By Emma Wilkinson
Health reporter, BBC News
HIV testing should be done more widely, experts say.
All 15-59 year olds in some areas of England should be offered a HIV test by their GP, new recommendations say.
In 42 trusts with more than two HIV cases for every 1,000 people, everyone should be offered the test when they join a GP surgery, experts said.
Around 20% of the population would fall under the universal testing policy.
The guidelines, backed by the Department of Health, also support improved testing in high-risk groups such as men who have sex with men.
Most of the high-prevalence areas are in London, but others include Brighton, Manchester, Blackpool and Birmingham.
Dr Adrian Palfreeman, author of the guidelines, and a consultant in Leicester said the idea was to "normalise" HIV testing.
"Until recently it was regarded as something exceptional that you needed special counselling for.
"What we're saying is that, in these areas, anyone attending primary health care the offer of the test should be made - for example when the patient registers with the GP for the first time."
All general medical admissions to hospital should also be offered the test, the guidelines advise.
Dr Palfreeman added that implementing the recommendations would require a change in the culture of primary care and also stressed no one would be tested without their consent.
The guidelines, developed by the British HIV Association, the British Association for Sexual Health and HIV and the British Infection Society also promote routine testing in antenatal clinics, sexual health clinics and drug dependency programmes in all areas of the country.
The Health Protection Agency (HPA), which has backed the recommendations, calculates a universal offer of HIV testing is cost-effective when the diagnosis rate is greater than one per 1,000 tests.
Professor Peter Borriello, director of the HPA Centre for Infections, said around a third of the 73,000 people with HIV in the UK do not know that they have the infection.
"The trouble with so many people being unaware of their infection is that onward transmission is more likely, and late diagnosis is associated with more serious HIV disease.
"Without earlier diagnosis we will not see the reduction in transmission that we need to see, nor a further fall in serious disease.
"Increased HIV testing under the new guidelines should lead to much earlier HIV diagnosis for those that are infected."
He added the guidelines would help to normalise testing and remove the "stigma".
Elizabeth Pisani, an epidemiologist and journalist who has worked on HIV programmes around the world said on the whole the recommendations were "extremely sensible".
But she questioned the need for a universal approach if high-risk groups were targeted properly.
"It's sort of a cop-out because it's allowing GPs and health services to not have to ask about high-risk behaviour.
"If you target your testing to those high-risk groups you will pick up a much higher proportion for much lower testing cost."