“…Most of these studies were based on specific populations (intravenous drug users, students, clients of family planning clinics, STD clinic attenders, etc.) (Evans et al, 1991;Lindan et al, 1990;Plitcha et al, 1992;Upchurch et al, 1992;Van Den Hoek et al, 1992) and/or focused on a limited segment of the population (Adolescents/young adults, one gender only, one city or one geographical region, etc.) (Evans et al, 1991;Levy et al, 1988;Lindan et al, 1990;Plitcha et al, 1992).…”