Factors associated with tuberculin skin test reactivity among HIV-infected people in Bangkok.

INH preventive therapy (IPT) has been shown in several randomized controlled trials to reduce the risk of developing active TB in tuberculin skin test (TST) or purified protein derivative (PPD) positive HIV infected individuals. Detection of latent tuberculosis by TST and determination of factors associated with the PPD positivity in HIV-infected persons are important for the targeting of chemoprophylaxis. Six hundred asymptomatic and early symptomatic HIV-infected subjects attending the AIDS Clinic of the Chulalongkorn University Hospital, Bangkok, Thailand were enrolled in two randomized clinical trials of chemoprophylaxis against TB from December 1994 to December 1996.