Prevalent HSV-2 infection is associated with a three-fold increased risk of HIV acquisition among both men and women in the general population, suggesting that, in areas of high HSV-2 prevalence, a high proportion of HIV is attributable to HSV-2.

We conducted a systematic review and meta-analysis of observational studies of the risk of HIV-1 transmission per heterosexual contact. The search to September 2008 identified 43 publications based on 25 different study populations. Pooled female-to-male (0·0004,95%CI=0·0001-0·0014) and male-to-female (0·0008,CI=0·0006-0·0011) transmission estimates in developed countries reflected a low risk of infection in the absence of antiretrovirals. Developing country female-to-male (0·0038,CI=0·0013-0·0110) and male-to-female (0·0030,CI=0·0014-0·0063) estimates in absence of commercial sex(CS) work were higher. In meta-regression analysis, the infectivity across estimates in absence of CS work was significantly associated with gender, setting, the interaction between setting and gender and HIV prevalence. The pooled receptive anal intercourse estimate was much higher (0·017,CI=0·003-0·089). Estimates for the early and late phase of HIV infection were 9·2(CI=4·5-18·8) and 7·3(CI=4·5-11·9)-fold larger than for the asymptomatic phase, respectively. After adjusting for CS exposure, presence or history of genital ulcers in either couple member increased per-act infectivity 5·3(CI=1·4-19·5)-fold compared to no sexually transmitted infection. Study estimates among non-circumcised men were at least twice those among circumcised men. Developing country estimates were more heterogeneous than developed country estimates, which indicates poorer study quality, greater heterogeneity in risk factors or under-reporting of high-risk behaviour. Efforts are needed to better understand these differences and quantify infectivity in developing countries.

The methods are illustrated using two case studies: an unmatched trial of the impact of impregnated bednets on child mortality in Kenya, and a pair-matched trial of improved sexually-transmitted disease (STD) treatment services for HIV prevention in Tanzania.

BackgroundHome-based HIV testing and counselling (HTC) achieves high uptake, but is difficult and expensive to implement and sustain. We investigated a novel alternative based on HIV self-testing (HIVST). The aim was to evaluate the uptake of testing, accuracy, linkage into care, and health outcomes when highly convenient and flexible but supported access to HIVST kits was provided to a well-defined and closely monitored population.Methods and FindingsFollowing enumeration of 14 neighbourhoods in urban Blantyre, Malawi, trained resident volunteer-counsellors offered oral HIVST kits (OraQuick ADVANCE Rapid HIV-1/2 Antibody Test) to adult (≥16 y old) residents (n = 16,660) and reported community events, with all deaths investigated by verbal autopsy. Written and demonstrated instructions, pre- and post-test counselling, and facilitated HIV care assessment were provided, with a request to return kits and a self-completed questionnaire. Accuracy, residency, and a study-imposed requirement to limit HIVST to one test per year were monitored by home visits in a systematic quality assurance (QA) sample.Overall, 14,004 (crude uptake 83.8%, revised to 76.5% to account for population turnover) residents self-tested during months 1–12, with adolescents (16–19 y) most likely to test. 10,614/14,004 (75.8%) participants shared results with volunteer-counsellors. Of 1,257 (11.8%) HIV-positive participants, 26.0% were already on antiretroviral therapy, and 524 (linkage 56.3%) newly accessed care with a median CD4 count of 250 cells/μl (interquartile range 159–426). HIVST uptake in months 13–24 was more rapid (70.9% uptake by 6 mo), with fewer (7.3%, 95% CI 6.8%–7.8%) positive participants. Being “forced to test”, usually by a main partner, was reported by 2.9% (95% CI 2.6%–3.2%) of 10,017 questionnaire respondents in months 1–12, but satisfaction with HIVST (94.4%) remained high. No HIVST-related partner violence or suicides were reported. HIVST and repeat HTC results agreed in 1,639/1,649 systematically selected (1 in 20) QA participants (99.4%), giving a sensitivity of 93.6% (95% CI 88.2%–97.0%) and a specificity of 99.9% (95% CI 99.6%–100%). Key limitations included use of aggregate data to report uptake of HIVST and being unable to adjust for population turnover.ConclusionsCommunity-based HIVST achieved high coverage in two successive years and was safe, accurate, and acceptable. Proactive HIVST strategies, supported and monitored by communities, could substantially complement existing approaches to providing early HIV diagnosis and periodic repeat testing to adolescents and adults in high-HIV settings.

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