Migrants have been identified as a population left behind by the AIDS (Acquired Immune Deficiency Syndrome) response, with evidence showing poorer HIV (Human Immunodeficiency Virus) outcomes and reduced intervention effectiveness in mobile populations. We used data from the HPTN 071 (PopART) trial (ClinicalTrials.gov number, NCT01900977) to investigate migration and HIV-related indicators, assessing whether community migration influenced PopART trial results and whether migration was associated with HIV status and position on the care continuum. The PopART trial, conducted in Zambia and South Africa (SA) from November 2013 to June 2018, evaluated a universal testing and treatment intervention using a three-arm design. A cohort of 18–44-year-olds was followed annually to estimate HIV incidence, with migration out of trial communities tracked using this cohort. migration into and within the community was tracked using intervention delivery data in community members aged 18 + . HIV-related indicators were HIV status, knowledge of HIV-positive status and ART use. Migration’s influence on the trial HIV incidence results was analysed using a two-stage approach for cluster-randomised trials, adjusting for community-level migration. Associations between HIV-related indicators and both out-migration (Poisson regression using cohort data) and in-migration (logistic regression using cross-sectional data) were also estimated. While migration differed between trial arms, there was no evidence that it confounded the intervention effect on HIV incidence. There was evidence out-migration was higher among HIV-positive individuals who did not know (or did not disclose) their HIV-positive status compared to those HIV-negative (adjusted rate ratio: Zambia 1.28, 95%CI 1.17-1.39; SA 1.27, 95%CI 1.17-1.38). Residents who had moved into the community within the previous year were less likely to be aware of their HIV-positive status than longer-term residents (adjusted odds ratio: Zambia 0.18, 95%CI 0.16-0.19; SA 0.23, 95%CI 0.20-0.28) and contributed to approximately one in four of the newly identified HIV infections. Following intervention delivery the gap in knowledge of HIV status and ART treatment coverage between recent in-migrants and longer-term residents closed. Countries with high HIV burden should aim to ensure a sustained delivery of HIV services in areas with high levels of population mobility and in areas with moderate to high HIV prevalence.
Macleod et al. (Mon,) studied this question.