WHO Warns Drug-Resistant TB Growing

By Lisa Schlein

Geneva

26 February 2008

The World Health Organization (WHO) warns multi-drug resistant tuberculosis is growing, as is the more deadly form of XDR-TB, or extensively drug-resistant tuberculosis. A new report, which surveyed 90,000 tuberculosis patients in 81 countries between 2002 and 2006, records the highest rates of multi-drug resistant tuberculosis ever found. Lisa Schlein reports for VOA from WHO headquarters in Geneva.

Every year, the World Health Organization estimates there are nine million new cases of TB worldwide. The survey results indicate 500,000 of these new cases are multi-drug resistant TB.

The highest rates were found in countries of the former Soviet Union, with nearly one-quarter of the MDR-TB cases recorded in Azerbaijan, followed by Moldova, Ukraine, Russia, and Uzbekistan.

WHO Coordinator for TB/HIV and Drug Resistance, Paul Nunn, tells VOA the breakup of the Soviet Union and the collapse of the economy weakened the TB-control measures that had been in place. He says a study of two administrative provinces in the Russian Federation shows overall TB rates are coming down, but the proportion and number of MDR-TB cases is rising.

"So, this is of extreme concern. It raises the possibility that the epidemic we have in that region of drug-susceptible TB is being replaced by multi-drug resistance or even extensively drug resistant TB, which seriously restrict treatment options with a significant increase in mortality between the two, MDR and XDR treatment," he said.

Surveys in China also suggest that drug-resistant TB is widespread in that country.

Tuberculosis can be successfully and inexpensively treated in six months. The bacteria responsible for TB become resistant when people do not complete a full course of medication.

Multi-drug resistant TB does not respond to the main drugs used in treating TB and requires treatment with very expensive drugs over two years.

Extensively drug-resistant tuberculosis is resistant to almost all drugs used to treat TB. Dr. Nunn says XDR-TB was discovered in patients in 45 of the 81 countries surveyed.

"In extensively drug-resistant TB, your XDR-TB, it does depend to some extent on the precise resistance pattern," he explained. "But the mortality rate in this group of patients is very high, especially if it is linked with HIV[/AIDS]."

Dr. Nunn notes the true scale of the problem remains unknown in sub-Saharan Africa, the region with the highest incidence of TB and HIV/AIDS. He says only six countries in Africa were able to provide drug resistance data for the report.

This is because other countries in the region lack the equipment and trained personnel needed to identify the disease.

He warns it is likely that drug-resistance will rise, get into the HIV population and be rapidly transmitted to other HIV sufferers.

The World Health Organization says faster and better diagnostic tools as well as new drugs are needed to treat resistant strains of tuberculosis.