Polymerase chain reaction for Mycobacterium tuberculosis: impact on clinical management of refugees with pulmonary infiltrates.

Abstract

STUDY OBJECTIVES: Screening for pulmonary tuberculosis (TB) in war refugees entering low-prevalence countries for TB is a common policy, but workup strategies are difficult and expensive. DESIGN: Prospective screening of war refugees for TB by chest radiograph and evaluation of the impact of additional polymerase chain reaction (PCR) testing for Mycobacterium tuberculosis complex (MTB) on clinical management in case of pulmonary infiltrates suspicious for TB. SETTING: Academic university medical center. PATIENTS: A total of 3,119 adult war refugees from the Kosovo war were screened by chest radiograph on arrival. Refugees with pulmonary infiltrates suspicious for TB were hospitalized, and a standardized diagnostic workup was performed. MEASUREMENTS AND RESULTS: Of 3,119 adult war refugees screened for TB, 29 patients (0.9%) were identified with pulmonary infiltrates suspicious for TB; 103 specimens (76 sputa; 27 BAL fluids) were collected for acid-fast smear (AFS), PCR, and culture. The prevalence of culture-proven TB infection in this population was 27.6%. Sensitivity for PCR was higher compared with AFS for all specimens (64% vs 20%; p < 0.01) and also for each refugee with at least one positive specimen finding (100% vs 37.5%; p = 0.025). More important, the negative predictive value for three consecutive PCRs (in two sputa and one BAL) was 100%. CONCLUSIONS: Repeated PCR testing for MTB in a population of asymptomatic war refugees with pulmonary infiltrates highly suggestive of TB is significantly more sensitive than AFS. Three negative PCR results allow discharge from isolation, thus reducing the economic burden of isolation strategies.