title: Increasing HIV-1 molecular complexity among men who have sex with men in Bangkok.
abstract: In Thailand, new HIV-1 infections are largely concentrated in certain risk groups such as men who have sex with men (MSM), where annual incidence may be as high as 12% per year. The paucity of information on the molecular epidemiology of HIV-1 in Thai MSM limits progress in understanding the epidemic and developing new prevention methods. We evaluated HIV-1 subtypes in seroincident and seroprevalent HIV-1-infected men enrolled in the Bangkok MSM Cohort Study (BMCS) between 2006 and 2011. We characterized HIV-1 subtype in 231 seroprevalent and 194 seroincident subjects using the multihybridization assay (MHA). Apparent dual infections, recombinant strains, and isolates found to be nontypeable by MHA were further characterized by targeted genomic sequencing. Most subjects were infected with HIV-1 CRF01_AE (82%), followed by infections with recombinants (11%, primarily CRF01_AE/B recombinants), subtype B (5%), and dual infections (2%). More than 11 distinct chimeric patterns were observed among CRF01B_AE/B recombinants, most involving recombination within integrase. A significant increase in the proportion of nontypeable strains was observed among seroincident MSM between 2006 and 2011. CRF01_AE and subtype B were the most and least common infecting strains, respectively. The predominance of CRF01_AE among HIV-1 infections in Thai MSM participating in the BMCS parallels trends observed in Thai heterosexuals and injecting drug users. The presence of complex recombinants and a significant rise in nontypeable strains suggest ongoing changes in the genetic makeup of the HIV-1 epidemic in Thailand, which may pose challenges for HIV-1 prevention efforts and vaccine development.
authors.affiliation: 1 Thailand Ministry of Public Health-U.S. Centers for Disease Control and Prevention Collaboration , Nonthaburi, Thailand .
authors.forename: Wanna
authors.initials: W
authors.lastname: Leelawiwat
authors.forename: Wiriya
authors.initials: W
authors.lastname: Rutvisuttinunt
authors.forename: Miguel
authors.initials: M
authors.lastname: Arroyo
authors.forename: Famui
authors.initials: F
authors.lastname: Mueanpai
authors.forename: Oranuch
authors.initials: O
authors.lastname: Kongpechsatit
authors.forename: Wannee
authors.initials: W
authors.lastname: Chonwattana
authors.forename: Supaporn
authors.initials: S
authors.lastname: Chaikummao
authors.forename: Mark
authors.initials: M
authors.lastname: de Souza
authors.forename: Frits
authors.initials: F
authors.lastname: vanGriensven
authors.forename: Janet M
authors.initials: JM
authors.lastname: McNicholl
authors.forename: Marcel E
authors.initials: ME
authors.lastname: Curlin
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D014644:Genetic Variation; D005838:Genotype; D015658:HIV Infections / Q000453:epidemiology / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000235:genetics*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D009693:Nucleic Acid Hybridization; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D013785:Thailand / Q000453:epidemiology; D055815:Young Adult