Acute HIV infection detection and immediate treatment estimated to reduce transmission by 89% among men who have sex with men in Bangkok

Abstract

Introduction: Antiretroviral treatment (ART) reduces HIV transmission. Despite increased ART coverage, incidence remains high among men who have sex with men (MSM) in many places. Acute HIV infection (AHI) is characterized by high viral replication and increased infectiousness. We estimated the feasible reduction in transmission by targeting MSM with AHI for early ART.Methods: We recruited a cohort of 88 MSM with AHI in Bangkok, Thailand, who initiated ART immediately. A risk calculator based on viral load and reported behaviour, calibrated to Thai epidemiological data, was applied to estimate the number of onwards transmissions. This was compared with the expected number without early interventions.Results: Forty of the MSM were in 4th-generation AHI stages 1 and 2 (4thG stage 1, HIV nucleic acid testing (NAT)+/4thG immunoassay (IA)-/3rdG IA–; 4thG stage 2, NAT+/4thG IA+/3rdG IA–) while 48 tested positive on third-generation IA but had negative or indeterminate western blot (4thG stage 3). Mean plasma HIV RNA was 5.62 log10 copies/ml. Any condomless sex in the four months preceding the study was reported by 83.7%, but decreased to 21.2% by 24 weeks on ART. After ART, 48/88 (54.6%) attained HIV RNA <50 copies/ml by week 8, increasing to 78/87 (89.7%), and 64/66 (97%) at weeks 24 and 48, respectively. The estimated number of onwards transmissions in the first year of infection would have been 27.3 (95% credible interval: 21.7–35.3) with no intervention, 8.3 (6.4–11.2) with post-diagnosis behaviour change only, 5.9 (4.4–7.9) with viral load reduction only and 3.1 (2.4–4.3) with both. The latter was associated with an 88.7% (83.8–91.1%) reduction in transmission.Conclusions: Disproportionate HIV transmission occurs during AHI. Diagnosis of AHI with early ART initiation can substantially reduce onwards transmission.

HIV incidence and factors associated with testing positive for HIV among men who have sex with men and transgender women in Myanmar: data from community‐based HIV testing services

“…While HIV incidence was calculated among clients receiving more than one test during the pilot period and whose repeat testing behaviour may have been prompted by higher levels of risk than single testers, this finding points to a high level of HIV transmission among clients already engaged with a HIV prevention service. While the short follow‐up period and relatively small number of incident cases detected and missing variable data (discussed further below) precluded analysis of factors prospectively associated with HIV acquisition risk, other findings suggest that undiagnosed HIV in the context of infrequent testing and ongoing sexual risk behaviours may be a key contributor to ongoing transmissions . While a lack of CD4 testing at HIV diagnosis in Myanmar prevents an assessment of time spent undiagnosed, the significant association between reporting no HIV testing history and baseline visit HIV positivity implies that some MSM and TW may have spent substantial time with unknown HIV.…”

Correlates of Undiagnosed HIV Infection and Retesting Among Voluntary HIV Testing Clients at Mildmay Clinic, Uganda

“…However, focusing on reducing the time between tests may come at the expense of testing others for the first time. Testing people more often with the result of identifying more new infections may result in fewer PLHIV being identified as such infections are relatively rare, but as they may be in the acute phase of infection their viral load might be higher and the transmission risk higher [24,25]. Data on community viral load among testers at Mildmay could facilitate prior-itization of groups for testing.…”

Go Where the Virus Is: An HIV Micro-epidemic Control Approach to Stop HIV Transmission

“…An analysis in Thailand suggested that early diagnosis and treatment during AHI among men who have sex with men could avert 89% of all new infections in this population. 25 Approaches that differentiate service delivery to better address the preferences and needs of unserved and underserved individuals have been identified as a priority to close outstanding gaps in access to HIV prevention and treatment. 26 In implementing differentiated services, it is increasingly clear that a focus on individuals and networks with the greatest viral burdens has strategic benefit.…”