Determining the prevalence of tuberculosis in emergency departments in the Eastern Cape region of South Africa and the utility of the World Health Organization tuberculosis screening tool

Background. South Africa (SA) faces a significant tuberculosis (TB) burden complicated by high rates of HIVTB coinfection. In SA, emergency departments (EDs) play an important role in screening for TB. Objectives. To determine the prevalence of TB in the ED and the effectiveness of the World Health Organization (WHO) TB screening tool. Methods. This was a crosssectional observational study, conducted in the ED at Livingstone Hospital, Port Elizabeth, from 4 June to 15 July 2018. All patients aged >18 years and able to consent were administered the WHO TB screening questions and underwent a pointofcare HIV test and demographic data collection. Patients were followed up for 1 year and tracked in the National Health Laboratory Service database to determine TB status using laboratory testing. Results. Over the study period, 790 patients were enrolled. Overall, 121 patients (15.3%) were TBpositive, with 46 (38.0%) diagnosed after presenting to the ED and 75 (62.0%) with a previous TB history determined by selfreport or confirmed laboratory testing. A greater proportion of the TBpositive patients were HIVpositive (49.6%) compared with the TBnegative population (24.8%). TBpositive individuals were more likely to present to the ED with a chief complaint of shortness of breath (SoB) (18.2%) compared with the TBnegative population (10.5%). Overall, the WHO TB screening tool had poor sensitivity (46.5%) and specificity (62.5%) for identifying TBpositive patients in the ED. A multiple logistic regression analysis, controlled for age and sex, showed HIV status (odds ratio (OR) 2.81; p<0.001) and SoB (OR 2.19; p<0.05) to be significant predictors of TB positivity. Adding positive HIV status and a presenting complaint of SoB increased sensitivity to 78.3%. Conclusions. EDs in SA face a high burden of TB. While WHO screening guidelines identify some of these patients, including routine HIV testing in the ED could significantly affect the number of TB diagnoses made.