title: Identification of a current hot spot of HIV type 1 transmission in Mongolia by molecular epidemiological analysis.
abstract: We investigated the current molecular epidemiological status of HIV-1 in Mongolia, a country with very low incidence of HIV-1 though with rapid expansion in recent years. HIV-1 pol (1065 nt) and env (447 nt) genes were sequenced to construct phylogenetic trees. The evolutionary rates, molecular clock phylogenies, and other evolutionary parameters were estimated from heterochronous genomic sequences of HIV-1 subtype B by the Bayesian Markov chain Monte Carlo method. We obtained 41 sera from 56 reported HIV-1-positive cases as of May 2009. The main route of infection was men who have sex with men (MSM). Dominant subtypes were subtype B in 32 cases (78%) followed by subtype CRF02_AG (9.8%). The phylogenetic analysis of the pol gene identified two clusters in subtype B sequences. Cluster 1 consisted of 21 cases including MSM and other routes of infection, and cluster 2 consisted of eight MSM cases. The tree analyses demonstrated very short branch lengths in cluster 1, suggesting a surprisingly active expansion of HIV-1 transmission during a short period with the same ancestor virus. Evolutionary analysis indicated that the outbreak started around the early 2000s. This study identified a current hot spot of HIV-1 transmission and potential seed of the epidemic in Mongolia. Comprehensive preventive measures targeting this group are urgently needed.
authors.affiliation: AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo, Japan. jdavaalkham@yahoo.com
authors.forename: Jagdagsuren
authors.initials: J
authors.lastname: Davaalkham
authors.forename: Puntsag
authors.initials: P
authors.lastname: Unenchimeg
authors.forename: Chultem
authors.initials: C
authors.lastname: Baigalmaa
authors.forename: Gombo
authors.initials: G
authors.lastname: Erdenetuya
authors.forename: Dulmaa
authors.initials: D
authors.lastname: Nyamkhuu
authors.forename: Teiichiro
authors.initials: T
authors.lastname: Shiino
authors.forename: Kiyoto
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Tsunefusa
authors.initials: T
authors.lastname: Hayashida
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Gatanaga
authors.forename: Shinichi
authors.initials: S
authors.lastname: Oka
mesh_terms: D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D001499:Bayes Theorem; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D015658:HIV Infections / Q000175:diagnosis / Q000453:epidemiology / Q000635:transmission* / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology / Q000379:methods*; D008986:Mongolia / Q000453:epidemiology; D010802:Phylogeny; D012367:RNA, Viral / Q000097:blood; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D055815:Young Adult; D054299:env Gene Products, Human Immunodeficiency Virus / Q000235:genetics; D054302:pol Gene Products, Human Immunodeficiency Virus / Q000235:genetics*
chemical_list: D012367:RNA, Viral; D054299:env Gene Products, Human Immunodeficiency Virus; D054302:pol Gene Products, Human Immunodeficiency Virus