HIV-1 RNA levels in an African population-based cohort and their relation to CD4 lymphocyte counts and World Health Organization clinical staging

Apart from a small number of reports from people who are based in hospitals , data on viral load in HIV-infected people in sub-Saharan Africa, where mo st infections occur, are lacking. We report serum HIV-1 RNA levels in a pop ulation-based cohort in rural Uganda using the nucleic acid sequence-based amplification procedure (NASBA) test kit and describe their relation to CD4 counts and World Health Organization (WHO) clinical staging. The median (i nterquartile range [IQR]) viral loads were 87,000 copies/ml (37,500-295,000 copies/ml) in 40 prevalent cases infected for >6 years, and 31,000 copies/ ml (7800-174,000 copies/ml) in 65 incident cases with seroconversion dates within the previous 6 years. Although we found a correlation between viral load and absolute CD4 count (p < .0001), there was no evidence for an assoc iation with CD4 decline (p = .1). Overall, there was a significant trend of increasing viral load with worsening clinical stage from a median viral lo ad of 15,000 for those in WHO stage 1 (asymptomatic) to 150,600 copies/ml f or those in stage 4 (AIDS; p < .001). However, the association was seen onl y in incident cases. Thus, we found that the NASBA test on serum was a usef ul indicator of disease stage especially in persons known to be infected fo r <6 years. Such baseline data are important for vaccine research, and if a ntiretroviral drugs become available to more than a few people in Africa, i t will be important that accurate viral load estimations are available at l east in a proportion of people to monitor the effectiveness of treatment, a nd measure the compliance and emerging resistance to these drugs.