Prevalence of pulmonary tuberculosis in adult population of Tanzania: a national survey, 2012.

SETTING: Tanzania is classified as one of the 22 high tuberculosis (TB) burden countries; however, the true burden of TB disease in the country remains unknown. OBJECTIVE: To assess the prevalence of bacteriologically confirmed pulmonary TB (PTB) in the adult population. DESIGN: This was a community-based cluster randomised survey with proportional-to-population-size selection of primary sampling units (districts). Participants were screened for TB using a symptom questionnaire and chest X-ray (CXR). Those with abnormal CXR and/or at least one symptom suggestive of TB were classified as individuals with presumptive TB, and asked to submit three sputum specimens for smear microscopy and culture. RESULTS: The weighted prevalence for sputum smear-positive TB cases was 249 per 100 000 adult population (95%CI 192-305) and that for bacteriologically confirmed TB cases was 293/100 000 (95%CI 228-358). Individuals aged ⩾45 years comprised 55% (71/129) of the identified smear-positive cases, but just 28% (6793/24 648) of the notified TB cases. CXR screening identified more TB cases than symptom screening. When weighted for human immunodeficiency virus prevalence among notified new smear-positive cases, the overall case detection of incident TB cases in 2012 was between 37% and 48%. CONCLUSIONS: The prevalence of sputum smear-positive PTB and bacteriologically confirmed PTB in the adult population was higher than previous World Health Organization estimates. There is a potential underestimation of the number of bacteriologically confirmed PTB cases in the adult population. The age distribution of prevalent cases suggests an epidemiological shift towards the older generations, which has been a sign of successful TB control activities in the past. However, the survey shows that many infectious TB cases are currently missed by the National Tuberculosis Programme.

Health care-seeking behaviour among people with cough in Tanzania: findings from a tuberculosis prevalence survey.

SETTING: The study was conducted within a nation-wide population-based tuberculosis (TB) prevalence survey in the adult population in Tanzania. OBJECTIVE: To assess the health care-seeking behaviour of coughers presumed to have TB. DESIGN: A survey in which participants were screened for TB using a symptom questionnaire and chest X-ray (CXR). Those with cough of ⩾ 2 weeks and/or who were coughing blood were interviewed about their health care-seeking behaviour and socio-demographic and clinical factors. RESULTS: Of 3388 people with presumptive TB, 31.0% (1051/3388) had sought treatment for their symptoms. Of these, about 42% (445/1051) sought care at sites with TB diagnostic capacity, where sputum examination was performed in 37.1% (165/445) and CXR in 28.1% (125/445). In sites with limited TB diagnostic capacity, fewer than 1% were referred for sputum examination or CXR. Individuals with additional symptoms were more likely to seek treatment. Knowledge about TB was significantly associated with care seeking at sites with TB diagnostic capacity. CONCLUSIONS: A third of the persons with cough symptoms consistent with TB had sought health care. About 42% sought care in sites with TB diagnostic capacity, but most did not undergo TB diagnostic procedures, precluding a timely diagnosis.