Frequency of Mycobacterium tuberculosis infection among Iranian patients with HIV/AIDS by PPD test

Persons infected with the Human Immunodeficiency Virus (HIV) are particularly susceptible to tuberculosis, either by latent infection reactivation or by a primary infection with rapid progression to active disease. This study was done to determine the frequency of tuberculosis infection among Iranian patients with HIV/AIDS. A total of 262 HIV/AIDS patients attending all three HIV/AIDS health care centers of Tehran, Iran were enrolled in this study. A detailed history and physical examination were obtained from all HIV patients suspected of having pulmonary M. tuberculosis. A positive PPD skin test was used as a diagnostic parameter for probability of TB infection. Out of 262 HIV/AIDS patients, a total of 63 (24%) were shown to have the tuberculosis infection based on a positive PPD skin test. Of the patients with positive PPD skin test, 22 (35%) had pulmonary Tuberculosis, 2 (3.2%) had extrapulmonary tuberculosis, and 39 (53%) had no evidence of M. tuberculosis infection (latent infection). Also 8 (12.7%) had history of long term residence in a foreign country, 32 (50.8%) were exposed to an index case, and 9 (14.3%) had past history of pulmonary tuberculosis, while only 33.3% had clinical manifestations of TB (active disease). There was no resistant case of tuberculosis. Our study showed that near 24% of Iranian patients with HIV/AIDS were infected with M. tuberculosis. This finding denotes the need to improve the diagnostic and preventive measures, and also prompt treatment of this type of infection in the HIV infected individuals.