Background HIV-1 incidence estimates and correlates of HIV-1 acquisition in African men who have sex with men are largely unknown. Methods Since 2005, HIV-1-uninfected men who reported sex with men and women (MSMW) or sex with men exclusively (MSME) were followed at scheduled visits for collection of behavioural and clinical examination data and plasma for HIV-1 testing. Urethral or rectal secretions were collected from symptomatic men to screen for gonorrhoea. Poisson regression methods were used to estimate adjusted incidence rate ratios (aIRR) to explore associations between risk factors and incident HIV-1 infection. Plasma viral loads (PVL) were assessed over two years following seroconversion. Results Overall HIV-1 incidence in 449 men was 8.6 (95% confidence interval [CI]: 6.7–11.0) per 100 person-years (py). Incidence was 5.8 (95% CI: 4.2–7.9) per 100 py among MSMW, and 35.2 (95% CI: 23.8–52.1) per 100 py among MSME. Unprotected sex, receptive anal intercourse, exclusive sex with men, group sex, and gonorrhoea in the past 6 months were strongly associated with HIV-1 acquisition, adjusted for confounders. PVL in seroconverters was >4 log10 copies/mL at 230 (73.4%) of 313 visits in MSMW and 153 (75.0%) of 204 visits in MSME. Conclusions HIV-1 incidence is very high among MSM in coastal Kenya, and many seroconverters maintain high PVL for up to two years after infection. Effective HIV-1 prevention interventions, including treatment as prevention, are urgently needed in this population.

BackgroundMore than 35 million people in developing countries are living with HIV infection. An enormous global effort is now underway to bring antiretroviral treatment to at least 3 million of those infected. While drug prices have dropped considerably, the cost and technical complexity of laboratory tests essential for the management of HIV disease, such as CD4 cell counts, remain prohibitive. New, simple, and affordable methods for measuring CD4 cells that can be implemented in resource-scarce settings are urgently needed.Methods and FindingsHere we describe the development of a prototype for a simple, rapid, and affordable method for counting CD4 lymphocytes. Microliter volumes of blood without further sample preparation are stained with fluorescent antibodies, captured on a membrane within a miniaturized flow cell and imaged through microscope optics with the type of charge-coupled device developed for digital camera technology. An associated computer algorithm converts the raw digital image into absolute CD4 counts and CD4 percentages in real time. The accuracy of this prototype system was validated through testing in the United States and Botswana, and showed close agreement with standard flow cytometry (r = 0.95) over a range of absolute CD4 counts, and the ability to discriminate clinically relevant CD4 count thresholds with high sensitivity and specificity.ConclusionAdvances in the adaptation of new technologies to biomedical detection systems, such as the one described here, promise to make complex diagnostics for HIV and other infectious diseases a practical global reality.

The high prevalence of HIV-1 in Kenyan MSM is probably attributable to unprotected receptive anal sex. There is an urgent need for HIV-1 prevention programmes to deliver targeted risk-reduction interventions and STD services to MSM in Kenya.

Genital HIV-1 shedding decreased rapidly after ART initiation, consistent with a rapid decrease in infectivity. However, incomplete viral suppression in half of these women may indicate an ongoing risk of transmission.

Cancer Consortium, and P30 AI027757 CFAR New During HIV infection, a reservoir of long-lived latently infected cells is established that persists during antiretroviral therapy (ART) and is the source of virus replication after treatment cessation. A better understanding of when viruses enter the HIV reservoir (reservoir seeding) will aid efforts to target these long-lived HIV infected cells during their establishment. We studied women infected at two different times with two genetically distinct HIV strains (called superinfection), and assessed the genetic relationship between sequences of the HIV strains that circulated throughout infection (pre-ART HIV RNA sequences) and the HIV strains that persisted in reservoir cells (HIV DNA sequences during ART). We estimated when HIV DNA sequences entered the reservoir by identifying the time the most genetically related HIV RNA sequence was detected. In most cases we observed that viruses in the reservoir included both the initial and superinfecting lineages, suggesting reservoir seeding occurs throughout HIV infection. However, the majority of HIV sequences entered the reservoir near the time of ART initiation, suggesting that novel strategies that aim to reduce reservoir size should focus on times immediately prior to ART.

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BackgroundAudio computer-assisted self-interview (ACASI) may elicit more frequent reporting of socially sensitive behaviours than face-to-face (FtF)-interview. However, no study compared responses to both methods in female and male sex workers (FSW; MSW) in Africa.Methodology/Principal FindingsWe sequentially enrolled adults recruited for an HIV-1 intervention trial into a comparative study of ACASI and FtF-interview, in a clinic near Mombasa, Kenya. Feasibility and acceptability of ACASI, and a comparative analysis of enrolment responses between ACASI and FtF on an identical risk assessment questionnaire were evaluated. In total, 139 women and 259 men, 81% of eligible cohort participants, completed both interviews. ACASI captured a higher median number of regular (2 vs. 1, p<0.001, both genders) and casual partners in the last week (3 vs. 2, p = 0.04 in women; 2 vs. 1, p<0.001 in men). Group sex (21.6 vs. 13.5%, p<0.001, in men), intravenous drug use (IDU; 10.8 vs. 2.3%, p<0.001 in men; 4.4 vs. 0%, p = 0.03 in women), and rape (8.9 vs. 3.9%, p = 0.002, in men) were reported more frequently in ACASI. A surprisingly high number of women reported in ACASI that they had paid for sex (49.3 vs. 5.8%, p<0.001). Behaviours for recruitment (i.e. anal sex, sex work, sex between males) were reported less frequently in ACASI. The majority of women (79.2%) and men (69.7%) felt that answers given in ACASI were more honest. Volunteers who were not able to take ACASI (84 men, and 37 women) mostly lacked reading skills.Conclusions/SignificanceAbout 1 in 5 cohort participants was not able to complete ACASI, mostly for lack of reading skills. Participants who completed ACASI were more likely to report IDU, rape, group sex, and payment for sex by women than when asked in FtF interview. ACASI appears to be a useful tool for high risk behaviour assessments in the African context.

Persistent genital HIV-1 shedding among women taking antiretroviral therapy (ART) may present a transmission risk. We investigated associations between genital HIV-1 suppression after ART initiation and adherence, resistance, pre-treatment CD4 count, and hormonal contraceptive use. First-line ART was initiated in 102 women. Plasma and genital HIV-1 RNA were measured at months 0, 3, and 6. Adherence was a strong and consistent predictor of genital HIV-1 suppression (p<0.001), while genotypic resistance was associated with higher vaginal HIV-1 RNA at 6 months (p=0.04). These results emphasize the importance of adherence to optimize the potential benefits of ART for reducing HIV-1 transmission risk.