Effect of herpes simplex suppression on incidence of HIV among women in Tanzania

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.

Impact of universal testing and treatment on sexual risk behaviour and herpes simplex virus type 2: a prespecified secondary outcomes analysis of the HPTN 071 (PopART) community-randomised trial

BACKGROUND

Comprehensive HIV prevention strategies have raised concerns that knowledge of interventions to reduce risk of HIV infection might mitigate an individual's perception of risk, resulting in riskier sexual behaviour. We investigated the prespecified secondary outcomes of the HPTN 071 (PopART) trial to determine whether a combination HIV prevention strategy, including universal HIV testing and treatment, changed sexual behaviour; specifically, we investigated whether there was evidence of sexual risk compensation.

METHODS

HPTN 071 (PopART) was a cluster-randomised trial conducted during 2013-18, in which we randomly assigned 21 communities with high HIV prevalence in Zambia and South Africa (total population, approximately 1 million) to combination prevention intervention with universal antiretroviral therapy (ART; arm A), prevention intervention with ART provided according to local guidelines (universal since 2016; arm B), or standard of care (arm C). The trial included a population cohort of approximately 2000 randomly selected adults (aged 18-44 years) in each community (N=38 474 at baseline) who were followed up for 36 months. A prespecified secondary objective was to evaluate the impact of the PopART intervention compared with standard of care on herpes simplex virus type 2 (HSV-2) and sexual behaviour (N=20 422 completed final visit). Secondary endpoints included differences in sexual risk behaviour measures at 36 months and were assessed using a two-stage method for matched cluster-randomised trials. This trial is registered with ClinicalTrials. gov, number NCT01900977.

FINDINGS

The PopART intervention did not substantially change probability of self-reported multiple sex partners, sexual debut, or pregnancy in women at 36 months. Adjusted for baseline community prevalence, reported condomless sex was significantly lower in arm A versus arm C (adjusted prevalence ratio 0·80 [95% CI 0·64-0·99]; p=0·04) but not in arm B versus arm C (0·94 [0·76-1·17]; p=0·55). 3-year HSV-2 incidence was reduced in arm B versus arm C (adjusted risk ratio 0·76 [95% CI 0·63-0·92]; p=0·010); no significant change was shown between arm A versus arm C (0·89 [0·73-1·08]; p=0·199).

INTERPRETATION

We found little evidence of any change in sexual behaviour owing to the PopART interventions, and reassuringly for public health, we saw no evidence of sexual risk compensation. The findings do not help to explain the differences between the two intervention groups of the HPTN 071 (PopART) trial.

FUNDING

National Institute of Allergy and Infectious Diseases, the National Institutes of Health, the International Initiative for Impact Evaluation (3ie), the Bill & Melinda Gates Foundation, the US President's Emergency Plan for AIDS Relief, and the Medical Research Council UK.

Prevalence of syphilis and chlamydia trachomatis infection among men who have sex with men in Jiangsu province, China: A cross-sectional survey

Background

Epidemics of sexually transmitted infections (STIs) among men who have sex with men (MSM) are major global public health concerns. This study aimed to examine the prevalence of syphilis and chlamydia trachomatis (CT) infection and associated factors among MSM in Jiangsu province, China, hoping to provide updated data for the formulation of relevant policies.

Methods

A cross-sectional survey was conducted among MSM from April to July 2021 in four cities in the province. Socio-demographic characteristics and behavioral information were collected through a face-to-face questionnaire interview. Venous blood specimens were collected for HIV, hepatitis C (HCV), and syphilis testing using serological testing methods. First-void urine specimens were collected for CT and Neisseria gonorrhoeae (NG) testing using nucleic acid amplification testing (NAAT) methods. Chi-square tests were used to compare differences in syphilis and CT infection between subgroups of variables. Multivariate logistic regression analysis was used to identify factors associated with syphilis and CT infection.

Results

A total of 1,087 participants were enrolled. The prevalence of HIV, HCV, syphilis, CT and NG infection were 6.6, 0.4, 6.3, 4.2, and 0.4%, respectively. MSM recruited online [adjusted odds ratio (aOR) = 2.189, P = 0.020], diagnosed with an STI in the past 12 months (aOR = 3.304, P < 0.001), and living with HIV (aOR = 4.721, P < 0.001) were more likely to have syphilis infection. MSM who were younger than 25 years (aOR = 4.286, P = 0.020), had senior high school level education (aOR = 2.521, P = 0.038), and were recruited via VCT clinics (aOR = 3.455, P = 0.001) were more likely to have CT infection.

Conclusions

Our study showed a high prevalence of syphilis and chlamydia among MSM in Jiangsu province, China. STI screening, diagnosis, and treatment services promotion should be a top priority on the prevention agenda.

Prevalence and antimicrobial resistance profiles of Neisseria gonorrhea and Chlamydia trachomatis isolated from individuals attending STD clinics in Kampala, Uganda

Background

Sexually transmitted diseases (STDs) management in sub-Saharan Africa is syndromic but molecular diagnostics provide quicker, sensitive diagnosis and treatment. Effective STD control hinges on identification and treatment of infected persons and sexual partner contact tracing.

Objectives

This study assessed feasibility of using the Xpert CT/NG test to identify prevalent Chlamydia trachomatis (CT) and Neisseria gonorrhea (NG) infections among STD clinic attendees and their sexual partners and tested for antimicrobial resistance for N. gonorrhea.

Methods

A cross-sectional study was conducted at 4 outpatient STD clinics in Kampala, Uganda from February 2019 to October 2019. Participants received a syndromic diagnosis, were tested for NG and CT, as well as their sexual partners. Urine (men) and high vaginal swabs (women) were collected, examined using Xpert CT/NG assay. A total of 79 participants were enrolled at baseline of whom 25 had CT/NG. 21 partners of infected baseline participants and 7 partners of the 21 primary partners were enrolled.

Results

The mean age of the reported sexual partners was 26 (18-43) years. The prevalence of NG was 25% at baseline and 18 % for CT. Nine (11.4%) people were dually infected. Men were more likely to have NG (p<0.001) at multivariable level. Two participants tested HIV-1 positive. On microbiological culture, 8 samples (2.5%) grew NG and all were resistant to penicillin, ciprofloxacin. For CT, we found a preponderance of the F-serovar in this population.

Conclusion

The most prevalent organism was Neisseria gonorrhea. Generally, the prevalence of CT and NG was high. Infection proportions increased among primary partners, particularly women. Etiologic testing without partner tracing and treatment may underestimate burden of CT/NG in this population and contribute to re-infection.

Age-Restriction of a Validated Risk Scoring Tool Better Predicts HIV Acquisition in South African Women: CAPRISA 004

We examined the predictive ability of the VOICE risk screening tool among adolescent girls and young women at heightened HIV risk in urban and peri-urban Kwa-Zulu-Natal, South Africa. Using participant data from CAPRISA 004’s control arm (N = 444), we applied the initial VOICE risk screening score (IRS), a modified risk score (MRS) based on predictive and non-predictive variables in our data, and age-restricted (AIRS and AMRS, respectively). We estimated incidence rates, 95% confidence bounds, sensitivity, specificity, negative and positive predictive values and area under the curve (AUC). The sample’s HIV incidence rate was 9.1/100 Person-Years [95% CI 6.9–11.7], resulting from 60 seroconversions (60/660.7 Person-Years). The IRS’ ≥ 8 cutpoint produced moderate discrimination [AUC = 0.66 (0.54–0.74), sensitivity = 63%, specificity = 57%]. Restricting to age < 25 years improved the score’s predictive ability (AIRS: AUC = 0.69, AMRS: AUC = 0.70), owing mainly to male partner having other partners and HSV-2. The risk tool predicted HIV acquisition at a higher cutpoint in this sample than in the initial VOICE analysis. After age-stratification, fewer variables were needed for maintaining score’s predictiveness. In this high incidence setting, risk screening may still improve the efficiency or effectiveness of prevention counseling services. However, PrEP should be offered to all prevention-seeking individuals, regardless of risk ascertainment.

Recent Advances and New Challenges in Cisgender Women's Gynecologic and Obstetric Health in the Context of HIV

Although rates of human immunodeficiency virus (HIV) have declined globally over the past 10 years, United Nations Programme on HIV/AIDS estimates 1.7 million new infections occurred in 2019, with cisgender women (cis women) and girls accounting for 48%. Acquired immune deficiency syndrome-related illnesses are the leading global cause of mortality in cis women aged 15 to 49, and in many sub-Saharan Africa countries, young women face substantially higher HIV risk than their male counterparts. Drivers of this increased risk include sexual and reproductive health characteristics unique to cis women. This review discusses the role of sexually transmitted infections, contraception and pregnancy in HIV risk, and biomedical HIV prevention technologies available and in development.

Brief Report: Herpes Simplex Virus Type-2 Shedding and Genital Ulcers During Early HIV in Zimbabwean Women

BACKGROUND

Herpes simplex virus type-2 (HSV-2) seropositive persons have a 3- to 5-fold higher risk of acquiring HIV, possibly because of HSV-2-induced inflammation and recruitment of susceptible immune cells to exposure sites. We hypothesized that cervical HSV-2 activation (ie, viral DNA shedding and/or ulcers) preceded HIV acquisition in the hormonal contraception and HIV cohort.

METHODS

Zimbabwean women who acquired HIV were matched to HIV-negative women on visit, age, and bacterial sexually transmitted infections. Up to 5 cervical swabs bracketing first polymerase chain reaction detection of HIV DNA (the index visit) were selected (t-6months, t-3months, tindex, t+3months, t+6months). Women with HSV-2 immunoglobulin G+ before tindex were polymerase chain reaction tested for viral shedding. Self-reported and clinician-diagnosed ulcers were documented. Multivariable logistic regression, accounting for matching, estimated adjusted odds ratios (aOR) and 95% confidence intervals (CIs) at each visit.

RESULTS

Of 387 HSV-2 seropositive women, most had prevalent as compared with incident HSV-2 (91% vs. 9%, respectively). HSV-2 viral shedding was more common among HIV seroconverters than HIV-negative women (26% vs. 14%, P < 0.01). Shedding occurred around HIV acquisition (t-3months aOR, 2.7; 95% CI, 0.8 to 8.8; tindex aOR, 2.6; 95% CI, 1.1 to 6.5; t+3months aOR, 2.6; 95% CI, 1.0 to 6.6). Genital ulcers were reported more often among HIV seroconverters than HIV-negative women (13% vs. 7%; P = 0.06) and detection was after HIV acquisition (t+6months aOR, 14.5; 95% CI, 1.6 to 133.9).

CONCLUSIONS

HSV-2 shedding appeared synergistic with HIV acquisition followed by presentation of ulcers. Evaluating all sexually transmitted infections rather than HSV-2 alone may clarify the relationship between inflammation and HIV acquisition.

Global and regional estimates of the contribution of herpes simplex virus type 2 infection to HIV incidence: a population attributable fraction analysis using published epidemiological data

BACKGROUND

A 2017 systematic review and meta-analysis of 55 prospective studies found the adjusted risk of HIV acquisition to be at least tripled in individuals with herpes simplex virus type 2 (HSV-2) infection. We aimed to assess the potential contribution of HSV-2 infection to HIV incidence, given an effect of HSV-2 on HIV acquisition.

METHODS

We used a classic epidemiological formula to estimate the global and regional (WHO regional) population attributable fraction (PAF) and number of incident HIV infections attributable to HSV-2 infection by age (15-24 years, 25-49 years, and 15-49 years), sex, and timing of HSV-2 infection (established vs recently acquired). Estimates were calculated by incorporating HSV-2 and HIV infection data with pooled relative risk (RR) estimates for the effect of HSV-2 infection on HIV acquisition from a systematic review and meta-analysis. Because HSV-2 and HIV have shared sexual and other risk factors, in addition to HSV-related biological factors that increase HIV risk, we only used RR estimates that were adjusted for potential confounders.

FINDINGS

An estimated 420 000 (95% uncertainty interval 317 000-546 000; PAF 29·6% [22·9-37·1]) of 1·4 million sexually acquired incident HIV infections in individuals aged 15-49 years in 2016 were attributable to HSV-2 infection. The contribution of HSV-2 to HIV was largest for the WHO African region (PAF 37·1% [28·7-46·3]), women (34·8% [23·5-45·0]), individuals aged 25-49 years (32·4% [25·4-40·2]), and established HSV-2 infection (26·8% [19·7-34·5]).

INTERPRETATION

A large burden of HIV is likely to be attributable to HSV-2 infection, even if the effect of HSV-2 infection on HIV had been imperfectly measured in studies providing adjusted RR estimates, potentially because of residual confounding. The contribution is likely to be greatest in areas where HSV-2 is highly prevalent, particularly Africa. New preventive interventions against HSV-2 infection could not only improve the quality of life of millions of people by reducing the prevalence of herpetic genital ulcer disease, but could also have an additional, indirect effect on HIV transmission.

FUNDING

WHO.

Sexual behaviour, changes in sexual behaviour and associated factors among women at high risk of HIV participating in feasibility studies for prevention trials in Tanzania

INTRODUCTION

Risk reduction towards safer behaviour is promoted after enrolment in HIV prevention trials. We evaluated sexual behaviour, changes in sexual behaviour and factors associated with risky behaviour after one-year of follow-up among women enrolled in HIV prevention trials in Northern Tanzania.

METHODS

Self-reported information from 1378 HIV-negative women aged 18-44 enrolled in microbicide and vaccine feasibility studies between 2008-2010,was used to assess changes in behaviour during a 12-month follow-up period. Logistic regression with random intercepts was used to estimate odds ratios for trends in each behaviour over time. A behavioural risk score was derived from coefficients of three behavioural variables in a Poisson regression model for HIV incidence and thereafter, dichotomized to risky vs less-risky behaviour. Logistic regression was then used to identify factors associated with risky behaviour at 12 months.

RESULTS

At baseline, 22% reported multiple partners, 28% were involved in transactional sex and only 22% consistently used condoms with non-regular partners. The proportion of women reporting multiple partners, transactional sex and high-risk sex practices reduced at each 3-monthly visit (33%, 43% and 47% reduction in odds per visit respectively, p for linear trend <0.001 for all), however, there was no evidence of a change in the proportion of women consistently using condoms with non-regular partners (p = 0.22). Having riskier behaviours at baseline, being younger than 16 years at sexual debut, having multiple partners, selling sex and excessive alcohol intake at baseline were strongly associated with increased odds of risky sexual behaviour after 12 months (p<0.005 for all).

CONCLUSION

An overall reduction in risky behaviours over time was observed in HIV prevention cohorts. Risk reduction counselling was associated with decreased risk behaviour but was insufficient to change behaviours of all those at highest risk. Biological HIV prevention interventions such as PrEP for individuals at highest risk, should complement risk reduction counselling so as to minimize HIV acquisition risk.

Biologic interactions between HSV-2 and HIV-1 and possible implications for HSV vaccine development

Development of a safe and effective vaccine against herpes simplex virus type 2 (HSV-2) has the potential to limit the global burden of HSV-2 infection and disease, including genital ulcer disease and neonatal herpes, and is a global sexual and reproductive health priority. Another important potential benefit of an HSV-2 vaccine would be to decrease HIV infections, as HSV-2 increases the risk of HIV-1 acquisition several-fold. Acute and chronic HSV-2 infection creates ulcerations and draws dendritic cells and activated CD4+ T cells into genital mucosa. These cells are targets for HIV entry and replication. Prophylactic HSV-2 vaccines (to prevent infection) and therapeutic vaccines (to modify or treat existing infections) are currently under development. By preventing or modifying infection, an effective HSV-2 vaccine could limit HSV-associated genital mucosal inflammation and thus HIV risk. However, a vaccine might have competing effects on HIV risk depending on its mechanism of action and cell populations generated in the genital mucosa. In this article, we review biologic interactions between HSV-2 and HIV-1, consider HSV-2 vaccine development in the context of HIV risk, and discuss implications and research needs for future HSV vaccine development.

Sexually Transmitted Bedfellows: Exquisite Association Between HIV and Herpes Simplex Virus Type 2 in 21 Communities in Southern Africa in the HIV Prevention Trials Network 071 (PopART) Study

Background

Human immunodeficiency virus (HIV) and herpes simplex virus type 2 (HSV2) are strongly associated, although mechanisms are not fully understood. An HIV prevention trial allowed reexamination of this association at individual and community levels.

Methods

The HIV Prevention Trials Network 071 (PopART) study evaluates a combination prevention intervention in 21 urban communities in Zambia and South Africa. To measure impact on HIV infection incidence, a cohort of approximately 2000 adults (age range, 18-44 years) was selected randomly from each community. Baseline data on sociodemographic characteristics, behavior, and HIV/HSV2 serologic findings were used to examine the association between HIV and HSV2. At the community level, HIV prevalence was plotted against HSV2 prevalence.

Results

A total of 38691 adults participated. HSV2 prevalence among women and men was 50% and 22%, respectively, in Zambia and 60% and 27%, respectively, in South Africa. Estimated HSV2 infection incidence among those aged 18-24 years was 8.06 cases/100 person-years (95% confidence interval [CI], 6.76-9.35) and 1.76 cases/100 person-years (95% CI, 1.30-2.22) among women and men, respectively. A 6-fold higher odds of HIV infection was seen in HSV2-infected individuals in both sexes, after adjustment for confounders (odds ratio, 6.66 [95% CI, 6.07-7.31] among women and 6.57 [95% CI, 5.56-7.77] among men). At the community-level, there was a strong linear relationship between HIV and HSV2 prevalence (ρ = 0.92; P < .001).

Conclusions

There was an exquisite association between these 2 infections, at the individual and community levels, likely due in part to a powerful cofactor effect of HSV2 on HIV transmission. HSV2 control could contribute to HIV prevention.

Sexually transmitted infections and HIV in the era of antiretroviral treatment and prevention: the biologic basis for epidemiologic synergy

INTRODUCTION

HIV is a unique sexually transmitted infection (STI) that is greatly affected by other concomitant "classical" bacterial and viral STIs that cause genital ulcers and/or mucosal inflammation. STIs also serve as a marker for risky sexual behaviours. STIs increase infectiousness of people living with HIV by increasing the viral concentration in the genital tract, and by increasing the potential for HIV acquisition in people at risk for HIV. In addition, some STIs can increase blood HIV concentration and promote progression of disease. This review is designed to investigate the complex relationship between HIV and classical STIs.

DISCUSSION

Treatment of STIs with appropriate antibiotics reduces HIV in blood, semen and female genital secretions. However, community-based trials could not reliably reduce the spread of HIV by mass treatment of STIs. Introduction of antiretroviral agents for the treatment and prevention of HIV has led to renewed interest in the complex relationship between STIs and HIV. Antiretroviral treatment (ART) reduces the infectiousness of HIV and virtually eliminates the transmission of HIV in spite of concomitant or acquired STIs. However, while ART interrupts HIV transmission, it does not stop intermittent shedding of HIV in genital secretions. Such shedding of HIV is increased by STIs, although the viral copies are not likely replication competent or infectious. Pre-exposure prophylaxis (PrEP) of HIV with the combination of tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) prevents HIV acquisition in spite of concomitant STIs.

CONCLUSIONS

STIs remain pandemic, and the availability of ART may have led to an increase in STIs, as fear of HIV has diminished. Classical STIs present a huge worldwide health burden that cannot be separated from HIV, and they deserve far more attention than they currently receive.

Herpes simplex virus-2 dynamics as a probe to measure the extremely rapid and spatially localized tissue-resident T-cell response

Herpes simplex virus-2 infection is characterized by frequent episodic shedding in the genital tract. Expansion in HSV-2 viral load early during episodes is extremely rapid. However, the virus invariably peaks within 18 hours and is eliminated nearly as quickly. A critical feature of HSV-2 shedding episodes is their heterogeneity. Some episodes peak at 10⁸ HSV DNA copies, last for weeks due to frequent viral re-expansion, and lead to painful ulcers, while others only reach 10³ HSV DNA copies and are eliminated within hours and without symptoms. Within single micro-environments of infection, tissue-resident CD8+ T cells (T_RM ) appear to contain infection within a few days. Here, we review components of T_RM biology relevant to immune surveillance between HSV-2 shedding episodes and containment of infection upon detection of HSV-2 cognate antigen. We then describe the use of mathematical models to correlate large spatial gradients in T_RM density with the heterogeneity of observed shedding within a single person. We describe how models have been leveraged for clinical trial simulation, as well as future plans to model the interactions of multiple cellular subtypes within mucosa, predict the mechanism of action of therapeutic vaccines, and describe the dynamics of 3-dimensional infection environment during the natural evolution of an HSV-2 lesion.

Does Male Circumcision Reduce Women's Risk of Sexually Transmitted Infections, Cervical Cancer, and Associated Conditions?

Background: Male circumcision (MC) is proven to substantially reduce men's risk of a number of sexually transmitted infections (STIs). We conducted a detailed systematic review of the scientific literature to determine the relationship between MC and risk of STIs and associated conditions in women. Methods: Database searches by "circumcision women" and "circumcision female" identified 68 relevant articles for inclusion. Examination of bibliographies of these yielded 14 further publications. Each was rated for quality using a conventional rating system. Results: Evaluation of the data from the studies retrieved showed that MC is associated with a reduced risk in women of being infected by oncogenic human papillomavirus (HPV) genotypes and of contracting cervical cancer. Data from randomized controlled trials and other studies has confirmed that partner MC reduces women's risk not only of oncogenic HPV, but as well Trichomonas vaginalis, bacterial vaginosis and possibly genital ulcer disease. For herpes simplex virus type 2, Chlamydia trachomatis, Treponema pallidum, human immunodeficiency virus and candidiasis, the evidence is mixed. Male partner MC did not reduce risk of gonorrhea, Mycoplasma genitalium, dysuria or vaginal discharge in women. Conclusion: MC reduces risk of oncogenic HPV genotypes, cervical cancer, T. vaginalis, bacterial vaginosis and possibly genital ulcer disease in women. The reduction in risk of these STIs and cervical cancer adds to the data supporting global efforts to deploy MC as a health-promoting and life-saving public health measure and supplements other STI prevention strategies.

Incidence of unintended pregnancy among female sex workers in low-income and middle-income countries: a systematic review and meta-analysis

OBJECTIVES

To determine the incidence of unintended pregnancy among female sex workers (FSWs) in low-income and middle-income countries (LMICs).

DESIGN

We searched MEDLINE, PsychInfo, Embase and Popline for papers published in English between January 2000 and January 2016, and Web of Science and Proquest for conference abstracts. Meta-analysis was performed on the primary outcomes using random effects models, with subgroup analysis used to explore heterogeneity.

PARTICIPANTS

Eligible studies targeted FSWs aged 15-49 years living or working in an LMIC.

OUTCOME MEASURES

Studies were eligible if they provided data on one of two primary outcomes: incidence of unintended pregnancy and incidence of pregnancy where intention is undefined. Secondary outcomes were also extracted when they were reported in included studies: incidence of induced abortion; incidence of birth; and correlates/predictors of pregnancy or unintended pregnancy.

RESULTS

Twenty-five eligible studies were identified from 3866 articles. Methodological quality was low overall. Unintended pregnancy incidence showed high heterogeneity (I²>95%), ranging from 7.2 to 59.6 per 100 person-years across 10 studies. Study design and duration were found to account for heterogeneity. On subgroup analysis, the three cohort studies in which no intervention was introduced had a pooled incidence of 27.1 per 100 person-years (95% CI 24.4 to 29.8; I²=0%). Incidence of pregnancy (intention undefined) was also highly heterogeneous, ranging from 2.0 to 23.4 per 100 person-years (15 studies).

CONCLUSIONS

Of the many studies examining FSWs' sexual and reproductive health in LMICs, very few measured pregnancy and fewer assessed pregnancy intention. Incidence varied widely, likely due to differences in study design, duration and baseline population risk, but was high in most studies, representing a considerable concern for this key population. Evidence-based approaches that place greater importance on unintended pregnancy prevention need to be incorporated into existing sexual and reproductive health programmes for FSWs.

PROSPERO REGISTRATION NUMBER

CRD42016029185.

Global population-level association between herpes simplex virus 2 prevalence and HIV prevalence

BACKGROUND

Our objective was to assess the population-level association between herpes simplex virus 2 (HSV-2) and HIV prevalence.

METHODS

Reports of HSV-2 and HIV prevalence were systematically reviewed and synthesized following PRISMA guidelines. Spearman rank correlation ((Equation is included in full-text article.)) was used to assess correlations. Risk ratios (RRHSV-2/HIV) and odds ratios (ORHSV-2/HIV) were used to assess HSV-2/HIV epidemiologic overlap. DerSimonian-Laird random-effects meta-analyses were conducted.

RESULTS

In total, 939 matched HSV-2/HIV prevalence measures were identified from 77 countries. HSV-2 prevalence was consistently higher than HIV prevalence. Strong HSV-2/HIV prevalence association was found for all data ((Equation is included in full-text article.) = 0.6, P < 0.001), all data excluding people who inject drugs (PWID) and children ((Equation is included in full-text article.) = 0.7, P < 0.001), female sex workers ((Equation is included in full-text article.) = 0.5, P < 0.001), and MSM ((Equation is included in full-text article.) = 0.7, P < 0.001). No association was found for PWID ((Equation is included in full-text article.) = 0.2, P = 0.222) and children ((Equation is included in full-text article.) = 0.3, P = 0.082). A threshold effect was apparent where HIV prevalence was limited at HSV-2 prevalence less than 20%, but grew steadily with HSV-2 prevalence for HSV-2 prevalence greater than 20%. The overall pooled mean RRHSV-2/HIV was 5.0 (95% CI 4.7-5.3) and ORHSV-2/HIV was 9.0 (95% CI 8.4-9.7). The RRHSV-2/HIV and ORHSV-2/HIV showed similar patterns that conveyed inferences about HSV-2 and HIV epidemiology.

CONCLUSION

HSV-2 and HIV prevalence are strongly associated. HSV-2 prevalence can be used as a proxy 'biomarker' of HIV epidemic potential, acting as a 'temperature scale' of the intensity of sexual risk behavior that drive HIV transmission. HSV-2 prevalence can be used to identify populations and/or sexual networks at high-risk of future HIV expansion, and help prioritization, optimization, and resource allocation of cost-effective prevention interventions.

Effects of spatiotemporal HSV-2 lesion dynamics and antiviral treatment on the risk of HIV-1 acquisition

Patients with Herpes Simplex Virus-2 (HSV-2) infection face a significantly higher risk of contracting HIV-1. This is thought to be due to herpetic lesions serving as entry points for HIV-1 and tissue-resident CD4+ T cell counts increasing during HSV-2 lesional events. We have created a stochastic and spatial mathematical model describing the dynamics of HSV-2 infection and immune response in the genital mucosa. Using our model, we first study the dynamics of a developing HSV-2 lesion. We then use our model to quantify the risk of infection with HIV-1 following sexual exposure in HSV-2 positive women. Untreated, we find that HSV-2 infected women are up to 8.6 times more likely to acquire HIV-1 than healthy patients. However, when including the effects of the HSV-2 antiviral drug, pritelivir, the risk of HIV-1 infection is predicted to decrease by up to 35%, depending on drug dosage. We estimate the relative importance of decreased tissue damage versus decreased CD4+ cell presence in determining the effectiveness of pritelivir in reducing HIV-1 infection. Our results suggest that clinical trials should be performed to evaluate the effectiveness of pritelivir or similar agents in preventing HIV-1 infection in HSV-2 positive women.

The risk of contracting HIV-1 is significantly higher in people who have genital HSV-2 infections. Here, we put forward a new mathematical model to describe HSV-2 infection and the process of HIV-1 infection in the genital mucosa surrounding HSV-2 lesions. We determine how the characteristics of HSV-2 infection affect the risk of HIV-1 infection, and determine whether reducing the severity of HSV-2 symptoms with antiviral drugs can be expected to decrease the risk of HIV-1 infection. We find that the risk of HIV-1 infection is dependent on three factors: the amount of HIV-1 the patient is exposed to, the severity of HSV-2 lesions, and the number of CD4+ T immune cells in the genital mucosa. Our model predicts that antiviral drugs targeting HSV-2 can cause a therapeutic decrease in lesion severity and CD4+ T cell count in the genital mucosa. This furthermore causes a significant decrease in the risk of HIV-1 infection but the dose of HSV-2 antiviral drug must be sufficiently high. Our results support further development and testing of new HSV-2 antiviral drugs to help decrease the world-wide burden of HIV-1.

Biomedical prevention: what is the current status?

Biomedical HIV prevention strategies for primary or secondary prevention of HIV transmission can be seen as an adjunct to behavioral prevention approaches. These interventions include vaccination, female controlled vaginal microbicides, male circumcision, treatment of sexually transmitted infections that cause genital ulceration, Pre-Exposure Prophylaxis (PREP) and Post-Exposure Prophylaxis (PEP). This article reviews results from recent randomized controlled trials of novel biomedical prevention approaches and discusses interpretation of the results. The only intervention consistently demonstrating reductions in HIV transmission was adult male circumcision in Sub-Saharan Africa. Results of PREP trials will be available in the next several years.

Prevalence of sexually transmitted infections and bacterial vaginosis among women in sub-Saharan Africa: An individual participant data meta-analysis of 18 HIV prevention studies

BACKGROUND

Estimates of sexually transmitted infection (STI) prevalence are essential for efforts to prevent and control STIs. Few large STI prevalence studies exist, especially for low- and middle-income countries (LMICs). Our primary objective was to estimate the prevalence of chlamydia, gonorrhea, trichomoniasis, syphilis, herpes simplex virus type 2 (HSV-2), and bacterial vaginosis (BV) among women in sub-Saharan Africa by age, region, and population type.

METHODS AND FINDINGS

We analyzed individual-level data from 18 HIV prevention studies (cohort studies and randomized controlled trials; conducted during 1993-2011), representing >37,000 women, that tested participants for ≥1 selected STIs or BV at baseline. We used a 2-stage meta-analysis to combine data. After calculating the proportion of participants with each infection and standard error by study, we used a random-effects model to obtain a summary mean prevalence of each infection and 95% confidence interval (CI) across ages, regions, and population types. Despite substantial study heterogeneity for some STIs/populations, several patterns emerged. Across the three primary region/population groups (South Africa community-based, Southern/Eastern Africa community-based, and Eastern Africa higher-risk), prevalence was higher among 15-24-year-old than 25-49-year-old women for all STIs except HSV-2. In general, higher-risk populations had greater prevalence of gonorrhea and syphilis than clinic/community-based populations. For chlamydia, prevalence among 15-24-year-olds was 10.3% (95% CI: 7.4%, 14.1%; I2 = 75.7%) among women specifically recruited from higher-risk settings for HIV in Eastern Africa and was 15.1% (95% CI: 12.7%, 17.8%; I2 = 82.3%) in South African clinic/community-based populations. Among clinic/community-based populations, prevalence was generally greater in South Africa than in Southern/Eastern Africa for most STIs; for gonorrhea, prevalence among 15-24-year-olds was 4.6% (95% CI: 3.3%, 6.4%; I2 = 82.8%) in South Africa and was 1.7% (95% CI: 1.2%, 2.6%; I2 = 55.2%) in Southern/Eastern Africa. Across the three primary region/population groups, HSV-2 and BV prevalence was high among 25-49-year-olds (ranging from 70% to 83% and 33% to 44%, respectively). The main study limitation is that the data are not from random samples of the target populations.

CONCLUSIONS

Combining data from 18 HIV prevention studies, our findings highlight important features of STI/BV epidemiology among sub-Saharan African women. This methodology can be used where routine STI surveillance is limited and offers a new approach to obtaining critical information on STI and BV prevalence in LMICs.

Herpes Simplex Virus Suppressive Therapy in Herpes Simplex Virus-2/Human Immunodeficiency Virus-1 Coinfected Women Is Associated With Reduced Systemic CXCL10 But Not Genital Cytokines

BACKGROUND

Herpes simplex virus type-2 (HSV-2) may heighten immune activation and increase human immunodeficiency virus 1 (HIV-1) replication, resulting in greater infectivity and faster HIV-1 disease progression. An 18-week randomized, placebo-controlled crossover trial of 500 mg valacyclovir twice daily in 20 antiretroviral-naive women coinfected with HSV-2 and HIV-1 was conducted and HSV-2 suppression was found to significantly reduce both HSV-2 and HIV-1 viral loads both systemically and the endocervical compartment.

METHODS

To determine the effect of HSV-2 suppression on systemic and genital mucosal inflammation, plasma specimens, and endocervical swabs were collected weekly from volunteers in the trial and cryopreserved. Plasma was assessed for concentrations of 31 cytokines and chemokines; endocervical fluid was eluted from swabs and assayed for 14 cytokines and chemokines.

RESULTS

Valacyclovir significantly reduced plasma CXCL10 but did not significantly alter other cytokine concentrations in either compartment.

CONCLUSIONS

These data suggest genital tract inflammation in women persists despite HSV-2 suppression, supporting the lack of effect on transmission seen in large scale efficacy trials. Alternative therapies are needed to reduce persistent mucosal inflammation that may enhance transmission of HSV-2 and HIV-1.

Meeting report: Initial World Health Organization consultation on herpes simplex virus (HSV) vaccine preferred product characteristics, March 2017

The development of vaccines against herpes simplex virus (HSV) is an important global goal for sexual and reproductive health. A key priority to advance development of HSV vaccines is the definition of preferred product characteristics (PPCs), which provide strategic guidance on World Health Organization (WHO) preferences for new vaccines, specifically from a low- and middle-income country (LMIC) perspective. To start the PPC process for HSV vaccines, the WHO convened a global stakeholder consultation in March 2017, to define the priority public health needs that should be addressed by HSV vaccines and discuss the key considerations for HSV vaccine PPCs, particularly for LMICs. Meeting participants outlined an initial set of overarching public health goals for HSV vaccines in LMICs, which are: to reduce the acquisition of HIV associated with HSV-2 infection in high HIV-prevalence populations and to reduce the burden of HSV-associated disease, including mortality and morbidity due to neonatal herpes and impacts on sexual and reproductive health. Participants also considered the role of prophylactic versus therapeutic vaccines, whether both HSV-2 and HSV-1 should be targeted, important target populations, and infection and disease endpoints for clinical trials. This article summarizes the main discussions from the consultation.

HIV and herpes simplex virus type 2 epidemiological synergy: misguided observational evidence? A modelling study

Objectives

To investigate whether observational studies of HIV and herpes simplex virus type 2 (HSV-2) infections have the capacity to assess the HIV/HSV-2 epidemiological synergy.

Methods

An individual-based Monte Carlo model was used to simulate HIV/HSV-2 epidemics in two scenarios: no HIV/HSV-2 biological interaction and HSV-2 seropositivity enhancing HIV acquisition. Cross-sectional observational studies were simulated by sampling individuals from the population to assess resulting crude and adjusted ORs of the HIV/HSV-2 association. Meta-analyses were conducted to estimate the pooled mean ORs. Impact of under-reporting of sexual behaviour and miscapture of high-risk individuals was assessed through sensitivity analyses.

Results

Assuming no HIV/HSV-2 biological interaction, the crude HIV/HSV-2 OR ranged between 1.38 and 9.93, with a pooled mean of 6.45 (95% CI 5.81 to 7.17). Adjustment for the number of sexual partners over last year, over lifetime and for both partner numbers simultaneously reduced the mean OR to 5.45 (95% CI 4.90 to 6.06), 3.70 (95% CI 3.32 to 4.12) and 3.54 (95% CI 3.17 to 3.94), respectively. Assuming HIV/HSV-2 biological interaction, the crude OR ranged between 3.44 and 9.95, with a pooled mean of 8.05 (95% CI 7.14 to 9.07). The adjustments reduced the mean OR to 7.00 (95% CI 6.21 to 7.90), 3.76 (95% CI 3.32 to 4.25) and 3.68 (95% CI 3.25 to 4.17), respectively. Under-reporting of partners reduced the confounder-adjustment effects. Miscapture of high-risk individuals considerably lowered the estimated ORs.

Conclusions

It is difficult to control for sexual-behaviour confounding in observational studies. The observed HIV/HSV-2 association appears more consistent with two infections sharing the same mode of transmission, rather than with HSV-2 enhancing HIV acquisition.

Risk factors for HIV infection among female sex workers in Bangui, Central African Republic

Objective

The aims of the study were i) to categorize female sex workers (FSW) according to socio-anthropologic criteria in Bangui; ii) to examine the association between a selection of demographic and risk variables with the different categories of female sex work as outcome, and iii) to investigate factors associated with HIV status.

Methods

A cross-sectional questionnaire survey was conducted to describe the spectrum of commercial sex work in Bangui among 345 sexually active women. After collection of social and behavioral characteristics, each woman received a physical examination and a blood sample was taken for biological analyses, including HIV testing. The relationships between sociodemographic characteristics, behavioral variables involved in high risk for HIV as well as biological results were investigated by bivariate analysis in relationship with FSW categories as main outcomes, and by bivariate analysis followed by multivariate logistic regression analysis in relationship with HIV as the main outcome. The strength of statistical associations was measured by crude and adjusted Odds ratios (OR) and their 95% confidence intervals.

Results

The typology of FSW comprised six different categories. Two groups were the “official” professional FSW primarily classified according to their locations of work [i) “kata“(18.55%) representing women working in poor neighborhoods of Bangui; ii) “pupulenge” (13.91%) working in hotels and night clubs to seek white men]. Four groups were “clandestine” nonprofessional FSW classified according to their reported main activity [i) “market and street vendors” (20.86%); ii) “schoolgirls or students” (19.13%) involved in occasional transactional sex (during holidays); iii) “housewives or unemployed women” (15.65%); iv) “civil servants” (11.88%) working as soldiers or in the public sector]. The overall prevalence of HIV-1 was 19.12% (66/345). HIV varied according to FSW categories. Thus, among professional FSW, the HIV prevalence was 6-fold higher in "kata" than "pupulenge" (39.13% versus 6.30%; P = 0.001). Among nonprofessional FSW, the "vendors" showed the highest HIV prevalence (31.91%), which was higher than in "students" (6.10%; P = 0.001), "civil servants" (9.83%; P = 0.005), and "housewives" (13.00%; P = 0.01). In bivariate analysis, the following variables showed statistically significant association with risk for HIV infection: nationality; age of first sexual intercourse; self-assessment of HIV risk; knowledge of HIV status; anal sex practice with last clients; irregular condom use in last week; consumption of alcohol; other psycho-active substances; past history of STIs; HBs Ag; HSV-2 and bacterial vaginosis. However, the variable “sex workers categories” dichotomized into professional versus nonprofessional FSW was no longer associated with HIV. In multivariate logistical regression analysis, HIV infection was strongly associated with nationality (15.65% versus 3.77%) [adjusted OR (aOR) 3.39: 95% CI:1.25–9.16, P<0.05]; age of first sexual intercourse (21.10% versus 14.00%) (aOR 2.13: 95% CI: 1.03–4.39, P<0.05); anal sex practice with last clients (43.40% versus 11.50%) (aOR 4.31: 95% CI:2.28–8.33, P<0.001); irregular condom use in past week (33.50% versus 3.00%) (aOR 5.49: 95% CI:1.89–15.98, P<0.001); alcohol consumption before sex (34.70% versus 7.80%) (aOR 2.69: 95% CI:1.22–4.96, P<0.05); past history of STIs (41.00% versus 10.80%) (aOR 2.46: 95% CI:1.22–4.97, P<0.05) and bacterial vaginosis (29.80% versus 4.29%) (aOR 6.36: 95% CI: 2.30–17.72, P<0.001).

Conclusion

Our observations highlight the high level of vulnerability for HIV acquisition of both poor professional “kata” and nonprofessional “street vendor” FSW categories. These categories should be particularly taken into account when designing specific prevention programs for STIs/HIV control purposes.

Risk of heterosexual HIV transmission attributable to sexually transmitted infections and non-specific genital inflammation in Zambian discordant couples, 1994-2012

Background

Studies have demonstrated the role of ulcerative and non-ulcerative sexually transmitted infections (STI) in HIV transmission/acquisition risk; less is understood about the role of non-specific inflammatory genital abnormalities.

Methods

HIV-discordant heterosexual Zambian couples were enrolled into longitudinal follow-up (1994-2012). Multivariable models estimated the effect of genital ulcers and inflammation in both partners on time-to-HIV transmission within the couple. Population-attributable fractions (PAFs) were calculated.

Results

A total of 207 linked infections in women occurred over 2756 couple-years (7.5/100 CY) and 171 in men over 3216 CY (5.3/100 CY). Incident HIV among women was associated with a woman's non-STI genital inflammation (adjusted hazard ratio (aHR) = 1.55; PAF = 8%), bilateral inguinal adenopathy (BIA; aHR = 2.33; PAF = 8%), genital ulceration (aHR = 2.08; PAF = 7%) and the man's STI genital inflammation (aHR = 3.33; PAF = 5%), BIA (aHR = 3.35; PAF = 33%) and genital ulceration (aHR = 1.49; PAF = 9%). Infection among men was associated with a man's BIA (aHR = 4.11; PAF = 22%) and genital ulceration (aHR = 3.44; PAF = 15%) as well as with the woman's non-STI genital inflammation (aHR = 1.92; PAF = 13%) and BIA (aHR = 2.76; PAF = 14%). In HIV-M+F- couples, the man being uncircumcised. with foreskin smegma. was associated with the woman's seroconversion (aHR = 3.16) relative to being circumcised. In F+M- couples, uncircumcised men with BIA had an increased hazard of seroconversion (aHR = 13.03 with smegma and 4.95 without) relative to being circumcised. Self-reporting of symptoms was low for ulcerative and non-ulcerative STIs.

Conclusions

Our findings confirm the role of STIs and highlight the contribution of non-specific genital inflammation to both male-to-female and female-to-male HIV transmission/acquisition risk. Studies are needed to characterize pathogenesis of non-specific inflammation including inguinal adenopathy. A better understanding of genital practices could inform interventions.

Condomless sex and HIV transmission among serodifferent couples: current evidence and recommendations

Human immunodeficiency virus (HIV) infection remains a global pandemic. The primary driver of HIV incidence is sexual transmission between serodifferent individuals. Condoms, when used consistently and correctly, are effective at preventing sexually transmitted HIV infections and are considered an integral component of a comprehensive approach to HIV prevention. However, the demonstrated effectiveness of antiretroviral therapy (ART) to prevent HIV transmission, known as treatment as prevention and of pre-exposure prophylaxis, have raised an intriguing dilemma on the necessity and additive preventive benefit of condom use among individuals in serodifferent relationships utilizing these prevention strategies. Recent published evidence, although of limited follow-up duration, has shown no linked HIV transmissions with condomless sex among serodifferent couples where the infected partner was on ART and virologically suppressed. This paper will review the evidence surrounding HIV transmission risk among serodifferent couples with and without the use of condoms and will highlight factors that increase or attenuate this risk. It will also address the important benefits that condomless sex offers couples. This paper aims to provide a template for providers to have personalized discussions with their patients, particularly those with an HIV-positive sexual partner, around their individual risk of HIV transmission and the role of condom use.

Effect of HSV-2 infection on subsequent HIV acquisition: an updated systematic review and meta-analysis

Background

HIV and herpes simplex virus type 2 (HSV-2) infections cause a substantial global disease burden and are epidemiologically correlated. Two previous systematic reviews of the association between HSV-2 and HIV found evidence that HSV-2 infection increases the risk of HIV acquisition, but these reviews are now more than a decade old.

Methods

For this systematic review and meta-analysis, we searched PubMed, MEDLINE, and Embase (from Jan 1, 2003, to May 25, 2017) to identify studies investigating the risk of HIV acquisition after exposure to HSV-2 infection, either at baseline (prevalent HSV-2 infection) or during follow-up (incident HSV-2 infection). Studies were included if they were a cohort study, controlled trial, or case-control study (including case-control studies nested within a cohort study or clinical trial); if they assessed the effect of pre-existing HSV-2 infection on HIV acquisition; and if they determined the HSV-2 infection status of study participants with a type-specific assay. We calculated pooled random-effect estimates of the association between prevalent or incident HSV-2 infection and HIV seroconversion. We also extended previous investigations through detailed meta-regression and subgroup analyses. In particular, we investigated the effect of sex and risk group (general population vs higher-risk populations) on the relative risk (RR) of HIV acquisition after prevalent or incident HSV-2 infection. Higher-risk populations included female sex workers and their clients, men who have sex with men, serodiscordant couples, and attendees of sexually transmitted infection clinics.

Findings

We identified 57 longitudinal studies exploring the association between HSV-2 and HIV. HIV acquisition was almost tripled in the presence of prevalent HSV-2 infection among general populations (adjusted RR 2·7, 95% CI 2·2–3·4; number of estimates [N_e]=22) and was roughly doubled among higher-risk populations (1·7, 1·4–2·1; N_e=25). Incident HSV-2 infection in general populations was associated with the highest risk of acquisition of HIV (4·7, 2·2–10·1; N_e=6). Adjustment for confounders at the study level was often incomplete but did not significantly affect the results. We found moderate heterogeneity across study estimates, which was explained by risk group, world region, and HSV-2 exposure type (prevalent vs incident).

Interpretation

We found evidence that HSV-2 infection increases the risk of HIV acquisition. This finding has important implications for management of individuals diagnosed with HSV-2 infection, particularly for those who are newly infected. Interventions targeting HSV-2, such as new HSV vaccines, have the potential for additional benefit against HIV, which could be particularly powerful in regions with a high incidence of co-infection.

Funding

World Health Organization.

Seroprevalence of Herpes Simplex Virus type-2 (HSV-2) among pregnant women who participated in a national HIV surveillance activity in Haiti

BACKGROUND

Herpes simplex virus type 2 (HSV-2), one the most common causes of genital ulcers, appears to increase both the risk of HIV acquisition and HIV transmission. HSV-2/HIV co-infection among pregnant women may increase the risk of perinatal transmission of HIV. This study describes rates of HSV-2 among pregnant women in Haiti and HSV-2 test performance in this population.

METHODS

Unlinked residual serum specimens from the 2012 National HIV and Syphilis Sentinel Surveillance Survey among pregnant women in Haiti were tested using two commercial kits (Focus HerpeSelect, Kalon) for HSV-2 antibodies. We evaluated rates of HSV-2 seropositivity and HSV-2/HIV co-infection, associations between HSV-2 and demographic characteristics using multivariable Cox proportional hazards modeling, and HSV-2 test performance in this population.

RESULTS

Serum samples from 1000 pregnant women (all 164 HIV positive and 836 random HIV negative) were selected. The overall weighted prevalence of HSV-2 was 31.4% (95% CI: 27.7-35.4) and the prevalence of HIV-positivity among HSV-2 positive pregnant women was five times higher than the prevalence among HSV-2 negative women (4.8% [95% CI: 3.9-6.0] vs. 0.9% [95% CI: 0.6-1.3], respectively). Factors significantly associated with HSV-2 positivity were HIV-positivity (PR: 2.27 [95% CI: 1.94-2.65]) and older age (PRs: 1.41 [95% CI: 1.05-1.91] for 20-24 years, 1.71 [95% CI:1.13-2.60] for 30-34 years, and 1.55 [95% CI: 1.10-2.19] for 35 years or greater]), while rural residence was negatively associated with HSV-2 positivity (PR 0.83 [95% CI: 0.69-1.00]), after controlling for other covariables. For this study a conservative Focus index cutoff of 3.5 was used, but among samples with a Focus index value ≥2.5, 98.4% had positive Kalon tests.

CONCLUSION

The prevalence of HSV-2 is relatively high among pregnant women in Haiti. Public health interventions to increase access to HSV-2 screening in antenatal services are warranted.

Sexual network drivers of HIV and herpes simplex virus type 2 transmission

OBJECTIVES

HIV and herpes simplex virus type 2 (HSV-2) infections are sexually transmitted and propagate in sexual networks. Using mathematical modeling, we aimed to quantify effects of key network statistics on infection transmission, and extent to which HSV-2 prevalence can be a proxy of HIV prevalence.

DESIGN/METHODS

An individual-based simulation model was constructed to describe sex partnering and infection transmission, and was parameterized with representative natural history, transmission, and sexual behavior data. Correlations were assessed on model outcomes (HIV/HSV-2 prevalences) and multiple linear regressions were conducted to estimate adjusted associations and effect sizes.

RESULTS

HIV prevalence was one-third or less of HSV-2 prevalence. HIV and HSV-2 prevalences were associated with a Spearman's rank correlation coefficient of 0.64 (95% confidence interval: 0.58-0.69). Collinearities among network statistics were detected, most notably between concurrency versus mean and variance of number of partners. Controlling for confounding, unmarried mean/variance of number of partners (or alternatively concurrency) were the strongest predictors of HIV prevalence. Meanwhile, unmarried/married mean/variance of number of partners (or alternatively concurrency), and clustering coefficient were the strongest predictors of HSV-2 prevalence. HSV-2 prevalence was a strong predictor of HIV prevalence by proxying effects of network statistics.

CONCLUSION

Network statistics produced similar and differential effects on HIV/HSV-2 transmission, and explained most of the variation in HIV and HSV-2 prevalences. HIV prevalence reflected primarily mean and variance of number of partners, but HSV-2 prevalence was affected by a range of network statistics. HSV-2 prevalence (as a proxy) can forecast a population's HIV epidemic potential, thereby informing interventions.

Prevalence, incidence and correlates of HSV-2 infection in an HIV incidence adolescent and adult cohort study in western Kenya

Background

Herpes simplex virus type 2 (HSV-2) infections are associated with increased risk of HIV transmission. We determined HSV-2 prevalence, incidence and associated risk factors, incidence among persons with indeterminate results, and prevalence of HSV-2/HIV co-infection among young adults (18–34 years) and adolescents (16–17 years) enrolled in an HIV incidence cohort study in western Kenya.

Methods

Participants (n = 1106; 846 adults) were screened and those HIV-1 negative were enrolled and followed-up quarterly for one year. HSV-2 was assessed using the Kalon enzyme immunoassay. HSV-2 incidence was calculated separately among HSV-2 seronegative participants and those indeterminate at baseline. Logistic regression was used to estimate the odds of HSV-2 infection and Poisson regression was used to assess HSV-2 incidence and associated factors.

Results

Overall, HSV-2 prevalence was 26.6% [95% confidence interval (CI): 23.9–29.4] and was higher in adults (31.5% [95% CI: 28.3–34.9]) than adolescents (10.7% [95% CI: 7.1–15.3]). Factors associated with prevalent HSV-2 included female gender, increasing age, HIV infection, history of sexually transmitted infection, low level of education, multiple sexual partners, and being married, divorced, separated or widowed. Overall HSV-2 incidence was 4.0 per 100 person-years (/100PY) 95% CI: 2.7–6.1 and was higher in adults (4.5/100PY) and females (5.1/100PY). In multivariable analysis only marital status was associated with HSV-2 incidence. Among 45 participants with indeterminate HSV-2 results at baseline, 22 seroconverted, resulting in an incidence rate of 53.2 /100PY [95% CI: 35.1–80.9]. Inclusion of indeterminate results almost doubled the overall incidence rate to 7.8 /100 PY [95% CI: 5.9–10.5]. Prevalence of HIV/HSV-2 co-infection was higher in female adults than female adolescents (17.1 [95% CI: 13.6–21.0] versus 3.4 [95% CI: 1.1–7.8]).

Conclusion

The high incidence rate among persons with indeterminate results underscores the public health concerns for HSV-2 spread and underreporting of the HSV-2 burden. Careful consideration is needed when interpreting HSV-2 serology results in these settings.

Genital inflammation, immune activation and risk of sexual HIV acquisition

PURPOSE OF REVIEW

Women who have genital inflammation are at increased risk of sexual HIV infection. The purpose of this review is to evaluate the mechanisms for this relationship, causes of genital inflammation, and strategies to manage this condition.

RECENT FINDINGS

We have recently shown in a cohort of South African women that HIV seroconversion was associated with persistently raised genital inflammatory cytokines (including MIP-1α, MIP-1β, and IP-10). Elevated inflammatory cytokine concentrations may facilitate HIV infection by recruiting and activating HIV target cells and disrupting the mucosal epithelial barrier. Bacterial vaginosis and sexually transmitted infections (STIs), which are predominantly asymptomatic in women, cause lower genital tract inflammation and increased HIV acquisition risk. In Africa, where syndromic management of STIs and bacterial vaginosis is standard-of-care, the substantial burden of asymptomatic infections has likely contributed to high-HIV incidence rates.

SUMMARY

A genital inflammatory profile contributes to the high risk of HIV acquisition in African women. STIs and bacterial vaginosis are poorly managed in Africa and other developing nations and as such remain major drivers of persistent genital inflammation and HIV acquisition among these women.

Current Concepts for Genital Herpes Simplex Virus Infection: Diagnostics and Pathogenesis of Genital Tract Shedding

Herpes simplex virus 2 (HSV-2) is a DNA virus that is efficiently transmitted through intimate genital tract contact and causes persistent infection that cannot be eliminated. HSV-2 may cause frequent, symptomatic self-limited genital ulcers, but in most persons infection is subclinical. However, recent studies have demonstrated that the virus is frequently shed from genital surfaces even in the absence of signs or symptoms of clinical disease and that the virus can be transmitted during these periods of shedding. Furthermore, HSV-2 shedding is detected throughout the genital tract and may be associated with genital tract inflammation, which likely contributes to increased risk of HIV acquisition. This review focuses on HSV diagnostics, as well as what we have learned about the importance of frequent genital HSV shedding for (i) HSV transmission and (ii) genital tract inflammation, as well as (iii) the impact of HSV-2 infection on HIV acquisition and transmission. We conclude with discussion of future areas of research to push the field forward.

Epidemiological impact of a syphilis vaccine: a simulation study

Despite the availability of inexpensive antimicrobial treatment, syphilis remains prevalent worldwide, affecting millions of individuals. Furthermore, syphilis infection is suspected of increasing both susceptibility to, and tendency to transmit, HIV. Development of a syphilis vaccine would be a potentially promising step towards control, but the value of dedicating resources to vaccine development should be evaluated in the context of the anticipated benefits. Here, we use a detailed mathematical model to explore the potential impact of rolling out a hypothetical syphilis vaccine on morbidity from both syphilis and HIV and compare it to the impact of expanded ‘screen and treat’ programmes using existing treatments. Our results suggest that an efficacious vaccine has the potential to sharply reduce syphilis prevalence under a wide range of scenarios, while expanded treatment interventions are likely to be substantially less effective. Our modelled interventions in our simulated study populations are expected to have little effect on HIV, and in some scenarios lead to small increases in HIV incidence, suggesting that interventions against syphilis should be accompanied with interventions against other sexually transmitted infections to prevent the possibility that lower morbidity or lower perceived risk from syphilis could lead to increases in other sexually transmitted diseases.

Prevalence and Correlates of Chlamydia trachomatis and Neisseria gonorrhoeae by Anatomic Site Among Urban Thai Men Who Have Sex With Men

BACKGROUND

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infection are prevalent among men who have sex with men (MSM) and may infect multiple anatomic sites. We measured site-specific prevalence and correlates of CT and NG infection among Bangkok MSM Cohort Study participants.

METHODS

In April 2006 to November 2010, 1744 men enrolled in the Bangkok MSM Cohort Study. Participants provided historical information and underwent physical examination. Rectal, urethral, and pharyngeal CT and NG screening were performed by nucleic acid amplification and/or culture. Logistic regression was used to identify correlates of site-specific CT, NG, and coinfection.

RESULTS

Among 1743 participants, 19.2% were infected with CT and/or NG. CT, NG, and CT-NG coinfection were detected in 11.6%, 4.6%, and 2.9%, of participants, respectively. Rectal, urethral, and pharyngeal CT infections were detected in 9.5%, 4.5%, and 3.6% of cases. N. gonorrhoeae was present at these sites in 6.1%, 1.8%, and 0.5% of cases. Most infections were asymptomatic (CT: 95.3%, NG: 83.2%). Rectal CT and NG infections were mutually associated (CT: adjusted odds ratio [AOR], 5.4; 95% confidence interval [CI], 3.4-8.7; NG: AOR, 2.4; 95% CI, 1.1-5.2) and independently associated with HIV infection (CT: AOR, 1.6, 95% CI, 1.0-2.4; NG: AOR, 2.0, 95% CI, 1.3-3.1). Numerous behavioral correlates of infection were observed.

CONCLUSIONS

CT and NG infections are highly prevalent among MSM in Bangkok, most frequently affect the rectum, and are most often asymptomatic. Routine screening of asymptomatic MSM for CT and NG infection should include rectal sampling and focus on men with HIV and a history of other sexually transmitted infections.

The Association Between Cervical Human Papillomavirus Infection and Subsequent HIV Acquisition in Tanzanian and Ugandan Women: A Nested Case-Control Study

OBJECTIVE

This study was performed to analyze the associations between cervical human papillomavirus (HPV) infection and human immunodeficiency virus (HIV) acquisition, using cervical samples from previous studies in Tanzania and Uganda.

METHODS

A total of 161 adult women who acquired HIV infection during follow-up and 464 individually matched HIV-seronegative controls were selected from 5 cohorts of women working in bars and recreational facilities. Stored cervical samples were tested for 37 HPV genotypes, using a polymerase chain reaction assay (Roche Linear Array genotyping assay). Multivariate matched analysis using conditional logistic regression was performed to evaluate HPV infection, persistence, and clearance as predictors of HIV acquisition.

RESULTS

HIV seroconverters were significantly more likely than controls to frequently drink alcohol and to be infected with Chlamydia trachomatis, Neisseria gonorrhoeae, or herpes simplex virus type 2. There was no evidence of an association between HIV acquisition and any detectable HPV at the visit prior to HIV seroconversion (adjusted odds ratio, 1.02; 95% confidence interval, .66-1.57) or between HIV acquisition and persistent HPV infection (defined as 2 positive HPV genotype-specific test results at least 6 months apart), cleared HPV infection (defined as a positive HPV test result followed by negative HPV genotype-specific test result), or newly acquired HPV infection, compared with HPV-negative women.

CONCLUSIONS

There was no evidence of association between HPV infection status and subsequent HIV acquisition. These results stand in contrast to other observational studies.

Inflammation and HIV Transmission in Sub-Saharan Africa

While the per-contact risk of sexual HIV transmission is relatively low, it is fourfold higher in sub-Saharan Africa, and this may partly explain the major global disparities that exist in HIV prevalence. Genital immune parameters are key determinants of HIV transmission risk, including epithelial integrity and the presence of highly HIV-susceptible intraepithelial or submucosal CD4+ T cell target cells. Biological parameters that may enhance mucosal HIV susceptibility in highly HIV-affected regions of sub-Saharan Africa include increased levels of mucosal inflammation, which can affect both epithelial integrity and target cell availability, as well as the increased mucosal surface area that is afforded by an intact foreskin, contraceptive choices, and intravaginal practices. There are multifactorial causes for increased mucosal inflammation, with the prevalence and nature of common co-infections being particularly relevant.

Immune Activation in the Female Genital Tract: Expression Profiles of Soluble Proteins in Women at High Risk for HIV Infection

Soluble cervicovaginal biomarkers of inflammation, immune activation and risk of HIV acquisition are needed to reliably assess the safety of new biomedical prevention strategies including vaccines and microbicides. However, a fuller understanding of expression profiles in women at high risk for HIV infection is crucial to the effective use of these potential biomarkers in Phase 3 trial settings. We have measured 45 soluble proteins and peptides in cervicovaginal lavage samples from 100 HIV negative women at high risk for HIV infection. Women were followed over one menstrual cycle to investigate modulation by hormonal contraception, menstrual cycle phase, recent sexual exposure and intravaginal practices. Women using injectable DMPA had increased concentration of several soluble proteins of the innate and adaptive immune system, including IL-1α, IL-1β, IL-2, MIP-1β, IP-10, IL-8, TGF-β, HBD4, IgA, IgG1, and IgG2. Women using combined oral contraceptives had a similar signature. There were differences in concentrations among samples from post-ovulation compared to pre-ovulation, notably increased immunoglobulins. Increased prostate-specific antigen, indicative of recent sexual exposure, was correlated with increased IL-6, MCP-1, and SLPI, and decreased GM-CSF and HBD3. The identified signature profiles may prove critical in evaluating the potential safety and impact on risk of HIV acquisition of different biomedical intervention strategies.

HIV and Men

INTRODUCTION

Since the initial description of HIV and AIDS, monumental efforts have been made both in the developed and developing countries to devise strategies and medications to control the disease. The advent of highly active antiretroviral therapy has now meant that the diagnosis of HIV is no longer a life-sentence and compliant patients with HIV can expect life expectancy similar to their noninfected peers. Consequently new challenges have arisen in the management of benign conditions.

AIM

To provide an overview of the key conditions and issues that HIV/AIDS patients may present with to an andrological service.

METHODS

Using PubMed, we screened the literature for studies on common andrological conditions specifically pertaining to HIV and AIDS.

MAIN OUTCOME MEASURES

The urological manifestations of HIV/AIDS in men have been summarized in an attempt to provide a useful guide for sexual health practitioners dealing with HIV-positive men.

RESULTS

As a result of advancements in pharmaceuticals, life expectancy of men infected with HIV has improved almost to that of the general population in developed countries. Therefore, clinicians are faced with non-life-threatening urological problems that affect the quality of life of men with HIV. The majority of these problems can be managed easily, by adapting a "patient-centered" approach, instead of "disease-centered" algorithms.

CONCLUSION

With improved survival and understanding, patients with HIV/AIDS can and do expect to enjoy a healthy sex life. With appropriate counseling around safe sex and careful management with consideration for disease-specific issues as well as the influence of medical therapy, patients can achieve a good quality of life.

Transient Increase in Herpes Simplex Virus Type 2 (HSV-2)-Associated Genital Ulcers Following Initiation of Antiretroviral Therapy in HIV/HSV-2-Coinfected Individuals

BACKGROUND

Immune reconstitution inflammatory syndrome (IRIS) in human immunodeficiency virus (HIV)-infected persons beginning antiretroviral therapy (ART) has been incompletely characterized for herpes simplex virus type 2 (HSV-2).

METHODS

We evaluated genital ulcer disease (GUD) and HSV-2-associated GUD at quarterly visits or when spontaneously reported at monthly visits in 3381 HIV/HSV-2-coinfected individuals in a placebo-controlled trial of suppressive acyclovir therapy to prevent HIV transmission, 349 of whom initiated ART during the study. Incidence was calculated for months before and after ART initiation, and incidence rate ratios (IRRs) were calculated.

RESULTS

GUD incidence increased from 15.0 episodes per 100 person-years before ART to 26.9 episodes per 100 person-years in the first full quarter after ART initiation (IRR, 1.83;P= .03), and the incidence of HSV-2-associated GUD increased from 8.1 to 19.0 episodes per 100 person-years (IRR, 2.20;P= .02). Subsequently, the incidence of GUD was similar to that before ART, although the numbers were small. Persons receiving suppressive acyclovir had fewer GUD episodes, but the IRR after beginning ART was similar in the acyclovir and placebo groups.

CONCLUSIONS

Initiation of ART in HIV/HSV-2-coinfected persons is associated with a transient increase in GUD and HSV-2 GUD. Acyclovir reduces the incidence of GUD but does not prevent an increase in GUD incidence during the first quarter following initiation of ART.

Risk Factors for HIV Acquisition in a Prospective Nairobi-Based Female Sex Worker Cohort

With two million new HIV infections annually, ongoing investigations of risk factors for HIV acquisition is critical to guide ongoing HIV prevention efforts. We conducted a prospective cohort analysis of HIV uninfected female sex workers enrolled at an HIV prevention clinic in Nairobi (n = 1640). In the initially HIV uninfected cohort (70 %), we observed 34 HIV infections during 1514 person-years of follow-up, i.e. an annual incidence of 2.2 % (95 % CI 1.6-3.1 %). In multivariable Cox Proportional Hazard analysis, HIV acquisition was associated with a shorter baseline duration of sex work (aHR 0.76, 95 % CI 0.63-0.91), minimum charge/sex act (aHR 2.74, 0.82-9.15, for low vs. intermediate; aHR 5.70, 1.96-16.59, for high vs. intermediate), N. gonorrhoeae infection (aAHR 5.89, 95 % CI 2.03-17.08), sex with casual clients during menses (aHR 6.19, 95 % CI 2.58-14.84), Depo Provera use (aHR 5.12, 95 % CI 1.98-13.22), and estimated number of annual unprotected regular partner contacts (aHR 1.004, 95 % CI 1.001-1.006). Risk profiling based on baseline predictors suggested that substantial heterogeneity in HIV risk is evident, even within a key population. These data highlight several risk factors for HIV acquisition that could help to re-focus HIV prevention messages.

The Art of HIV Elimination: Past and Present Science

INTRODUCTION

Remarkable strides have been made in controlling the HIV epidemic, although not enough to achieve epidemic control. More recently, interest in biomedical HIV control approaches has increased, but substantial challenges with the HIV cascade of care hinder successful implementation. We summarise all available HIV prevention methods and make recommendations on how to address current challenges.

DISCUSSION

In the early days of the epidemic, behavioural approaches to control the HIV dominated, and the few available evidence-based interventions demonstrated to reduce HIV transmission were applied independently from one another. More recently, it has become clear that combination prevention strategies targeted to high transmission geographies and people at most risk of infections are required to achieve epidemic control. Biomedical strategies such as male medical circumcision and antiretroviral therapy for treatment in HIV-positive individuals and as pre-exposure prophylaxis in HIV-negative individuals provide immense promise for the future of HIV control. In resource-rich settings, the threat of HIV treatment optimism resulting in increased sexual risk taking has been observed and there are concerns that as ART roll-out matures in resource-poor settings and the benefits of ART become clearly visible, behavioural disinhibition may also become a challenge in those settings. Unfortunately, an efficacious vaccine, a strategy which could potentially halt the HIV epidemic, remains elusive.

CONCLUSION

Combination HIV prevention offers a logical approach to HIV control, although what and how the available options should be combined is contextual. Therefore, knowledge of the local or national drivers of HIV infection is paramount. Problems with the HIV care continuum remain of concern, hindering progress towards the UNAIDS target of 90-90-90 by 2020. Research is needed on combination interventions that address all the steps of the cascade as the steps are not independent of each other. Until these issues are addressed, HIV elimination may remain an unattainable goal.

Changes in the contribution of genital tract infections to HIV acquisition among Kenyan high-risk women from 1993 to 2012

OBJECTIVE

The objective of this study was to understand temporal trends in the contribution of different genital tract infections to HIV incidence over 20 years of follow-up in a cohort of high-risk women.

DESIGN

A prospective cohort study.

METHODS

We performed monthly evaluations for HIV, vaginal yeast, bacterial vaginosis, Trichomonas vaginalis, Neisseria gonorrhoeae, nonspecific cervicitis, herpes simplex virus type two (HSV-2), genital ulcer disease (GUD) and genital warts. We used Cox regression to evaluate the association between sexually transmitted infections (STIs) and HIV acquisition over four time periods (1993-1997, 1998-2002, 2003-2007, 2008-2012). Models were adjusted for age, workplace, sexual risk behaviour, hormonal contraceptive use and other STIs. The resulting hazard ratios were used to calculate population attributable risk percentage (PAR%).

RESULTS

Between 1993 and 2012, 1964 women contributed 6135 person-years of follow-up. The overall PAR% for each infection was prevalent HSV-2 (48.3%), incident HSV-2 (4.5%), bacterial vaginosis (15.1%), intermediate microbiota (7.5%), vaginal yeast (6.4%), T. vaginalis (1.1%), N. gonorrhoeae (0.9%), nonspecific cervicitis (0.7%), GUD (0.8%) and genital warts (-0.2%). Across the four time periods, the PAR% for prevalent HSV-2 (40.4%, 61.8%, 58.4%, 48.3%) and bacterial vaginosis (17.1%, 19.5%, 14.7%, 17.1%) remained relatively high and had no significant trend for change over time. The PAR% for trichomoniasis, gonorrhoea, GUD and genital warts remained less than 3% across the four periods.

CONCLUSION

Bacterial vaginosis and HSV-2 have consistently been the largest contributors to HIV acquisition risk in the Mombasa Cohort over the past 20 years. Interventions that prevent these conditions would benefit women's health and could reduce their risk of becoming infected with HIV.

Rush to judgment: the STI-treatment trials and HIV in sub-Saharan Africa

INTRODUCTION

The extraordinarily high incidence of HIV in sub-Saharan Africa led to the search for cofactor infections that could explain the high rates of transmission in the region. Genital inflammation and lesions caused by sexually transmitted infections (STIs) were a probable mechanism, and numerous observational studies indicated several STI cofactors. Nine out of the ten randomized controlled trials (RCTs), however, failed to demonstrate that treating STIs could lower HIV incidence. We evaluate all 10 trials to determine if their design permits the conclusion, widely believed, that STI treatment is ineffective in reducing HIV incidence.

DISCUSSION

Examination of the trials reveals critical methodological problems sufficient to account for statistically insignificant outcomes in nine of the ten trials. Shortcomings of the trials include weak exposure contrast, confounding, non-differential misclassification, contamination and effect modification, all of which consistently bias the results toward the null. In any future STI-HIV trial, ethical considerations will again require weak exposure contrast. The complexity posed by HIV transmission in the genital microbial environment means that any future STI-HIV trial will face confounding, non-differential misclassification and effect modification. As a result, it is unlikely that additional trials would be able to answer the question of whether STI control reduces HIV incidence.

CONCLUSIONS

Shortcomings in published RCTs render invalid the conclusion that treating STIs and other cofactor infections is ineffective in HIV prevention. Meta-analyses of observational studies conclude that STIs can raise HIV transmission efficiency two- to fourfold. Health policy is always implemented under uncertainty. Given the known benefits of STI control, the irreparable harm from not treating STIs and the likely decline in HIV incidence resulting from STI control, it is appropriate to expand STI control programmes and to use funds earmarked for HIV prevention to finance those programmes.

Dynasore disrupts trafficking of herpes simplex virus proteins

Dynasore, a small-molecule inhibitor of the GTPase activity of dynamin, inhibits the entry of several viruses, including herpes simplex virus (HSV), but its impact on other steps in the viral life cycle has not been delineated. The current study was designed to test the hypothesis that dynamin is required for viral protein trafficking and thus has pleiotropic inhibitory effects on HSV infection. Dynasore inhibited HSV-1 and HSV-2 infection of human epithelial and neuronal cells, including primary genital tract cells and human fetal neurons and astrocytes. Similar results were obtained when cells were transfected with a plasmid expressing dominant negative dynamin. Kinetic studies demonstrated that dynasore reduced the number of viral capsids reaching the nuclear pore if added at the time of viral entry and that, when added as late as 8 h postentry, dynasore blocked the transport of newly synthesized viral proteins from the nucleus to the cytosol. Proximity ligation assays demonstrated that treatment with dynasore prevented the colocalization of VP5 and dynamin. This resulted in a reduction in the number of viral capsids isolated from sucrose gradients. Fewer capsids were observed by electron microscopy in dynasore-treated cells than in control-treated cells. There were also reductions in infectious progeny released into culture supernatants and in cell-to-cell spread. Together, these findings suggest that targeting dynamin-HSV interactions may provide a new strategy for HSV treatment and prevention.

IMPORTANCE

HSV infections remain a global health problem associated with significant morbidity, particularly in neonates and immunocompromised hosts, highlighting the need for novel approaches to treatment and prevention. The current studies indicate that dynamin plays a role in multiple steps in the viral life cycle and provides a new target for antiviral therapy. Dynasore, a small-molecule inhibitor of dynamin, has pleiotropic effects on HSV-1 and HSV-2 infection and impedes viral entry, trafficking of viral proteins, and capsid formation.

Prevalence and factors associated with sexually transmitted infections among HIV positive women opting for intrauterine contraception

Background

Women living with HIV/AIDS (WLHA) are a high risk group for sexually transmitted infections (STIs). However, the majority of women with STIs are asymptomatic. Data on prevalence of STIs among WLHA in Uganda are limited. The objective of the study was to determine prevalence and factors associated with STIs among WLHA opting for intrauterine contraceptive device (IUD).

Methods

Three hundred fifty one WLHA deemed free of STIs using a syndromic logarithm were enrolled into the study. Endo-cervical swabs were taken before IUD insertion and PCR test for Nisseria gonorrhea (NG), Trichomonas vaginalis (TV) and Chlamydia trachomatis (CT) infections conducted.

Results

Participants’ mean age was 29.4 ± 6.2 years, 83% were under 35years, 50% had secondary education and 73% were married. The majority (69%) had disclosed their HIV sero status to their spouses, 82% used Cotrimoxazole prophylaxis, 70% were on antiretroviral therapy, 90% had CD4 count greater than 350, about 60% reported condoms use and 70% were of parity 2-4. Over 50% of the participants’ spouses were older than 35 years and 72% had attained secondary education. STIs prevalence was 11.1%, (95% CI 7.8-14.4) and individual prevalence for TV, NG, and CT was 5.9%, 5.4% and 0.9% respectively. Factors independently associated with STI were having primary or less education (OR= 2.3, 95% CI: 1.09 - 4.85) having a spouse of primary or less education (OR= 3.3, 95% CI: 1.6 - 6.78) and muslim faith (OR= 0.2, 95% CI: 0.04 - 0.78).

Conclusion

STI prevalence was 11.1%. TV and NG were the commonest STIs in this population. Having primary or less education for both participant and spouse was associated with increased risk while being of muslim faith was associated with reduced risk of STI.

Genital herpes: oral antiviral treatments

INTRODUCTION

Genital herpes is an infection with herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2), and is among the most common sexually transmitted diseases.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of different oral antiviral treatments versus each other for a first episode of genital herpes in HIV-negative people? What are the effects of different antiviral treatments for genital herpes in HIV-positive people? We searched: Medline, Embase, The Cochrane Library, and other important databases up to October 2013 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found eight studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: aciclovir, famciclovir, and valaciclovir.

Sample size calculations for skewed distributions

Background

Sample size calculations should correspond to the intended method of analysis. Nevertheless, for non-normal distributions, they are often done on the basis of normal approximations, even when the data are to be analysed using generalized linear models (GLMs).

Methods

For the case of comparison of two means, we use GLM theory to derive sample size formulae, with particular cases being the negative binomial, Poisson, binomial, and gamma families. By simulation we estimate the performance of normal approximations, which, via the identity link, are special cases of our approach, and for common link functions such as the log. The negative binomial and gamma scenarios are motivated by examples in hookworm vaccine trials and insecticide-treated materials, respectively.

Results

Calculations on the link function (log) scale work well for the negative binomial and gamma scenarios examined and are often superior to the normal approximations. However, they have little advantage for the Poisson and binomial distributions.

Conclusions

The proposed method is suitable for sample size calculations for comparisons of means of highly skewed outcome variables.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-015-0023-0) contains supplementary material, which is available to authorized users.