The mainland has developed some of the highest rates of multiple-drug-resistant tuberculosis (MDR-TB) in the world, according to a report to be released today by the World Health Organisation. The WHO says it urgently requires more information on the prevalence of MDR-TB after finding 10 per cent of new cases in Liaoning and almost 8 per cent in Henan did not respond to two or more of the commonly used treatments. Of the 69 locations surveyed - which included several countries and seven Chinese provinces - Liaoning had the sixth-highest rate of resistance among new cases, while Henan was ninth. Kazakhstan and Israel had the highest rates, about 14 per cent. A co-author of the report, Mohamed Abdel Aziz, said the rate of MDR-TB on the mainland was a concern due to the huge population involved. Liaoning and Henan have a combined population of more than 133 million. 'China is a very big country and even a small percentage can translate into a huge number of cases,' he said. 'We need to know more about the situation there.' Dr Abdel Aziz said the WHO was expanding its survey on the mainland and would cover half of the provinces by the end of next year and the whole country by the end of 2008. The central government was criticised by the WHO for a lack of co-operation and transparency during the initial stages of the Sars outbreak last year. But Dr Abdel Aziz said the agency had never had problems getting information on tuberculosis. MDR-TB develops when tuberculosis patients are improperly treated, usually taking the wrong dose of drugs or not taking all the medication. Once patients develop resistance, they can spread the resistant strain to other people. Along with the increased health risks to the patient, MDR-TB is far more expensive to treat. Dr Abdel Aziz said a MDR-TB case costs US$500 to US$1,000 to treat, as much as 100 times the cost of curing a non-resistant case.