WESTPORT, CT (Reuters Health) - UK investigators found that the rate of HIV infection among tuberculosis clinic attendees in London was 11 percent, twice the previously estimated rate. They therefore recommend that HIV testing should be offered to all patients diagnosed with Mycobacterium tuberculosis infection.
Little information is available on HIV and TB co-infection in London and among individuals of different ethnic groups, Dr. Charlotte F.J. Rayner, of St. George's Hospital, London, and colleagues report in the October 28th issue of Lancet. Furthermore, "there is no guidance about when patients with TB should be offered HIV testing or which patients should be tested."
To further investigate, the investigators prospectively collected blood samples by anonymous methods from 202 patients with TB who were attending three London chest clinics between December 1998 and November 1999. They also collected saliva samples from 97 TB contacts and 115 new UK entrants.
"To prevent deductive disclosure," they say, "we collected demographic data on only age group, ethnic origin and sex." The researchers found that 11. 4 percent of the TB patients were HIV-positive. In addition, 5 percent of the individuals screened for TB and 4.3 percent of the new UK entrants were also HIV-positive. They note that the distribution of HIV-positive patients across ethnic groups, age groups and by sex was similar.
"The servoprevalence of HIV-1 in TB patients is more than double previous estimates," Dr. Rayner and his colleagues conclude. "Moreover, because we specifically excluded patients already known to be HIV-positive, the true co-infection rate in South London may be as high as 17 to 20 percent."