Aids was reported first in 1981 from the United States, and by 1986 the World Health Organisation recorded that 77 per cent of the world's total Aids cases had been in the US - 10,000 compared with 37 in Africa. Between 1986 and 1991, WHO Weekly Epidemiological Records show the US's share of new Aids cases falling from 75 per cent to 48 per cent of the world's total, while Africa's rose from 0.2 per cent to 25 per cent. Raw cases do not, however, give a clear picture and must be considered as proportions of each region's population to show the relative prevalence of disease.
Aids has always been most prevalent in the US, and in mid-1990 the US reported more than 53 cases per 100,000, compared with 10 for Africa, 7 for Europe and 5 for the world as a whole.
Bear in mind also that diagnoses in the US are likely to be more certain and to be confirmed by pathological tests, whereas when laboratory facilities are scarce, diagnoses are based on
a set of Aids-related signs that
are neither specific nor selective enough (Gallant et al, Aids, 1992, 6, 295-299) to be reliable. The same is sometimes unfortunately true of Aids-related reporting.
Thames Valley University