Contribution of Xpert® MTB/RIF to tuberculosis case finding among pregnant women in Botswana.

Abstract

Seven health facilities with antenatal care (ANC) clinics in two districts near Gaborone, Botswana. To determine 1) the prevalence of tuberculosis (TB) and HIV-TB co-infection in pregnancy, and 2) the sensitivities of symptomatic TB screening and Xpert testing against gold standard culture. This was a cross-sectional study. Pregnant women were randomly enrolled and screened using TB symptoms. HIV status was determined from ANC clinics' client records. Two sputum specimens were collected from all clients and each was tested using Xpert® and culture for Mycobacterium tuberculosis. Of 407 cases, eight had one or more TB symptoms, and all tested negative with Xpert® and culture. Another two (0.5%, 95%CI 0.08-1.96) asymptomatic clients tested positive with both tests. The adjusted TB prevalence was higher than that of the general population (0.6% vs. 0.24%; P < 0.001). The prevalence of TB among HIV-positive and HIV-negative clients was 1/69 (1.45%, 95%CI 0.29-2.61) and 1/336 (0.3%, 95%CI 0.23-0.83), respectively (Fisher's exact test P = 0.312). Xpert® demonstrated a 100% sensitivity and 100% specificity, while symptom screening had 0.0% sensitivity and 98% specificity. TB prevalence among pregnant women was high and TB symptom screening had limited ability to detect TB. An alternative TB screening algorithm for pregnant women is urgently needed irrespective of TB symptoms.