Quick diagnoses of drug-resistant TB crucial: experts

By Tan Ee Lyn

KUALA LUMPUR (Reuters) - Countries with huge caseloads of tuberculosis are finding it hard to cope because they do not have the laboratories to make speedy diagnoses that are essential to save lives.

Speaking at an infectious disease conference in Kuala Lumpur, TB specialists spoke about how it could take up to five months for patients to get test results and often the patients would be dead by then.

This was especially true for patients with drug-resistant forms of TB and immune systems that were seriously compromised by other diseases, such as AIDS.

Drug-resistant TB is more difficult to treat and patients can die without stronger, second-line drugs.

"We have treatments that are moderately effective and that are available at affordable prices, but the bottleneck is diagnosing the cases and getting them the right treatment," said David Moore, an infectious disease expert at Peru's Cayetano University.

Not only has Peru a substantial caseload of TB. In some parts of the country, up to 6 percent of TB cases are drug-resistant forms. These need to be tested in more sophisticated laboratories, which are in short supply.

"Very few countries in the world have labs to test for resistance and there aren't resources to get samples into labs and results out of labs (in Peru)," Moore said, adding that samples spent most of the time sitting in refrigerators waiting to get transported here and there.

Such delays can be fatal.

"Delayed diagnoses mean they (patients) transmit more to other people and 60 percent of your patients are dead by the time the MDR-TB (multi-drug-resistant TB) results are back," he said.

TREATING THE WRONG TYPE

Roxana Rustomjee, director of the Medical Research Council's TB Unit in Durban, South Africa, said faster diagnoses were urgently needed in Africa, where the most severe form of TB, extensively drug-resistant TB (XDR-TB), is increasingly seen.

Up to 99 percent of patients with XDR-TB die even before they get test results, she told the conference.

"They die of TB because you are treating the wrong (less severe) type of TB," she explained.

In places with advance healthcare systems, such as Hong Kong, it takes 2 weeks to diagnose drug-resistant TB.

Globally, there were 489,139 cases of MDR-TB in 2006, and 72.4 percent of these were in Asia. Together, China and India accounted for half of all the cases.