Reducing HIV infection in people who inject drugs is impossible without targeting recently-infected subjects.

Tetyana I Vasylyeva,Angelos Hatzakis,Jose Lourenco,Dimitrios Paraskevis,Aris Katzourakis,Pavlo Smyrnov,Timokratis Karamitros,Gkikas Magiorkinis,Samuel R Friedman,Oliver G Pybus,Sunetra Gupta

doi:10.1097/qad.0000000000001291

Abstract

Objective:Although our understanding of viral transmission among people who inject drugs (PWID) has improved, we still know little about when and how many times each injector transmits HIV throughout the duration of infection. We describe HIV dynamics in PWID to evaluate which preventive strategies can be efficient.Design:Due to the notably scarce interventions, HIV-1 spread explosively in Russia and Ukraine in 1990s. By studying this epidemic between 1995 and 2005, we characterized naturally occurring transmission dynamics of HIV among PWID.Method:We combined publicly available HIV pol and env sequences with prevalence estimates from Russia and Ukraine under an evolutionary epidemiology framework to characterize HIV transmissibility between PWID. We then constructed compartmental models to simulate HIV spread among PWID.Results:In the absence of interventions, each injector transmits on average to 10 others. Half of the transmissions take place within 1 month after primary infection, suggesting that the epidemic will expand even after blocking all the post–first month transmissions. Primary prevention can realistically target the first month of infection, and we show that it is very efficient to control the spread of HIV-1 in PWID. Treating acutely infected on top of primary prevention is notably effective.Conclusion:As a large proportion of transmissions among PWID occur within 1 month after infection, reducing and delaying transmissions through scale-up of harm reduction programmes should always form the backbone of HIV control strategies in PWID. Growing PWID populations in the developing world, where primary prevention is scarce, constitutes a public health time bomb.

Highlights

HIV in people who inject drugs (PWID) has, to date, posed a secondary burden worldwide after sexual transmission, with the striking exceptions of eastern European and central Asian countries [1]
Primary prevention can realistically target the first month of infection, and we show that it is very efficient to control the spread of HIV-1 in PWID
As a large proportion of transmissions among PWID occur within 1 month after infection, reducing and delaying transmissions through scale-up of harm reduction programmes should always form the backbone of HIV control strategies in PWID

Summary

Introduction

HIV in people who inject drugs (PWID) has, to date, posed a secondary burden worldwide after sexual transmission, with the striking exceptions of eastern European and central Asian countries [1]. Much work has been done to study how HIV spreads in PWID, and we have interventions that proved to be effective to slow down the HIVepidemic in this group [2]. With almost 1 million HIV-infected individuals and a PWID population of around 2 million people [1], Russia and Ukraine provide a unique opportunity for studying HIV transmission dynamics in this group. The epidemic in these countries has been accompanied by very limited harm reduction services [4], making it a large-scale ‘natural experiment’ of HIV spread among PWID. Harm reduction approaches among PWID since the 1980s have had significant effects in the developed world [11], it remains unclear whether these preventive strategies should be prioritized over newer approaches such as treatment as prevention (TasP) [12] in resource-limited settings

Methods

Results

Conclusion