RAISING AWARENESS: Medical workers disseminate materials on tuberculosis prevention to residents in Yinchuan, Ningxia Hui Autonomous Region, on March 24, the World Tuberculosis Day (LI RAN)

In 2011, there were an estimated 8.7 million new cases of tuberculosis (TB) around the world and 1.4 million people died of the disease, said the World Health Organization in a statement marking World TB Day on March 24.

According to Wang Yu, Director of the Chinese Center for Disease Control and Prevention (CDC), China ranks second following India among 22 countries most heavily plagued by TB, with 5 million Chinese people suffering from active TB.

"As many as 50,000 people die of TB annually in China, with about 1 million new cases reported each year," Wang said.

He added that more than 80 percent of China's TB patients live in rural areas or are part of the floating population, who receive far fewer medical services than urban patients. "Poor compliance with the long-term standard treatment can result in TB resistant to one or multiple drugs," Wang warned.

According to the National Anti-TB Drug Resistance Survey conducted by the CDC's National TB Reference Laboratory in 2007-08, one in 10 cases of TB in China could be classified as drug-resistant. About 120,000 new cases of multi-drug resistant TB (MDR-TB) were estimated to occur each year, with China ranking first in the world, the survey showed.

"Since the majority of MDR-TB patients cannot get effective treatment, their continuous discharge of the bacteria that cause TB is a serious threat to public health," Wang said.

Drug resistance

TB is a stubborn disease to treat. An infectious TB patient can infect 10 to 15 people in a year.

According to Wang, the current regimen for standard TB cases usually involves a mixture of four antibiotics taken for six to nine months. "But if treatment is interrupted or the dose reduced, the bacteria will mutate into a tougher strain that can no longer be killed by standard drugs," he said.

However, no new anti-TB drugs have been developed since the last one was discovered almost half a century ago with a completely new mechanism.

"In the current situation, the treatment of MDR-TB, which is mainly dependent on second-line anti-TB drugs, can last up to 24 months and involves complicated and more expensive treatment regimens that have lower patient adherence and a higher dropout rate," he said.

In the National TB Reference Laboratory's national survey, more than 40 percent of patients with MDR-TB previously treated for TB had not completed their last treatment course.

The survey report, which was published last June, said that a quarter of TB patients treated in the public health system received inadequate treatment because they had MDR-TB but were still given first-line TB drugs as part of standard treatment.

Patients being treated at local TB hospitals should be tested for drug resistance before the start of treatment, with treatment options based on the results, but such tests are not routinely performed at TB hospitals, according to the report.

Xu Biao, Director of the TB Research Center of Shanghai-based Fudan University, said that many county-level hospitals were not following national guidelines when treating TB patients, resulting in increased drug resistance.

"The use of second-line anti-TB medicines has been found in newly diagnosed TB patients without bacteriological confirmation and the prescription of the second-line medicines mainly depends on the treatment history of the patients rather than the patients' drug resistance profiles," Xu said. "It may have to do with poor TB training or simply wanting to see a quick improvement, but the side effect is that it leads to a high rate of drug resistance or even extensive drug resistance."

According to TB treatment guidelines issued by the former Ministry of Health, each patient should receive individual diagnosis, treatment and case management, but Xu said that the guidelines were poorly followed due to shortage of funds and staff.

"We need specially trained doctors with extensive experience in treating TB, but only provincial-level hospitals can guarantee that," she said.

Meanwhile, a lack of advanced technology results in low treatment coverage. According to a CDC report, the diagnosis and treatment coverage of MDR-TB is less than 30 percent in China.

"Due to the limitations of the approach used to detect the disease, diagnosis is mainly reliant on passive discovery when a patient seeks medical treatment," Wang said.

Furthermore, the detection rate of sputum smear microscopy, which has been widely used for 130 years, is low, and MDR-TB cases remain undetected due to the lack of expensive testing technology.

Meanwhile, MDR-TB often goes unnoticed during a routine TB exam because its symptoms are similar to the more common form of TB, which can cause those infected to delay treatment and spread the disease.

"In order to make the fight against the killer disease more focused, we need to find a way to identify high-risk populations," Wang said.

He suggested that health authorities at all levels should mobilize social organizations to accelerate the building of the country's TB prevention system.

Wang Weibing, an associate professor of epidemiology at Fudan University's School of Public Health, said that the multiple factors that lead to death in TB patients must be considered when control measures are being developed. He suggested that running TB control programs alongside other public health programs might be necessary to better address the health of these patients and reduce mortality.