HIV-1 genetic subtype A/B recombinant strain causing an explosive epidemic in injecting drug users in Kaliningrad.
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.
Liitsola
K
K
Department of Infectious Disease Epidemiology, National Public Health Institute, Helsinki, Finland.
Tashkinova
I
I
Laukkanen
T
T
Korovina
G
G
Smolskaja
T
T
Momot
O
O
Mashkilleyson
N
N
Chaplinskas
S
S
Brummer-Korvenkontio
H
H
Vanhatalo
J
J
Leinikki
P
P
Salminen
M O
MO
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*