant women . 
 the genital infection by hsv-2 was higher in women with changed colposcopy and/or cytology , and it was associated with ethnicity , marital status , and number of sexual partners . 