Heterosexual transmission of HIV in Haiti

Comparative analysis of virulence determinants, phylogroups, and antibiotic susceptibility patterns of typical versus atypical Enteroaggregative E. coli in India

Enteroaggregative Escherichia coli (EAEC) is an evolving enteric pathogen that causes acute and chronic diarrhea in developed and industrialized nations in children. EAEC epidemiology and the importance of atypical EAEC (aEAEC) isolation in childhood diarrhea are not well documented in the Indian setting. A comparative analysis was undertaken to evaluate virulence, phylogeny, and antibiotic sensitivity among typical tEAEC versus aEAEC. A total of 171 EAEC isolates were extracted from a broad surveillance sample of diarrheal (N = 1210) and healthy children (N = 550) across North India. Polymerase chain reaction (PCR) for the aggR gene (master regulator gene) was conducted to differentiate tEAEC and aEAEC. For 21 virulence genes, we used multiplex PCR to classify possible virulence factors among these strains. Phylogenetic classes were identified by a multiplex PCR for chuA, yjaA, and a cryptic DNA fragment, TspE4C2. Antibiotic susceptibility was conducted by the disc diffusion method as per CLSI guidelines. EAEC was associated with moderate to severe diarrhea in children. The prevalence of EAEC infection (11.4%) was higher than any other DEC group (p = 0.002). tEAEC occurrence in the diarrheal group was higher than in the control group (p = 0.0001). tEAEC strain harbored more virulence genes than aEAEC. astA, aap, and aggR genes were most frequently found in the EAEC from the diarrheal population. Within tEAEC, this gene combination was present in more than 50% of strains. Also, 75.8% of EAEC strains were multidrug-resistant (MDR). Phylogroup D (43.9%) and B1 (39.4%) were most prevalent in the diarrheal and control group, respectively. Genetic analysis revealed EAEC variability; the comparison of tEAEC and aEAEC allowed us to better understand the EAEC virulence repertoire. Further microbiological and epidemiological research is required to examine the pathogenicity of not only typical but also atypical EAEC.

Enteroaggregative E. coli (EAEC) are an increasingly important cause of diarrhea. E. coli belonging to this category cause watery diarrhea, which is often persistent and can be inflammatory. It is also associated with traveler’s diarrhea in children and adults in middle and high-income countries. EAEC are defined by their ability to adhere to epithelial cells in a characteristic stacked brick-like pattern. However, the identification of these pathogenic strains remains elusive because of its heterogeneous nature. Genes that could contribute to the pathogenicity of EAEC encode adhesions, toxins, and other factors. Due to the heterogeneity of EAEC strains and differing host immune responses, not all EAEC infections are symptomatic. A critical factor in both recognizing EAEC pathogenesis and defining typical EAEC (tEAEC) strains is AggR, a transcriptional control for many EAEC virulence genes. The central role of aggR in virulence confers a strong priority to understand its pathogenicity. To identify EAEC, the CVD432 probe has been used. The CVD432 is a DNA probe from pAA plasmid of EAEC, has been reported to be specific for the detection of EAEC. The lack of sensitivity comes from the genetic heterogeneity of the EAEC strains and the wide geographic dispersal of strains. In our study, we performed a large surveillance of EAEC from North India among the pediatric population. Samples were collected by the microbiology staff at the Postgraduate Institute of Medical Education and Research (PGIMER) and referral system labs in Chandigarh (Manimajra), Punjab (Ludhiana), Haryana (Panchkula and Ambala Cantt), Himachal Pradesh (Hamirpur, Shimla, and Tanda), and Uttarakhand (Rishikesh, Rudrapur, and Haridwar)]. PGIMER is the largest tertiary care hospital in North India and serves patients from across Punjab, Jammu and Kashmir, Himachal Pradesh and Haryana. EAEC infections were detected using molecular methods. In our finding, astA, aap, and aggR genes were most frequently found in the EAEC from the diarrheal population. Within tEAEC, this gene combination is present in more than 50% of strains and helps to differentiate tEAEC from aEAEC. Our collection of EAEC strains helps in finding an appropriate marker for the early detection of EAEC. Our signature sequence (astA, aap, and aggR) will be ideal as focus genes for EAEC identification, as well as tEAEC and aEAEC. The multidrug resistance (MDR) was observed in 75.8% of the EAEC strains. tEAEC exhibits resistance to a greater number of antibiotics with respect to aEAEC. The phylogenetic analysis revealed that EAEC phylogeny is diverse and dispersed in all the phylogroups.

Predictors and Barriers to Condom Use in the African Cohort Study

Consistent condom use is an inexpensive and efficacious HIV prevention strategy. Understanding factors associated with condom use and barriers to use can inform strategies to increase condom uptake. The ongoing African Cohort Study prospectively enrolls adults at 12 clinical sites in Uganda, Kenya, Tanzania, and Nigeria. At enrollment, participants are asked about condom use at last sex with a regular partner. Robust Poisson regression models were used to evaluate predictors of self-reported condom use. Participants who reported not using condoms were asked to provide reasons. From January 2013 to September 2019, 2482 participants reported having at least one regular sexual partner in the preceding 6 months. Of those, 1577 (63.5%) reported using a condom at last sex. Condom use was more common among older participants, males, HIV-infected participants, and those with an HIV-infected partner. Married participants, those with a partner of unknown HIV status, and those reporting alcohol use were less likely to report condom use at last sex. Condom use at last sex also varied significantly by clinical site. Partner disapproval or refusal to use a condom was a consistent driver of disparities in condom use among participants who were HIV infected, female, and aged 18-24 years. Effective HIV prevention programs should integrate condom education with the tools necessary to negotiate condom use with regular partners.

Prevalence of Neisseria gonorrhoeae and Chlamydia trachomatis in men having sex with men in Port-au-Prince, Haiti: a cross-sectional study

OBJECTIVES

Over the last 15 years, the prevalence of HIV in Haiti has stabilised to around 2.0%. However, key populations remain at higher risk of contracting HIV and other sexually transmitted infections (STIs). The prevalence of HIV is 12.9% among men having sex with men (MSM). There is limited information about the prevalence of other STI in the Haitian population in general and even less among key populations. We assessed the burden of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) and risk factors for infections among MSM in Haiti.

METHODS

A cross-sectional study was conducted. MSM were recruited from seven health facilities in Port-au-Prince. All samples were tested by nucleic acid amplification test, using GeneXpert. A survey was administered to the participants to collect socio-demographic, clinical and risk behaviour data.

RESULTS

A total of 216 MSM were recruited in the study. The prevalence rates of CT and NG were 11.1% and 16.2%, respectively. CT NG co-infections were found in 10/216 (4.6%) of the participants. There were 39 MSM with rectal STI compared with 17 with genital infections. Participants between 18-24 and 30-34 years old were significantly more likely to be infected with NG than those aged 35 years or older (OR: 22.96, 95% CI: 2.79 to 188.5; OR: 15.1, 95% CI: 1.68 to 135.4, respectively). Participants who never attended school or had some primary education were significantly more likely to be infected with NG than those with secondary education or higher (OR: 3.38, 95% CI: 1.26 to 9.07). People tested negative for HIV were significantly more likely to be infected with CT than people living with HIV/AIDS (OR: 3.91, 95% CI: 1.37 to 11.2).

CONCLUSIONS

Periodic risk assessment and testing for STI should be offered in Haiti as part of a comprehensive strategy to improve the sexual health of key populations.

Union break-up after HIV diagnosis among sub-Saharan African migrants in France: disclosing HIV status is linked with staying in union

Sub-Saharan African migrants living in France are particularly affected by HIV. Due to the fear of sexual transmission of the virus, those in a relationship could experience a union break-up after an HIV diagnosis. Based on data from the time-event ANRS-Parcours survey that was conducted among a representative sample of sub-Saharan migrants living with HIV (France, 2012-2013), we studied union break-ups after HIV diagnosis among people who were in a relationship at the time of their diagnosis. Women experienced a more rapid union break-up after HIV diagnosis than did men. The living conditions of men were not correlated to their risk of union break-up while among women, having a personal dwelling reduced the risk of union break-up. For both sexes, less established relationships were more likely to break up after HIV diagnosis. Having disclosed the HIV status to a partner was associated with a reduced risk of separation between partners, after adjustment on socio-economic conditions and migration characteristics.

Determinants of Safer Sexual Behavior in a Long-term HIV-seropositive Population

Determinants of safer sexual behaviors among HIV-infected adult men with hemophilia were examined. A model was proposed that personal adjustment, communication skills, self-efficacy, and perceived advantages of condom use would influence safer sex practices. The model was tested with 181 men with hemophilia and HIV infection from 27 hemophilia treatment centers across the United States. The hypothesized model was tested using LISREL and explained 35 percent of the variance in safer sexual behaviors. Personal adjustment was significantly associated with general communication skills. General communication was linked with communication about safer sex which, in turn, influenced self-efficacy and perceived advantages of condom use. Communication about safer sex, efficacy and perceived advantages of condom use were all directly related to safer sexual behaviors.

HIV-1 subtype B: Traces of a pandemic

Human migration is a major process that shaped the origin and dissemination of HIV. Within HIV-1, subtype B (HIV-1B) is the most disseminated variant and it is assumed to be the causative agent in approximately 11% of all cases of HIV worldwide. Phylogenetic studies have revealed that HIV-1B emerged in Kinshasa (Africa) and was introduced into the Caribbean region via Haiti in or around 1966 by human migration. After localized dispersion, the virus was brought to the United States of America via homosexual/bisexual contact around 1969. Inside USA, the incidence of HIV-1B infection increased exponentially and it became established in the population, affecting not only homosexual individuals but also heterosexual individuals and injecting drug users. Soon after, the virus was disseminated and became established in other regions, including Europe, Asia, Latin America, and Australia. Recent studies suggest that, in addition to this pandemic clade, several lineages have emerged from Haiti and reached other Caribbean and Latin American countries via short-distance dissemination. Different subtype B genetic variants have also been detected in these epidemics. Four genetic variants have been described to date: subtype B', which mainly circulates in Thailand and other Asian countries; a specific variant mainly found in Trinidad and Tobago; the GPGS variant, which is primarily detected in Korea; and the GWGR variant, which is mainly detected in Brazil. This paper reviews the evolution of HIV-1B and its impact on the human population.

High HIV Prevalence and Associated Risk Factors Among Female Sexual Partners of Male Injection Drug Users (MWID) in Ho Chi Minh City, Vietnam

Injection drug use is a major factor in acquiring and transmitting HIV in Vietnam. This analysis aims to present estimates of HIV infection and factors associated with HIV infection among female sex partners (FSP) of MWID in Ho Chi Minh City (HCMC), Vietnam. Cross-sectional surveys were conducted in 2011 and 2013 among males who inject drugs (MWID) who then referred their FSP for a behavioral and biologic survey. In total, 445 MWID and FSPs were enrolled. HIV prevalence among MWID was 50 and 35 % among FSPs. Among FSPs, 60.3 % reported ever using illegal drugs and among those, 72.7 % reported ever injecting illicit drugs. Among FSP, injection drug for >1 year [adjusted Odds Ratio (aOR), 95 % CI 2.94, 1.19-7.26), p value = <0.001] and having a male partner infected with HIV [(aOR 3.35: 1.97-5.69), p value = <0.001] were associated with HIV infection. The prevalence of HIV infection is high among FSP of MWID in HCMC and is highly associated with the injection drug use behavior of the FSP. Harm-reduction intervention programs that focus on the MWID-FSP couple or directly on the FSPs are required.

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.

Condom effectiveness in reducing heterosexual HIV transmission: a systematic review and meta-analysis of studies on HIV serodiscordant couples

OBJECTIVE

This systematic review and meta-analysis aimed to reassess the effectiveness of condoms in reducing heterosexual transmission of HIV.

METHODS

Medline, Scopus, and the ISI Web of Science databases were searched up to June 2014. Eligible studies were synthesized using random-effects models.

RESULTS

Twenty-five studies with 10,676 HIV serodiscordant heterosexual couples were analyzed. The risk of HIV transmission was considerably lower among couples that were always using condoms compared to never-users (RR: 0.29, 95% CI: 0.20-0.43) or inconsistent users (RR:  0.23, 0.13-0.40). The protective effect was slightly higher when the male rather than the female partner was infected (RR: 0.31, 0.20-0.48; vs. RR: 0.44, 0.24-0.80), and very high in Asian settings (RR: 0.06, 0.01-0.46).

CONCLUSIONS

Though imperfect, condoms reduce HIV transmission by more than 70% when used consistently by HIV serodiscordant heterosexual couples. Social, cultural and biological differences need to be studied further to inform projection modelers and policy makers.

High proportion of HIV serodiscordance among HIV-affected married couples in northern Vietnam

INTRODUCTION

Little is known about the state of HIV transmission among married couples in Vietnam. This study aims to clarify HIV serostatus in this group and elucidate risk factors for intra-marital HIV transmission.

METHODS

In 2012, we enrolled a group of HIV-positive married men registered at the HIV outpatient clinic of a referral hospital in northern Vietnam, along with their wives. Sociodemographic, behavioural and clinical data were collected from men and wives. HIV serodiscordant couples were followed until March 2014 to determine seroconversion rate. A phylogenetic analysis was performed based on env V3 sequence to detail cluster formation among men.

RESULTS

Of the 163 HIV-positive men enrolled in the study, 101 (62.0%) had wives testing HIV-negative. Half of men reported injecting drug use (IDU) as a likely transmission route. Couples reported a high incidence of unprotected sexual intercourse prior to diagnosis; the median (inter quartile range) was 4 (4-8) times per month. Only 17 couples (10.4%) reported using condoms during at least half these instances. Multivariable analysis revealed IDU history among men was independently associated with HIV-negative wives (adjusted OR 0.31; 95% CI 0.10-0.95, p=0.041). Phylogenetic analysis of 80 samples indicated CRF01_AE. Of these, 69 (86.3%) clustered with IDU-associated viruses from Vietnam. No HIV seroconversion was identified during a follow-up of 61 serodiscordant couples, with 126.5 person-years of observation during which HIV-infected men were on antiretroviral drug therapy (ART).

CONCLUSION

High HIV serodiscordance was observed among HIV-affected married couples in northern Vietnam. A large number of at-risk wives therefore remain HIV-negative and can be protected with measures including proper use of ART if couples are made aware of the serodiscordance through screening.

Factors impacting the provision of antiretroviral therapy to people living with HIV: the view from Haiti

Haiti is the poorest country in the Western Hemisphere and has the highest number of people living with HIV in the Caribbean, the region most impacted by HIV outside of Africa. Despite continuous political, socioeconomic and natural catastrophes, Haiti has mounted a very successful response to the HIV epidemic. Prevention and treatment strategies implemented by the government in collaboration with non-governmental organizations have been instrumental in decreasing the national HIV prevalence from a high of 6.2% in 1993 to 2.2% in 2012. We describe the history and epidemiology of HIV in Haiti and the expansion of antiretroviral therapy (ART) over the past decade, with the achievement of universal access to ART for patients meeting the 2010 World Health Organization guidelines. We also describe effective models of care, successes and challenges of international funding, and current challenges in the provision of ART. We are optimistic that the goal of providing ART for all in need remains in reach.

Systematic review of couple-based HIV intervention and prevention studies: advantages, gaps, and future directions

We conducted a systematic review of couple-based HIV biobehavioral (skills-building, VCT, and adherence) and biomedical (ART, circumcision) prevention and intervention studies designed to reduce sexual- and drug-risk behaviors and HIV transmission and acquisition. Of the 11,162 papers identified in the search, 93 peer-reviewed papers met the inclusion criteria and yielded a total of 33 studies conducted globally. Biobehavioral couple-based prevention and intervention studies have been efficacious in reducing sexual- and drug-risk behaviors, increasing access to HIV testing and care, and improving adherence. Biomedical couple-based studies were found to reduce HIV incidence among HIV-negative sex partners and viral load among HIV-positive partners. Despite much progress, couple-based HIV prevention and intervention studies remain limited; a number of methodological gaps exist and studies focusing on MSM, people who inject drugs, and sex workers are scarce.

A Pilot Intervention to Promote Safer Sex in Heterosexual Puerto Rican Couples

Although the sexual transmission of HIV occurs in the context of an intimate relationship, preventive interventions with couples are scarce, particularly those designed for Hispanics. In this article, we present the effect of a pilot intervention directed to prevent HIV/AIDS in heterosexual couples in Puerto Rico. The intervention was theory-based and consisted of five three-hour group sessions. Primary goals included increasing male condom use and the practice of mutual masturbation as a safer sex method, and promoting favorable attitudes toward these behaviors. Twenty-six couples participated in this study. Fifteen were randomly assigned to the intervention group and eleven to a control group. Retention rates at post-intervention and follow-up were 82% for the whole sample. Results showed that there was a significant increase in the use of male condoms with main partners in the intervention group when compared with the control group. Couples in the intervention group also had better scores on secondary outcomes, such as attitudes toward condom use and mutual masturbation, HIV information, sexual decision-making, and social support. We found that these effects persisted over the three month follow up. A significant effect was also observed for the practice of mutual masturbation, but not for sexual negotiation. These results showed that promoting male condom use in dyadic interventions among heterosexual couples in Puerto Rico is feasible. Our findings suggest that because vaginal penetration has been constructed as the sexual script endpoint among many Hispanic couples, promoting other non-penetrative practices, such as mutual masturbation, may be difficult.

HIV sexual transmission risk among serodiscordant couples: assessing the effects of combining prevention strategies

BACKGROUND

The number of strategies to prevent HIV transmission has increased following trials evaluating antiretroviral therapy (ART), preexposure prophylaxis (PrEP) and male circumcision. Serodiscordant couples need guidance on the effects of these strategies alone, and in combination with each other, on HIV transmission.

METHODS

We estimated the sexual risk of HIV transmission over 1-year and 10-year periods among male-male and male-female serodiscordant couples. We assumed the following reductions in transmission: 80% from consistent condom use; 54% from circumcision in the negative male partner of a heterosexual couple; 73% from circumcision in the negative partner of a male-male couple; 71% from PrEP in heterosexual couples; 44% from PrEP in male-male couples; and 96% from ART use by the HIV-infected partner.

FINDINGS

For couples using any single prevention strategy, a substantial cumulative risk of HIV transmission remained. For a male-female couple using only condoms, estimated risk over 10 years was 11%; for a male-male couple using only condoms, estimated risk was 76%. ART use by the HIV-infected partner was the most effective single strategy in reducing risk; among male-male couples, adding consistent condom use was necessary to keep the 10-year risk below 10%.

CONCLUSION

Focusing on 1-year and longer term transmission probabilities gives couples a better understanding of risk than those illustrated by data for a single sexual act. Long-term transmission probabilities to the negative partner in serodiscordant couples can be high, though these can be substantially reduced with the strategic use of preventive methods, especially those that include ART.

The Haiti research-based model of international public health collaboration: the GHESKIO Centers

For 3 decades, GHESKIO (the Groupe Haitien d'Etude du Sarcome de Kaposi et des Infections Opportunistes), the Haitian Ministry of Health, and Weill Cornell have pursued a tripartite mission of service, training, and translational research. The initial focus was on AIDS and tuberculosis. The mission has expanded to include the local community and now provides maternal-child health, family planning, cancer prevention and treatment, immunizations (including human papillomavirus, cholera), and primary education through vocational and microcredit programs. Outcome measures include a reduction in HIV prevalence from 6.2% to the current 2.2%, extensive tuberculosis and cholera prevention and treatment programs, and national training programs for biomedical and community health workers.

Heterosexual HIV-1 infectiousness and antiretroviral use: systematic review of prospective studies of discordant couples

BACKGROUND

Recent studies have estimated the reduction in HIV-1 infectiousness with antiretroviral therapy (ART), but high-quality studies such as randomized controlled trials, accompanied by rigorous adherence counseling, are likely to overestimate the effectiveness of treatment-as-prevention in real-life settings.

METHODS

We attempted to summarize the effect of ART on HIV transmission by undertaking a systematic review and meta-analysis of HIV-1 infectiousness per heterosexual partnership (incidence rate and cumulative incidence over study follow-up) estimated from prospective studies of discordant couples. We used random-effects Poisson regression models to obtain summary estimates. When possible, the analyses were further stratified by direction of transmission (man-to-woman or woman-to-man) and economic setting (high- or low-income countries). Potential causes of heterogeneity of estimates were explored through subgroup analyses.

RESULTS

Fifty publications were included. Nine allowed comparison between ART and non-ART users within studies (ART-stratified studies), in which summary incidence rates were 3.6/100 person-years (95% confidence interval = 2.0-6.5) and 0.2/100 person-years (0.07-0.7) for non-ART- and ART-using couples, respectively (P < 0.001), constituting a 91% (79-96%) reduction in per-partner HIV-1 incidence rate with ART use. The 41 studies that did not stratify by ART use provided estimates with high levels of heterogeneity (I statistic) and few reported levels of ART use, making interpretation difficult. Nevertheless, estimates tended to be lower with ART use. Infectiousness tended to be higher for low-income than high-income settings, but there was no clear pattern by direction of transmission (man-to-woman and woman-to-man).

CONCLUSIONS

ART substantially reduces HIV-1 infectiousness within discordant couples, based on observational studies, and could play a major part in HIV-1 prevention efforts. However, the non-zero risk from partners receiving ART demonstrates that appropriate counseling and other risk-reduction strategies for discordant couples are still required. Additional estimates of ART effectiveness by adherence level from real-life settings will be important, especially for persons starting treatment early without symptoms.

Depression, substance abuse and other contextual predictors of adherence to antiretroviral therapy (ART) among Haitians

Haiti has the highest number of individuals living with HIV in the Caribbean. Due to Haiti's resource-poor environment and inadequate mental health and substance abuse services, adherence to antiretroviral therapy (ART) may be especially difficult. This study examined associations among demographics, maladaptive coping, partner conflict, alcohol problems, depression, and negative attitudes about medications and their impact on adherence among 194 HIV-positive Haitians. In a mediated directional structural equation model, depression and negative attitudes about ART directly predicted poorer adherence. Greater partner conflict, maladaptive coping and alcohol problems predicted more depression. Maladaptive coping predicted a negative attitude about ART. Alcohol problems predicted partner conflict and maladaptive coping. Significant indirect effects on adherence mediated through both depression and negative attitudes about ART include negative effects of female gender, alcohol problems and maladaptive coping. Results highlight the importance of integrated care for depression, alcohol use and other psychosocial problems to increase ART adherence.

Modeling the impact of Trichomonas vaginalis infection on HIV transmission in HIV-infected individuals in medical care

BACKGROUND

To assess factors associated with having a Trichomonas vaginalis (TV) infection among persons receiving care for human immunodeficiency virus (HIV) and estimate the number of transmitted HIV infections attributable to TV.

METHODS

HIV clinic patients were recruited from 2 secondary prevention studies, screened by urine nucleic-acid amplification tests for sexually transmitted infections, and interviewed about risk factors (baseline, 6, and 12 months). We conducted mathematical modeling of the results to estimate the number of transmitted HIV infections attributable to TV among a cohort of HIV-infected patients receiving medical care in North Carolina.

RESULTS

TV was prevalent in 7.4%, and incident in 2% to 3% of subjects at follow-up. Individuals with HIV RNA <400 copies/mL (odds ratio, 0.32; 95% CI: 0.14-0.73) and at least 13 years of education (odds ratio, 0.24; 95% CI: 0.08-0.70) were less likely to have TV. Mathematical modeling predicted that 0.062 HIV transmission events occur per 100 HIV-infected women in the absence of TV infection and 0.076 HIV infections per 100 HIV- and TV-infected women (estimate range: 0.070-0.079), indicating that 23% of the HIV transmission events from HIV-infected women may be attributable to TV infection when 22% of women are coinfected with TV.

CONCLUSIONS

The data suggest the need for improved diagnosis of TV infection and suggest that HIV-infected women in medical care may be appropriate targets for enhanced testing and treatment.

MODELING PRIMARY AND SECONDARY DRUG RESISTANCES UNDER CHINA'S "FOUR-FREE-ONE-CARE POLICY"

We propose a mathematical model to evaluate the effect of China's "Four-Free-One-Care Policy" in MSM population in Beijing. We divided the drug resistant HIV patients into two sub-populations: primary drug resistance and secondary drug resistance. Uncertainty and sensitivity analysis based on Latin Hypercube Sampling (LHS) were used for these thresholds of our model. We find that drug-resistant HIV will spread fast in MSM population under China's current treatment policy. Especially, primary-resistant strain is very likely to dominate the HIV positive MSM individuals after 10 years. The conclusions hint that, China's outlook on HIV infections is not optimistic if sufficient kinds free second-line drugs in China cannot be put into use in the near future.

Environmental Change, Risky Sexual Behavior, and the HIV/AIDS Pandemic: Linkages Through Livelihoods in Rural Haiti

Local natural resources are central to rural livelihoods across much of the developing world. Such "natural capital" represents one of several types of assets available to households as they craft livelihood strategies. In order to explore the potential for environmental scarcity and change to contribute to perpetuation of the HIV/AIDS pandemic, we examine the association between declining natural capital and engaging in risky sexual behaviors, as potentially another livelihood strategy. Such association has been demonstrated in Kenya and Tanzania, through the fish-for-sex trade. To explore the possibility of this connection within rural Haitian livelihoods we use Demographic and Health Survey data, with a focus on rural women, combined with vegetation measures generated from satellite imagery. We find that lack of condom use in recent sexual encounters is associated with local environmental scarcity - controlling for respondent age, education, religion and knowledge of AIDS preventive measures. The results suggest that explicit consideration of the environmental dimensions of HIV/AIDS may be of relevance in scholarship examining factors shaping the pandemic.

A single-blind randomized controlled trial to evaluate the effect of extended counseling on uptake of pre-antiretroviral care in Eastern Uganda

Background

Many newly screened people living with HIV (PLHIV) in Sub-Saharan Africa do not understand the importance of regular pre-antiretroviral (ARV) care because most of them have been counseled by staff who lack basic counseling skills. This results in low uptake of pre-ARV care and late treatment initiation in resource-poor settings. The effect of providing post-test counseling by staff equipped with basic counseling skills, combined with home visits by community support agents on uptake of pre-ARV care for newly diagnosed PLHIV was evaluated through a randomized intervention trial in Uganda.

Methods

An intervention trial was performed consisting of post-test counseling by trained counselors, combined with monthly home visits by community support agents for continued counseling to newly screened PLHIV in Iganga district, Uganda between July 2009 and June 2010, Participants (N = 400) from three public recruitment centres were randomized to receive either the intervention, or the standard care (the existing post-test counseling by ARV clinic staff who lack basic training in counseling skills), the control arm. The outcome measure was the proportion of newly screened and counseled PLHIV in either arm who had been to their nearest health center for clinical check-up in the subsequent three months +2 months. Treatment was randomly assigned using computer-generated random numbers. The statistical significance of differences between the two study arms was assessed using chi-square and t-tests for categorical and quantitative data respectively. Risk ratios and 95% confidence intervals were used to assess the effect of the intervention.

Results

Participants in the intervention arm were 80% more likely to accept (take up) pre-ARV care compared to those in the control arm (RR 1.8, 95% CI 1.4-2.1). No adverse events were reported.

Conclusions

Provision of post-test counseling by staff trained in basic counseling skills, combined with home visits by community support agents had a significant effect on uptake of pre-ARV care and appears to be a cost-effective way to increase the prerequisites for timely ARV initiation.

Trial registration

The trial was registered by Current Controlled Trials Ltd C/OBioMed Central Ltd as ISRCTN94133652 and received financial support from Sida and logistical support from the European Commission.

Efficacy of HIV prevention interventions in Latin American and Caribbean nations, 1995-2008: a meta-analysis

This meta-analysis synthesized 37 HIV prevention interventions (from 28 studies) that were evaluated in Latin American and Caribbean nations. These studies were obtained through systematic searches of English, Spanish, and Portuguese-language databases available as of January 2009. Overall, interventions significantly increased knowledge (d = 0.40) and condom use (d = 0.25) but the effects varied widely. Interventions produced more condom use when they focused on high-risk individuals, distributed condoms, and explicitly addressed social-cultural components. The best-fitting models utilized factors related to geography, especially indices of a nations' human development index (HDI) and income inequality (i.e., Gini index). Interventions that provided at least 3 h of content succeeded better when HDI and income inequality were lower, suggesting that intensive HIV prevention activities succeed best where the need is greatest. Implications for HIV intervention development in Latin America and the Caribbean are discussed.

HIV transmission risk among serodiscordant couples: a retrospective study of former plasma donors in Henan, China

OBJECTIVES: To estimate the HIV incidence and assess the behavioral, clinical, and quality-of-life risk factors for HIV transmission among serodiscordant couples from Henan Province, China. METHODS: Between January 2006 and December 2008, initially seronegative spouses were tested for HIV at six month intervals. Retrospectively identified subjects were interviewed through face-to-face questionnaire. Cox proportional-hazards model was used to assess the relationship between risk factors and HIV seroconversion. RESULTS: Out of 1927 couples, 84 (4.3%) seroconversions occurred, representing a seroconversion rate of 1.71 per 100 person-years. Seroconversion rates increased over time. Not always using condoms (RR=8.42; 95% CI, 4.83-14.67), sexual activity ≥ 4 times per month (RR=5.24; 95% CI, 2.55-10.77), not switching anti-retroviral treatment regimen (RR=1.99; 95% CI, 0.85-4.65), and a quality of life score <12 on the psychological domain (RR=2.33; 95% CI, 1.21-4.48) were associated with increased risk of seroconversion. Seventy one percent of index spouses were on ART. There was no association between rate of HIV seroconversion and last recorded CD4 cell count level of the index spouse. CONCLUSIONS: Effective HIV prevention interventions targeting discordant couples should focus on sustaining health education, increasing psychosocial support services, and increasing medication adherence monitoring.

Determinants of intention to use condoms among clients of female sex workers in Haiti

A cross-sectional survey was conducted to examine factors influencing intention of condom use among 378 clients of female sex workers (FSWs) visiting commercial sex sites in St-Marc and Gonaives, Haiti. Mean age of the study participants was 24 years. A structured questionnaire was used to collect data on socio-demographic characteristics, behaviors, and the theory of planned behavior (TPB) constructs. Seventy-four percentage of clients reported having used condoms with a FSW the last time they had had sexual intercourse. The majority (81.7%) firmly intended to use condoms during the next sexual encounter with a FSW. Multivariate logistic models revealed that subjective norms (odds ratio (OR)=1.75; 95% confidence interval (CI): 1.06-2.88), perceived behavioral control (OR=1.34; 95% CI: 1.09-1.63) and attitudes (OR=1.23; 95% CI: 1.04-1.44) were predictors of intention to use condoms, with norms being more important. Clients having used condoms the last time they had a sexual intercourse with a FSW, were more likely to have the intention to use them in the future (OR=3.17; 95% CI: 1.65-6.10), indicating an adopted behavior. Lastly, having had a previous sexually transmitted infection was associated with intention, suggesting that a negative experience can influence a future behavior. In conclusion, intention to use condoms among the clients of Haitian FSWs was well predicted by TPB constructs. Our findings provide evidence for designing interventions targeted at reducing risky sex behaviors in this population.

Economic risk factors for HIV infection among women in rural Haiti: implications for HIV prevention policies and programs in resource-poor settings

AIMS

The goals of this study were to (1) estimate the prevalence of HIV infection among women accessing services at a women's health center in rural Haiti and (2) to identify economic risk factors for HIV infection in this population.

METHODS

Women who accessed healthcare services at this center between June 1999 and December 2002 were recruited to participate. The analysis was based on data from a case-control study of sexually transmitted diseases (STDs) in rural Haiti. HIV prevalence in the study population was 4%.

RESULTS

In multivariate analyses, partner occupation was associated with HIV infection in women, with mechanic (OR 9.0, 95% CI 1.8-45) and market vendor (OR 4.2, 95% CI 1.6-11) reflecting the strongest partner occupational risk factors. Partner's occupation as a farmer reduced the risk of infection in women by 60% (95% CI 0.14-1.1). Factors indicating low socioeconomic status (SES), such as food insecurity (OR 2.0, 95% CI 0.75-5.6) and using charcoal for cooking (OR 1.7, 95% CI 0.72-3.8) suggested an association with HIV infection.

CONCLUSIONS

Given pervasive gender inequality in Haiti, women's economic security often relies on their partners' income earning activities. Our findings show that although factors reflecting poverty are associated with HIV-positive status, stronger associations are observed for women whose partners indicated a more secure occupation (e.g., mechanic or market vendor). Policies and programs that expand access to education and economic opportunities for women and girls may have long-term implications for HIV prevention in Haiti and other resource-poor settings.

Interpreting sexually transmissible infection prevention trials by adjusting for the magnitude of exposure

Background Exposures to sexually transmitted infections are discrete identifiable events. Interventions to prevent sexually transmitted infections have a certain probability of effectiveness in reducing risk in any given event.

Purpose Randomized control trials for sexually transmitted infections interventions are designed to estimate the effectiveness in preventing acquisition of infection. Typically, randomized control trials are run over a specific period of time and incidence in the control arm is compared with incidence in an intervention arm. However, it is possible that the effectiveness of an intervention over the duration of a clinical trial may be different to the actual effectiveness of the intervention in every single exposure event or the overall effectiveness over different periods than the duration of the trial.

Methods In this study a simple mathematical framework is used, similar to methods in conception research, to describe the expected effectiveness that would be observed in a clinical trial of an intervention per-exposure and for clinically relevant shorter and longer durations than the trial, where each subject has multiple risk exposures.

Results It is theoretically demonstrated that the actual effectiveness of the intervention per risk event is not equal to the overall preventative effectiveness of the intervention in preventing transmission over many exposures. Examples are given for sexually transmitted infections with diverse transmission probabilities (HIV and HPV) and for interventions with different levels of effectiveness (condoms and circumcision). The observed effectiveness of an intervention is likely to be maintained over many exposures for infections with low transmission risk (like HIV) but the observed effectiveness decreases substantially with number of exposures for moderate or high risk infections (like HPV). An equation is provided for interpreting randomized control trials’ estimates of effectiveness with respect to various degrees of risk exposure.

Limitations The difficulty in adjusting the interpretation of randomized control trials results in this manner is that collection of accurate data on the number of discrete exposure events is not always possible and that there is substantial heterogeneity in degree of risk exposure between participants in trials.

Conclusions The implications of this analysis are that common interpretations of clinical trial interventions are insufficient for understanding the true efficacy of an intervention in some circumstances. Estimates of effectiveness in trials may misrepresent effectiveness per exposure event and effectiveness over a lifetime of risk. Care should be taken when designing protocols for analysis of trial results when the expected incidence is high. No change to the current practice of designing randomized control trials is suggested but analysis of trial data could be extended to calculate other statistics of effectiveness. A type of extrapolation and interpolation method for estimating levels of effectiveness is proposed. Clinical Trials 2010; 7: 36—43. http://ctj.sagepub.com

A sex-role-preference model for HIV transmission among men who have sex with men in China

Background

Men who have sex with men (MSM) are much more likely to be infected with HIV than the general population. China has a sizable population of MSM, including gay, bisexual men, money boys and some rural workers. So reducing HIV infection in this population is an important component of the national HIV/AIDS prevention and control program.

Methods

We develop a mathematical model using a sex-role-preference framework to predict HIV infection in the MSM population and to evaluate different intervention strategies.

Results

An analytic formula for the basic reproduction ratio R₀ was obtained; this yields R₀ = 3.9296 in the current situation, so HIV will spread very fast in the MSM population if no intervention measure is implemented in a timely fashion. The persistence of HIV infection and the existence of disease equilibrium (or equilibria) are also shown. We utilized our model to simulate possible outcomes of antiretroviral therapy and vaccination for the MSM population. We compared the effects of these intervention measures under different assumptions about MSM behaviour. We also found that R₀ is a decreasing function of the death rate of HIV-infected individuals, following a power law at least asymptotically.

Conclusion

HIV will spread very fast in the MSM population unless intervention measures are implemented urgently. Antiretroviral therapy can have substantial impact on the reduction of HIV among the MSM population, even if disinhibition is considered. The effect of protected sexual behaviour on controlling the epidemic in the MSM population largely depends on the sex-ratio preference of different sub-populations.

Condom failure: examining the objective and cultural meanings expressed in interviews with African American adolescents

The purpose of this study was to explore the meaning and context of self-reported "condom failure" among sexually active African American adolescents. Semistructured interviews regarding methods of protection from pregnancy and sexually transmitted disease (STD) with 124 youth (ages 14-19 years) were content analyzed. The findings suggested three meanings of condom failure. First, condom failure represents a legitimate and important risk related to sexual activity. Second, it can serve as an excuse repertoire for adolescents who engaged in unprotected sex and later experienced either pregnancy or a STD. Third, it may serve as an explanation for males who deceive their partners into having unprotected sex. The findings are discussed with regard to their implications for HIV or STD prevention and research.

Contraception and HIV infection in women

BACKGROUND

More than 15 million women, many of reproductive age, were infected with human immunodeficiency virus (HIV) at the end of 2007. As the HIV epidemic evolves, heterosexual intercourse is increasingly risky: the risk of infection in exposed young women is 4- to 7-fold higher than in young men and nearly half a million newborns annually have HIV. This review aims to show the effect of contraceptive choices on risk of HIV and on the course of disease in women with HIV.

METHODS

Relevant citations were selected by agreement between the authors after a search of MEDLINE using the terms HIV/AIDS and contraception.

RESULTS

Risk of transmission of HIV varies from 1 in 200 to 1 in 10 000 coital incidents, depending in part on the integrity of the vaginal epithelium. Consistent use of male condoms has been proven to reduce horizontal transmission of HIV by 80% among HIV-serodiscordant couples. Hormonal contraception may increase the risk of HIV acquisition in high-risk women such as commercial sex workers, but not in women at low risk of HIV. While hormonal contraception did not affect progression of disease in two cohort studies involving 370 women, in a randomized trial among women not receiving antiretroviral medication, clinical disease accelerated in the oral contraception group (13.2/100 woman-years) compared with the copper intrauterine devices group (8.6/100 woman-years; hazard ratio, 1.5; 95% confidence interval, 1.04-2.1). Hormonal contraception does not interfere with antiviral drug effectiveness.

CONCLUSIONS

All the available reversible contraceptive methods can generally be used by women at risk of HIV infection and by HIV-infected women. Further studies are needed to investigate the safety and efficiency of hormonal contraception in women living with HIV/AIDS.

Male circumcision and risk of HIV infection among heterosexual African American men attending Baltimore sexually transmitted disease clinics

BACKGROUND

Male circumcision has received international attention as an intervention for reducing HIV infection among high-risk heterosexual men; however, few US studies have evaluated its association with the risk of HIV infection.

METHODS

We analyzed visit records for heterosexual African American men who underwent HIV testing while attending sexually transmitted disease (STD) clinics in Baltimore, Maryland, from 1993 to 2000. We used multivariable binomial regression to evaluate associations between circumcision and the risk of HIV infection among visits by patients with known and unknown HIV exposure.

RESULTS

Overall, 1096 (2.7%) of 40,571 clinic visits yielded positive HIV test results. Among 394 visits by patients with known HIV exposure, circumcision was significantly associated with lower HIV prevalence (10.2% vs. 22.0%; adjusted prevalence rate ratio [PRR], 0.49 [95% confidence interval [CI], 0.26-0.93]). Conversely, among 40,177 visits by patients with unknown HIV exposure, circumcision was not associated with reduced HIV prevalence (2.5% vs. 3.3%; adjusted PRR, 1.00 [95% CI, 0.86-1.15]), and age >or=25 years old and diagnosis of ulcerative STD were associated with increased prevalence.

CONCLUSIONS

Circumcision was associated with substantially reduced HIV risk in patients with known HIV exposure, suggesting that results of other studies demonstrating reduced HIV risk for circumcision among heterosexual men likely can be generalized to the US context.

Heterosexual risk of HIV-1 infection per sexual act: systematic review and meta-analysis of observational studies

We did a systematic review and meta-analysis of observational studies of the risk of HIV-1 transmission per heterosexual contact. 43 publications comprising 25 different study populations were identified. Pooled female-to-male (0.04% per act [95% CI 0.01-0.14]) and male-to-female (0.08% per act [95% CI 0.06-0.11]) transmission estimates in high-income countries indicated a low risk of infection in the absence of antiretrovirals. Low-income country female-to-male (0.38% per act [95% CI 0.13-1.10]) and male-to-female (0.30% per act [95% CI 0.14-0.63]) estimates in the absence of commercial sex exposure (CSE) were higher. In meta-regression analysis, the infectivity across estimates in the absence of CSE was significantly associated with sex, setting, the interaction between setting and sex, and antenatal HIV prevalence. The pooled receptive anal intercourse estimate was much higher (1.7% per act [95% CI 0.3-8.9]). Estimates for the early and late phases of HIV infection were 9.2 (95% CI 4.5-18.8) and 7.3 (95% CI 4.5-11.9) times larger, respectively, than for the asymptomatic phase. After adjusting for CSE, presence or history of genital ulcers in either couple member increased per-act infectivity 5.3 (95% CI 1.4-19.5) times versus no sexually transmitted infection. Study estimates among non-circumcised men were at least twice those among circumcised men. Low-income country estimates were more heterogeneous than high-income country estimates, which indicates poorer study quality, greater heterogeneity of risk factors, or under-reporting of high-risk behaviour. Efforts are needed to better understand these differences and to quantify infectivity in low-income countries.

Clients of female sex workers in Gonaives and St-Marc, Haiti characteristics, sexually transmitted infection prevalence and risk factors

BACKGROUND

Few data exist on the role of clients of female sex workers (FSWs) in STI transmission. This study examined sociodemographic characteristics, risk behaviors, and STI prevalence among clients of FSWs in Haiti.

METHODS

A cross-sectional survey among clients of FWSs (n = 378). Clients were recruited by collaborating local FSWs directly on commercial sex sites. Dried blood spot samples were used to determine prevalence of HIV, syphilis, and herpes simplex virus 2 (HSV-2).

RESULTS

Of the respondents, 88% were younger than 30 years, and 60.7% were living with a partner. Fifty-nine percent of clients reported always using condoms with FSWs, 32.8% did so with their stable partners, and 44.9% with casual partners. Clients had a high number of partners; 39.9% had 10 or more within the previous 3 months. The prevalence of HIV-1, previous or active syphilis, and HSV-2 was 7.2%, 13.4%, and 22%, respectively. Multivariate analysis indicated that clients who had tried marijuana, were practicing Voodoo, had a history of STI or were infected with HSV-2 were more often HIV-positive. Living in Gonaives, not being Protestant, being employed, and having tried marijuana were associated with syphilis infection. Older clients, residents of Gonaives and Voodoo practitioners were more likely to be infected with HSV-2.

CONCLUSION

STI prevalence was remarkably high among clients of FSWs. These men had many sex partners and condom use differed, depending on the category of partner. Clients of FSWs likely act as a bridge population, facilitating the spread of STI throughout the general population in Haiti, and should be targeted in prevention programs.

Methodological overview of an African American couple-based HIV/STD prevention trial

OBJECTIVE

To provide an overview of the National Institute of Mental Health Multisite HIV/sexually transmitted disease (STD) Prevention Trial for African American Couples conducted in 4 urban areas: Atlanta, Los Angeles, New York, and Philadelphia. The rationale, study design methods, proposed data analyses, and study management are described.

DESIGN

This is a 2-arm randomized trial, implementing a modified randomized block design, to evaluate the efficacy of a couples-based intervention designed for HIV-serodiscordant African American couples.

METHODS

The study phases consisted of formative work, pilot studies, and a randomized clinical trial. The sample is 535 HIV-serodiscordant heterosexual African American couples. There are 2 theoretically derived behavioral interventions with 8 group and individual sessions: the Eban HIV/STD Risk Reduction Intervention (treatment) versus the Eban Health Promotion Intervention (control). The treatment intervention was couples based and focused on HIV/STD risk reduction whereas the control was individual based and focused on health promotion. The 2 study conditions were structurally similar in length and types of activities. At baseline, participants completed an audio computer-assisted self-interview and interviewer-administered questionnaire and provided biological specimens to assess for STDs. Similar follow-up assessments were conducted immediately after the intervention, at 6 months, and at 12 months.

RESULTS

The trial results will be analyzed across the 4 sites by randomization assignment. Generalized estimating equations and mixed-effects modeling are planned to test: (1) the effects of the intervention on STD incidence and condom use and on mediator variables of these outcomes and (2) whether the effects of the intervention differ depending on key moderator variables (eg, gender of the HIV-seropositive partners, length of relationship, psychological distress, sexual abuse history, and substance abuse history).

CONCLUSIONS

The lessons learned from the design and conduct of this clinical trial provide guidelines for future couples-based clinical trials in HIV/STD risk reduction and can be generalized to other couples-based behavioral interventions.

Time from HIV seroconversion to death: a collaborative analysis of eight studies in six low and middle-income countries before highly active antiretroviral therapy

OBJECTIVES

To estimate survival patterns after HIV infection in adults in low and middle-income countries.

DESIGN

An analysis of pooled data from eight different studies in six countries.

METHODS

HIV seroconverters were included from eight studies (three population-based, two occupational, and three clinic cohorts) if they were at least 15 years of age, and had no more than 4 years between the last HIV-negative and subsequent HIV-positive test. Four strata were defined: East African cohorts; South African miners cohort; Thai cohorts; Haitian clinic cohort. Kaplan-Meier functions were used to estimate survival patterns, and Weibull distributions were used to model and extend survival estimates. Analyses examined the effect of site, age, and sex on survival.

RESULTS

From 3823 eligible seroconverters, 1079 deaths were observed in 19 671 person-years of follow-up. Survival times varied by age and by study site. Adjusting to age 25-29 years at seroconversion, the median survival was longer in South African miners: 11.6 years [95% confidence interval (CI) 9.8-13.7] and East African cohorts: 11.1 years (95% CI 8.7-14.2) than in Haiti: 8.3 years (95% CI 3.2-21.4) and Thailand: 7.5 years (95% CI 5.4-10.4). Survival was similar for men and women, after adjustment for age at seroconversion and site.

CONCLUSION

Without antiretroviral therapy, overall survival after HIV infection in African cohorts was similar to survival in high-income countries, with a similar pattern of faster progression at older ages at seroconversion. Survival appears to be significantly worse in Thailand where other, unmeasured factors may affect progression.

Potential impact of antiretroviral chemoprophylaxis on HIV-1 transmission in resource-limited settings

Background

The potential impact of pre-exposure chemoprophylaxis (PrEP) on heterosexual transmission of HIV-1 infection in resource-limited settings is uncertain.

Methodology/Principle Findings

A deterministic mathematical model was used to simulate the effects of antiretroviral PrEP on an HIV-1 epidemic in sub-Saharan Africa under different scenarios (optimistic, neutral and pessimistic) both with and without sexual disinhibition. Sensitivity analyses were used to evaluate the effect of uncertainty in input parameters on model output and included calculation of partial rank correlations and standardized rank regressions. In the scenario without sexual disinhibition after PrEP initiation, key parameters influencing infections prevented were effectiveness of PrEP (partial rank correlation coefficient (PRCC) = 0.94), PrEP discontinuation rate (PRCC = −0.94), level of coverage (PRCC = 0.92), and time to achieve target coverage (PRCC = −0.82). In the scenario with sexual disinhibition, PrEP effectiveness and the extent of sexual disinhibition had the greatest impact on prevention. An optimistic scenario of PrEP with 90% effectiveness and 75% coverage of the general population predicted a 74% decline in cumulative HIV-1 infections after 10 years, and a 28.8% decline with PrEP targeted to the highest risk groups (16% of the population). Even with a 100% increase in at-risk behavior from sexual disinhibition, a beneficial effect (23.4%–62.7% decrease in infections) was seen with 90% effective PrEP across a broad range of coverage (25%–75%). Similar disinhibition led to a rise in infections with lower effectiveness of PrEP (≤50%).

Conclusions/Significance

Mathematical modeling supports the potential public health benefit of PrEP. Approximately 2.7 to 3.2 million new HIV-1 infections could be averted in southern sub-Saharan Africa over 10 years by targeting PrEP (having 90% effectiveness) to those at highest behavioral risk and by preventing sexual disinhibition. This benefit could be lost, however, by sexual disinhibition and by high PrEP discontinuation, especially with lower PrEP effectiveness (≤50%).

Coital bleeding and HIV risks among men and women in Cape Town, South Africa

BACKGROUND

South Africa has one of the world's fastest growing HIV epidemics. Genital bleeding during sexual intercourse may play a role in facilitating HIV transmission in South Africa.

PURPOSE

The purpose of this study was to examine the prevalence and sources of coital bleeding among men and women living in a Cape Town South Africa township.

METHODS

A purposive sample of 464 men and 531 women completed anonymous street intercept surveys of HIV risk history and sexual behaviors.

RESULTS

Thirty-one percent of men and 26% of women had a lifetime history of engaging in sexual intercourse that involved genital bleeding, and 21% of men and 16% of women reported coital bleeding in the previous 3 months. Over 75% of coital bleeding was attributed to menses. Across genders and controlling for demographic, sexual behavior, and life history factors, coital bleeding in the previous 3 months was associated with being an indigenous African, having multiple sexual partners, and higher rates of unprotected intercourse during that time period. People who reported coital bleeding were over 3 times more likely to have been diagnosed with a sexually transmitted infection even after controlling for having had genital ulcers.

CONCLUSIONS

Coital bleeding may be common in South Africa. Prevention messages that promote condom use or refraining from sex when there is genital bleeding are therefore needed.

STD treatment: how can it improve HIV prevention in the South?

BACKGROUND

Rates of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) and sexually transmitted diseases (STDs) are disproportionately high in the Southern United States. A high percentage of the population is black, and STD/HIV rates are particularly high among this group. Control and treatment of STDs offers promise as an HIV prevention strategy, and nowhere more than in the South.

OBJECTIVE

Identify those specific recommendations for control and treatment of STDs that available evidence indicates can reduce HIV transmission.

STUDY

Review of published literature.

RESULTS

Community trials produced inconsistent results but still suggest that STD treatment can reduce HIV transmission in the United States. Treatment of symptomatic STDs among those with HIV-infection should reduce HIV infectivity. There is as yet only limited evidence that STD treatment can reduce HIV susceptibility, although promising studies addressing herpes simplex virus are under way.

CONCLUSIONS

The unacceptably large racial disparities in STD rates must be addressed, symptomatic STDs among HIV-infected individuals treated, and syphilis prevention activities continued. Detection of unrecognized HIV infections among those seeking STD services should be a priority; identification of those with STDs and acute HIV infection may provide unique HIV prevention opportunities.

Understanding the reasons for decline of HIV prevalence in Haiti

OBJECTIVES

HIV sero-surveillance rounds and projection estimates suggest a decline of HIV prevalence among pregnant women and the general population in Haiti. This study aimed to evaluate the decline of HIV prevalence and understand the reasons for the decline.

METHODS

Following an epidemiological analysis, three mathematical models were used to re-create the national epidemic, calculate HIV incidence, and confirm the decline of HIV prevalence. Declining trends in prevalence data were compared with observed trends in behavioural data.

RESULTS

HIV progressed rapidly from initial infection to AIDS and death, with people dying twice as fast as in developed countries. With the rapid progression of the disease and the early intervention efforts in securing the blood supply, prevalence among commercial sex workers and blood donors peaked in the late 1980s followed by a decline in the mid-1990s in the general population. The observed decline among pregnant women and in the general population was confirmed after controlling for confounding variables. The Haitians are well informed: there is an increase in condom use with occasional partners at last contact and in abstinence and fidelity, and a decrease in the number of occasional partners. However, the age of sexual debut is lower and the proportion of sexually active youth has increased.

CONCLUSIONS

There is evidence of decline in HIV prevalence among pregnant women, specifically among pregnant women living in urban areas and pregnant women 25 years and older, but not among pregnant women living in rural areas and pregnant women 24 years and younger. Although many factors have acted in synergy to halt the AIDS epidemic in Haiti, the main reasons for decline seem to point to mortality and blood safety intervention efforts in the early stages of the epidemic.

Potential Impact of Antiretroviral Therapy on HIV-1 Transmission and AIDS Mortality in Resource-Limited Settings

OBJECTIVE

To estimate the potential impact of antiretroviral therapy on the heterosexual spread of HIV-1 infection and AIDS mortality in resource-limited settings.

METHODS

A mathematic model of HIV-1 disease progression and transmission was used to assess epidemiologic outcomes under different scenarios of antiretroviral therapy, including implementation of World Health Organization guidelines.

RESULTS

Implementing antiretroviral therapy at 5% HIV-1 prevalence and administering it to 100% of AIDS cases are predicted to decrease new HIV-1 infections and cumulative deaths from AIDS after 10 years by 11.2% (inter-quartile range [IQR]: 1.8%-21.4%) and 33.4% (IQR: 26%-42.8%), respectively. Later implementation of therapy at endemic equilibrium (40% prevalence) is predicted to be less effective, decreasing new HIV-1 infections and cumulative deaths from AIDS by 10.5% (IQR: 2.6%-19.3%) and 27.6% (IQR: 20.8%-36.8%), respectively. Therapy is predicted to benefit the infected individual and the uninfected community by decreasing transmission and AIDS deaths. The community benefit is greater than the individual benefit after 25 years of treatment and increases with the proportion of AIDS cases treated.

CONCLUSIONS

Antiretroviral therapy is predicted to have individual and public health benefits that increase with time and the proportion of infected persons treated. The impact of therapy is greater when introduced earlier in an epidemic, but the benefit can be lost by residual infectivity or disease progression on treatment and by sexual disinhibition of the general population.

High rates of syphilis among STI patients are contributing to the spread of HIV-1 in India

BACKGROUND

Recent syphilis outbreaks have raised concern regarding the potential enhancement of HIV transmission. The incidence of syphilis and its association with HIV-1 infection rates among a cohort of sexually transmitted infection (STI) clinic attendees was investigated.

METHODS

2732 HIV-1 seronegative patients attending three STI and one gynaecology clinic, were enrolled from 1993-2000 in an ongoing prospective cohort study of acute HIV-1 infection in Pune, India. At screening and quarterly follow up visits, participants underwent HIV-1 risk reduction counselling, risk behaviour assessment and HIV/STI screening that included testing for serological evidence of syphilis by RPR with TPHA confirmation. Patients with genital ulcers were screened with dark field microscopy.

RESULTS

Among 2324 participants who were HIV-1 and RPR seronegative at baseline, 172 participants were found to have clinical or laboratory evidence of syphilis during follow up (5.4 per 100 person years, 95% CI 4.8 to 6.5 per 100 person years). Independent predictors of syphilis acquisition based on a Cox proportional hazards model included age less than 20 years, lack of formal education, earlier calendar year of follow up, and recent HIV-1 infection. Based on a median follow up time of 11 months, the incidence of HIV-1 was 5.8 per 100 person years (95% CI 5.0 to 6.6 per 100 person years). Using a Cox proportional hazards model to adjust for known HIV risk factors, the adjusted hazard ratio of HIV-1 infection associated with incident syphilis was 4.44 (95% CI 2.96 to 6.65; p<0.001).

CONCLUSIONS

A high incidence rate of syphilis was observed among STI clinic attendees. The elevated risk of HIV-1 infection that was observed among participants with incident syphilis supports the hypothesis that syphilis enhances the sexual transmission of HIV-1 and highlights the importance of early diagnosis and treatment of syphilis.

Cost-effectiveness of environmental-structural communication interventions for HIV prevention in the female sex industry in the Dominican Republic

Behavior change communication often focuses on individual-level variables such as knowledge, perceived risk, self-efficacy, and behavior. A growing body of evidence suggests, however, that structural interventions to change the policy environment and environmental interventions designed to modify the physical and social environment further bolster impact. Little is known about the cost-effectiveness of such comprehensive intervention programs. In this study we use standard cost analysis methods to examine the incremental cost-effectiveness of two such interventions conducted in the Dominican Republic in sex establishments. In Santo Domingo the intervention was environmental; in Puerto Plata it was both environmental and structural (levying financial sanctions on sex establishment owners who failed to follow the intervention). The interventions in both sites included elements found in more conventional behavior change communication (BCC) programs (e.g., community mobilization, peer education, educational materials, promotional stickers). One key aim was to examine whether the addition of policy regulation was cost-effective. Data for the analysis were gleaned from structured behavioral questionnaires administered to female sex workers and their male regular paying partners in 41 sex establishments conducted pre- and post-intervention (1 year follow-up); data from HIV sentinel surveillance, STI screening results conducted for the intervention; and detailed cost data we collected. We estimated the number of HIV infections averted from each of the two intervention models and converted these estimates to the number of disability life years saved as compared with no intervention. One-way, two-way, three-way, and multivariate sensitivity analysis were conducted on model parameters. We examine a discount rate of 0%, 3% (base case), and 6% for future costs and benefits. The intervention conducted in Santo Domingo (community mobilization, promotional media, and interpersonal communication) was estimated to avert 64 HIV infections per 10,000 clients reached, and resulted in a cost per disability-adjusted life year (DALY) saved of $1,186. In Puerto Plata a policy/regulatory intervention was added, which resulted in 162 HIV infections averted per 10,000 clients reached, and yielded a cost per DALY saved of $457. Cost-effectiveness estimates were most correlated to the discount rate used and base rates of sexually transmitted infection (which affects the HIV transmission rate). Both intervention models resulted in cost-effective outcomes; however, the intervention that included policy regulation resulted in a substantially more cost-effective outcome.

Metaanalysis and metaregression in interpreting study variability in the impact of sexually transmitted diseases on susceptibility to HIV infection

BACKGROUND

Observational studies examining the effects of other sexually transmitted diseases (STDs) on HIV susceptibility differ in the populations observed and in which "other STDs" are examined. The extent to which an STD alters the risk of transmission of HIV may vary according to disease and population characteristics.

GOALS

The goals of this study were to review studies examining the effect of other STDs on HIV-1 susceptibility and to correlate their effect estimates with type of "other STD", study design, and population characteristics.

STUDY

Relevant studies with longitudinal design were identified through a systematic search of the PubMed database, and their evidence was critically evaluated. Metaregression techniques were then used to correlate study characteristics with corresponding effect estimates.

RESULTS

Of 31 studies included, 4 contained direct data on exposure to HIV-1. Three of these were inconclusive, the fourth indicating a strong relationship between STDs and transmission of HIV. Pooled effect estimates using all studies are statistically significant and indicate a 2- to 3-fold increase in risk of HIV-1 acquisition. Effect estimates corresponding some of the "other STD" categories exhibit heterogeneity, but no significant associations with study characteristics were found.

CONCLUSIONS

Most of the studies lack direct exposure data, lending them susceptible to exposure bias. Another problem may be measurement error about risk factors and STD status at time of HIV-1 infection. Because direct exposure data are difficult to come by (4 of 31 studies contained such data, all but 1 inconclusive), future observational studies on the influence of STDs on HIV-1 transmission should include quantitative analyses of the sensitivity of results to potential confounding and measurement error if they are to further understanding.

Trichomonas vaginalis-induced epithelial monolayer disruption and human immunodeficiency virus type 1 (HIV-1) replication: implications for the sexual transmission of HIV-1

The objective of this study was to evaluate potential mechanisms of Trichomonas vaginalis involvement in human immunodeficiency virus type 1 (HIV-1) transmission. Polarized monolayer integrity of primary cervical and prostate epithelial cells or cell lines cultured with T. vaginalis was measured by monitoring transepithelium resistance. The effect of T. vaginalis isolates on HIV-1 passage through polarized epithelial cell monolayers was evaluated for HIV-1 p24gag in the basolateral supernatants. Coincubation with T. vaginalis isolates induced disruption of monolayer integrity and resulted in passage of virus to the basolateral side of the monolayer. Furthermore, there was isolate variability in which two isolates induced greater monolayer damage and increased HIV-1 passage than did the other two isolates. Coincubation of T. vaginalis isolates with acutely HIV-1-infected peripheral blood mononuclear cells enhanced HIV-1 replication. This enhancement was associated with cellular proliferation and activation, as well as with tumor necrosis factor alpha production. In contrast to the monolayer disruption, the effect of T. vaginalis on HIV-1 replication was not isolate dependent. Thus, two mechanisms have been identified that could contribute to the epidemiologic association of trichomoniasis with the sexual transmission of HIV-1. (i) T. vaginalis disruption of urogenital epithelial monolayers could facilitate passage of HIV-1 to underlying layers. (ii) Activation of local immune cells by T. vaginalis in the presence of infectious HIV-1 might lead to increased viral replication. Collectively, these data suggest the need for more vigilant efforts in the diagnosis and treatment of T. vaginalis in women and men, especially in countries with a high prevalence of HIV-1.

Factors associated with forced sex among women accessing health services in rural Haiti: implications for the prevention of HIV infection and other sexually transmitted diseases

The goals of the current study were to: (1) estimate the prevalence of forced sex among women accessing services at a women's health clinic in rural Haiti; and (2) examine factors associated with forced sex in this population. Based on data from a case-control study of risk factors for sexually transmitted diseases (STDs), a cross-sectional analysis to examine factors associated with forced sex was performed. A number of factors related to gender inequality/socioeconomic vulnerability placed women in rural Haiti at higher risk of forced sex. The strongest factors associated with forced sex in multivariate analyses were: age, length of time in a relationship, occupation of the woman's partner, STD-related symptoms, and factors demonstrating economic vulnerability. The findings suggest that prevention efforts must go beyond provision of information and education to the pursuit of broader initiatives at both local and national levels. At the community level, policy-makers should consider advancing economic opportunities for women who are vulnerable to forced sex. Improving access to community-based income-generating activities may begin to address this problem. However, the viability of these local projects depends largely upon Haiti's 'macro-economic' situation. In order to ensure the success of local initiatives, external humanitarian and development assistance to Haiti should be supported. By broadening the definition of "prevention" interventions, we may begin to address the systemic problems that contribute to the occurrence of forced sex and the increasing incidence of HIV infection throughout the world, such as gender inequality and economic vulnerability. Taking into account factors influencing risk at the local level as well as the macro-level will potentially improve our capacity to reduce the risk of forced sex and the spread of STDs, including HIV infection, for millions of women living in poverty worldwide.

Cost-effectiveness of screening for HIV in the era of highly active antiretroviral therapy

BACKGROUND

The costs, benefits, and cost-effectiveness of screening for human immunodeficiency virus (HIV) in health care settings during the era of highly active antiretroviral therapy (HAART) have not been determined.

METHODS

We developed a Markov model of costs, quality of life, and survival associated with an HIV-screening program as compared with current practice. In both strategies, symptomatic patients were identified through symptom-based case finding. Identified patients started treatment when their CD4 count dropped to 350 cells per cubic millimeter. Disease progression was defined on the basis of CD4 levels and viral load. The likelihood of sexual transmission was based on viral load, knowledge of HIV status, and efficacy of counseling.

RESULTS

Given a 1 percent prevalence of unidentified HIV infection, screening increased life expectancy by 5.48 days, or 4.70 quality-adjusted days, at an estimated cost of 194 dollars per screened patient, for a cost-effectiveness ratio of 15,078 dollars per quality-adjusted life-year. Screening cost less than 50,000 dollars per quality-adjusted life-year if the prevalence of unidentified HIV infection exceeded 0.05 percent. Excluding HIV transmission, the cost-effectiveness of screening was 41,736 dollars per quality-adjusted life-year. Screening every five years, as compared with a one-time screening program, cost 57,138 dollars per quality-adjusted life-year, but was more attractive in settings with a high incidence of infection. Our results were sensitive to the efficacy of behavior modification, the benefit of early identification and therapy, and the prevalence and incidence of HIV infection.

CONCLUSIONS

The cost-effectiveness of routine HIV screening in health care settings, even in relatively low-prevalence populations, is similar to that of commonly accepted interventions, and such programs should be expanded.

[Interventions for HIV/STD prevention in Latin America and the Caribbean: a review of the regional experience]

The HIV/AIDS epidemic has completed its second decade in Latin America and the Caribbean, the latter being the second most heavily affected region in the world. In UNGASS (2001), governments renewed their commitment to confront the epidemic with adequate prevention and care. This review begins by characterizing the regional epidemic as concentrated on vulnerable groups (except for certain areas of generalization). Subsequently, we summarize the prevention work with each target group and contrast it with the epidemiological profile, concluding that the epidemic was not addressed in either timely or sufficient fashion in vulnerable groups, all of which are linked to other population groups. We also point out conditions that could foster greater impact by prevention strategies and analyze ways by which prevention activities could be better integrated with impact/reduction measures. Finally, we analyze the available information on expenditures in prevention.

Notification of positive HIV test results in Haiti: can we better intervene at this critical crossroads in the life of HIV-infected patients in a resource-poor country?

The current study was conducted in Port au Prince, Haiti, to determine if information collected at HIV notification during voluntary counseling and testing (VCT) can predict patients' future adherence with risk reduction counseling and medical referral. Case histories describe HIV-infected patients with signs of depression during counseling who do not return for medical care, and women afraid of economic ruin and domestic violence who do not notify their sexual partners. Quantitative predictors of seeking medical care include: denial at the announcement of HIV test results (odds ratio [OR] 0.3, 95% confidence interval [CI] 0.1-0.6), belief that HIV can be transmitted by magic (OR 0.6, 95% CI 0.3-0.9), and having symptoms at the time of HIV testing (OR 1.9, 95% CI 1.6-2.3). Predictors of refusal to notify sexual partner of HIV status include: being poor (OR 1.8, 95% CI 1.1-2.5), female (OR 2.1, 95% CI 1.7-2.5), and belief that HIV can be transmitted by magic (OR 2.3, 95% CI 1.9-2.6) In conclusion, information collected during HIV counseling and testing can predict patients' future adherence with counseling and medical referral. Counselors can use information such as signs of severe depression, economic hardship, and denial of HIV disease to identify patients at risk for nonadherence and to provide them with specialized counseling and care.