title: Subtype classification of Iranian HIV-1 sequences registered in the HIV databases, 2006-2013.
abstract: BACKGROUND
  The rate of human immunodeficiency virus type 1 (HIV-1) infection in Iran has increased dramatically in the past few years. While the earliest cases were among hemophiliacs, injection drug users (IDUs) fuel the current epidemic. Previous molecular epidemiological analysis found that subtype A was most common among IDUs but more recent studies suggest CRF_35AD may be more prevalent now. To gain a better understanding of the molecular epidemiology of HIV-1 infection in Iran, we analyzed all Iranian HIV sequence data from the Los Alamos National Laboratory.
  
  
  METHODS
  All Iranian HIV sequences from subtyping studies with pol, gag, env and full-length HIV-1 genome sequences registered in the HIV databases (www.hiv.lanl.gov) between 2006 and 2013 were downloaded. Phylogenetic trees of each region were constructed using Neighbor-Joining (NJ) and Maximum Parsimony methods.
  
  
  RESULTS
  A total of 475 HIV sequences were analyzed. Overall, 78% of sequences were CRF_35AD. By gene region, CRF_35AD comprised 83% of HIV-1 pol, 62% of env, 78% of gag, and 90% of full-length genome sequences analyzed. There were 240 sequences re-categorized as CRF_AD. The proportion of CRF_35AD sequences categorized by the present study is nearly double the proportion of what had been reported.
  
  
  CONCLUSIONS
  Phylogenetic analysis indicates HIV-1 subtype CRF_35AD is the predominant circulating strain in Iran. This result differed from previous studies that reported subtype A as most prevalent in HIV- infected patients but confirmed other studies which reported CRF_35AD as predominant among IDUs. The observed epidemiological connection between HIV strains circulating in Iran and Afghanistan may be due to drug trafficking and/or immigration between the two countries. This finding suggests the possible origins and transmission dynamics of HIV/AIDS within Iran and provides useful information for designing control and intervention strategies.
authors.affiliation: Iranian Research Center for HIV/AIDS, Iranian Institute for Reduction of High Risk Behaviors, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Kazem
authors.initials: K
authors.lastname: Baesi
authors.affiliation: Iranian Research Center for HIV/AIDS, Iranian Institute for Reduction of High Risk Behaviors, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Samaneh
authors.initials: S
authors.lastname: Moallemi
authors.affiliation: Iranian Research Center for HIV/AIDS, Iranian Institute for Reduction of High Risk Behaviors, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Molood
authors.initials: M
authors.lastname: Farrokhi
authors.affiliation: Iranian Research Center for HIV/AIDS, Iranian Institute for Reduction of High Risk Behaviors, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Seyed Ahmad Seyed
authors.initials: SA
authors.lastname: Alinaghi
authors.affiliation: University of California, San Francisco, CA, United States of America; Gladstone Institute of Virology and Immunology, San Francisco, CA, United States of America.
authors.forename: Hong-Ha M
authors.initials: HM
authors.lastname: Truong
mesh_terms: D000346:Afghanistan / Q000208:ethnology; D030561:Databases, Nucleic Acid; D005260:Female; D015752:Genes, env; D015750:Genes, gag; D015751:Genes, pol; D016679:Genome, Viral; D015658:HIV Infections / Q000453:epidemiology / Q000635:transmission / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000235:genetics*; D006467:Hemophilia A / Q000150:complications; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D015819:Substance Abuse, Intravenous / Q000150:complications