Prevalence of<i>Mycobacterium tuberculosis</i>in Sputum and Reported Symptoms Among Clinic Attendees Compared With a Community Survey in Rural South Africa
Indira Govender, Aaron S Karat, Stephen Olivier, Kathy Baisley, Peter Beckwith, Njabulo Dayi, Jaco Dreyer, Dickman Gareta, Resign Gunda, Karina Kielmann, Olivier Koole, Ngcebo Mhlongo, Tshwaraganang Modise, Sashen Moodley, Xolile Mpofana, Thumbi Ndung’u, Deenan Pillay, Mark J. Siedner, Theresa Smit, Ashmika Surujdeen, Emily Wong, Alison D. Grant
Abstract
BACKGROUND: Tuberculosis (TB) case finding efforts typically target symptomatic people attending health facilities. We compared the prevalence of Mycobacterium tuberculosis (Mtb) sputum culture-positivity among adult clinic attendees in rural South Africa with a concurrent, community-based estimate from the surrounding demographic surveillance area (DSA). METHODS: Clinic: Randomly selected adults (≥18 years) attending 2 primary healthcare clinics were interviewed and requested to give sputum for mycobacterial culture. Human immunodeficiency virus (HIV) and antiretroviral therapy (ART) status were based on self-report and record review. Community: All adult (≥15 years) DSA residents were invited to a mobile clinic for health screening, including serological HIV testing; those with ≥1 TB symptom (cough, weight loss, night sweats, fever) or abnormal chest radiograph were asked for sputum. RESULTS: Clinic: 2055 patients were enrolled (76.9% female; median age, 36 years); 1479 (72.0%) were classified HIV-positive (98.9% on ART) and 131 (6.4%) reported ≥1 TB symptom. Of 20/2055 (1.0% [95% CI, .6-1.5]) with Mtb culture-positive sputum, 14 (70%) reported no symptoms. Community: 10 320 residents were enrolled (68.3% female; median age, 38 years); 3105 (30.3%) tested HIV-positive (87.4% on ART) and 1091 (10.6%) reported ≥1 TB symptom. Of 58/10 320 (0.6% [95% CI, .4-.7]) with Mtb culture-positive sputum, 45 (77.6%) reported no symptoms. In both surveys, sputum culture positivity was associated with male sex and reporting >1 TB symptom. CONCLUSIONS: In both clinic and community settings, most participants with Mtb culture-positive sputum were asymptomatic. TB screening based only on symptoms will miss many people with active disease in both settings.