BOX 2-2Drug-Resistant TB in China: Surveillance Resultsa

Renzhong Li of the Center for Disease Control and Prevention, China, reported that China has been engaged in an effort to establish a surveillance system for resistance to anti-TB drugs according to guidelines from WHO and the International Union Against Tuberculosis and Lung Disease. The goals have been to collect data on initial and acquired drug resistance in 11 provinces initially and then for the whole country, to determine the prevalence of drug-resistant TB at the provincial and national levels, and to evaluate the efficacy of ongoing TB control strategies.

During the national drug resistance surveillance in 2007–2008, 70 counties in all 31 provinces of China were randomly selected for surveillance by cluster sampling. Sputum smears and cultures were examined at the county level, while drug susceptibility tests were performed at the national level. Bacterial typing and susceptibility testing were done for all positive samples. The patient's history was carefully obtained, and available medical records were reviewed to determine whether the patient had previously received anti-TB drugs. All laboratory processes were quality assured in cooperation with the Hong Kong Supranational Reference Laboratory.

In the national drug resistance survey, MDR TB cases were found to be 8.3 percent of all cases. Among new cases, 5.7 percent were MDR TB, and the MDR TB rate among retreatment cases was 25.6 percent. The proportion of XDR TB cases was 0.7 percent among all cases, 0.5 percent among new cases, and 2.1 percent among retreatment cases.

Of the 11 provinces where surveillance has been conducted to date, Inner Mongolia has shown the highest percentage of MDR TB cases, at 16.1 percent (see the figure below). Among new cases of TB, the resistance rate is 7.0 percent, while resistance is found in 36.8 percent of retreatment cases.

Bar graph showing % of MDR TB in new & acquired cases in 11 Chinese provinces & China as a nation.

Percentages of MDR TB among initial (new) and retreatment (acquired) cases differ among 11 surveyed provinces and in comparison with China as a nation (last bar graph on right)

SOURCE: Li, 2010.

The proportion of resistance to isoniazid (19 percent) or streptomycin (28.9 percent) among all cases is higher than for other drugs. The proportions of resistance to streptomycin, ethambutol, ofloxacin, and kanamycin among MDR TB cases are 73 percent, 55 percent, 27 percent, and 12.5 percent, respectively. MDR and XDR TB prevalence is higher in rural and developing areas than in developed areas.

a

The information presented this box is based on the work of Renzhong Li, Lixia Wang, Mingting Chen, Yanlin Zhao, Caihong Xu, and Cheng Chen of the National Center for Tuberculosis Control and Prevention, Center for Disease Control and Prevention, China.

From: 2, A Global Perspective on Drug-Resistant Tuberculosis

Cover of The New Profile of Drug-Resistant Tuberculosis in Russia
The New Profile of Drug-Resistant Tuberculosis in Russia: A Global and Local Perspective: Summary of a Joint Workshop.
Institute of Medicine (US) Forum on Drug Discovery, Development, and Translation; Russian Academy of Medical Science.
Washington (DC): National Academies Press (US); 2011.
Copyright © 2011, National Academy of Sciences.

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