Decline of Tuberculosis Burden in Vietnam Measured by Consecutive National Surveys, 2007–2017
Hai Viet Nguyen, Hoa Binh Nguyen, Nguyen Viet Nhung, Frank Cobelens, Alyssa Finlay, Cu Huy Dao, Veriko Mirtskhulava, Philippe Glaziou, Huyen T. T. Pham, Petra de Haas, Edine Tiemersma
Abstract
Vietnam, a high tuberculosis (TB) burden country, conducted national TB prevalence surveys in 2007 and 2017. In both surveys participants were screened by using a questionnaire and chest radiograph; sputum samples were then collected to test for Mycobacterium tuberculosis by smear microscopy and Löwenstein-Jensen culture. Culture-positive, smear-positive, and smear-negative TB cases were defined by laboratory results, and the prevalence of tuberculosis was compared between the 2 surveys. The results showed prevalence of culture-positive TB decreased by 37% (95% CI 11.5%-55.4%), from 199 (95% CI 160-248) cases/100,000 adults in 2007 to 125 (95% CI 98-159) cases/100,000 adults in 2017. Prevalence of smear-positive TB dropped by 53% (95% CI 27.0%-69.7%), from 99 (95% CI 78-125) cases/100,000 adults to 46 (95% CI 32-68) cases/100,000 adults; smear-negative TB showed no substantial decrease. Replacing microscopy with molecular methods for primary diagnostics might enhance diagnosis of pulmonary TB cases and further lower TB burden.