The effect of tuberculosis control in China.

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.