Multiple HIV-1 introductions into the Swedish intravenous drug user population
2008 (English)In: Infection, Genetics and Evolution, ISSN 1567-1348, E-ISSN 1567-7257, Vol. 8, no 5, 545-552 p.Article in journal (Refereed) Published
In 2001, an increase of HIV-1 diagnoses among intravenous drug users (IVDU) was reported in Sweden. In nearby countries, Finland, Russia and the Baltic states, recent outbreaks had been described. Since there was a concern that these outbreaks would carry over to Sweden a study was initiated to determine the factors leading to the Swedish increase of HIV-1 diagnosed IVDUs. HIV-1 env V3 sequences were obtained from 97 patients enrolled in ongoing epidemiological studies encompassing the years 1987-2004 with a focus on 2001-2002. The sequences were used for maximum likelihood and Bayesian inference of the molecular epidemiology. Among the virus spreading in 2001-2002, we found that four different subtypes/CRFs were present in the Swedish IVDU population (A, B, CRF01_AE and CRF06_cpx). Subtype B constituted 85% of the infections, established by 12 independent introductions into the IVDU population. The worrisome increase in 2001 was mainly not a result of import of the outbreaks in nearby countries, but rather a higher detection rate of secondary cases due to efficient epidemiological tracing of the generally slow spread of established forms of subtype B in the IVDU community. However, a few of the non-subtype B cases were linked to the outbreaks in Finland, Estonia and Latvia. Because HIV-1 outbreaks can easily be exported from one country to another amongst IVDUs, this prompts continued surveillance in the Baltic Sea Region.
Place, publisher, year, edition, pages
2008. Vol. 8, no 5, 545-552 p.
Evolutionary rate, HIV-1, Intravenous drug users, Molecular epidemiology, Outbreak, Phylogeny, Tree node height
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-50364DOI: 10.1016/j.meegid.2008.03.004OAI: oai:DiVA.org:liu-50364DiVA: diva2:271260