Home grown heterosexually acquired HIV infection.

The public and the health professions might well feel confused about the heterosexual spread of HIV in the United Kingdom. Press headlines swing from dire warnings of a major epidemic to arguments based on the available data that the risks are minuscule, the public education campaigns erroneous, and the policy makers guilty of scare mongering. Two articles published by the Communicable Disease Surveillance Centre last month help to clarify the situation, if not to resolve the uncertainty about future heterosexual spread.' 2 Evans et al reported that by the end of last year 417 cases of AIDS and 1620 cases of HIV-1 infection probably acquired through heterosexual intercourse had been reported in people in England, Wales, and Northern Ireland. Between 1986 and 1991 the proportion of cases of AIDS attributable to heterosexual transmission increased from 2% to 14% and diagnosed HIV infections from 4% to 23%.3 Similar increases have been reported from Edinburgh, southern Europe, and the United States, particularly in association with concurrent epidemics among injecting drug misusers.36 Most of the heterosexually acquired cases of HIV infection and AIDS in England, Wales, and Northern Ireland, however, are attributable to sexual contact in parts of the world where heterosexual transmission predominates (largely sub-Saharan Africa).' The recent public debate has focused on the lack of prominence given to this epidemiological fact in public health campaigns and an ill defined feeling that infection acquired abroad can be discounted because it does not involve heterosexual transmission within the United Kingdom. Evans et al defined three categories of heterosexual transmission .' "First generation transmission" describes heterosexual transmission of HIV infection from a partner infected by other means-for example, injecting drug misuse, blood products, or sex between men. "Second generation trans-mission" describes heterosexual infection by partners who were themselves infected through heterosexual intercourse. Cases of second generation transmission are subdivided according to where infection is presumed to have occurred-either abroad or in the United Kingdom. Ten per cent of cases of AIDS acquired heterosexually (17% of HIV infections) were due to first generation transmission , with injecting drug misuse the commonest route of infection in the source partners. Four out of five cases of heterosexually acquired AIDS (74% of HIV infections) were categorised as due to second generation transmission abroad. Second generation transmission in England, Wales, and Northern Ireland accounted for 11% (n=47) of cases of heterosexually acquired AIDS and 9% (n= 131) of cases …