The long asymptomatic stage from infection to disease, approximately seven to ten years, further complicated by the non-specific nature of the opportunistic infections, has masked the emergence of the epidemic to the general population. Prior to 1985 HIV infection was rare among the heterosexual population. The doubling time is relatively short, estimated at 11 to 13 months, but shows no sign of increasing despite the substantial rise in prevalence. The epidemic has taken root and is well established in all the population groups, although HIV infection is most common among Africans. Comparisons for 1994 were not available at the time of going to press.
Infection is more common among women than men.
The virus is spreading most rapidly among young people between the ages of 15 and 30. Behavioural strategies include practising mutually faithful monogamy, reducing the number of concurrent sexual partners, postponing engaging in penetrative sex, especially among young women, appropriate care-seeking behaviour for STDs, especially ulcerative STDs, and consistent and correct use of male and female condoms. 16,17 Unprotected multiple partner relationships are the major facilitator of the rapid transmission of the virus. Many women have many children by different consorts and sex is sometimes used to obtain security, favours and money. However, consistent condom use in every sexual encounter is rare.