TB prevalence in China down by half in 20 years

The prevalence of tuberculosis in China has decreased by more than half within the past 20 years, according to a report in The Lancet.

The number of cases of smear-positive TB decreased from 170 cases per 100,000 population in 1990 to 59 cases per 100,000 in 2010. In the 1990s, TB prevalence declined only in the 13 provinces where a directly observed treatment, short-course (DOTS) strategy was implemented. The DOTS program was expanded to the entire country by 2005, after which prevalence declined in all provinces.

“One of the key global TB targets set by the Stop TB Partnership aims to reduce tuberculosis prevalence by 50% between 1990 and 2015,” Yu Wang, MD, of the Chinese CDC in Beijing, said in a press release. “This study in China is the first to show the feasibility of achieving such a target, and China achieved this 5 years earlier than the target date. Huge improvements in TB treatment, driven by a major shift in treatment from hospitals to local public health centers implementing the DOTS strategy, were largely responsible for this success.”

Wang and colleagues conducted a longitudinal analysis by comparing national TB prevalence surveys conducted in 1990, 2000 and 2010. From 1990 to 2000, the percent reduction was 19%, and from 2000 to 2010, the percent reduction was nearly tripled at 57%. In addition, there was an increase of known TB cases that were treated using DOTS, from 15% in 2000 to 66% in 2010. There was also a decrease in treatment default (43% to 22%) and re-treatment (84% to 31%).

“The DOTS program has been much more effective in reducing the prevalence of tuberculosis in known cases than in new cases,” Wang and colleagues wrote. “Because the prevalence in known cases is already very low, future reduction in tuberculosis prevalence is likely to slow substantially unless control efforts in addition to the DOTS strategy are implemented, especially in earlier case detection and treatment and use of new instruments.”

In an accompanying comment, Giovanni Battista Migliori, MD, director of the WHO Collaborating Centre for TB and Lung Diseases in Italy, and Giovanni Sotgiu, MD, PhD, of the University of Sassari-Research in Italy, said many developing countries have improved TB treatment using the DOTS strategy, but more efforts are needed for TB elimination.

“Long-term, rapid reduction in the tuberculosis burden leading to tuberculosis elimination will need additional efforts, including adoption of new instruments in diagnosis (rapid molecular testing for drug-susceptible and drug-resistant tuberculosis) and treatment (new drugs effective against drug-resistant cases), systematic diagnosis and treatment of latent tuberculosis infection, and better access to care by high-risk populations (including free diagnosis and treatment, and social protection mechanisms preventing income loss),” they wrote.

For more information:

Migliori G. Lancet. 2014;doi:10.1016/S0140-6736(14)60032-5.

Wang L. Lancet. 2014;doi:10.1016/S0140-6736(13)62639-2.