title: Molecular evidence for polyphyletic origin of human immunodeficiency virus type 1 subtype C in Bangladesh.
abstract: HIV-1 positive blood samples were collected between 1999 and 2005 from population groups most at risk of HIV infection in Bangladesh through the national surveillance, from clients of the Voluntary Counseling and Testing (VCT) Unit for HIV at ICDDR,B and a survey of HIV in patients with tuberculosis. Partial sequences of the gag gene were used for subtyping the HIV strains by nested PCR using selective primers. Of the 198 HIV strains tested, subtype C (41.4%) was the commonest strain identified. Phylogenetic analysis of Bangladeshi subtype C strains showed that they clustered in polyphyletic branches representing HIV strains from different parts of the world. Most of the strains from injecting drug users (IDU) clustered together and were similar to Indian strains. The VCT strains however were very heterogeneous and clustered with strains from India, Myanmar, Ethiopia and Zimbabwe. Data suggest that there have been few introductions into the IDU population where the epidemic is driven by indigenous transmission. On the other hand there have been many and regular introductions of subtype C viruses through migrant workers in the VCT group. Very little overlap was observed in the strains obtained from IDU and those from other population groups.
authors.affiliation: Virology Laboratory, Laboratory Sciences Division, International Centre for Diarrhoeal Diseases Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sharani, Mohakhali, Dhaka 1212, Bangladesh. sarker_s@yahoo.com
authors.forename: M Safiullah
authors.initials: MS
authors.lastname: Sarker
authors.forename: Mustafizur
authors.initials: M
authors.lastname: Rahman
authors.forename: David
authors.initials: D
authors.lastname: Yirrell
authors.forename: Eileen
authors.initials: E
authors.lastname: Campbell
authors.forename: A S M Matiur
authors.initials: AS
authors.lastname: Rahman
authors.forename: Laila N
authors.initials: LN
authors.lastname: Islam
authors.forename: Tasnim
authors.initials: T
authors.lastname: Azim
mesh_terms: D001459:Bangladesh / Q000453:epidemiology; D004641:Emigration and Immigration / Q000706:statistics & numerical data; D005260:Female; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism; D015658:HIV Infections / Q000453:epidemiology / Q000635:transmission / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012689:Sequence Homology, Nucleic Acid
chemical_list: D015683:Gene Products, gag