The dynamics of HCV transmission among injection drug users in St. Petersburg

Elijah Paintsil and co-workers from the Sexual Transmission and Acquisition of HIV Cooperative Agreement Program (SATH-CAP) project in St. Petersburg presented findings from a study in which they compared network linkages with linkages among the viral genomes among a group of people with HCV recruited by respondent-driven sampling in St. Petersburg.

The investigators reported that sequences from 77 people studied showed 3 main genotypes (3a, 1a, and 1b) circulating in the study population, with a majority of genotype 3a (62%). Genotypes 1b and 1a were 21% and 17%, respectively.

Of the total, 67/77 samples belonged to 11 recruitment chains of productive seeds or chains with more than 2 people; 4 chains with 6, 4, 2, and 3 people (excluding seeds) had a single genotype (3a); 4 chains with 7, 11, 5, and 4 members (excluding seeds) had multiple genotypes with >50% of them belonging to 3a; 3 chains with 13, 4, and 2 members (excluding seeds) contained discordant genotypes in variable amounts.

They concluded that these data suggest that molecular epidemiological tools could provide data to support or refute transmission within social networks that are exploited in assembling respondent-driven sampling study populations.

They wrote: The ability of respondent-driven sampling to capture transmission patterns for prevalent infections appears limited, but the two data sets combined could provide a more robust exploration of incident transmissions of infectious diseases like HCV and HIV.

Paintsil E, Abdala N, Niccolai L et al. The dynamics of HCV transmission among injection drug users in St. Petersburg, Russia: Sexual Transmission and Acquisition of HIV Cooperative Agreement Program. 14th CROI, 2007, Los Angeles. Abstract 131.