The effect of tuberculosis control in China

Abstract

Background: China has 1.4 million new cases of tuberculosis every year, more than any country except India. A new tuberculosis control project based on short-course chemotherapy was introduced in half the country in 1991, after a national survey of tuberculosis prevalence in 1990. Another survey was done in 2000 to re-evaluate the national tuberculosis burden, providing the opportunity to assess the effect of the control project.

Methods: The survey in 2000 identified 375599 eligible individuals at 257 investigation points chosen from all 31 mainland provinces by stratified random sampling. Children (aged 0-14 years) were suspected of having tuberculosis if they had an induration of 10 mm or greater after a tuberculin skin test, and an abnormal fluorograph. Adults were suspected if they had a persistent cough, abnormal fluorograph, or both. Tuberculosis was diagnosed by chest radiograph, sputum-smear microscopy, and culture.

Findings: 365097 people were examined (97% of those eligible). Prevalences of pulmonary, culture-positive, and smear-positive tuberculosis in 2000 were 367 (95% CI 340-397), 160 (144-177), and 122 (110-137) per 100000 population, respectively. Between 1990 and 2000, prevalences of these three forms of the disease had fallen, respectively, by 32% (5-68), 37% (7-66), and 32% (9-51) more in areas in which the project was implemented than in non-project areas. For culture-positive disease, a 30% (9-48) reduction was directly attributable to the project.

Interpretation: Between 1991 and 2000, prevalence of tuberculosis was reduced significantly in areas of China by use of short-course chemotherapy following WHO guidelines. We estimate that in 2000, in a population of more than half a billion, there were 382000 fewer prevalent culture-positive cases and 280000 fewer prevalent smear-positive cases than there would otherwise have been.