Type of partnership and heterosexual spread of HIV infection in rural Uganda: results from simulation modelling

HIV Risk Perceptions, the Transition to Marriage, and Divorce in Southern Malawi

Little is known about whether the timing of marriage is used as a strategy to avoid HIV infection among young people in sub-Saharan Africa. Analyzing five rounds of longitudinal data from the Malawi Schooling and Adolescent Survey, we do not find support for the hypothesis that young women's perceived chances of future HIV infection are associated with the transition to marriage, but we do find evidence that young married women who see themselves as at risk of future infection have a greater likelihood of divorcing than do women who perceive no chance of future infection. We also use individual-level fixed-effects regressions to examine how the transition to marriage affects respondents' expectations of future HIV infection. Respondents are consistently more likely to perceive any chance of future HIV infection in the years following marriage than in the years preceding it. Our findings suggest that young women revise their risk perceptions based on their marital experiences and that divorce may serve as a protective strategy for young married women concerned about their chance of future HIV infection.

The rise and fall of HIV in high-prevalence countries: a challenge for mathematical modeling

Several countries with generalized, high-prevalence HIV epidemics, mostly in sub-Saharan Africa, have experienced rapid declines in transmission. These HIV epidemics, often with rapid onsets, have generally been attributed to a combination of factors related to high-risk sexual behavior. The subsequent declines in these countries began prior to widespread therapy or implementation of any other major biomedical prevention. This change has been construed as evidence of behavior change, often on the basis of mathematical models, but direct evidence for behavior changes that would explain these declines is limited. Here, we look at the structure of current models and argue that the common “fixed risk per sexual contact" assumption favors the conclusion of substantial behavior changes. We argue that this assumption ignores reported non-linearities between exposure and risk. Taking this into account, we propose that some of the decline in HIV transmission may be part of the natural dynamics of the epidemic, and that several factors that have traditionally been ignored by modelers for lack of precise quantitative estimates may well hold the key to understanding epidemiologic trends.

HIV sexual transmission is predominantly driven by single individuals rather than discordant couples: a model-based approach

Understanding the relative contribution to HIV transmission from different social groups is important for public-health policy. Information about the importance of stable serodiscordant couples (when one partner is infected but not the other) relative to contacts outside of stable partnerships in spreading disease can aid in designing and targeting interventions. However, the overall importance of within-couple transmission, and the determinants and correlates of this importance, are not well understood. Here, we explore how mechanistic factors – like partnership dynamics and rates of extra-couple transmission – affect various routes of transmission, using a compartmental model with parameters based on estimates from Sub-Saharan Africa. Under our assumptions, when sampling model parameters within a realistic range, we find that infection of uncoupled individuals is usually the predominant route (median 0.62, 2.5%–97.5% quantiles: 0.26–0.88), while transmission within discordant couples is usually important, but rarely represents the majority of transmissions (median 0.33, 2.5%–97.5% quantiles: 0.10–0.67). We find a strong correlation between long-term HIV prevalence and the contact rate of uncoupled individuals, implying that this rate may be a key driver of HIV prevalence. For a given level of prevalence, we find a negative correlation between the proportion of discordant couples and the within-couple transmission rate, indicating that low discordance in a population may reflect a relatively high rate of within-couple transmission. Transmission within or outside couples and among uncoupled individuals are all likely to be important in sustaining heterosexual HIV transmission in Sub-Saharan Africa. Hence, intervention policies should be broadly targeted when practical.

Incident HSV-2 infections are common among HIV-1-discordant couples

BACKGROUND

The synergy between herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus type 1 (HIV-1) is well known, but lack of knowledge about the epidemiology of HSV-2 acquisition in HIV-1-discordant couples hampers development of HSV-2 prevention interventions that could reduce HIV-1 transmission.

METHODS

HIV-1-discordant couples were enrolled in Nairobi, Kenya, and followed for up to 2 years. HSV-2 status was determined using HerpeSelect HSV-2 ELISA. Correlates of prevalence and incidence were assessed. RESULTS.: Of 469 HIV-1-discordant couples, at baseline, 353 (75.3%) were affected by HSV-2, of which 189 (53.5%) were concordantly HSV-2 seropositive and 164 (46.5%) were HSV-2-discordant. Prevalence was lowest among HIV-1-uninfected men (39.9%) compared to HIV-1-infected women (64.8%), HIV-1-infected men (66.7%), and HIV-1-uninfected women (68.5%). During follow-up, HSV-2 seroincidence was 14.9 per 100 person-years. Incidence was 1.6-fold higher among females compared to males (95% confidence interval [CI], 1.00-2.48) and 2.5-fold higher in HIV-1-infected compared to uninfected women (95% CI, 1.12-5.74). At least 30% of incident HSV-2 infections originated from an outside partner.

CONCLUSIONS

The high HSV-2 prevalence and incidence in HIV-1-discordant couples in sub-Saharan Africa suggest HSV-2 treatment and prevention could be an effective targeted strategy to reduce HSV-2 and HIV-1 transmission in this high-risk population.

Prevalence of HIV and other sexually transmitted infections among female sex workers in Kisumu, Western Kenya, 1997 and 2008

Background

In 1997, a survey in Kisumu found a prevalence of HIV infection among female sex workers (FSW) of 75%. Only 50% reported using a condom with the last client. In 2008, we conducted another survey to collect data to inform an intervention targeting FSW in Kisumu.

Methods

In 2008 FSW were recruited by respondent-driven sampling. Women completed a questionnaire and were tested for HIV and other sexually transmitted infections (STIs). Multiple logistic regression analysis was done to explore factors associated with HIV-infection, and with condom use. Prevalence of HIV infection was compared in the two surveys from 1997 and 2008. Multivariate analysis was used to assess whether a change in HIV prevalence between the two surveys could be explained by changes in socio-demographic characteristics and/or behavioral factors.

Results

481 FSW participated in the 2008 study. HIV prevalence was 56.5% (95% CI 52.0–61.6). Factors independently associated with HIV were age older than 29 years; being a widow; STI treatment in the past year; herpes simplex virus Type-2 infection; bacterial vaginosis; and trichomoniasis. Condom use with last client was reported by 75.0% (95% CI 70.9–78.9). Predictors of condom use with the last client were age older than 29 years; higher price paid by last client; ever having been tested for HIV. Predictors of unprotected sex were being drunk during last sex act; usually having sex during menses; and STI treatment in the past year. The odds ratio of HIV infection associated with year of survey was 0.49 (95% CI 0.33–0.75) after adjusting for socio-demographic and behavioral factors.

Conclusions

The prevalence of HIV among FSW in Kisumu was found to be lower in 2008 than in 1997, while reported condom use was higher. However, access to HIV/STI prevention and care services needs to improve to further decrease HIV transmission between FSW and their clients.

Outside sexual partnerships and risk of HIV acquisition for HIV uninfected partners in African HIV serodiscordant partnerships

BACKGROUND

As African countries scale-up couples HIV testing, little is known about sexual behaviors and HIV risk for HIV-uninfected partners in known HIV-serodiscordant relationships.

METHODS

We conducted a prospective study of 3380 HIV-serodiscordant partnerships from 7 African countries. Self-reported sexual behavior data were collected quarterly from HIV-uninfected partners.

RESULTS

The proportion of HIV-uninfected partners reporting sex with their known primary HIV-infected partner decreased during follow-up (from 93.5% in the prior month at baseline to 73.2% at 24 months, P < 0.001). Simultaneously, an increasing proportion reported sex with an outside partner (from 3.1% to 13.9%, P < 0.001). A small proportion (<5%, stable throughout follow-up) reported sex with the infected partner and an outside partner in the same month (concurrent). Unprotected sex was more common with outside partners than with their primary known HIV-infected partners (risk ratio 4.6; 95% confidence interval: 4.2 to 5.2). HIV incidence was similar for those reporting sex only with their primary HIV-infected partner compared with those who reported an outside partner (2.87 vs. 3.02 per 100 person-years, P = 0.7), although those who had outside partners were more likely to acquire HIV that was virologically distinct from that of their primary partner (P < 0.001).

CONCLUSION

For uninfected members of HIV-serodiscordant couples, sex with the infected partner declined as sex with outside partners increased, likely reflecting relationship dissolution and risk shifting from a known infected partner. Risk-reduction messages for HIV-uninfected partners in serodiscordant partnerships should include strategies to reduce HIV acquisition from outside partners.

Human immunodeficiency virus, sexually transmitted infections, and risk behaviors among clients of sex workers in Guatemala: are they a bridge in human immunodeficiency virus transmission?

OBJECTIVES

Clients of female sex workers (FSWs) are an important target group for human immunodeficiency virus/sexually transmitted infection (HIV/STI) prevention. This study aimed to estimate their HIV and other STI prevalence, examine their risk behaviors, and evaluate their role as a bridge population in the spread of HIV/STIs.

METHODS

A cross-sectional study was performed among 553 clients recruited in commercial sex sites in the province of Escuintla, Guatemala. They were interviewed and tested for HIV and other STIs.

RESULTS

Half of the clients who were approached refused participation. Median age was 28.9 years; 57.7% had a regular partner, of whom, 10.1% had concurrent noncommercial partnerships. Consistent condom use with FSWs and regular partners was 72.5% and 17.1%, respectively. Approximately 18% formed a bridge, and 40.0% a potential bridge. Among those who provided samples (70.5% provided a blood sample and 89.7%, urine sample), prevalence of HIV, syphilis, gonorrhea, chlamydia, and herpes simplex virus 2 was 1.5%, 1.0%, 0.8%, 5.5%, and 3.4%, respectively. Unprotected sex with FSWs and drug use just before sex were risk factors for having any STI (9.8% of participants). Bridge clients were significantly less educated, more employed, paid lower prices to the FSW just visited, and had a previous STI.

CONCLUSIONS

There is a relatively high prevalence of HIV in clients compared to national estimates, and a substantial proportion of them act as a bridge for HIV/STI transmission between FSWs and the general population in Escuintla. Given that this is fuelling the current HIV epidemic, preventive interventions addressing this hard-to-reach group are urgently required.

Clients of street-based female sex workers and potential bridging of HIV/STI in Russia: results of a pilot study

In Russia, sexual transmission of HIV is increasing and street-based female sex workers (FSW) have a high HIV prevalence, but the role of male clients of FSW in HIV transmission and bridging to the general population has not been studied. Sixty-two male clients completed structured interviews during February-March of 2010 in St. Petersburg Russia. Descriptive analyses focused on condom use with different types of sex partners, substance use, and STI/HIV testing histories. The median lifetime and past 12 month numbers of FSW partners were 10 and 3, respectively. A majority of clients (74%) reported having non-FSW partners during the past 12 months, and nearly half (47%) reported having regular sex partners. Consistent condom use was reported in 61% of relationships with FSW partners and in 43% of relationships with non-FSW partners. A majority of clients (58%) was classified as active or potential bridgers based on having both FSW and non-FSW partners and reporting inconsistent condom use with their non-FSW partners. A majority (61%) also reported concurrent partnerships with FSW and non-FSW partners. Nearly half (48%) of last contacts with FSW partners involved consumption of alcohol by the client. Noninjection and injection drug use in the past 30 days were reported by 15% and 7% of clients, respectively. Twenty-nine percent reported history of a sexually transmitted infection (STI) and 74% reported a previous HIV test; active/potential bridgers were significantly less likely than unlikely bridgers to have ever been tested for HIV. These data signal the potential for HIV/STI transmission among male clients of street-based FSW in St. Petersburg Russia due to their variety of partner types, sub-optimal condom use, and concurrent partnerships. Larger studies are needed to confirm these findings, further explore the roles of alcohol and drug use, and identify effective strategies and interventions for HIV prevention.

HIV treatment as prevention: considerations in the design, conduct, and analysis of cluster randomized controlled trials of combination HIV prevention

The rigorous evaluation of the impact of combination HIV prevention packages at the population level will be critical for the future of HIV prevention. In this review, we discuss important considerations for the design and interpretation of cluster randomized controlled trials (C-RCTs) of combination prevention interventions. We focus on three large C-RCTs that will start soon and are designed to test the hypothesis that combination prevention packages, including expanded access to antiretroviral therapy, can substantially reduce HIV incidence. Using a general framework to integrate mathematical modelling analysis into the design, conduct, and analysis of C-RCTs will complement traditional statistical analyses and strengthen the evaluation of the interventions. Importantly, even with combination interventions, it may be challenging to substantially reduce HIV incidence over the 2- to 3-y duration of a C-RCT, unless interventions are scaled up rapidly and key populations are reached. Thus, we propose the innovative use of mathematical modelling to conduct interim analyses, when interim HIV incidence data are not available, to allow the ongoing trials to be modified or adapted to reduce the likelihood of inconclusive outcomes. The preplanned, interactive use of mathematical models during C-RCTs will also provide a valuable opportunity to validate and refine model projections.

Disclosure of HIV status between spouses in rural Malawi

Disclosure of HIV status after HIV voluntary counseling and testing has important implications for the spread of the HIV epidemic and the health of individuals who are HIV positive. Here, we use individual and couples level data for currently married respondents from an ongoing longitudinal study in rural Malawi to (1) examine the extent of HIV status disclosure by HIV serostatus; (2) identify reasons for not sharing one's HIV status with a spouse; and (3) evaluate the reliability of self-reports of HIV status disclosure. We find that disclosure of HIV status is relatively common among rural Malawians, where most have shared their status with a spouse, and many disclose to others in the community. However, there are significant differences in disclosure patterns by HIV status and gender. Factors associated with non-disclosure are also gendered, where women who perceive greater HIV/AIDS stigma and HIV positive are less likely to disclose HIV status to a spouse, and men who are worried about HIV infection from extramarital partners are less likely to disclose their HIV status to a spouse. Finally, we test the reliability of self-reported HIV status disclosure and find that self-reports of HIV-positive men are of questionable reliability.

HIV incidence and risk factors for acquisition in HIV discordant couples in Masaka, Uganda: an HIV vaccine preparedness study

Objectives

To determine the incidence of and risk factors for HIV acquisition in a cohort of HIV-uninfected partners from HIV discordant couples in Masaka, Uganda, and to establish its suitability for HIV vaccine trials.

Methods

HIV-uninfected adults living in HIV discordant couple relationships were enrolled and followed for 2 years. Interviews, medical investigations, HIV counseling and testing, syphilis and urine pregnancy (women) tests were performed at quarterly visits. Sexual risk behaviour data were collected every 6 months.

Results

495 participants were enrolled, of whom 34 seroconverted during 786.6 person-years of observation (PYO). The overall HIV incidence rate [95% confidence interval (CI)] was 4.3 [3.1–6]; and 4.3 [2.8–6.4] and 4.4 [2.5–8] per 100 PYO in men and women respectively. Independent baseline predictors for HIV acquisition were young age [18–24 (aRR = 4.1, 95% CI 1.6–10.8) and 25–34 (aRR = 2.7, 95% CI 1.2–5.8) years]; alcohol use (aRR = 2.6, 95% CI 1.1–6); and reported genital discharge (aRR = 3.4, 95% CI 1.6–7.2) in the past year. Condom use frequency in the year preceding enrolment was predictive of a reduced risk of HIV acquisition [sometimes (aRR = 0.4, 95% CI 0.2–0.8); always (aRR = 0.1, 95% CI 0.02–0.9)]. In the follow-up risk analysis, young age [18–24 (aRR = 6.2, 95% CI 2.2–17.3) and 25-34 (aRR = 2.3, 95% CI 1.1–5.0) years], reported genital discharge (aRR = 2.5, 95% CI 1.1–5.5), serological syphilis (aRR 3.2, 95% CI 1.3–7.7) and the partner being ART naïve (aRR = 4.8, 95% CI 1.4–16.0) were independently associated with HIV acquisition. There were no seroconversions among participants who reported consistent condom use during the study.

Conclusions

The study has identified important risk factors for HIV acquisition among HIV discordant couples. HIV-uninfected partners in discordant couples may be a suitable population for HIV vaccine efficacy trials. However, recent confirmation that ART reduces heterosexual HIV transmission may make it unfeasible to conduct HIV prevention trials in this population.

Study of HIV-1 subtypes in serodiscordant couples attending an integrated counselling and testing centre in Mumbai using heteroduplex mobility analysis and DNA sequencing

AIMS

To determine the prevalent subtypes of HIV-1 in serodiscordant couples.

SETTING

Integrated Counselling and Testing Centre (ICTC), Department of Microbiology.

STUDY DESIGN

Prospective pilot study.

PARTICIPANTS

Thirty HIV-1 serodiscordant couples.

INCLUSION CRITERIA

a) Documentation of HIV-1 infection in one partner and seronegative status in the other, current history of continued unprotected sexual activity within the partnership, demonstration that they have been in a partnership for at least 1 year and are not currently on highly active antiretroviral therapy HAART; b) willingness of both partners to provide written informed consent including consent to continued couple counselling for 3 months.

MATERIALS AND METHODS

HIV-1 subtyping was carried out by heteroduplex mobility analysis (HMA) by amplifying env region; and DNA sequencing by amplifying gag region.

RESULTS

HIV-1 env gene was amplified successfully in 10/30 samples; gag gene, in 25/30 samples; and both env and gag gene were amplified successfully in 5/30 samples. HIV-1 subtype C was detected from 21 samples; subtype B, from 7; and subtype A, from 2. Sample from 1 positive partner was detected as subtype C by env HMA and subtype B by gag sequencing.

CONCLUSION

HIV-1 subtype C was found to be the predominant subtype of HIV-1 in serodiscordant couples attending our ICTC, followed by HIV-1 subtype B and HIV-1 subtype A, respectively. DNA sequencing was found to be the most reliable method for determining the subtypes of HIV-1.

The role of the natural epidemic dynamics and migration in explaining the course of the HIV epidemic in rural Uganda: a modelling study

BACKGROUND

Human immunodeficiency virus (HIV) prevalence in Uganda fell during the 1990s and has risen since 2000. The changing trends since 2000 may be due to changing risky sexual behaviour, but other factors may also contribute. We explore the possible impact that two factors may have on cohort trends: natural epidemic dynamics and local migration. We simultaneously fit a mathematical model to the contrasting prevalence trends by age/gender in a southwest Ugandan cohort, which has never been done before.

METHODS

We fit a model to HIV trends, by age groups and gender, assuming: (i) neither migration nor intentional behaviour change, (ii) migration changes, (iii) intentional behaviour changes and (iv) both change. The model fits were assessed through sum of squares goodness of fits. We also explored the impact of the natural course of the epidemic on average partner acquisition rates, under the condition of no intentional behaviour change over time.

RESULTS

Without allowing intentional change in partner acquisition rates, an excellent fit was achievable to prevalence trends by gender. However, all of the contrasting trends by age/gender could not be replicated simultaneously. Adding intentional behaviour change improved the fit to some groups, but not all. Adding both intentional behaviour change and migration further improved the fit.

CONCLUSIONS

While some of the increasing HIV prevalence in Uganda since 2000 may be due to increased risky behaviour, some of the observed epidemiologic trends would likely occur without any intentional change in behaviour. Average population-level behaviour can change due to preferential mortality among higher risk takers, without individuals changing their behaviour.

High uptake of home-based, district-wide, HIV counseling and testing in Uganda

More than 80% of the people infected with HIV in low-income countries of sub-Saharan Africa do not know their HIV serostatus. Innovative measures of increasing access to HIV counseling and testing (HCT) are urgently needed so as to improve care and prevention. We implemented a home-based HCT program in Bushenyi District from September 2004 to March 2007, in Uganda where approximately 90% of people aged older than 14 years had never tested for HIV to gauge whether it was acceptable and increased uptake of HCT. Twenty-nine teams comprising a counselor and a laboratory assistant systematically visited homes offering HCT for all people older than 14 years of age and at-risk children (mother deceased or HIV infected) using a rapid HIV testing three-test algorithm. HIV-infected people received cotrimoxazole prophylaxis, were supplied with long-lasting insecticide-treated bed nets and equipment for treatment of drinking water at home, and were referred for assessment for antiretroviral therapy. The program reached 92,984 (63%) of all the homes in the district. Of these, 32,3621 people were eligible for HCT, and 28,2857 (87%) were present at home and were offered pretest counseling. A total of 264,966 (94%) accepted testing and received their results, of whom 11,359 (4.3%) were HIV-infected. Ninety percent of those testing had never tested before. The cost of testing was $7.83 per previously untested client. Ninety-seven percent of HIV-infected people initiated cotrimoxazole prophylaxis, 74% received bed nets, 70% received water treatment equipment, and 11% began antiretroviral therapy. Forty-four percent of people who were in an HIV-discordant relationship were infected. These results demonstrate that home-based HCT was well-accepted, feasible, and effective in identifying HIV-infected individuals who did not know their HIV status in rural Uganda.

Perceptions of couple HIV counseling and testing in Botswana: a stakeholder analysis

OBJECTIVE

To explore stakeholder's perceptions of Couples HIV Counseling and Testing (CHCT) as opposed to individual testing and potential couples' preferences for CHCT promotion and service provision.

METHODS

Study was conducted as formative research for a phase III clinical trial of Herpes (HSV-2) suppression to prevent HIV transmission among HIV discordant couples. We used non-probability purposive sampling and snowballing techniques to identify study participants. Data were collected using key informant interviews and focus group discussions. Systematic textual data analysis was used. Two independent coders coded and compared their codes for agreement. Data was categorized by emerging themes.

RESULTS

The general themes from both key informant interviews and focus group discussions were a preference for CHCT as opposed to individual counseling in HIV prevention and the need for a client-centered approach to promotion and provision of couple HIV testing services.

CONCLUSION

CHCT is important in HIV prevention and should be integrated in existing HIV testing programs. The study also demonstrates the challenges of HIV status disclosure and discordance among sexual partners who test as individuals.

PRACTICE IMPLICATIONS

Current low HIV status disclosure rates imply that reducing HIV incidence rates will require integrating CHCT into current testing programs. Increasing CHCT uptake however, requires improving access, training providers and addressing social, cultural, political and logistical barriers.

HIV risk among currently married couples in rural Malawi: what do spouses know about each other?

In countries with generalized HIV/AIDS epidemics, married couples have a shared risk of acquiring HIV/AIDS. Yet very little research has adopted a couple-level perspective to investigate perceived risk of HIV infection. In this paper, we used population-based data from 768 married monogamous couples in the 2004 Malawi Diffusion and Ideational Change Project (MDICP) to compare respondents' perceptions about their spouses' HIV status to their spouses' actual HIV status. Using chi-squared and Kappa coefficient statistics, we evaluated how accurately respondents assess their spouse's HIV status, and compared the assessment of their spouse's HIV status with their assessment of their own serostatus. We found that individuals tend to overestimate their spouse's as well as their own risk of having HIV. Husbands were generally more accurate in assessing their own risk of HIV infection than that of their wives, but wives were more accurate in assessing the HIV status of their spouses. In our multivariate logistic regression results, we found that marital infidelity is the most important correlate of overestimating individual and spousal HIV risk.

Sexually transmitted infections among HIV-1-discordant couples

Introduction

More new HIV-1 infections occur within stable HIV-1-discordant couples than in any other group in Africa, and sexually transmitted infections (STIs) may increase transmission risk among discordant couples, accounting for a large proportion of new HIV-1 infections. Understanding correlates of STIs among discordant couples will aid in optimizing interventions to prevent HIV-1 transmission in these couples.

Methods

HIV-1-discordant couples in which HIV-1-infected partners were HSV-2-seropositive were tested for syphilis, chlamydia, gonorrhea, and trichomoniasis, and HIV-1-uninfected partners were tested for HSV-2. We assessed sociodemographic, behavioral, and biological correlates of a current STI.

Results

Of 416 couples enrolled, 16% were affected by a treatable STI, and among these both partners were infected in 17% of couples. A treatable STI was found in 46 (11%) females and 30 (7%) males. The most prevalent infections were trichomoniasis (5.9%) and syphilis (2.6%). Participants were 5.9-fold more likely to have an STI if their partner had an STI (P<0.01), and STIs were more common among those reporting any unprotected sex (OR = 2.43; P<0.01) and those with low education (OR = 3.00; P<0.01). Among HIV-1-uninfected participants with an HSV-2-seropositive partner, females were significantly more likely to be HSV-2-seropositive than males (78% versus 50%, P<0.01).

Conclusions

Treatable STIs were common among HIV-1-discordant couples and the majority of couples affected by an STI were discordant for the STI, with relatively high HSV-2 discordance. Awareness of STI correlates and treatment of both partners may reduce HIV-1 transmission.

Trial Registration

ClinicalTrials.gov NCT00194519

The costs and effectiveness of four HIV counseling and testing strategies in Uganda

OBJECTIVE

HIV counseling and testing (HCT) is a key intervention for HIV/AIDS control, and new strategies have been developed for expanding coverage in developing countries. We compared costs and outcomes of four HCT strategies in Uganda.

DESIGN

A retrospective cohort of 84 323 individuals received HCT at one of four Ugandan HCT programs between June 2003 and September 2005. HCT strategies assessed were stand-alone HCT; hospital-based HCT; household-member HCT; and door-to-door HCT.

METHODS

We collected data on client volume, demographics, prior testing and HIV diagnosis from project monitoring systems, and cost data from project accounts and personnel interviews. Strategies were compared in terms of costs and effectiveness at reaching key population groups.

RESULTS

Household-member and door-to-door HCT strategies reached the largest proportion of previously untested individuals (>90% of all clients). Hospital-based HCT diagnosed the greatest proportion of HIV-infected individuals (27% prevalence), followed by stand-alone HCT (19%). Household-member HCT identified the highest percentage of discordant couples; however, this was a small fraction of total clients (<4%). Costs per client (2007 USD) were $19.26 for stand-alone HCT, $11.68 for hospital-based HCT, $13.85 for household-member HCT, and $8.29 for door-to-door-HCT.

CONCLUSION

All testing strategies had relatively low per client costs. Hospital-based HCT most readily identified HIV-infected individuals eligible for treatment, whereas home-based strategies more efficiently reached populations with low rates of prior testing and HIV-infected people with higher CD4 cell counts. Multiple HCT strategies with different costs and efficiencies can be used to meet the UNAIDS/WHO call for universal HCT access by 2010.

Overestimating HIV infection: The construction and accuracy of subjective probabilities of HIV infection in rural Malawi

In the absence of HIV testing, how do rural Malawians assess their HIV status? In this paper, we use a unique dataset that includes respondents' HIV status as well as their subjective likelihood of HIV infection. These data show that many rural Malawians overestimate their likelihood of current HIV infection. The discrepancy between actual and perceived status raises an important question: Why are so many wrong? We begin by identifying determinants of self-assessed HIV status, and then compare these assessments with HIV biomarker results. Finally, we ask what characteristics of individuals are associated with errors in self-assessments.

Probability of HIV transmission during acute infection in Rakai, Uganda

Accurate estimates of the probability of HIV transmission during various stages of infection are needed to inform epidemiological models. Very limited information is available about the probability of transmission during acute HIV infection. We conducted a secondary analysis of published data from the Rakai, Uganda seroconversion study. Mathematical and computer-based models were used to quantify the per-act and per-partnership transmission probabilities during acute and chronic HIV infection, and to estimate how many of the transmission events reported in the Rakai study were due to acute-phase HIV transmission. The average per-act transmission probability during acute infection equaled 0.03604 vs. 0.00084 for chronic HIV infection. Overall, HIV was transmitted during acute infection in 46.5% of 23 "incident index partner couples." Acute-phase transmission accounted for 89.1% of all transmission events in the first 20 months of follow-up. These results highlight the substantial risk of transmission during acute HIV infection.

The importance of context: model projections on how microbicide impact could be affected by the underlying epidemiologic and behavioral situation in 2 African settings

OBJECTIVE

The objective of this study was to explore how a microbicide's HIV impact is affected by behavioral and epidemiologic factors in 2 African settings: Cotonou, Benin, and Hillbrow, South Africa.

METHODS

A mathematical model, fit to epidemiologic data from each setting, was used to estimate the HIV impact of introducing a microbicide with different HIV/sexually transmitted infection (STI) efficacies. Simulations were compared to explore how impact is affected by context.

RESULTS

Widespread microbicide use results in a greater relative reduction in HIV incidence in Cotonou, where HIV/STIs are less prevalent. Most infections averted are from commercial sex in Cotonou but noncommercial sex in Hillbrow. The microbicide's STI efficacy is important in determining its HIV impact in both settings, but especially in Cotonou where the microbicide's HIV impact was mainly the result of its STI efficacy.

CONCLUSIONS

It is important to develop and evaluate microbicides that are efficacious against STIs. However, even with the same patterns of use, a microbicide's impact and the importance of its STI efficacy will vary considerably between settings.

Living with discordance: knowledge, challenges, and prevention strategies of HIV-discordant couples in Uganda

Prevalence of HIV-discordance among couples in sub-Saharan Africa is high. Negative partners are at high risk of HIV infection but few HIV/AIDS service providers have developed effective counseling messages for HIV-discordant couples. To identify clients' explanations for discordance, challenges, and prevention strategies, 24 in-depth interviews and 4 focus group discussions were conducted with 32 female and 35 male members of HIV-discordant couples who sought HIV voluntary counseling and testing (VCT) in Uganda. In addition, counselor explanations for discordance were gathered from 62 counselor trainers during 3 interactive workshops. Misconceptions about discordance were widespread among clients and counselors. Common explanations included: the concept of a hidden infection not detectable by HIV tests, belief in immunity, the thought that gentle sex protected HIV-negative partners, and belief in protection by God. Such explanations for discordance reinforced denial of HIV risk for the negative partner within discordant couples and potentially increased transmission risk. Couples identified negotiation of sexual relations as their most formidable challenge. Prevention strategies included condom use, abstinence and separation of beds, contractual agreements for outside sexual partners, and relationship cessation. Discordant couples represent a critical risk group and improved counseling protocols that clearly explain discordance, emphasize high risk of transmission, and support risk reduction are urgently needed.

Male clients of brothel prostitutes as a bridge for HIV infection between high risk and low risk groups of women in Senegal

OBJECTIVE

To explore the extent to which male clients of prostitutes have a role as a bridge in the spread of HIV into the general population of Dakar, Senegal.

METHODS

A sexual behaviour HIV prevalence survey was carried out among clients of female prostitutes working in brothels recruited outside the prostitutes' rooms after the encounter. All men entering the house and leaving the women's rooms were asked to answer the questions and to donate saliva for HIV-1 and HIV-2 testing.

RESULTS

Findings suggest that a proportion of clients form a potential bridge for HIV transmission between prostitutes and partners from the general population. They have unprotected sexual contacts with both brothel prostitutes, and steady and casual partners, and expose both unmarried and married women to HIV infection. Findings also indicate that wives are more exposed to HIV than other categories of women in the population.

CONCLUSIONS

Clients of brothels' prostitutes have a significant potential for spreading HIV beyond the initial high risk behaviour groups in Senegal. Efforts should be provided to target specific groups at higher risk for HIV infection, such as young men from the densely populated working class neighbourhoods of Dakar, and women outside the commercial sex networks for HIV education and prevention.

Transactional sex is the driving force in the dynamics of HIV in Accra, Ghana

OBJECTIVE

To delineate the population attributable fraction (PAF) of transactional sex in prevalent cases of HIV infection in the male adult population of Accra, Ghana.

DESIGN AND METHODS

Cross-sectional study of clients who visited a sex worker (SW), of boyfriends of SW and of male personnel in prostitution venues. A questionnaire was administered and urine obtained for detection of anti-HIV antibodies. The PAF of prevalent HIV acquired from SW was calculated using a combination of data from this survey of clients, from on-going SW surveys, the national HIV surveillance system and the national census.

RESULTS

HIV prevalence was 4.9% (8/162) among clients of mobile SW, 15.8% (53/335) among clients of home-based SW, 17.5% (10/57) among personnel and 32.1% (9/28) among boyfriends. A condom was used in 90% of intercourses, according to clients. Non-use of a condom was clustered in selected locations and independently associated with older age of client, frequency of intercourse with SW in the last year and current urethritis. Among the male population of Accra aged 15-59 years, 84% of prevalent cases of HIV were attributable to transactional sex. A sensitivity analysis showed that under various assumptions PAF varied between 47% and 100%.

CONCLUSIONS

In Accra, approximately four-fifths of prevalent cases of HIV in adult males were acquired from SW. Comprehensive interventions providing education, condoms and treatment for sexually transmitted diseases for SW and their clients should be approached as other public health priorities and provided in all cities, large and small, of West Africa.

Prevalence of HIV and other sexually transmitted infections, and risk behaviours in unregistered sex workers in Dakar, Senegal

OBJECTIVES

To estimate the prevalence rates of HIV and other sexually transmitted infections (STI) among unregistered sex workers, and to describe their sociodemographic characteristics and sexual behaviours, and the reasons why they were not officially registered as sex workers, in order to design specific public health interventions.

METHODS

A one-stage cluster-sample survey was conducted in Dakar in 2000. Unregistered sex workers were interviewed in randomly selected establishments (official and clandestine bars, brothels and nightclubs), and blood, endocervical and vaginal samples were collected for laboratory diagnosis.

RESULTS

A total of 390 women with a median age of 29 years were recruited. One-seventh of them were under the legal age for prostitution in Senegal (21 years). The median length of prostitution was 24 months and 73.5% of the women stated regular prostitution. Three-quarters of the women were found to have markers for at least one infection. The prevalence rates were as follows: HIV-1, 6.0%; HIV-2, 3.6%; HIV-1+2, 0.4%; syphilis, 23.8%; gonorrhea, 22.0%; chlamydial infection, 20.0%; trichomoniasis, 22.4%; candidiasis, 19.0%; and bacterial vaginosis, 28.8%. The main reported reason for non-registration was ignorance of the legal system and its procedures (19.4%); 18.9% of the women refused to register. One-third of the women reported that their clients used condoms inconsistently or never.

CONCLUSION

This survey suggests that a multidimensional public health response is needed in Senegal, comprising legal information, downwards revision of the legal age for prostitution, and specific medical follow-up based on education, condom promotion and management of STI for non-registered sex workers.

Factors influencing acceptability of voluntary counselling and testing for HIV in Bushenyi district of Uganda

OBJECTIVE

To understand the factors influencing choice of voluntary counselling and testing (VCT) for HIV with a view of suggesting measures for increased uptake.

DESIGN

Focus group discussions were used to elicit reasons for carrying out VCT and a cross sectional survey to estimate the proportion of people who undertake VCT.

SETTING

Bushenyi district, Uganda.

PARTICIPANTS

A cluster random sample of 219 people and four purposively selected focus group discussions with 32 participants.

MAIN OUTCOME MEASURES

Elicited attitudinal beliefs, self-efficacy expectations, and social influences that are probably associated with VCT for HIV based on the Attitude Social influence self-Efficacy (ASE) Model. The proportion of people who had ever undertaken VCT for HIV was also determined.

RESULTS

Thirty-eight (17%) of the 219 people interviewed had ever undergone HIV. The factors influencing VCT for HIV were consequences of a test result, influences from a sexual partner, cost of VCT, physical accessibility of VCT, awareness, risk of HIV infection, need for linking VCT with care (especially availability of anti-retrovirals) and perceived quality of care of VCT services.

CONCLUSIONS

Increased mobilisation and access for VCT, reducing costs of VCT, linking of VCT with care, and emphasising the positive consequences of VCT as well as providing high quality VCT services may increase the number of people seeking VCT.

Commercial sex and the spread of HIV in four cities in sub-Saharan Africa

OBJECTIVE

To examine whether commercial sex transactions were more common and/or transmission between sex workers and clients more efficient in two African cities with high HIV prevalence (Kisumu, Kenya and Ndola, Zambia) compared with two with relatively low HIV prevalence (Cotonou, Benin and Yaoundé, Cameroon).

METHODS

Data on sexual behaviour, HIV and sexually transmitted infections were collected from representative samples of around 300 female sex workers in each city. Sexual behaviour data from a population-based study of around 1000 men aged 15-49 in each city were used to estimate the extent of contact with sex workers.

RESULTS

The number of sex workers per 1000 males was highest in Kisumu and Ndola, but other estimates of the extent or characteristics of sex work contact showed no consistent differences between high or low prevalence cities. HIV prevalence among sex workers was 75% in Kisumu, 69% in Ndola, 55% in Cotonou and 34% in Yaoundé. The prevalence of genital ulceration and trichomoniasis was higher among sex workers in Kisumu and Ndola but no clear pattern was seen for the other sexually transmitted infections. Around 70% of sex workers in Cotonou reported use of a condom with the last client, markedly higher than in the other cities.

CONCLUSIONS

Although sex work is likely to have played an important role in the spread of HIV in all four cities, differences in present patterns of sex work do not appear to explain the differential spread of HIV. However, high levels of condom use among sex workers may have slowed the spread from sex workers to the general population in Cotonou, highlighting the importance of interventions among sex workers and their clients.

Efficacy of patient-delivered partner medication in the treatment of sexual partners in Uganda

BACKGROUND

Patient-based partner referral (PBPR), which is the main method for treating sexual partners of patients with sexually transmitted diseases (STDs), has limited effectiveness.

GOAL

The authors compared the efficacy of PBPR with patient-delivered partner medication (PDPM) among patients attending the Mulago STD clinic in Kampala, Uganda.

STUDY DESIGN

A total of 383 patients (187 women, 196 men) with STDs were randomized to the PBPR or PDPM group. The proportion of sexual partners treated in either group was compared using the chi-square statistic by intention to treat for partners whose follow-up status was unknown.

RESULTS

The two groups had similar background characteristics. Of the 237 partners elicited, 176 (74%) were reported treated in the PDPM group. In the PBPR group, in which 234 partners were elicited, 79 (34%) were referred to the treatment clinic. This difference was statistically significant (risk ratio [RR], 2.44; 95% CI, 1.95-3.07; P < 0.001). Furthermore, PDPM was more effective than PBPR for women and for casual partners for whom PBPR is considered difficult. For women, 86 of 103 partners in the PDPM group were reported treated, compared with 23 of 104 partners in the PBPR group (RR, 4.55; 95% CI, 2.92-7.08; P < 0.001). For casual partners, 18 of 51 (34%) were reported treated in the PDPM group, compared with only three of 45 partners (7%) who were referred in the PBPR group (RR, 1.43; 95% CI, 1.40-2.65; P < 0.01).

CONCLUSION

Patient-delivered partner medication is more effective than patient-based partner referral in the treatment of sexual partners.