Dr David Barlow, consultant in genito-urinary medicine at St Thomas's Hospital, London, said at a meeting on women and HIV that predictions of a heterosexual epidemic had been based on an incorrect assumption. 'I present a less pessimistic view because the predicted epidemic has not happened. If you call just an increase in figures an epidemic then, yes, there is one. But if by definition you mean an increase in transmission then I think the figures suggest the answer is no.' He said most predictions made previously by the medical profession about the numbers of heterosexual people who would be HIV- positive by the end of 1992 were overestimated by as much as 10 times. By the end of last year there were about 7,000 reported cases of HIV infection through heterosexual sex.
Speaking at the biennial symposium, HIV Infection and Women, Dr Barlow said the error had arisen from a mistaken assumption that people had 'random' sexual partners, which was the key to the models of sexual behaviour used to make the predictions. This assumed that all people were the same in choosing their sexual partners - that an individual was as likely to have sex with someone from Sweden or Africa as they would with a British person.
Dr Barlow said that according to his research, people did not have sex 'randomly' in this way. He pointed to the fact that only 1 of 51 infected African patients had a British-born partner. The St Thomas's survey shows more than 75 per cent of HIV-infected patients detected in the last eight months were not born in the UK.
'The majority of infected heterosexuals in the UK were infected abroad. The old-fashioned view was it does not matter where you caught HIV. But in general people do not have sex randomly. The earlier models do not take this into account,' he said.
He added that the low incidence in Britain of other sexually transmitted diseases such as gonorrhoea was another factor which had affected the spread of HIV.
Delegates at the conference from the health education field expressed concern that Dr Barlow's findings implied the need to target certain groups for testing, and that this could lead to social tension.
Dr Kaye Wellings, of St Mary's Hospital Medical School, London, warned that the danger with targeting was that those outside the groups aimed at might stop practising safe sex and expose themselves to HIV infection.
Dr Wellings, a researcher for the National Survey of Sexual Attitudes and Lifestyles, said: 'Sixty per cent of women in the mid- to late-Eighties used condoms at the time of first sexual intercourse. This is 50 per cent higher than it was for people having intercourse for the first time before the Eighties.
'The government campaigns have succeeded because more women are using condoms than women who first had sex in the pre-Pill days. This really is quite striking.'Reuse content