Analysis of HIV-1 genetic subtypes in Finland reveals good correlation between molecular and epidemiological data

The molecular epidemiology of HIV-1 genetic subtypes was studied in a cross -sectional sample collected from HIV-infected individuals living in Finland between 1988 and 1994 and compared with independently collected epidemiolo gical data. Subtypes were determined by sequencing and phylogenetic analysi s of the gag NCp7 and the env coding regions of PBMC provirus. Finnish viru ses belonging to 7 subtypes were found. Two thirds (n = 70) of the sequence s could be classified as subtype B, while others belonged to subtypes A, C, D, F and G and the circulating recombinant form AE(CM240) (n = 25), There were significant differences in gender distribution and mode-of-transmissio n between B-type infections and infections with the other subtypes, Most su btype B strains in Finland mere associated with homosexual transmission and about half of these were acquired in Finland, while most individuals harbo uring non-B infections indicated heterosexual transmission and direct or in direct contact with Africa or Southeast Asia. The heterogeneity of genetic subtypes in the country was in good agreement with the epidemiological data suggesting that a significant proportion of infections were imported. HIV- I subtype determination may prove to be a valuable tool for providing objec tive epidemiological data.