Drug resistant tuberculosis (TB) is spreading faster than medical experts had expected, according to a report the World Health Organization issued on Tuesday.

In a survey involving 90,000 TB patients in 81 countries, the WHO found that levels of multi-drug resistant tuberculosis were much higher than expected.

The survey also included analysis of extensively drug-resistant tuberculosis, known as XDR-TB, which is virtually untreatable, because the bacteria that cause it are resistant to almost all of the TB drugs. The XDR-TB was reported in 45 countries, but as few countries have the necessary equipment to detect it, the data were limited.

"Ten years ago, it would have been unthinkable to see rates like this," said Dr. Mario Raviglione, director of WHO's "Stop TB" department, according to The Associated Press. "This demonstrates what happens when you keep making mistakes in TB treatment."

The governments in many countries have lost control of tuberculosis because they have not invested enough to build and equip laboratories to treat the disease. Also, the doctors have not monitored TB patients, to make sure they completed the therapy.

If the full course of therapy is not completed, the tuberculosis bacteria develop strains that are resistant to at least two drugs.

Drug-resistant TB, as well as common TB, can be transmitted from a sick person to a noninfected one in minuscule droplets through coughing or sneezing. The symptoms are fever, coughing, blood-tinged sputum, weight loss. If it is not detected and treated on time, tuberculosis is lethal.

The resistant form of tuberculosis needs to be treated with drugs that are 100 times as expensive as the first-line drugs, in a therapy that lasts at least two years.

About one in every 20 new tuberculosis cases around the globe is drug-resistant tuberculosis, and there are some regions in the former Soviet Union where the proportion is one in every five cases.

Alarmingly high rates of MDR-TB were found in Baku, Azerbaijan (22.3 percent), Moldavia (19.4 percent), Ukraine (16 percent) and Russia (15 percent), according to The New York Times.

A very worrying situation exists in Africa, where MDR-TB is linked with HIV and AIDS, and therefore, spreading alarmingly fast.

"We really don't know what the situation is in Africa," Raviglione said, according to The Associated Press. "If multi-drug resistant TB has penetrated Africa and coincides with AIDS, there's bound to be a disaster."