Résumé
Introduction: Direct measurement of antiretroviral treatment (ART) program indicators essential for evidence-based planning and evaluation - especially HIV incidence, population viral load, and ART eligibility - is rare in sub-Saharan Africa.
Design/methods: To measure key indicators in rural western Kenya, an area with high HIV burden, we conducted a population survey in September to November 2012 via multistage cluster sampling, recruiting everyone aged 15-59 years living in 3330 randomly selected households. Consenting individuals were interviewed and tested for HIV at home. Participants testing positive were assessed for CD4(+) cell count and viral load, and their infections classified as either recent or long term based on Limiting Antigen Avidity assays. HIV-negative participants were tested by nucleic acid amplification to detect acute infections.
Results: Of 6833 household members eligible for the study, 6076 (94.7% of all women and 81.0% of men) agreed to participate. HIV prevalence and incidence were 24.1% [95% confidence interval [CI] 23.0-25.2] and 1.9 new cases/100person-years (95% CI 1.1-2.7), respectively. Among HIV-positive participants, 59.4% (95% CI 56.8-61.9) were previously diagnosed, 53.1% (95% CI 50.5-55.7) were receiving care, and 39.7% (95% CI 37.1-42.4) had viral load less than 1000copies/ml. Applying 2013 WHO recommendations for ART initiation increased the proportion of ART-eligible people from 60.0% (based on national guidelines in place during the survey; 95% CI 57.3-62.7) to 82.0% (95% CI 79.5-84.5). Among HIV-positive people not receiving ART, viral load increased with decreasing CD4(+) cell count (500-749 vs. 750cells/l, adjusted mean difference, 0.40log(10)copies/ml, 95% CI 0.20-0.60, P<0.01).
Conclusion: This study demonstrates how population-level data can help optimize HIV programs. Based on these results, new regional programs are prioritizing diagnosis and expanding ART eligibility, key steps to reach undetectable viral load. Copyright (C) 2015 Wolters Kluwer Health, Inc. All rights reserved.