Mapping geographic clusters of new HIV diagnoses to inform granular-level interventions for HIV epidemic control in western Kenya.

BACKGROUND: As countries make progress towards HIV epidemic control, there is increasing need to identify finer geographic areas to target HIV interventions. We mapped geographic clusters of new HIV diagnoses, and described factors associated with HIV-positive diagnosis, in order to inform targeting of HIV interventions to finer geographic areas and sub-populations. METHODS: We analyzed data for clients aged > 15 years who received home-based HIV testing as part of a routine public health program between May 2016 and July 2017 in Siaya County, western Kenya. Geospatial analysis using Kulldorff's spatial scan statistic was used to detect geographic clusters (radius < 5 kilometers) of new HIV diagnoses. Factors associated with new HIV diagnosis were assessed in a spatially-integrated Bayesian hierarchical model. RESULTS: Of 268,153 clients with HIV test results, 2906 (1.1%) were diagnosed HIV-positive. We found spatial variation in the distribution of new HIV diagnoses, and identified nine clusters in which the number of new HIV diagnoses was significantly (1.56 to 2.64 times) higher than expected. Sub-populations with significantly higher HIV-positive yield identified in the multivariable spatially-integrated Bayesian model included: clients aged 20-24 years [adjusted relative risk (aRR) 3.45, 95% Bayesian Credible Intervals (CI) 2.85-4.20], 25-35 years (aRR 4.76, 95% CI 3.92-5.81) and > 35 years (aRR 2.44, 95% CI 1.99-3.00); those in polygamous marriage (aRR 1.84, 95% CI 1.55-2.16), or separated/divorced (aRR 3.36, 95% CI 2.72-4.08); and clients who reported having never been tested for HIV (aRR 2.35, 95% CI 2.02-2.72), or having been tested > 12 months ago (aRR 1.53, 95% CI 1.41-1.66). CONCLUSION: Our study used routine public health program data to identify granular geographic clusters of higher new HIV diagnoses, and sub-populations with higher HIV-positive yield in the setting of a generalized HIV epidemic. In order to target HIV testing and prevention interventions to finer granular geographic areas for maximal epidemiologic impact, integrating geospatial analysis into routine public health programs can be useful.

Correlates of Rectal Douching Practices Among Men Who Have Sex With Men in Kenya.

BACKGROUND: Among men who have sex with men (MSM), rectal douching (RD) has been associated with increased prevalence of human immunodeficiency virus and other sexually transmitted infections. Substances commonly used for RD, especially water-based solutions, could disrupt the rectal epithelium and increase susceptibility to infection. The few existing reports on RD among MSM are primarily in middle- and high-income settings, and to date, no study has focused on RD among MSM in Africa. METHODS: We conducted a secondary data analysis of programmatic data from key population service centers in western Kenya. Data were extracted from records of clients who identified as MSM and accessed services between January 1, 2014, and September 1, 2016. We compared demographic and behavioral characteristics of men who did and did not practice RD. Logistic regression assessed associations with RD. RESULTS: Of the 202 MSM in this analysis, 63% engaged in RD. All who engaged in RD used water-based substances. Those who engaged in receptive anal intercourse in the last 3 months were more likely to report RD (odds ratio, 3.19; 95% confidence interval, 1.67-6.07). Among MSM who engaged in sex work, those who practiced RD reported more regular clients per week (2.8 clients vs. 1.3 clients, P = 0.01). Rectal douching practices did not vary by other sexual risk practices. CONCLUSIONS: Rectal douching is common in this population of Kenyan MSM, especially among those who have recently engaged in receptive anal intercourse, suggesting that a rectal douche that delivers microbicides could be a potential intervention to reduce human immunodeficiency virus/sexually transmitted infection within this population.