More than a third of HIV diagnoses in the United Kingdom occur late, increasing HIV/AIDS-related morbidities and the likelihood of onward transmission, researchers at a conference in Manchester said Thursday. Voluntary HIV testing should be routine in high-prevalence areas to fight steadily rising infections, they said.

"It is in the interest of everyone for local health authorities and health care professionals to take a real stance on this issue," said Dr. Keith Radcliffe, president of the British Association for Sexual Health and HIV, which was holding its annual conference with the British HIV Association.

One presentation involved testing patterns at a large inner-city hospital in an area with high HIV prevalence. Of HIV-positive patients, 41 percent had not been offered screening for the virus though they had been in contact with a health provider for an HIV-related reason during the previous two years.

In a second, six-month study of acute general medical admissions, just one-third of undiagnosed HIV-positive patients had been targeted for testing. Under routine testing, the remaining two-thirds would have been properly diagnosed.

"I still get people saying, 'When I offered a test, the patient got up and left the room,'" said Dr. Mark Pakianathan, a London-based HIV expert. "It's about how you offer the test, as well." Some clinicians may also have missed out on the changes in treatment over the decades, he added.

"Changing patterns of HIV transmission further underscore the need to raise awareness among physicians and make the test a standard first-line investigation in many secondary care settings," said Professor Ian Gilmore, president of the Royal College of Physicians.