Dual infection with human immunodeficiency virus type 1 and type 2: impact on HIV type 1 viral load and immune activation markers in HIV-seropositive female sex workers in Abidjan, Ivory Coast.

To determine the impact of dual infection with HIV-1 and HIV-2 on HIV-1 viral load and markers of immune activation among HIV-seropositive FSWs in Abidjan, we analyzed blood samples obtained from consenting HIV-seropositive FSWs attending a confidential clinic between September 1996 and June 1997 in Abidjan. Among HIV-1 and HIV-2 dually seropositive FSWs, polymerase chain reaction (PCR) testing with HIV-1 and HIV-2 primers was used to differentiate between FSWs who were PCR positive only for HIV-1 and those positive for both HIV-1 and HIV-2 (dually infected). Of the 203 FSWs, 151 (74%) were HIV-1 seropositive only (median age, 26 years), 4 (2%) were HIV-2 seropositive, and 48 (24%) were dually seropositive (median age, 30 years). Of the 48 dually seropositive FSWs, 33 (69%) were dually infected and 15 (31%) were dually seropositive. Median CD4+ T cell counts per microliter were not significantly different among the three groups (525 for HIV-1 positive only, 502 for dually infected, and 416 for dually seropositive) (p = 0.14). Median viral load (log10 copies/ml) was not significantly different among the HIV-1-only FSWs (4.8 log10 copies/ml) compared with the 32 dually infected FSWs (4.6 log10 copies/ml) and 14 dually seropositive FSWs (4.7 log10 copies/ml; p = 0.95). Median levels of HLA-DR immune activation were increased in both CD4+ and CD8+ T cells for the dually infected (n = 27) FSWs compared with those infected with HIV-1 only (n = 123) (p = 0.019 and p = 0.01, respectively). Dual infection does not appear to influence levels of HIV-1 viral load in vivo. However, levels of HLA-DR are higher among FSWs dually infected with HIV-1 and HIV-2 than among those infected with HIV-1 only.