The stability between two HIV-1 RNA measurements one year apart and the relationship with HIV subtype in rural Uganda

We compared HIV-1 RNA levels using the nucleic acid sequenced based amplifi cation (NASBA) test kit in 2 samples taken one year apart from participants infected with env subtype A or D in a population-based cohort in Uganda. F ifty participants were infected with subtype A and 70 with subtype D. HIV-1 RNA levels were significantly higher in subtype D unadjusted (P=0.001), an d after adjusting for age, gender, and CD4 count (P<0.001). Eighty-six part icipants had HIV-1 RNA measurements in both years and 67 (78%) were within one log(10) of their result a year before. There was no relationship betwee n the difference in log viral load and proportion of CD4 change. Individual s infected with subtype D had a higher average increase in viral load and t his was statistically significant if adjusted for baseline levels and CD4 c ount (P=0.015).