MORTALITY AMONG HUMAN-IMMUNODEFICIENCY-VIRUS TYPE 2-POSITIVE VILLAGERS IN RURAL GUINEA-BISSAU IS CORRELATED WITH VIRAL GENOTYPE

We present the results of a 6-year study of 131 human immunodeficiency virus (HIV) type 2 (HIV-2)-infected individuals from a rural populati on in Guinea-Bissau. Proviral DNA sequences 1.3 kb in length were obta ined from each individual and, together with clinical data, including proviral load and CD4 and CD8 levels, were used to assess whether vira l genotype influences clinical outcome. With a phylogenetic model, a c orrelation was found between viral genotype and mortality; this correl ation was not due to confounding factors, such as age-specific viral s trains or cohabitation of patients. The data provide strong evidence f or the involvement of viral genetic factors in determining HIV disease progression in vivo. The pattern of association found suggests that v irulence factors are multiple and scattered throughout the HIV-2 genom e and can be rapidly gained or lost by the virus through a combination of mutation and recombination. These findings may lead to the identif ication of viral determinants of HIV disease progression.