The couples in the study come from the Rakai Cohort, a Uganda-based population in a long-term study of HIV infection. The researchers tested each couple's viral RNA to determine which variants, or kinds of HIV-1 strain, were present in each man and woman. Variants of HIV-1 can be distinguished by differences in the gene (gp160) for their protein envelope. The findings showed that only a subset of HIV-1 variants in the initially infected partner was transmitted to the newly infected partner, and the predominant variant in males was not the kind that infected their female partners. And, women infected by men had a greater number of variants than men infected by women.
The selection of HIV-1 during sexual transmission: differences in gp160 diversity in male-to-female versus female-to-male transmission. Oliver Laeyendecker, Jordyn Gamiel, James Shepard, Xianbin Li, David Serwadda, Nelson Sewankambo, Fred Wabwire-Mangen, Francine McCutchan, Jonathan Toma, Wei Huang, Ronald Gray, Maria Wawer, and Thomas Quinn
Poster presentation #339, Hall D, Hynes Convention Center