Epidemiology of Mycobacterium tuberculosis infection among Iranian HIV–infected patients

BACKGROUND: The global epidemic of HIV infection has secluded a large population who are highly suspected to be infected by Mycobacterium tuberculosis (TB), resulting in marked increase in morbidity and mortality rates among these patients. In this study, we defined the prevalence of TB infection in a HIV–infected population. In addition, a number of probable related risk factors were evaluated in these cases. METHODS: A total number of 262 HIV–infected patients from two diagnostic and therapeutic centers of infectious disease in Tehran, Iran, were enrolled in this study. Diagnosis of TB infection was based on PPD test. The induration of more than 5 mm was considered TB infection. RESULTS: A total number of 63 cases (24.0%) of TB infection were found. Twenty-four patients (9.2%) had a past history of TB disease. Only 20 patients (7.6%) had a history of prophylaxis therapy for TB. There was a significant association between TB infection rate and history of imprisonment (p < 0.001), history of drug abuse (p < 0.001) and history of close contact with a known TB patient (p < 0.001). On the other hand, we did not find any significant association between TB rate and the type of drug abuse, past history of treated TB disease, presenting clinical symptoms, and infection by Pneumosystis carinii. CONCLUSION: HIV–infected patients are at a high risk of being infected by TB. A number of risk factors of HIV acquisition such as drug abuse and imprisonment can increase the risk of TB co-infection in Iran. These mentioned features are related to some special socioeconomic conditions in Iran.