Surveillance of subtype and genetic variation of the circulating strains of HIV-1 in Thailand.
Two HIV-1 strains, CRF01_AE and subtype B', were reported in Thailand during the early years of the epidemic. Recently, an intersubtype recombination of HIV-1 strain was found in Thailand. Eight-hundred and twenty-eight samples collected during years 1995-2004 from high-risk groups in Bangkok, northern, northeastern, and southern region of Thailand were studied. HIV-1 env nucleotide sequences were used for phylogenetic analysis of the circulating HIV-1 strain. By single HIV-1 region (env) genotyping, CRFO1_AE was found in 97.3% and HIV-1 subtype B was found in 2.7%. A predominance of CRF01_AE was found in all geographic regions. Parallel analysis of the HIV-1 gag and env genes demonstrated that 2.1% and 4.0% of recombinant HIV-1 strains were found using p17 and p24 region sequences, respectively. The recombinant gag gene was also found in one southern isolate. Phylogenetic analysis of HIV-1 isolated from 20 provinces in 2002 suggested the northern and northeastern isolates were more related than the southern isolates which had the lowest genetic diversity of 0.13. The GPGQ V3 loop tip was also present in isolates from all regions. The molecular epidemiological data from this study may be useful for surveillance design as well as targeting prevention efforts. It also provides information regarding new antigenic regions of circulating strains responsible for the HIV-1 epidemic in Thailand.
Wirachsilp
Piyanot
P
Department of Microbiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkoknoi, Bangkok, Thailand.
Kantakamalakul
Wannee
W
Foongladda
Suporn
S
Chuenchitra
Thippawan
T
Kohriangudom
Surapol
S
Athipanyasilp
Niracha
N
Tanprasertsuk
Sombat
S
Gasitrong
Malee
M
Sutthent
Ruengpung
R
D000595:Amino Acid Sequence; D001483:Base Sequence; D005260:Female; D015752:Genes, env; D015750:Genes, gag; D014644:Genetic Variation; D006031:Glycosylation; D015658:HIV Infections / Q000453:epidemiology / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D011995:Recombination, Genetic; D018571:Sentinel Surveillance; D013785:Thailand / Q000453:epidemiology