Mainland battles drug-resistant TB

PUBLISHED : Thursday, 24 March, 2011, 12:00am
UPDATED : Thursday, 24 March, 2011, 12:00am

China is fighting an uphill battle against drug-resistant TB even though a tuberculosis control project is estimated to have prevented two million deaths over the past 10 years.

Drug-resistant TB, far more expensive to treat, emerges when patients fail to follow treatment regimes or stop treatment too early. When the TB bacteria is not fully eliminated, it can mutate, re-emerge later and become resistant to the small range of drugs that can fight the disease.

A national survey last year showed that incidence of multi-drug-resistant TB (MDR-TB) among pulmonary TB cases was about 6.8 per cent.

Although it was a significant drop from the figure in 2000, which stood at 10.7 per cent, it is still higher than the world's average of 5.3 per cent, said Wang Lixia, director of TB prevention department of the Chinese Centre for Disease Control and Prevention.

The ratio in developed countries is about 2 per cent, Wang said.

China is identified by the World Health Organisation as one of the 27 'high MDR-TB burden countries'. The disease would be the greatest challenge for China's TB control project, Hao Yang, deputy director of the Health Ministry's disease control department said.

Treatment for MDR-TB is more time-consuming and costly. Treatment took two years as opposed to six to eight months for pulmonary TB and was 100 times more expensive to treat, Wang said.

Hao said that the main reason for that problem was that some TB patients could not receive proper treatment in hospitals at grassroots levels, especially in some clinics in rural areas and the country's less-developed western regions, and patients' failure to follow doctors' instructions in the treatment also was a problem. The survey indicated that only 59 per cent of patients were found to have strictly followed instructions for care and completed their treatment.

Each year 1.3 million people contract the disease. TB has killed about 3,000 people in China annually for the last three years, according to the Ministry of Health, but the WHO estimates much higher numbers.

If a TB infection does not receive proper and complete treatment, it could easily develop into an MDR-TB, Hao said.

Dr Zhao Yanlin, a TB specialist at the Beijing Chest Hospital, said many patients had poor awareness of the disease and did not obey doctors' instructions about taking drugs. 'After several weeks of treatment they feel much better and think that they are completely cured,' Zhao said.

'Then they stop taking the drugs. But actually at that moment it's quite possible that the TB virus will mutate into a drug-resistant one.' He said there was an increasing number of TB patients with slight symptoms who did not go to clinics, because they thought their problem was only a cold or cough.

'This situation is not good for their illness' future diagnosis and treatment,' he said.

Ma Zhenkun, chief scientific officer for the non-profit organisation, Global Alliance for TB Drug Development, said people had to take a combination of five to seven drugs for at least 18 months on top of six months' worth of daily injections to treat MDR-TB. The long and costly process made it difficult for people to strictly follow the treatment.

'There are about 500,000 MDR-TB patients globally and China accounts for one fifth of them,' Ma said. 'But only 1 per cent of patients are following the treatment.'

The alliance has agreed with the International Scientific Exchange Foundation of China to build a research and development centre in Langfang with the aim of developing new drugs that can eliminate MDR-TB in six months, thereby cutting treatment costs.

In China, diagnosis and treatment is free at specialist TB outpatient clinics but must still be paid for at general hospitals.

Last year the central government put 560 million yuan (HK$665.39 million) into the TB control project, exceeding the 400 million yuan injected by various local governments.