Characteristics of 563 Zambians who were HIV-1 seropositive at enrollment and 221 seroconverters who became seropositive during quarterly follow-up visits.

Dates (month/year) of seropositive tests, duration of follow-up (DOF, for SPs), and duration of infection (DOI, for SCs) are shown as median and interquartile range (in parentheses). The difference between patient groups is assessed using Mann-Whitney U test. All other comparisons between patient groups are based on Student's t-test (for quantitative measures) and χ2 test (for categorical measures). F = female; M = male; NA = not applicable; SD = standard deviation of the mean.