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


METHODS
Phylogenetic analysis was performed of partial gag sequences, generated using PCR, from 26 HIV-positive IDU samples.


RESULTS
Our 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.


CONCLUSIONS
Specific measures need to implemented to control transmission of HIV infection in Pakistan through infected migrant workers.
Rai
Mohammad A
MA
Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan.
Nerurkar
Vivek R
VR
Khoja
Suhail
S
Khan
Saeed
S
Yanagihara
Richard
R
Rehman
Arish
A
Kazmi
Shahana U
SU
Ali
Syed H
SH
D000328:Adult; D055030:Drug Users; D018703:Founder Effect; D015658:HIV Infections / Q000453:epidemiology*; D015497:HIV-1 / Q000145:classification / Q000235:genetics*; D006801:Humans; D008297:Male; D010154:Pakistan / Q000453:epidemiology; D010802:Phylogeny; D011159:Population Surveillance; D012367:RNA, Viral / Q000235:genetics; D016415:Sequence Alignment; D017423:Sequence Analysis, RNA; D011477:Sex Work; D014171:Transients and Migrants; D055815:Young Adult
D012367:RNA, Viral