Some epidemiological and clinical characteristics of African AIDS.

Abstract

The virological pattern of AIDS in Africa is quite different from that found in Western countries. For example viral isolates (LAV-II) related by their glycoprotein to the simian T lymphotropic virus type III (STLV-III) and by their core proteins to LAV-I have been isolated in AIDS patients from West Africa. Further antibodies against STLV-III and HTLV-IV have been identified in residents of Senegal who previously had no history of AIDS or AIDS-related illness until now. Additionally scientists have found that HTLV-III/LAV is linked to visna virus and to bovine leukemia virus. Therefore it is possible that the HTLVs are related to a continuum of genomic evolution from a common animal ancestor present for a long time in Africa. This hypothesis is supported by the fact that the Aids virus or a related virus has been present in Africa since the early 1960s and its prevalence was a low .2%. There are also differences between the epidemiology of AIDS in African and that in the US and Europe. In Africa AIDS is primarily transmitted heterosexually rather than homosexually and via intravenous (IV) drug use as is the case in the US and Europe. In a study of 36 African AIDS patients in a Belgian hospital the most frequent opportunistic infections included digestive candidiasis cerebral toxoplasmosis and cryptococcal meningitis. This study confirmed the remarkable differences in the type of opportunistic infections between african heterosexual patients and US homosexuals or IV drug users. For example 58-63% of US AIDS patients acquired Pneumocystis carinii pneumonia while only 25% of the African patients had it. On the other hand 7% US patients had cryptococcal meningitis and 4% had Toxoplasma gondii encephalitis and 13% and 21% of the African patients acquired them respectively.