Almost 30 per cent of HIV infections by the end of 1991 were estimated to be due to heterosexual exposure. Although most of these infections were acquired abroad, they could lead to an 'acceleration' of transmission in the heterosexual community here, the report says.
A marked reduction in the number of new Aids cases among injecting drug users is likely, and there is now little evidence to show 'appreciable current HIV transmission through needle sharing', the report concludes.
The report of a Public Health Laboratory Service working group, chaired by Professor Nicholas Day of the Medical Research Biostatistics Unit at Cambridge University, follows similar surveys in 1988 and 1990. The latest figures are in line with earlier predictions, with some reductions. The working party has drawn on new data from the anonymous blood screening programme, which began in January 1990, and a national survey of sexual attitudes in 1991, allowing more accurate estimates.
The 1995 and 1997 planning projections for new Aids cases among homosexual men are 1,490 and 1,350; among injecting drug users, 145 and 165; and those exposed heterosexually, 605 and 770. At the end of 1997, there will be 4,190 Aids cases alive, and 4,205 cases of other severe forms of HIV disease. The report estimates that at the end of 1991 there were 23,400 HIV positive people in England and Wales, of whom 13,900 had been infected through homosexual exposure, 2,000 through injecting drugs and 6,500 through heterosexual exposure.
By March this year, a total of 117 heterosexuals infected within the UK with no obvious risk factors for HIV, had been reported. Detailed interviews with 30 of them showed their sexual lifestyle to be 'unremarkable', the report said. In 24 of the cases, HIV infection was recognised because of the onset of illness in the individual, a partner or a child; through blood donor screening in two cases; partner notification in two; antenatal testing in one and HIV testing at the beginning of a new relationship for another. Half of those interviewed had contracted another sexually transmitted infection, and the most frequent number of partners in the past five years was three. Of the group, 23 had never practised anal intercourse, and only one had paid for sex.
Baroness Cumberlege, parliamentary secretary at the Department of Health, said that the report 'vindicates' government policies to combat the spread of the disease. 'The UK now has one of the lowest estimated HIV prevalence rates in Western Europe,' she said. But there was no room for complacency and no question of the Government down-grading Aids/HIV prevention. Money would continue to be 'ring-fenced', Lady Cumberlege added.
The incidence and prevalence of Aids and other severe HIV disease in England and Wales for 1992-1997: projections using data to the end of June 1992; Public Health Laboratory Service.