HIV seroconversion interval and demographic characteristics: no evidence of selection bias

Objectives: To determine if the interval between the last negative and the first positive HIV test is associated with demographic characteristics of H IV seroconverters. Methods: A prospective cohort of patients with HIV seroconversion enrolled in the Lyons HIV hospital database was analysed. Comparisons of demographic characteristics were performed after stratification on the duration of the interval between the last HIV negative screening test and the first HIV po sitive screening test, which ranged from 1 day to 24 months. Linear regress ion methods were used to identify the covariates associated with a negative HIV antibody test followed by a positive test. Results: Age (p=0.54), sex (p=0.78), heterosexual route of infection (p=0.7 8), other route (p=0.40) compared with homosexual route, and estimated year of HIV infection (p value ranged from 0.84 to 0.95) were not associated wi th a shorter seroconversion interval after multivariate analyses. The prese nce of an acute HIV illness was the only predictor of a short seroconversio n interval (p=0.006) with a reduction of 84 days of the interval when it wa s reported. Conclusions: No selection bias for demographic characteristics of HIV seroc onverters seems associated with the length of the seroconversion interval, at least for intervals less than or equal to 24 months.