Absence of HIV-1 and HIV-2 seroconversions in a cohort medical students in a Nigerian medical school.

: A cohort of 70, HIV-1 and HIV-2 seronegative medical students were followed up for 30 months, after which 65 were retested for HIV antibody. None of the students was infected by HIV during the period of study. A questionnaire survey carried out showed that all the students had a very good knowledge of HIV, its mode of transmission, control and prevention. Most of the students have never had sex or had a single sex partner and used condoms always or most of the time during sexual intercourse.