title: HIV-1 genetic subtype A/B recombinant strain causing an explosive epidemic in injecting drug users in Kaliningrad.
abstract: OBJECTIVE
  To investigate the molecular epidemiology and genetic structure of the virus strain(s) causing an outbreak of HIV-1 infection in the Kaliningrad province of the Russian Federation and to investigate the relationship of this outbreak to some other emerging HIV-1 epidemics in the countries of the former Soviet Union.
  
  
  METHODS
  A molecular epidemiological investigation was conducted in the city of Kaliningrad amongst individuals recently diagnosed as HIV-1-positive. Samples were also collected from neighbouring Lithuania and from the Ukraine.
  
  
  METHODS
  Incident and population data was collected from official health statistics in Kaliningrad. A standardized questionnaire was administered to newly diagnosed individuals to assess risk factors for HIV-1 infection. For genotyping, two regions of the virus (env C2-V3 and gag NCp7) were directly sequenced.
  
  
  RESULTS
  The number of newly diagnosed individuals testing seropositive for HIV-1 infection in Kaliningrad rose from less than one per month to more than 100 per month during the period of July-October 1996. A total of 1335 new infections were identified between 1 July 1996 and 30 June 1997. The main reported risk factor for HIV-1 infection (80%) was injecting drug use, in particular with a locally produced opiate. Sequence analysis of patient viruses in Kaliningrad (n = 50) showed that the epidemic was caused by a highly homogenous HIV-1 strain, recombinant between the genetic subtypes A and B. Comparison with subtype A strains prevalent amongst injecting drug users (IDU) in the Ukraine showed that one of these strains was the direct subtype A parent of the epidemic A/B recombinant strain in Kaliningrad.
  
  
  CONCLUSIONS
  The HIV-1 epidemic in Kaliningrad probably started from a single source, with rapid spread of the virus through the IDU population. The origin of the epidemic strain is a recombination event occurring between the subtype A strain virus prevalent among IDU in some southern CIS countries, and a subtype B strain of unknown origin.
authors.affiliation: Department of Infectious Disease Epidemiology, National Public Health Institute, Helsinki, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Liitsola
authors.forename: I
authors.initials: I
authors.lastname: Tashkinova
authors.forename: T
authors.initials: T
authors.lastname: Laukkanen
authors.forename: G
authors.initials: G
authors.lastname: Korovina
authors.forename: T
authors.initials: T
authors.lastname: Smolskaja
authors.forename: O
authors.initials: O
authors.lastname: Momot
authors.forename: N
authors.initials: N
authors.lastname: Mashkilleyson
authors.forename: S
authors.initials: S
authors.lastname: Chaplinskas
authors.forename: H
authors.initials: H
authors.lastname: Brummer-Korvenkontio
authors.forename: J
authors.initials: J
authors.lastname: Vanhatalo
authors.forename: P
authors.initials: P
authors.lastname: Leinikki
authors.forename: M O
authors.initials: MO
authors.lastname: Salminen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005260:Female; D005814:Genes, Viral; D014644:Genetic Variation; D015658:HIV Infections / Q000150:complications / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D015497:HIV-1 / Q000145:classification / Q000235:genetics*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D011995:Recombination, Genetic; D012426:Russia / Q000453:epidemiology; D015819:Substance Abuse, Intravenous / Q000150:complications*