Ide Cremin

Voluntary counselling and testing: uptake, impact on sexual behaviour, and HIV incidence in a rural Zimbabwean cohort

Objectives:To examine the determinants of uptake of voluntary counselling and testing (VCT) services, to assess changes in sexual risk behaviour following VCT, and to compare HIV incidence amongst testers and non-testers. Methods:Prospective population-based cohort study of adult men and women in the Manicaland province of eastern Zimbabwe. Demographic, socioeconomic, sexual behaviour and VCT utilization data were collected at baseline (1998–2000) and follow-up (3 years later). HIV status was determined by HIV-1 antibody detection. In addition to services provided by the government and non-governmental organizations, a mobile VCT clinic was available at study sites. Results:Lifetime uptake of VCT increased from under 6% to 11% at follow-up. Age, increasing education and knowledge of HIV were associated with VCT uptake. Women who took a test were more likely to be HIV positive and to have greater HIV knowledge and fewer total lifetime partners. After controlling for demographic characteristics, sexual behaviour was not independently associated with VCT uptake. Women who tested positive reported increased consistent condom use in their regular partnerships. However, individuals who tested negative were more likely to adopt more risky behaviours in terms of numbers of partnerships in the last month, the last year and in concurrent partnerships. HIV incidence during follow-up did not differ between testers and non-testers. Conclusion:Motivation for VCT uptake was driven by knowledge and education rather than sexual risk. Increased sexual risk following receipt of a negative result may be a serious unintended consequence of VCT. It should be minimized with appropriate pre- and post-test counselling.

Maximising the effect of combination HIV prevention through prioritisation of the people and places in greatest need: a modelling study

BACKGROUND Epidemiological data show substantial variation in the risk of HIV infection between communities within African countries. We hypothesised that focusing appropriate interventions on geographies and key populations at high risk of HIV infection could improve the effect of investments in the HIV response. METHODS With use of Kenya as a case study, we developed a mathematical model that described the spatiotemporal evolution of the HIV epidemic and that incorporated the demographic, behavioural, and programmatic differences across subnational units. Modelled interventions (male circumcision, behaviour change communication, early antiretoviral therapy, and pre-exposure prophylaxis) could be provided to different population groups according to their risk behaviours or their location. For a given national budget, we compared the effect of a uniform intervention strategy, in which the same complement of interventions is provided across the country, with a focused strategy that tailors the set of interventions and amount of resources allocated to the local epidemiological conditions. FINDINGS A uniformly distributed combination of HIV prevention interventions could reduce the total number of new HIV infections by 40% during a 15-year period. With no additional spending, this effect could be increased by 14% during the 15 years-almost 100,000 extra infections, and result in 33% fewer new HIV infections occurring every year by the end of the period if the focused approach is used to tailor resource allocation to reflect patterns in local epidemiology. The cumulative difference in new infections during the 15-year projection period depends on total budget and costs of interventions, and could be as great as 150,000 (a cumulative difference as great as 22%) under different assumptions about the unit costs of intervention. INTERPRETATION The focused approach achieves greater effect than the uniform approach despite exactly the same investment. Through prioritisation of the people and locations at greatest risk of infection, and adaption of the interventions to reflect the local epidemiological context, the focused approach could substantially increase the efficiency and effectiveness of investments in HIV prevention. FUNDING The Bill & Melinda Gates Foundation and UNAIDS.

The new role of antiretrovirals in combination HIV prevention: a mathematical modelling analysis.

Background and objectives:Antiretroviral drugs can reduce HIV acquisition among uninfected individuals (as pre-exposure prophylaxis: PrEP) and reduce onward transmission among infected individuals (as antiretroviral treatment: ART). We estimate the potential impact and cost-effectiveness of antiretroviral-based HIV prevention strategies. Design and methods:We developed and analysed a mathematical model of a hyperendemic setting with relatively low levels of condom use. We estimated the prevention impact and cost of various PrEP interventions, assuming a fixed amount of spending on PrEP; investigated the optimal role of PrEP and earlier ART in terms of epidemiological impact and cost; and systematically explored the impact of earlier ART and PrEP, in combination with medical male circumcision services; on HIV transmission. Results:A PrEP intervention is unlikely to generate a large reduction in HIV incidence, unless the cost is substantially reduced. In terms of infections averted and quality adjusted life years gained, at a population-level maximal cost-effectiveness is achieved by providing ART to more infected individuals earlier rather than providing PrEP to uninfected individuals. However, early ART alone cannot reduce HIV incidence to very low levels and PrEP can be used cost-effectively in addition to earlier ART to reduce incidence further. If implemented in combination and at ambitious coverage levels, medical male circumcision, earlier ART and PrEP could produce dramatic declines in HIV incidence, but not stop transmission completely. Conclusion:A combination prevention approach based on proven-efficacy interventions provides the best opportunity for achieving the much hoped for prevention advance and curbing the spread of HIV.

Transformation of HIV from pandemic to low-endemic levels: a public health approach to combination prevention

Large declines in HIV incidence have been reported since 2001, and scientific advances in HIV prevention provide strong hope to reduce incidence further. Now is the time to replace the quest for so-called silver bullets with a public health approach to combination prevention that understands that risk is not evenly distributed and that effective interventions can vary by risk profile. Different countries have different microepidemics, with very different levels of transmission and risk groups, changing over time. Therefore, focus should be on high-transmission geographies, people at highest risk for HIV, and the package of interventions that are most likely to have the largest effect in each different microepidemic. Building on the backbone of behaviour change, condom use, and medical male circumcision, as well as expanded use of antiretroviral drugs for infected people and pre-exposure prophylaxis for uninfected people at high risk of infection, it is now possible to consider the prospect of what would be one of the most remarkable achievements in the history of public health: reduction of HIV transmission from a pandemic to low-level endemicity.

Distinct HIV discordancy patterns by epidemic size in stable sexual partnerships in sub-Saharan Africa

Objective To describe patterns of HIV infection among stable sexual partnerships across sub-Saharan Africa (SSA). Methods The authors defined measures of HIV discordancy and conducted a comprehensive quantitative assessment of discordancy among stable partnerships in 20 countries in SSA through an analysis of the Demographic and Health Survey data. Results HIV prevalence explained at least 50% of the variation in HIV discordancy, with two distinct patterns of discordancy emerging based on HIV prevalence being roughly smaller or larger than 10%. In low-prevalence countries, approximately 75% of partnerships affected by HIV are discordant, while only about half of these are discordant in high-prevalence countries. Out of each 10 HIV infected persons, two to five are engaged in discordant partnerships in low-prevalence countries compared with one to three in high-prevalence countries. Among every 100 partnerships in the population, one to nine are affected by HIV and zero to six are discordant in low-prevalence countries compared with 16–45 and 9–17, respectively, in high-prevalence countries. Finally, zero to four of every 100 sexually active adults are engaged in a discordant partnership in low-prevalence countries compared with six to eight in high-prevalence countries. Conclusions In high-prevalence countries, a large fraction of stable partnerships were affected by HIV and half were discordant, whereas in low-prevalence countries, fewer stable partnerships were affected by HIV but a higher proportion of them were discordant. The findings provide a global view of HIV infection among stable partnerships in SSA but imply complex considerations for rolling out prevention interventions targeting discordant partnerships.

Patterns of Self-reported Behaviour Change Associated with Receiving Voluntary Counselling and Testing in a Longitudinal Study from Manicaland, Zimbabwe

Voluntary counselling and testing (VCT) is promoted as a potential HIV prevention measure. We describe trends in uptake of VCT for HIV, and patterns of subsequent behaviour change associated with receiving VCT in a population-based open cohort in Manicaland, Zimbabwe. The relationship between receipt of VCT and subsequent reported behaviour was analysed using generalized linear models with random effects. At the third survey, 8.6% of participants (1,079/12,533), had previously received VCT. Women who received VCT, both those positive and negative, reduced their reported number of new partners. Among those testing positive, this risk reduction was enhanced with time since testing. Among men, no behavioural risk reduction associated with VCT was observed. Significant increases in consistent condom use, with regular or non-regular partners, following VCT, were not observed. This study suggests that, among women, particularly those who are infected, behavioural risk reduction does occur following VCT.

Patterns of uptake of HIV testing in sub‐Saharan Africa in the pre‐treatment era

Objectives  To compare nationally representative trends in self‐reported uptake of HIV testing and receipt of results in selected countries prior to treatment scale‐up.

Measuring trends in age at first sex and age at marriage in Manicaland, Zimbabwe

Objective: To identify reporting biases and to determine the influence of inconsistent reporting on observed trends in the timing of age at first sex and age at marriage. Methods: Longitudinal data from three rounds of a population-based cohort in eastern Zimbabwe were analysed. Reports of age at first sex and age at marriage from 6837 individuals attending multiple rounds were classified according to consistency. Survival analysis was used to identify trends in the timing of first sex and marriage. Results: In this population, women initiate sex and enter marriage at younger ages than men but spend much less time between first sex and marriage. Among those surveyed between 1998 and 2005, median ages at first sex and first marriage were 18.5 years and 21.4 years for men and 18.2 years and 18.5 years, respectively, for women aged 15–54 years. High levels of reports of both age at first sex and age at marriage among those attending multiple surveys were found to be unreliable. Excluding reports identified as unreliable from these analyses did not alter the observed trends in either age at first sex or age at marriage. Tracing birth cohorts as they aged revealed reporting biases, particularly among the youngest cohorts. Comparisons by birth cohorts, which span a period of >40 years, indicate that median age at first sex has remained constant over time for women but has declined gradually for men. Conclusions: Although many reports of age at first sex and age at marriage were found to be unreliable, inclusion of such reports did not result in artificial generation or suppression of trends.

Seasonal PrEP for partners of migrant miners in southern Mozambique: a highly focused PrEP intervention.

To be used most effectively, pre‐exposure prophylaxis (PrEP) should be prioritized to those at high risk of acquisition and would ideally be aligned with time periods of increased exposure. Identifying such time periods is not always straightforward, however. Gaza Province in southern Mozambique is characterized by high levels of HIV transmission and circular labour migration to mines in South Africa. A strong seasonal pattern in births is observable, reflecting an increase in conception in December. Given the potential for increased HIV transmission between miners returning in December and their partners in Gaza Province, PrEP use by the latter would be a useful means of HIV prevention, especially for couples who wish to conceive.

The role of testing and counselling for HIV prevention and care in the era of scaling-up antiretroviral therapy ☆

OBJECTIVE HIV Testing and Counselling (TC) programmes are being scaled-up as part of efforts to provide universal access to antiretroviral treatment (ART). METHODS AND FINDINGS Mathematical modelling of TC in Zimbabwe shows that if universal access is to be sustained, TC must include prevention counselling that enables behaviour change among infected and uninfected individuals. The predicted impact TC is modest, but improved programmes could generate substantial reductions in incidence, reducing need for ART in the long-term. CONCLUSIONS TC programmes that focus only on identifying those in need of treatment will not be sufficient to bring the epidemic under control.