Factors associated with diagnostic evaluation for tuberculosis among adults hospitalized for clinical pneumonia in Thailand.

Objective: Thailand is one of 22 countries designated by the World Health Organization as "high burden" with regard to tuberculosis. Preventing nosocomial tuberculosis transmission remains an important, unmet need. We investigated the adequacy of current practices to evaluate hospitalized patients for tuberculosis, which is critical in preventing delayed diagnosis and nosocomial tuberculosis transmission.

Methods: Thailand conducts active, population-based surveillance for pneumonia in 2 rural provinces. Case report forms are completed for all persons who are hospitalized and meet a case definition of having clinical pneumonia. We analyzed how frequently patients had an adequate diagnostic evaluation for infectious pulmonary tuberculosis, in accordance with national guidelines. We conducted multivariate analyses to determine patient and health-system factors associated with an inadequate diagnostic evaluation for tuberculosis and with tuberculosis disease.

Results: Of 8,853 cases of clinical pneumonia between September 2003 and March 2006, 73% were in patients not adequately evaluated for tuberculosis. Acid-fast bacilli (AFB)-positive tuberculosis was diagnosed in 188 cases, which was 2% of all pneumonia cases and 12% of pneumonia cases in patients adequately evaluated for tuberculosis. Diagnostic evaluations for tuberculosis were less commonly performed among those who were younger than 25 years of age, were female, and lacked cough, sputum production, hemoptysis, and dyspnea. Among patients adequately evaluated, a clinical syndrome of no cough, no hemoptysis, and normal chest radiography findings had a 95% negative predictive value.

Conclusions: The prevalence of AFB-positive, pulmonary tuberculosis was high among adults hospitalized with clinical pneumonia in Thailand. Most patients were not adequately evaluated for tuberculosis. Efforts are needed to improve identification and diagnosis of infectious tuberculosis cases in hospitalized patients.