SCIENCE REPORT- New TB Test

By Nancy Steinbach

This is Bill White with the VOA Special English SCIENCE REPORT.

Researchers in the United States and Peru have developed an improved test to find out if people have the lung disease tuberculosis, also known as TB.

The World Health Organization says about eight-million people become sick with tuberculosis every year. The disease kills about two-million people each year. TB is caused by bacteria that damage and sometimes destroy the lungs. It spreads through the air to other people when an infected person coughs, sneezes, talks or spits.

It can take many weeks before doctors can tell if a person is suffering from TB. First, they must collect a substance that a suspected victim produces by coughing. Doctors examine the substance under a microscope to find any tuberculosis bacteria. Then the bacteria must be grown in a laboratory so doctors can decide what kind of medicine will kill the bacteria.

Doctors say this can take more than two months because tuberculosis bacteria grow very slowly. This delays necessary treatment of the disease. Researchers have been seeking a faster method because tuberculosis has developed resistance to many drugs.

About five years ago, scientists developed a faster way to test for TB by growing the bacteria in a special liquid substance. The bacteria grow faster in liquid. This method reduces the time to grow the bacteria to about two weeks. But it requires costly equipment. Now, American and Peruvian researchers say they have improved the method to tell if a person is infected with the tuberculosis bacteria. They have found a way to grow the bacteria in liquid without costly equipment. The researchers say this makes the test cheap enough to be used in developing countries where the threat of tuberculosis is greatest.

Tests in Peru showed that the method is just as effective as the earlier ones. The researchers reported the new method in The Journal of Clinical Microbiology.

The United States government is helping pay for the use of the new TB test throughout Peru. It is also helping several medical workers from Bangladesh to visit Peru and learn the method. The researchers say their goal is to teach the method to medical workers in South America, Asia and Africa.

This VOA Special English SCIENCE REPORT was written by Nancy Steinbach. This is Bill White.