The major focus of my research is HIV-1 pathogenesis, more specific the effect of dual HIV-1 infections. This research line started with the description of the first patient with a double HIV-1 superinfection, resulting in a triple infection with different virus subtypes: B-B'-AE (van der Kuyl et al, NEJM 2005 352: 2557-9). Longitudinal analysis of the patient's samples showed that all three strains remained present both in blood and seminal plasma for years, and that recombinant virus strains were formed.
Studies using RNA- or retroviruses have indicated that superinfections and especially co-infections lead to an increase in viral fitness. We speculated that HIV-1 co- or superinfection, contributes to the process of HIV-1 fitness gain and possibly to the higher virulence of the virus observed in contemporary cohorts in the western world.