Viral dynamics of primary HIV-1 infection in Senegal, West Africa

Few studies have addressed primary human immunodeficiency virus (HIV) type 1 infection in sub-Saharan Africa, where the epidemic is of a predominantly heterosexual character and is caused by different subtypes. The present study examines the dynamics of viral replication in subjects infected with various HIV-1 subtypes.

Seven hundred fifty-two HIV-negative Senegalese women at high risk for infection were monitored every 3 months for acute/early HIV infection; 26 infections were identified (23 HIV-1 and 3 HIV-2), with an HIV-1 incidence rate of 3.23 cases/person-years observation. Multiple viral-load measurements were taken for all seroconverters.

The mean+/-standard deviation viral load for all subjects during the early stage of infection was 4.13+/-0.66 log10 copies/mL, with an overall decrease of 0.22 log10 copies/mL after the early stage; the viral set point was reached after 12 months of infection. Most subjects had relatively low viral loads during the early stage of infection. HIV-1 CRF02_AG-infected women had a significantly higher mean viral load during the early stage of infection (mean +/- SD, 4.45+/-0.60 log(10) copies/mL) than did non-HIV-1 CRF02_AG-infected women (mean+/-SD, 3.78+/-0.46 log(10) copies/mL) (P=.008). None of the subjects reported symptoms consistent with primary HIV-1 infection.

Our findings in Senegalese women differ from what have been described for primary HIV-1 infection. Further investigations of primary infections with non-B subtypes are warranted, to better characterize their differences with primary infections with subtype B.