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 HIV 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 positive screening test, which ranged from 1 day to 24 months. Linear regression 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 = 0.78), 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 with a shorter seroconversion interval after multivariate analyses. The presence of an acute HIV illness was the only predictor of a short seroconversion interval (p = 0.006) with a reduction of 84 days of the interval when it was reported.
CONCLUSIONS: No selection bias for demographic characteristics of HIV seroconverters seems associated with the length of the seroconversion interval, at least for intervals < or = 24 months.