Publications

BACKGROUND

As sub-Saharan Africa transitions to a new era of universal antiretroviral therapy (ART), up-to-date assessments of population-level HIV RNA suppression are needed to inform interventions to optimise ART delivery. We sought to measure population viral load metrics to assess viral suppression and characterise demographic groups and geographical locations with high-level detectable viraemia in east Africa.

METHODS

The Sustainable East Africa Research in Community Health (SEARCH) study is a cluster-randomised controlled trial of an HIV test-and-treat strategy in 32 rural communities in Uganda and Kenya, selected on the basis of rural setting, having an approximate population of 10 000 people, and being within the catchment area of a President's Emergency Plan for AIDS Relief-supported HIV clinic. During the baseline population assessment in the SEARCH study, we did baseline HIV testing and HIV RNA measurement. We analysed stable adult (aged ≥15 years) community residents. We defined viral suppression as a viral load of less than 500 copies per mL. To assess geographical sources of transmission risk, we established the proportion of all adults (both HIV positive and HIV negative) with a detectable viral load (local prevalence of viraemia). We defined transmission risk hotspots as geopolitical subunits within communities with an at least 5% local prevalence of viraemia. We also assessed serodiscordant couples, measuring the proportion of HIV-positive partners with detectable viraemia. The SEARCH study is registered with ClinicalTrials.gov, number NCT01864603.

FINDINGS

Between April 2, 2013, and June 8, 2014, of 303 461 stable residents, we enumerated 274 040 (90·3%), of whom 132 030 (48·2%) were adults. Of these, 117 711 (89·2%) had their HIV status established, of whom 11 964 (10·2%) were HIV positive. Of these, we measured viral load in 8828 (73·8%) people. Viral suppression occurred in 3427 (81·6%) of 4202 HIV-positive adults on ART and 4490 (50·9%) of 8828 HIV-positive adults. Regional viral suppression among HIV-positive adults occurred in 881 (48·2%) of 1827 people in west Uganda, 516 (45·0%) of 1147 in east Uganda, and 3093 (52·8%) of 5854 in Kenya. Transmission risk hotspots occurred in three of 21 parishes in west Uganda and none in east Uganda and in 24 of 26 Kenya geopolitical subunits. In Uganda, 492 (2·9%) of 16 874 couples were serodiscordant: in 287 (58·3%) of these couples, the HIV-positive partner was viraemic (and in 69 [14·0%], viral load was >100 000 copies per mL). In Kenya, 859 (10·0%) of 8616 couples were serodiscordant: in 445 (53·0%) of these couples, the HIV-positive partner was viraemic (and in 129 [15%], viral load was >100 000 copies per mL).

INTERPRETATION

Before the start of the SEARCH trial, 51% of east African HIV-positive adults had viral suppression, reflecting ART scale-up efforts to date. Geographical hotspots of potential HIV transmission risk and detectable viraemia among serodiscordant couples warrant intensified interventions.

FUNDING

National Institute of Allergy and Infectious Diseases (National Institutes of Health) and the President's Emergency Plan for AIDS Relief.

Mutation of highly conserved residues in transcription factors may affect protein-protein or protein-DNA interactions, leading to gene network dysregulation and human disease. Human mutations in GATA4, a cardiogenic transcription factor, cause cardiac septal defects and cardiomyopathy. Here, iPS-derived cardiomyocytes from subjects with a heterozygous GATA4-G296S missense mutation showed impaired contractility, calcium handling, and metabolic activity. In human cardiomyocytes, GATA4 broadly co-occupied cardiac enhancers with TBX5, another transcription factor that causes septal defects when mutated. The GATA4-G296S mutation disrupted TBX5 recruitment, particularly to cardiac super-enhancers, concomitant with dysregulation of genes related to the phenotypic abnormalities, including cardiac septation. Conversely, the GATA4-G296S mutation led to failure of GATA4 and TBX5-mediated repression at non-cardiac genes and enhanced open chromatin states at endothelial/endocardial promoters. These results reveal how disease-causing missense mutations can disrupt transcriptional cooperativity, leading to aberrant chromatin states and cellular dysfunction, including those related to morphogenetic defects.