Abstract: Objective The purpose of this study is to determine the role of TB screening questionnaire in diagnosis and ruling out active TB in people living with HIV/AIDS, and provide reference for basic level doctors.  Methods HIV/AIDS patients were consecutively enrolled in 4 counties during Sep.2006 to Feb.2007. For each HIV/AIDS patient, TB suspicious symptoms were obtained through TB screening questionnaire, and part of patients received further clinical evaluation. Sensitivity, specificity, likelihood ratios, and post-test probability were analyzed for any single symptom, and combination of multiple symptoms. The gold standard is the diagnosis result by sputum smear, X ray, and clinical expert committee.  Results Current TB screening questionnaire adopted by China has 100% sensitivity and 65.6% specificity. The highest frequency of symptoms occurred in HIV/AIDS patients were: cough, night sweat, and fatigue. The probability of active TB increased significantly in patients with bloody sputum and those with recurrent fever. The single symptom of cough has the highest 92.1% sensitivity among all single symptoms, and its specificity is 73.8%. Cough negative is a strong indicator in ruling out active TB. 85.4% of HIV/AIDS patients have 1 to 3 symptoms. Active TB detected among them contributes to 78.6% of all diagnosed TB cases. For HIV/AIDS with only 1 TB suspicious symptom, the post test probability of active TB is 5%; while for those with 2 to 5 symptoms, this probability is around 12%. Therefore patient with 2 to 5 symptoms are equally important.  Conclusion TB screening questionnaire constitute a low-cost and effective tool to increase detection of active TB in people living with HIV/AIDS, especially in resource-constraint setting, simple and feasible screening could facilitate the detection.

Key words: AIDS, tuberculosis,pulmonary, superinfection, questionaires