PrEP uptake and adherence in relation to HIV-1 incidence among Kenyan men who have sex with men.

Elizabeth W Wahome,Susan M Graham,Prof Maria Prins,Khamisi Mohamed,John Mwambi,Alexander N Thiong'O,Elise Van Der Elst,Prof Eduard J Sanders,Evans Gichuru,Tony Oduor

doi:10.1016/j.eclinm.2020.100541

Abstract

BackgroundData on HIV-1 incidence following programmatic pre-exposure prophylaxis (PrEP) uptake by men who have sex with men (MSM) are limited in sub-Saharan Africa.MethodsSince June 2017, MSM participating in an ongoing cohort study in Kenya were offered daily PrEP, assessed for PrEP uptake and adherence, and evaluated for HIV-1 acquisition monthly. We determined tenofovir-diphosphate (TFV-DP) concentrations in dried blood spots 6–12 months after PrEP initiation, and tenofovir (TFV) concentrations and genotypic drug resistance in plasma samples when HIV-1 infection occurred. We assessed HIV-1 incidence by reported PrEP use.FindingsOf 172 MSM, 170 (98·8%) were eligible for PrEP, 140 (82·4%) started it, and 64 (57·7%) reported PrEP use at end of study. Of nine MSM who acquired HIV-1 [incidence rate: 3·9 (95% confidence interval (CI), 2·0–7·4) per 100 person-years (PY)], five reported PrEP use at the time of HIV-1 acquisition [incidence rate: 3·6 (95% CI, 1·5–8·6) per 100 PY)] and four had stopped or had never started PrEP [incidence rate: 4·3 (95% CI, 1·6–11·3) per 100 PY]. Among 76 MSM who reported PrEP use, 11 (14·5%) had protective TFV-DP concentrations of ≥700 fmol/punch (≥4 tablets a week). Among the five MSM who acquired HIV-1 while reporting PrEP use, only one had detectable but low TFV concentrations in plasma and none had genotypic HIV-1 resistance.InterpretationHIV-1 incidence among MSM with access to programmatic PrEP was high and did not differ by reported PrEP use. Only one in seven MSM taking PrEP had protective tenofovir concentrations and four out of five MSM who acquired HIV-1 while reporting PrEP use had not taken it. Strengthened PrEP adherence support is required among MSM in Kenya.FundingThis work was supported by the International AIDS Vaccine Initiative (IAVI).

Highlights

Kenya has the fifth largest number of people living with HIV-1 in the world [1], with an estimated 1¢3 million people infected with HIV-1 [2]
Our results show that while pre-exposure prophylaxis (PrEP) uptake among men who have sex with men (MSM) was high, the HIV-1 incidence rate was substantial (39 per 100 PY) and did not differ between men reporting PrEP use and those who had never started PrEP or discontinued it, suggesting that PrEP adherence was poor
We document a substantial overall HIV-1 incidence rate (3¢9 per 100 PY) among MSM with access to programmatic PrEP who were followed in a HIV-1 vaccine feasibility cohort study in coastal Kenya

Summary

Introduction

Kenya has the fifth largest number of people living with HIV-1 in the world [1], with an estimated 1¢3 million people infected with HIV-1 [2]. Counties with an estimated high or medium HIV-1 incidence rate in the general population and those with a high or medium number of KP (including MSM) are prioritized for PrEP roll-out [7]. Methods: Since June 2017, MSM participating in an ongoing cohort study in Kenya were offered daily PrEP, assessed for PrEP uptake and adherence, and evaluated for HIV-1 acquisition monthly. Of nine MSM who acquired HIV-1 [incidence rate: 3¢9 (95% confidence interval (CI), 2¢0À7¢4) per 100 person-years (PY)], five reported PrEP use at the time of HIV-1 acquisition [incidence rate: 3¢6 (95% CI, 1¢5À8¢6) per 100 PY)] and four had stopped or had never started PrEP [incidence rate: 4¢3 (95% CI, 1¢6À11¢3) per 100 PY]. Among the five MSM who acquired HIV-1 while reporting PrEP use, only one had detectable but low TFV concentrations in plasma and none had genotypic HIV-1 resistance.

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