Provisional country estimates of prevalent adult human immunodeficiency virus infections as of end 1994: a description of the methods

Background A country-by-country review of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) data was undertaken by the World Health Organization. This paper describes the methods used to make estimates of HIV prevalence. Results It is estimated that, globally, approximately 16.9 million adults were living with HIV infections at the end of 1994. The majority (66%) of the infections were in sub-Saharan Africa (over 11 000 000), followed by South and South East Asia (over 3 000 000). Estimated prevalence rates for HIV infection ranged from less than 1 per 100 000 sexually active adult population to 18 per 100 (18%), with a median prevalence of 14 per 10 000. In 50 countries the estimated HIV prevalence rate was less than 5 per 10 000 sexually active adults. In 15 countries (all in sub-Saharan Africa) the prevalence rate was above 5%. The lowest estimated prevalence rates were seen in Central and East Asia and the highest in Central and Southern Africa. Conclusions Estimates of prevalent HIV infections are intended to give an indication of the magnitude of the HIV pandemic but, due to the difficulties in accurately assessing the levels of HIV infections in national populations, should be considered provisional.