Herpes Simplex Virus Type 2 and Risk of Intrapartum Human Immunodeficiency Virus Transmission

20 years of herpes simplex virus type 2 (HSV-2) research in low-income and middle-income countries: systematic evaluation of progress made in addressing WHO priorities for research in HSV-2/HIV interactions, HSV-2 control and mathematical modelling

INTRODUCTION

Reviewing and updating research priorities is essential to assess progress and to ensure optimal allocation of financial and human resources in research. In 2001, WHO held a research priority setting workshop for herpes simplex virus type 2 (HSV-2) research in low-income and middle-income countries (LMICs). This study aimed to describe progress between 2000 and 2020 in three of the five key research priority areas outlined in the workshop: HSV-2/HIV interactions, HSV-2 control measures and HSV-2 mathematical modelling. The remaining priorities are addressed in a companion paper.

METHOD

A systematic literature search of MEDLINE, CINAHL, Global Health and Cochrane databases was carried out. Relevant primary research studies based in LMICs, written in English and published on 2000-2020 were included. Papers were screened by two independent reviewers, and suitable variables were selected for manual extraction from study texts. Data were organised into an Excel spreadsheet and analysed using IBM SPSS.

RESULTS

In total, 3214 discrete papers were identified, of which 180 were eligible for inclusion (HSV-2/HIV interactions, 98; control measures, 58; mathematical modelling, 24). Most studies were conducted in East Africa. The majority of the 2001 WHO HSV-2 research priorities were addressed at least in part. Overall, despite several studies describing a strong relationship between HSV-2 and the acquisition and transmission of HIV, HSV-2 control repeatedly demonstrated little effect on HIV shedding or transmission. Further, although mathematical modelling predicted that vaccines could significantly impact HSV-2 indicators, HSV-2 vaccine studies were few. Studies of antiviral resistance were also few.

CONCLUSION

Since 2000, LMIC HSV-2 research addressing its control, HIV interactions and mathematical modelling has largely addressed the priorities set in the 2001 WHO HSV-2 workshop. However, key knowledge gaps remain in vaccine research, antiviral cost-effectiveness, antiviral resistance and specific geographical areas.

Prevention of Mother-to-Child Human Immunodeficiency Virus Transmission in Resource-Limited Countries

The first pediatric AIDS cases were reported in 1982. A decade later, the World Health Organization estimated there were more than 500,000 pediatric AIDS cases resulting from mother-to-child transmission, 90% of which were in sub-Saharan Africa. Although the rate of new infections globally has been cut in half since the peak of the pandemic, human immunodeficiency virus (HIV) remains a public health threat, and rates of new infections continue to increase in some regions. Mother-to-child transmission of HIV has now been virtually eliminated in many parts of the world but remains an issue in resource-limited countries.

Understanding Viral and Immune Interplay During Vertical Transmission of HIV: Implications for Cure

Despite the significant progress that has been made to eliminate vertical HIV infection, more than 150,000 children were infected with HIV in 2019, emphasizing the continued need for sustainable HIV treatment strategies and ideally a cure for children. Mother-to-child-transmission (MTCT) remains the most important route of pediatric HIV acquisition and, in absence of prevention measures, transmission rates range from 15% to 45% via three distinct routes: in utero, intrapartum, and in the postnatal period through breastfeeding. The exact mechanisms and biological basis of these different routes of transmission are not yet fully understood. Some infants escape infection despite significant virus exposure, while others do not, suggesting possible maternal or fetal immune protective factors including the presence of HIV-specific antibodies. Here we summarize the unique aspects of HIV MTCT including the immunopathogenesis of the different routes of transmission, and how transmission in the antenatal or postnatal periods may affect early life immune responses and HIV persistence. A more refined understanding of the complex interaction between viral, maternal, and fetal/infant factors may enhance the pursuit of strategies to achieve an HIV cure for pediatric populations.

Mycoplasma genitalium infection among HIV-infected pregnant African women and implications for mother-to-child transmission of HIV

OBJECTIVE

Many sexually transmitted infections increase risk of mother-to-child transmission (MTCT) of HIV, but the effect of Mycoplasma genitalium is not known. We hypothesized that M. genitalium infection would be common among HIV-infected pregnant women and could be associated with in-utero and intrapartum MTCT.

DESIGN

Observational case-cohort study.

METHODS

The current study used specimens from a Kenyan perinatal MTCT cohort (1999-2005) involving HIV-infected women and their infants, who received short-course zidovudine for prevention of MTCT. Vaginal swabs collected at 32 weeks gestation were tested for M. genitalium using a transcription-mediated amplification assay. Infant perinatal HIV infection was determined at birth and 4 weeks of age by DNA PCR. Using a case-cohort design, a random sample was generated with 3 : 1 control : case ratio; prevalence and correlates of M. genitalium were assessed with chi-squared and t tests; predictors of infant outcomes were analyzed using logistic regression.

RESULTS

Among 220 HIV-infected pregnant women evaluated, 47 women (21.4%) had M. genitalium. Antenatal M. genitalium infection was associated with higher HIV RNA in plasma (5.0 vs. 4.6 log10 copies/ml in M. genitalium-positive vs. M. genitalium-negative women, P = 0.02) at 32 weeks. Women with M. genitalium were less likely to report prior sexually transmitted infections and genital ulcers (both P = 0.05). There was no association found between exposure to M. genitalium and perinatal MTCT (odds ratio = 0.72, 95% confidence interval 0.35, 1.51, P = 0.39).

CONCLUSION

Vaginal M. genitalium infection was frequently detected among Kenyan HIV-infected pregnant women and was associated with higher plasma HIV levels, but was not associated with perinatal transmission of HIV.

Minimizing the Risk of Perinatal Human Immunodeficiency Virus Transmission

Importance

There are approximately 284,500 adolescent and adult women living with human immunodeficiency virus (HIV) in the United States. It is estimated that approximately 8500 of these women give birth annually. While the rate of perinatal transmission in the United States has decreased by more than 90% since the early 1990s, potentially preventable HIV transmission events still occur and cause significant morbidity and mortality.

Objective

The aim of this review was to summarize the current data regarding perinatal HIV transmission timing and risk factors, current management recommendations, and implications of timing of transmission on patient management.

Evidence Acquisition

Literature review.

Results

This review reiterates that the risk of perinatal HIV transmission can be reduced to very low levels by following current recommendations for screening for HIV in all pregnant women and properly treating HIV-infected mothers, as well as using evidence-based labor management practices.

Conclusions and Relevance

Familiarity with the pathogenesis of HIV transmission is important for obstetric care providers to appropriately manage HIV-infected women in pregnancy, intrapartum, and the postpartum period.

Combined evaluation of sexually transmitted infections in HIV-infected pregnant women and infant HIV transmission

Background

Sexually transmitted infections (STIs) including Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Treponema pallidum (TP), and cytomegalovirus (CMV) may lead to adverse pregnancy and infant outcomes. The role of combined maternal STIs in HIV mother-to-child transmission (MTCT) was evaluated in mother-infant pairs from NICHD HPTN 040.

Methodology

Urine samples from HIV-infected pregnant women during labor were tested by polymerase chain reaction (PCR) for CT, NG, and CMV. Infant HIV infection was determined by serial HIV DNA PCR testing. Maternal syphilis was tested by VDRL and confirmatory treponemal antibodies.

Results

A total of 899 mother-infant pairs were evaluated. Over 30% had at least one of the following infections (TP, CT, NG, and/or CMV) detected at the time of delivery. High rates of TP (8.7%), CT (17.8%), NG (4%), and CMV (6.3%) were observed. HIV MTCT was 9.1% (n = 82 infants). HIV MTCT was 12.5%, 10.3%, 11.1%, and 26.3% among infants born to women with CT, TP, NG or CMV respectively. Forty-two percent of HIV-infected infants were born to women with at least one of these 4 infections. Women with these infections were nearly twice as likely to have an HIV-infected infant (aOR 1.9, 95% CI 1.1–3.0), particularly those with 2 STIs (aOR 3.4, 95% CI 1.5–7.7). Individually, maternal CMV (aOR 4.4 1.5–13.0) and infant congenital CMV (OR 4.1, 95% CI 2.2–7.8) but not other STIs (TP, CT, or NG) were associated with an increased risk of HIV MTCT.

Conclusion

HIV-infected pregnant women identified during labor are at high risk for STIs. Co-infection with STIs including CMV nearly doubles HIV MTCT risk. CMV infection appears to confer the largest risk of HIV MTCT.

Trial registration

NCT00099359.

[Management of pregnant women with first episode of genital herpes. Guidelines for clinical practice from the French college of gynecologists and obstetricians (CNGOF)]

OBJECTIVE

To provide guidelines for the management of first episode genital herpes during pregnancy and in the immediate postpartum period.

METHODS

MedLine and Cochrane Library databases search and review of the main foreign guidelines.

RESULTS

In case of first episode genital herpes during pregnancy, antiviral treatment with acyclovir (200mg 5 times daily) or valacyclovir (1000mg twice daily) for 5 to 10 days is recommended (grade C). The patient should be tested for HIV if not previously done (grade B). Daily suppressive antiviral treatment with acyclovir (400mg 3 times daily) or valacyclovir (500mg twice daily) is recommended from 36 weeks for women who have had a first episode genital herpes during pregnancy (grade B). A cesarean section should be performed in case of suspicion of first episode genital herpes at the onset of labor (grade B) or premature rupture of the membranes at term (professional consensus), or in case of first episode genital herpes less than 6 weeks before delivery (professional consensus). In the event of first episode genital herpes highlighted in the postpartum period, the neonatologist should be informed (professional consensus). The patient may be treated according the scheme described above.

CONCLUSION

A cesarean section should be performed in case of first episode genital herpes less than 6 weeks before delivery.

2017 European guidelines for the management of genital herpes

Genital herpes is one of the commonest sexually transmitted infections worldwide. Using the best available evidence, this guideline recommends strategies for diagnosis, management, and follow-up of the condition as well as for minimising transmission. Early recognition and initiation of therapy is key and may reduce the duration of illness or avoid hospitalisation with complications, including urinary retention, meningism, or severe systemic illness. The guideline covers a range of common clinical scenarios, such as recurrent genital herpes, infection during pregnancy, and co-infection with human immunodeficiency virus.

Does maternal HSV-2 coinfection increase mother-to-child transmission of HIV? A systematic review

Background

Reducing HIV mother-to-child transmission (MTCT) is critical to ending the HIV pandemic. Reports suggest that herpes simplex virus-2 (HSV-2), a common coinfection in HIV-infected individuals, is associated with increased MTCT, but results have been conflicting. We conducted a systematic review of observational studies to quantify the magnitude of this relationship (PROSPERO no. CRD42016043315).

Methods

We searched Medline (1981 to June week 3, 2016), EMBASE (1981 to week 26, 2016), relevant conferences (2013–2016) and bibliographies of identified studies for cohort and case–control studies enrolling HIV-positive women during pregnancy or peripartum that quantified the effect of HSV-2 infection on MTCT. The primary outcome was the risk of perinatal HIV transmission associated with maternal HSV-2 status. Risk of bias was evaluated using a standardised tool, and results were meta-analysed where appropriate using a random-effects model, with studies weighted using the inverse variance method.

Results

From 2103 hits, 112 studies were considered for inclusion, and 10 were ultimately included. Of the included studies, three used a case–control design, three were retrospective cohorts and four were prospective cohorts. Risk of bias was low in three studies, moderate in six and high in one. The median sample size was 278.5 mother–infant pairs (range: 48–1513). The most common strategy for classifying maternal HSV-2 status was type-specific serology (n=6), followed by genital shedding (n=3) or genital culture (n=3), clinical diagnosis of herpes (n=2) or genital ulcer disease (n=1). Results from five studies that provided quantitative estimates of the association between HSV-2 seropositivity and MTCT were meta-analysed, yielding a pooled unadjusted OR=1.17 (95% CI=0.69 to 1.96, I²=58%). Three of these studies further considered key confounding variables, specifically antiretroviral use and/or viral load (n=3), and mode of delivery (n=2), yielding a pooled adjusted OR=1.57 (95% CI=1.17 to 2.11, I²=0).

Conclusions

Maternal HSV-2 coinfection appears to be associated with increased perinatal HIV transmission. Further study of the effect of HSV-2 treatment on MTCT is warranted.

Role of Interleukin 32 in Human Immunodeficiency Virus Reactivation and Its Link to Human Immunodeficiency Virus-Herpes Simplex Virus Coinfection

Background

Herpes simplex virus type 2 (HSV-2; herpes) exacerbates human immunodeficiency virus type 1 (HIV) by unclear mechanisms. These studies tested the impact of HSV-2 on systemic T-cells and HIV reservoirs.

Methods

Peripheral blood mononuclear cells from HIV-infected women on antiretroviral therapy who were HSV-2 seropositive or seronegative and HIV-uninfected controls were analyzed by flow cytometry. Cell-associated HIV DNA and RNA were quantified in the absence or presence of activating stimuli, recombinant interleukin 32γ (IL-32γ), and a RUNX1 inhibitor. RNA was assessed by nanostring.

Results

CD4, but not CD8, T-cell phenotypes differed in HIV+/HSV-2+ versus HIV+/HSV-2- (overall P = .002) with increased frequency of CCR5+, CXCR4+, PD-1+, and CD69+ and decreased frequency of CCR10+ and CCR6+ T-cells. The changes were associated with higher HIV DNA. Paradoxically, IL-32, a proinflammatory cytokine, was lower in subpopulations of CD4+ T-cells in HSV-2+ versus HSV-2- women. Recombinant IL-32γ blocked HIV reactivation in CD4+ T-cells and was associated with an increase in RUNX1 expression; the blockade was overcome by a RUNX1 inhibitor.

Conclusions

Herpes is associated with phenotypic changes in CD4+ T-cells, including a decrease in IL-32, which may contribute to increased HIV reservoirs. Blocking IL-32 may facilitate HIV reactivation to improve shock and kill strategies.

Maternal HIV infection alters the immune balance in the mother and fetus; implications for pregnancy outcome and infant health

PURPOSE OF REVIEW

With the rapid roll-out of combination antiretroviral therapy to prevent mother-to-child transmission of HIV, there is an annual increase in the number of uninfected infants born to HIV-infected women. Although the introduction of combination antiretroviral therapy has vastly improved pregnancy outcome and the health of infants born to HIV-infected women, concerns remain regarding the impact the maternal HIV infection on the pregnancy outcome and the health of HIV-exposed uninfected infants.

RECENT FINDINGS

Maternal HIV infection is associated with negative pregnancy outcomes such as low birth weight. In addition, an increased susceptibility to infections is reported in HIV-exposed uninfected infants compared with infants born to uninfected women. Studies have shown that HIV-exposure affects the maternal/fetal unit, with increase of proinflammatory cytokine produced by placental cells, as well as altered infant immune responses. These changes could provide the underlying conditions for negative pregnancy outcomes and facilitate mother-to-child transmission of HIV in the infant. Further studies are required to understand the underlying mechanisms and investigate whether these altered infant immune responses persist and have clinical consequences beyond childhood.

SUMMARY

HIV infection in pregnant women is associated with altered immune responses in HIV-infected women and their offspring with clinical consequences for pregnancy outcome and the HIV-exposed uninfected infant. Further studies are required to address the origin and long-term consequences of prenatal HIV-exposure and subsequent immune activation for infant health.

Chlamydia and Gonorrhea in HIV-Infected Pregnant Women and Infant HIV Transmission

BACKGROUND

Sexually transmitted infections (STIs) such as Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) can lead to adverse pregnancy and neonatal outcomes. The prevalence of STIs and its association with HIV mother-to-child transmission (MTCT) were evaluated in a substudy analysis from a randomized, multicenter clinical trial.

METHODOLOGY

Urine samples from HIV-infected pregnant women collected at the time of labor and delivery were tested using polymerase chain reaction testing for the detection of CT and NG (Xpert CT/NG; Cepheid, Sunnyvale, CA). Infant HIV infection was determined by HIV DNA polymerase chain reaction at 3 months.

RESULTS

Of the 1373 urine specimens, 249 (18.1%) were positive for CT and 63 (4.6%) for NG; 35 (2.5%) had both CT and NG detected. Among 117 cases of HIV MTCT (8.5% transmission), the lowest transmission rate occurred among infants born to CT- and NG-uninfected mothers (8.1%) as compared with those infected with only CT (10.7%) and both CT and NG (14.3%; P = 0.04). Infants born to CT-infected mothers had almost a 1.5-fold increased risk for HIV acquisition (odds ratio, 1.47; 95% confidence interval, 0.9-2.3; P = 0.09).

CONCLUSIONS

This cohort of HIV-infected pregnant women is at high risk for infection with CT and NG. Analysis suggests that STIs may predispose to an increased HIV MTCT risk in this high-risk cohort of HIV-infected women.

High prevalence of herpes simplex virus (HSV)- type 2 co-infection among HIV-positive women in Ukraine, but no increased HIV mother-to-child transmission risk

Background

Over 3500 HIV-positive women give birth annually in Ukraine, a setting with high prevalence of sexually transmitted infections. Herpes simplex virus Type 2 (HSV-2) co-infection may increase HIV mother-to-child transmission (MTCT) risk. We explored factors associated with HSV-2 seropositivity among HIV-positive women in Ukraine, and its impact on HIV MTCT.

Methods

Data on 1513 HIV-positive women enrolled in the Ukraine European Collaborative Study from 2007 to 2012 were analysed. Poisson and logistic regression models respectively were fit to investigate factors associated with HSV-2 seropositivity and HIV MTCT.

Results

Median maternal age was 27 years (IQR 24–31), 53 % (796/1513) had been diagnosed with HIV during their most recent pregnancy and 20 % had a history of injecting drugs. Median antenatal CD4 count was 430 cells/mm³ (IQR 290–580). Ninety-six percent had received antiretroviral therapy antenatally. HSV-2 seroprevalence was 68 % (1026/1513). In adjusted analyses, factors associated with HSV-2 antibodies were history of pregnancy termination (APR 1.30 (95 % CI 1.18–1.43) for ≥2 vs. 0), having an HIV-positive partner (APR 1.15 (95 % CI 1.05–1.26) vs partner’s HIV status unknown) and HCV seropositivity (APR 1.23 (95 % CI 1.13–1.35)). The overall HIV MTCT rate was 2.80 % (95 % CI 1.98–3.84); no increased HIV MTCT risk was detected among HSV-2 seropositive women after adjusting for known risk factors (AOR 1.43 (95 % CI 0.54–3.77).

Conclusion

No increased risk of HIV MTCT was detected among the 68 % of HIV-positive women with antibodies to HSV-2, in this population with an overall HIV MTCT rate of 2.8 %. Markers of ongoing sexual risk among HIV-positive HSV-2 seronegative women indicate the importance of interventions to prevent primary HSV-2 infection during pregnancy in this high-risk group.

Research gaps in defining the biological link between HIV risk and hormonal contraception

Epidemiologic data suggest an association between depot medroxyprogesterone acetate (DMPA), a progesterone-based hormonal contraceptive, and increased risk of HIV acquisition and transmission. DMPA is highly effective and is among the most commonly used form of hormonal contraception in areas of high HIV prevalence. Thus, defining the biological mechanisms that contribute to the potential negative synergy between DMPA and HIV is key and may facilitate the identification of alternative contraceptive strategies. Proposed mechanisms include thinning or disruption of the cervicovaginal epithelial barrier, induction of mucosal inflammation, interference with innate and adaptive soluble and cellular immune responses, and/or alterations in the vaginal microbiome. DMPA may also indirectly increase the risk of HIV by promoting genital herpes or other sexually transmitted infections. However, there is a paucity of rigorous in vitro, animal model and clinical data to support these potential mechanisms highlighting the need for future research.

Adolescents' and young women's use of a microbicide surrogate product when receiving oral sex

STUDY OBJECTIVE

Genital herpes, which can be spread through oral sex, is an important target for microbicides. We examined episode-specific predictors of young women's receptive oral sex and of microbicide surrogate use.

DESIGN

Longitudinal study.

SETTING

Participants were recruited to participate in a microbicide acceptability study from adolescent clinics and local colleges and through snowballing.

PARTICIPANTS

Young women (ages 14 to 21 y) who reported sexual contact on at least 1 weekly phone interview (n = 181) were included from the larger sample of 208 young women.

MAIN OUTCOME MEASURES

On weekly diary phone interviews, participants reported whether or not their last sexual contact included receptive oral sex and whether or not their last sexual contact included use of a microbicide surrogate.

RESULTS AND CONCLUSIONS

Participants reported a total of 1042 episodes of sexual contact of which 311 included receptive oral sex and 354 included microbicide surrogate use. Being older, having sex for the first time with a partner, and having given oral sex were associated with having received oral sex during a sexual episode. Being older, being African American, and having discussed the microbicide surrogate with their partner were associated with having used the microbicide surrogate use during a sexual episode. These results indicate that oral sex should be considered in the design of clinical trials. Future studies need to evaluate ways to promote consistent microbicide use in the context of receiving oral sex as well as those factors (eg, taste, pleasure) which may serve as a barrier.

The role of co-infections in mother-to-child transmission of HIV

In HIV-infected women, co-infections that target the placenta, fetal membranes, genital tract, and breast tissue, as well as systemic maternal and infant infections, have been shown to increase the risk for mother-to-child transmission of HIV (MTCT). Active co-infection stimulates the release of cytokines and inflammatory agents that enhance HIV replication locally or systemically and increase tissue permeability, which weakens natural defenses to MTCT. Many maternal or infant co-infections can affect MTCT of HIV, and particular ones, such as genital tract infection with herpes simplex virus, or systemic infections such as hepatitis B, can have substantial epidemiologic impact on MTCT. Screening and treatment for co-infections that can make infants susceptible to MTCT in utero, peripartum, or postpartum can help reduce the incidence of HIV infection among infants and improve the health of mothers and infants worldwide.

Effects of valacyclovir on markers of disease progression in postpartum women co-infected with HIV-1 and herpes simplex virus-2

Objective

Herpes simplex virus type 2 (HSV-2) suppression has been shown to reduce HIV-1 disease progression in non-pregnant women and men, but effects on pregnant and postpartum women have not been described.

Methods

We analyzed data from a cohort of Kenyan women participating in a randomized clinical trial of HSV-2 suppression. Pregnant HIV-1-seropositive, HSV-2-seropositive women who were not eligible for antiretroviral therapy (WHO stage 1–2, CD4>250 cells/µl) were randomized to either 500 mg valacyclovir or placebo twice daily from 34 weeks gestation through 12 months postpartum. Women received zidovudine and single-dose nevirapine for prevention of mother-to-child HIV-1 transmission. HIV-1 progression markers, including CD4 count and plasma HIV-1 RNA levels, were measured serially. Multivariate linear regression was used to compare progression markers between study arms.

Results

Of 148 women randomized, 136 (92%) completed 12 months of postpartum follow-up. While adjusted mean CD4 count at 12 months (565 cells/µl placebo arm, 638 cells/µl valacyclovir arm) increased from antenatal levels in both arms, the mean CD4 count increase was 73 cells/µl higher in the valacyclovir arm than placebo arm (p = 0.03). Mean increase in CD4 count was 154 cells/µl in the valacyclovir arm, almost double the increase of 78 cells/µl in the placebo arm. At 12 months, adjusted HIV-1 RNA levels in the placebo arm increased by 0.66 log₁₀ copies/ml from baseline, and increased by only 0.21 log₁₀ copies/ml in the valacyclovir arm (0.40 log₁₀ copies/ml difference, p = 0.001).

Conclusion

Women randomized to valacyclovir suppressive therapy during pregnancy and postpartum had greater increases in CD4 counts and smaller increases in plasma HIV-1 RNA levels than women in the placebo arm. Valacyclovir suppression during pregnancy and breastfeeding may improve outcomes and delay antiretroviral therapy for HIV-1/HSV-2 co-infected women.

Infant safety during and after maternal valacyclovir therapy in conjunction with antiretroviral HIV-1 prophylaxis in a randomized clinical trial

BACKGROUND

Maternal administration of the acyclovir prodrug valacyclovir is compatible with pregnancy and breastfeeding. However, the safety profile of prolonged infant and maternal exposure to acyclovir in the context of antiretrovirals (ARVs) for prevention of mother-to-child HIV-1 transmission (PMTCT) has not been described.

METHODS

Pregnant Kenyan women co-infected with HIV-1/HSV-2 with CD4 counts > 250 cells/mm(3) were enrolled at 34 weeks gestation and randomized to twice daily 500 mg valacyclovir or placebo until 12 months postpartum. Women received zidovudine from 28 weeks gestation and single dose nevirapine was given to women and infants at the time of delivery for PMTCT. Infant blood was collected at 6 weeks for creatinine and ALT. Breast milk specimens were collected at 2 weeks postpartum from 71 women in the valacyclovir arm; acyclovir levels were determined for a random sample of 44 (62%) specimens. Fisher's Exact and Wilcoxon rank-sum tests were used for analysis.

RESULTS

One hundred forty-eight women were randomized and 146 mother-infant pairs were followed postpartum. PMTCT ARVs were administered to 98% of infants and all mothers. Valacyclovir was not associated with infant or maternal toxicities or adverse events, and no congenital malformations were observed. Infant creatinine levels were all normal (< 0.83 mg/dl) and median creatinine (median 0.50 mg/dl) and infant growth did not differ between study arms. Acyclovir was detected in 35 (80%) of 44 breast milk samples collected at 2 weeks postpartum. Median and maximum acyclovir levels were 2.62 and 10.15 mg/ml, respectively (interquartile range 0.6-4.19).

CONCLUSIONS

Exposure to PMTCT ARVs and acyclovir after maternal administration of valacyclovir during pregnancy and postpartum to women co-infected with HIV-1/HSV-2 was not associated with an increase in infant or maternal toxicities or adverse events.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00530777.

Valacyclovir suppressive therapy reduces plasma and breast milk HIV-1 RNA levels during pregnancy and postpartum: a randomized trial

BACKGROUND

The effect of herpes simplex virus type 2 (HSV-2) suppression on human immunodeficiency virus type 1 (HIV-1) RNA in the context of prevention of mother-to-child transmission (PMTCT) interventions is unknown.

METHODS

Between April 2008 and August 2010, we conducted a randomized, double-blind trial of twice daily 500 mg valacyclovir or placebo beginning at 34 weeks gestation in 148 HIV-1/HSV-2 coinfected pregnant Kenyan women ineligible for highly active antiretroviral therapy (CD4 > 250 cells/mm(3)). Women received zidovudine and single dose nevirapine for PMTCT and were followed until 12 months postpartum.

RESULTS

Mean baseline plasma HIV-1 RNA was 3.88 log(10) copies/mL. Mean plasma HIV-1 was lower during pregnancy (-.56 log(10) copies/mL; 95% confidence interval [CI], -.77 to -.34) and after 6 weeks postpartum (-.51 log(10) copies/mL; 95% CI, -.73 to -.30) in the valacyclovir arm than the placebo arm. Valacyclovir reduced breast milk HIV-1 RNA detection at 6 and 14 weeks postpartum compared with placebo (30% lower, P = .04; 46% lower, P = .01, respectively), but not after 14 weeks. Cervical HIV-1 RNA detection was similar between arms (P = .91).

CONCLUSIONS

Valacyclovir significantly decreased early breast milk and plasma HIV-1 RNA among women receiving PMTCT.

CLINICAL TRIALS REGISTRATION

NCT00530777.

Host factors that influence mother-to-child transmission of HIV-1: genetics, coinfections, behavior and nutrition

Mother-to-child transmission (MTCT) is the most important mode of HIV-1 acquisition among infants and children and it can occur in utero, intrapartum and postnatally through breastfeeding. Great progress has been made in preventing MTCT through use of antiretroviral regimens during gestation, labor/delivery and breastfeeding. The mechanisms of MTCT, however, are multifactorial and remain incompletely understood. This review focuses on select host factors affecting MTCT, in particular genetic factors, coexisting infections, behavioral factors and nutrition. Whereas much emphasis has been placed on decreasing maternal HIV-1 viral load, an important determinant of MTCT, through use of antiretroviral agents, complementary focus on overall maternal health is often neglected. By addressing coinfections in mothers and infants, improving the mother's nutritional status and modifying risky behaviors and practices, not only is maternal and child health improved, but a direct benefit in reducing MTCT can be derived. The study of genetic variations in susceptibility to HIV-1 infection is rapidly evolving, and the future is likely to bring revolutionary changes in HIV-1 prevention by enhancing natural resistance to infection and by individually tailoring pharmacologic regimens.

The role of HIV replicative fitness in perinatal transmission of HIV

Perinatal transmission of Human immunodeficiency virus (HIV), also called mother-to-child transmission (MTCT), accounts for 90% of infections in infants worldwide and occurs in 30%-45% of children born to untreated HIV-1 infected mothers. Among HIV-1 infected mothers, some viruses are transmitted from mothers to their infants while others are not. The relationship between virologic properties and the pathogenesis caused by HIV-1 remains unclear. Previous studies have demonstrated that one obvious source of selective pressure in the perinatal transmission of HIV-1 is maternal neutralizing antibodies. Recent studies have shown that viruses which are successfully transmitted to the child have growth advantages over those not transmitted, when those two viruses are grown together. Furthermore, the higher fitness is determined by the gp120 protein of the virus envelope. This suggests that the selective transmission of viruses with higher fitness occurred exclusively, regardless of transmission routes. There are many factors contributing to the selective transmission and HIV replicative fitness is an important one that should not be neglected. This review summarizes current knowledge of the role of HIV replicative fitness in HIV MTCT transmission and the determinants of viral fitness upon MTCT.

European guideline for the management of genital herpes, 2010

This is the guideline for genital herpes simplex virus (HSV) management for the IUSTI/WHO Europe, 2010. They describe the epidemiology, diagnosis, clinical features, treatment and prevention of genital HSV infection. They include details on the management of HSV in pregnancy, those who are immunocompromised and the clinical investigation and management of suspected HSV-resistant disease.

Herpes simplex virus type 2, genital ulcers and HIV-1 disease progression in postpartum women

Background

Co-infection with herpes simplex virus type 2 (HSV-2) has been associated with increased HIV-1 RNA levels and immune activation, two predictors of HIV-1 progression. The impact of HSV-2 on clinical outcomes among HIV-1 infected pregnant women is unclear.

Methods

HIV-1 infected pregnant women in Nairobi were enrolled antenatally and HSV-2 serology was obtained. HIV-1 RNA and CD4 count were serially measured for 12–24 months postpartum. Survival analysis using endpoints of death, opportunistic infection (OI), and CD4<200 cells µL, and linear mixed models estimating rate of change of HIV-1 RNA and CD4, were used to determine associations between HSV-2 serostatus and HIV-1 progression.

Results

Among 296 women, 254 (86%) were HSV-2-seropositive. Only 30 (10%) women had prior or current genital ulcer disease (GUD); median baseline CD4 count was 422 cells µL. Adjusting for baseline CD4, women with GUD were significantly more likely to have incident OIs (adjusted hazard ratio (aHR) 2.79, 95% CI: 1.33–5.85), and there was a trend for association between HSV-2-seropositivity and incident OIs (aHR 3.83, 95% CI: 0.93–15.83). Rate of change in CD4 count and HIV-1 RNA did not differ by HSV-2 status or GUD, despite a trend toward higher baseline HIV-1 RNA in HSV-2-seropositive women (4.73 log10 copies/ml vs. 4.47 log10 copies/ml, P = 0.07).

Conclusions

HSV-2 was highly prevalent and pregnant HIV-1 infected women with GUD were significantly more likely to have incident OIs than women without GUD, suggesting that clinically evident HSV-2 is a more important predictor of HIV-1 disease progression than asymptomatic HSV-2.

Genital HSV detection among HIV-1-infected pregnant women in labor

OBJECTIVE

To compare genital HSV shedding among HIV-positive and HIV-negative women.

METHODS

Women with and without known HIV infection who delivered at the University of Washington Medical Center between 1989-1996 had HSV serologies done as part of clinical care. Genital swabs from HSV-2-seropositive women were evaluated by real-time quantitative HSV DNA PCR.

RESULTS

HSV-2 seroprevalence was 71% and 30% among 75 HIV-positive and 3051 HIV-negative women, respectively, (P < .001). HSV was detected at delivery in the genital tract of 30.8% of HIV-seropositive versus 9.5% of HIV-negative women (RR = 3.2, 95% CI 1.6 to 6.5, P = .001). The number of virion copies shed per mL was similar (log 3.54 for HIV positive versus 3.90 for HIV negative, P = .99).

CONCLUSIONS

Our study demonstrated that HIV-, HSV-2-coinfected women are more likely to shed HSV at delivery.

Diagnosis of sexually transmitted infections and bacterial vaginosis among HIV-1-infected pregnant women in Nairobi

HIV-infected women with sexually transmitted infections (STIs) or bacterial vaginosis (BV) during pregnancy are at increased risk for poor obstetric outcomes. In resource-limited settings, diagnostic testing for STIs and BV is often not available and most pregnant women are managed using syndromic algorithms. As part of a Nairobi perinatal cohort, HIV-1-infected pregnant women were interviewed and samples were collected for STIs and BV testing. Diagnostic accuracy of STIs and BV by syndromic algorithms was evaluated with comparison to the reference standard. Among 441 women, prevalence of BV was 37%, trichomoniasis 16%, chlamydia 4%, syphilis 3% and gonorrhoea 2%. Significantly more women with STIs were aged 21-years-old, had not attended secondary school and had a history of STIs. Syndromic diagnosis of STIs and BV demonstrated a sensitivity of 45% and 57%, and positive predictive value of 30% and 42%, respectively. Among these HIV-infected, pregnant women, STIs and vaginal infections were common and syndromic diagnosis was insensitive, resulting in missed opportunities to intervene and improve infant and maternal health.

Immune-based approaches to the prevention of mother-to-child transmission of HIV-1: active and passive immunization

Despite more than 2 decades of research, an effective vaccine that can prevent HIV-1 infection in populations exposed to the virus remains elusive. In the pursuit of an HIV-1 vaccine, does prevention of exposure to maternal HIV-1 in utero, at birth or in early life through breast milk require special consideration? This article reviews what is known about the immune mechanisms of susceptibility and resistance to mother-to-child transmission (MTCT) of HIV-1 and summarizes studies that have used passive or active immunization strategies to interrupt MTCT of HIV-1. Potentially modifiable infectious cofactors that may enhance transmission and/or disease progression (especially in the developing world) are described. An effective prophylactic vaccine against HIV-1 infection needs to be deployed as part of the Extended Program of Immunization recommended by the World Health Organization for use in developing countries, so it is important to understand how the infant immune system responds to HIV-1 antigens, both in natural infection and presented by candidate vaccines.

Mother-to-child transmission of HIV: pathogenesis, mechanisms and pathways

More than 400,000 children were infected with (HIV-1) worldwide in 2008, or more than 1000 children per day. Mother-to-child transmission (MTCT) of HIV-1 is the most important mode of HIV acquisition in infants and children. MTCT of HIV-1 can occur in utero, intrapartum, and postnatally through breastfeeding. Great progress has been made in preventing such transmission, through the use of antiretroviral prophylactic regimens to the mother during gestation and labor and delivery and to either mother or infant during breast feeding. The timing and mechanisms of transmission, however, are multifactorial and remain incompletely understood. This article summarizes what is known about the pathogenetic mechanisms and routes of MTCT of HIV-1, and includes virologic, immunologic, genetic, and mucosal aspects of transmission.

Screening of Herpes simplex virus 2 infection among pregnant women in southern China

The aim was to investigate the prevalence of Herpes simplex virus (HSV)-2 infection among pregnant women in southern China and analyze the relationship between the HSV-2 infection and pregnancy outcome. We examined 1740 sera collected from pregnant women aged 21-39 years, using enzyme-linked immunosorbent assay for the detection of specific antibodies against HSV-2. The overall prevalence of HSV-2 infection was 23.56% (95% confidence interval [CI]=21.53-26.00). The prevalence of HSV-2 infection in the women with abnormal pregnancy was 35.93% (95% CI=26.23-42.44) (83/231), which was much higher than that in women who had been pregnant before but without abnormal pregnancy and that in the primipara group. (P<0.05). The presence of HSV-2 antibodies was also associated with status of education. The prevalence of HSV-2 infection in the 26-30-year age group (27.49%) (95% CI=24.53-30.33) was the highest among all age groups. The prevalence of HSV-2 infection in pregnant women in southern China is quite high. Women with asymptomatic or subclinical genital infection should be identified by examining the HSV-2 antibody, which would be helpful to reduce the abnormal pregnancy outcome.

New concepts in understanding genital herpes

Herpes simplex virus (HSV)-2 is a lifelong infection that causes recurrent genital ulcers and, rarely, disseminated and visceral disease. HSV-1 infection is an increasingly important cause of genital ulcers. HSV infections are the most common cause of genital ulcers in adults, but acquisition and chronic infection are more commonly asymptomatic than symptomatic. Both the symptomatic and asymptomatic forms of HSV are of clinical consequence for several reasons. HSV-2 infection enhances HIV-1 acquisition and transmission. In addition, sexual and perinatal transmission can occur during asymptomatic viral shedding. Perinatal transmission is of particular concern because neonatal HSV infection results in severe morbidity to the newborn. Antiviral medicines are effective for limiting recurrence duration and decreasing transmission likelihood, although no available intervention completely prevents transmission. This fact highlights the importance of laboratory diagnostics for this lifelong infection, and the need for an HSV vaccine.

New insights on interactions between HIV-1 and HSV-2

Herpes simplex type 2 (HSV-2) infection is common and frequently asymptomatic. Concerns exist about the high prevalence of HSV-2, particularly in areas of high HIV prevalence, because of observations that HSV-2 is associated with an increased risk of HIV acquisition, transmission, and disease progression. Several randomized trials have tested or are testing whether HSV-2 treatment can limit the spread of HIV, with mixed results. Although treatment with acyclovir, 400 mg twice daily, does not reduce HIV incidence, suppressive acyclovir and valacyclovir reduce HIV levels in plasma and in the genital tract. Ongoing trials are evaluating whether HSV suppression will reduce HIV transmission and disease progression. Until a protective HSV-2 or HIV vaccine is available, effective interventions that reduce the effect of HSV-2 on HIV transmission are critically needed.

Illness during pregnancy and bacterial vaginosis are associated with in-utero HIV-1 transmission

HIV-1 transmission in utero accounts for 20-30% of vertical transmission events in breast-feeding populations. In a prospective study of 463 HIV-1-infected mothers and infants, illness during pregnancy was associated with 2.6-fold increased risk of in-utero HIV-1 transmission [95% confidence interval (CI) 1.2-5.8] and bacterial vaginosis with a three-fold increase (95% CI 1.0-7.0) after adjusting for maternal HIV-1 viral load. Interventions targeting these novel risk factors could lead to more effective prevention of transmission during pregnancy.

Timing and determinants of mother-to-child transmission of HIV in Nigeria

OBJECTIVE

To characterize the timing and determinants of mother-to-child transmission (MTCT) of HIV among mothers receiving single-dose nevirapine to prevent MTCT in Nigeria.

METHODS

Three hundred and seventy-one HIV-infected mothers and their infants were followed from birth, at 1 week, and at 1, 3, 6, and 12 months. Risks of in utero (IU), intrapartum (IP/EPP), and postnatal (PP) transmission were quantified using conditional Cox regressions.

RESULTS

Maternal viral load was the only risk factor for IU transmission after controlling for known risk factors. Low birth weight, premature birth, mixed feeding, and maternal viral load were associated with IP/EPP transmission. Increased PP transmission was associated with low birth weight and mixed feeding. At 6 months, mixed-fed infants were more likely to acquire infection than formula-fed infants (hazard ratio=5.74; 95% CI, 1.26-26.2).

CONCLUSION

Risk factors for IU transmission differed from those of IP and PP transmission. Reducing mixed feeding and low birth weight delivery among HIV-infected mothers can further decrease IP and PP transmission.

Prevalence of sexually transmitted infections among pregnant women with known HIV status in northern Tanzania

OBJECTIVES

To determine the prevalence of sexually transmitted infections (STIs) and other reproductive tract infections (RTIs) among pregnant women in Moshi, Tanzania and to compare the occurrence of STIs/RTIs among human immunodeficiency virus (HIV)-infected and uninfected women.

METHODS

Pregnant women in their 3rd trimester (N = 2654) were recruited from two primary health care clinics between June 2002 and March 2004. They were interviewed, examined and genital and blood samples were collected for diagnosis of STIs/RTIs and HIV.

RESULTS

The prevalence of HIV, active syphilis and herpes simplex virus - type 2 (HSV-2) were 6.9%, 0.9% and 33.6%, respectively, while 0.5% were positive for N gonorrhoeae, 5.0% for T vaginalis and 20.9% for bacterial vaginosis. Genital tract infections were more prevalent in HIV-seropositive than seronegative women, statistically significant for syphilis (3.3% vs 0.7%), HSV-2 (43.2% vs 32.0%), genital ulcers (4.4% vs 1.4%) and bacterial vaginosis (37.2% vs 19.6%). In comparison with published data, a declining trend for curable STIs/RTIs (syphilis, trichomoniasis and bacterial vaginosis) was noted.

CONCLUSION

Rates of STIs and RTIs are still high among pregnant women in Moshi. Where resources allow, routine screening and treatment of STIs/RTIs in the antenatal care setting should be offered. Higher STIs/RTIs in HIV-seropositive women supports the expansion of HIV-counseling and testing services to all centers offering antenatal care. After identification, STIs/RTIs need to be aggressively addressed in HIV-seropositive women, both at antenatal and antiretroviral therapy care clinics.

Maternal herpes simplex virus type 2 coinfection increases the risk of perinatal HIV transmission: possibility to further decrease transmission?

OBJECTIVES

To evaluate the association between maternal herpes simplex virus type 2 seropositivity and genital herpes simplex virus type 2 shedding with perinatal HIV transmission.

STUDY DESIGN

Evaluation of women who participated in a 1996-1997 perinatal HIV transmission prevention trial in Thailand.

METHODS

In this nonbreastfeeding population, women were randomized to zidovudine or placebo from 36 weeks gestation through delivery; maternal plasma and cervicovaginal HIV viral load and infant HIV status were determined for the original study. Stored maternal plasma and cervicovaginal samples were tested for herpes simplex virus type 2 antibodies by enzyme-linked immunoassay and for herpes simplex virus type 2 DNA by real-time PCR, respectively.

RESULTS

Among 307 HIV-positive women with available samples, 228 (74.3%) were herpes simplex virus type 2 seropositive and 24 (7.8%) were shedding herpes simplex virus type 2. Herpes simplex virus type 2 seropositivity was associated with overall perinatal HIV transmission [adjusted odds ratio, 2.6; 95% confidence interval, 1.0-6.7)], and herpes simplex virus type 2 shedding was associated with intrapartum transmission (adjusted odds ratio, 2.9; 95% confidence interval, 1.0-8.5) independent of plasma and cervicovaginal HIV viral load, and zidovudine treatment. Median plasma HIV viral load was higher among herpes simplex virus type 2 shedders (4.2 vs. 4.1 log(10)copies/ml; P = 0.05), and more shedders had quantifiable levels of HIV in cervicovaginal samples, compared with women not shedding herpes simplex virus type 2 (62.5 vs. 34.3%; P = 0.005).

CONCLUSION

We found an increased risk of perinatal HIV transmission among herpes simplex virus type 2 seropositive women and an increased risk of intrapartum HIV transmission among women shedding herpes simplex virus type 2. These novel findings suggest that interventions to control herpes simplex virus type 2 infection could further reduce perinatal HIV transmission.

[Genital herpes and HSV transmission in HIV patients]

There is a bidirectional relationship between HSV-2 and HIV-1, both at the cellular level, as well as regarding transmission and even progression of HIV-1 infection. There is clear evidence that anti-herpetic therapy reduces the plasma and mucosal HIV-1 viral load, as well as transmission. Serologic testing for HSV-2 in patients with an increased HIV-1 risk, coupled with a better understanding of the interaction between the viruses and appropriate anti-herpetic suppression therapy could both reduce the HIV-1 transmission rate and help the individual with an HIV infection.

No association between antepartum serologic and genital tract evidence of herpes simplex virus-2 coinfection and perinatal HIV-1 transmission

OBJECTIVE

The purpose of this study was to assess the risk of perinatal HIV-1 transmission in women who are coinfected with herpes simplex virus-2 (HSV-2).

STUDY DESIGN

We performed a nested case-control study of 26 women whose HIV-1 was transmitted to their infants and 52 control subjects whose HIV-1 was not transmitted. We assessed antepartum serologic evidence of HSV-2 by HSV-2 serostatus and genital tract evidence of HSV-2 by presence of HSV-2 DNA.

RESULTS

There was no significant association between antepartum serologic evidence of HSV-2 coinfection and the risk of perinatal HIV-1 transmission. There was also no association between antepartum genital tract evidence of HSV-2 coinfection and risk of perinatal HIV-1 transmission.

CONCLUSION

Women who were infected with HIV-1 with antepartum serologic and genital tract evidence of HSV-2 coinfection did not appear to have an increased risk of perinatal HIV-1 transmission. However, further investigations are needed to assess HSV-2 reactivation and the risk of perinatal HIV-1 transmission at the time of delivery.

Biological mechanisms of vertical human immunodeficiency virus (HIV-1) transmission

In the absence of interventions, 30-45% of exposed infants acquire human immunodeficiency virus type 1 (HIV-1) through mother-to-child transmission. It remains unclear why some infants become infected while others do not, despite significant exposure to HIV-1 in utero, during delivery and while breastfeeding. Here we discuss the correlates of vertical transmission with an emphasis on factors that increase maternal HIV-1 levels, either systemically or locally in genital secretions and breast milk. Immune responses may influence maternal viral load, and data suggest that maternal neutralising antibodies reduce infection rates. In addition, infants may be capable of mounting HIV-specific cellular immune responses. We propose that both humoral and cellular responses are necessary to reduce infection because cell-free as well as cell-associated virus appears to play a role in vertical transmission. These distinct forms of the virus may be targeted most effectively by different components of the immune system. We also discuss the use of antiretrovirals to reduce transmission, focusing on the mechanisms of action of regimens currently used in developing country settings. We conclude that prevention relies not only on reducing maternal HIV-1 levels within blood, genital tract and breast milk, but also on pre- and/or post-exposure prophylaxis to the infant. However, HIV-1 has the capacity to mutate under drug pressure and rapidly acquires mutations conferring antiretroviral resistance. This review concludes with data on persistence of low-level resistance after delivery as well as recent guidelines for maternal and infant regimens designed to limit resistance.