Evidence for a "Founder Effect" among HIV-infected injection drug users (IDUs) in Pakistan

Mohammad A Rai,Arish Rehman,Shahana U Kazmi,Syed H Ali,Vivek R Nerurkar,Richard Yanagihara,Suhail Khoja,Saeed Khan

doi:10.1186/1471-2334-10-7

Mohammad A Rai, Arish Rehman + Show 6 more

Open Access

https://doi.org/10.1186/1471-2334-10-7

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Abstract

BackgroundWe have previously reported a HIV-1 subtype A infection in a community of injection drug users (IDUs) in Karachi, Pakistan. We now show that this infection among the IDUs may have originated from a single source.MethodsPhylogenetic analysis was performed of partial gag sequences, generated using PCR, from 26 HIV-positive IDU samples.ResultsOur results showed formation of a tight monophyletic group with an intra-sequence identity of < 98% indicating a "founder effect". Our data indicate that the HIV-1 epidemic in this community of IDUs may have been transmitted by an HIV positive overseas contract worker who admitted to having contact with commercial sex workers during stay abroad.ConclusionSpecific measures need to implemented to control transmission of HIV infection in Pakistan through infected migrant workers.

Highlights

We have previously reported a Human immunodeficiency virus (HIV)-1 subtype A infection in a community of injection drug users (IDUs) in Karachi, Pakistan
Based on the phylogenetic analysis, the HIV-1 strains from Pakistan clustered closely with HIV-1 subtype A sequences from Senegal and Uganda
The HIV-1 subtype A strains from Pakistan were similar to those circulating in Africa, as opposed to those in neighboring India

Summary

Introduction

We have previously reported a HIV-1 subtype A infection in a community of injection drug users (IDUs) in Karachi, Pakistan. The first evidence of Human immunodeficiency virus (HIV) infection in Pakistan was reported in 1987 among patients receiving tainted blood or blood products [1]. In 2004, in the remote desert town of Larkana, Pakistan experienced its first HIV outbreak [2]. The implicated populace was a community of Injection Drug Users (IDU), who documented an HIV prevalence approaching an outstanding 27%. HIV prevalence in IDUs was reported by the National AIDS Control Program as bordering around 0.4% in December, 2003. After the Larkana episode, outbreaks were recorded in other major cities of Pakistan [3]. The changing trend denotes that the country is transitioning from a low prevalence to a concentrated epidemic stage

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