Oct. 11 (Bloomberg) -- Doctors say they have found a better way to detecting tuberculosis, advancing efforts to fight the often-deadly infection in poor nations.

It takes about a week for the test to identify TB in a patient and determine if the case will respond to basic drug therapy, compared with three weeks for automated tests and 10 for standard culture screening, according to a study in tomorrow's New England Journal of Medicine.

TB infected about 9 million people worldwide in 2004 and caused 2 million deaths, according to the World Health Organization. While antibiotics have helped reduce the rate of new cases in the U.S. and other developed nations, researchers say poorer countries need better tools to detect the disease.

``The faster you diagnose, the faster you treat, the more you diminish the number of contacts that will be infected,'' Robert Gilman, a co-author of the study, said in a telephone interview yesterday from Lima. Gilman is a professor of international health at Johns Hopkins Bloomberg School of Public Health in Baltimore.

The new method costs about $2 a patient, compared with $6 for culture screening and $52 for the automated tests, the researchers wrote in the study, after trials conducted in Peru in 2003 and 2004.

The method uses liquids to grow bacteria in saliva samples, an inverted-light microscope to examine the samples, antibiotics to test for drug resistance and a trained person to read the results.

Saliva Samples

Most developing countries already have the necessary resources stocked in their TB labs, Gilman said.

Researchers compared their test with automated and culture- screening tests in an examination of 3,760 samples of saliva coughed up by people in Peru who were suspected to have TB, were at risk for infection or were infected with HIV, the virus that causes AIDS. The new test was the most sensitive of the three, detecting 98 percent of bacteria, according to the report.

Industrialized nations probably won't adopt the new testing method because it requires a person to be trained to read the results rather than relying on testing by a computer, David Moore, a co-author on the study, said in a telephone interview yesterday from Lima. Moore is a senior lecturer in infectious diseases and tropical medicine at Imperial College London.

Lab technicians can be trained to detect TB with this test in less than two weeks, while learning to use it to measure the susceptibility of a disease strain to drugs takes several months, according to the study.

Talks in Peru

The researchers are in talks with health officials in Peru to implement the new testing method on a wider scale in that country, Moore said. Authorities in other South American countries, as well as Africa and Asia, have asked for help in setting up similar programs, he said.

In an editorial in the journal, Michael Iseman and Leonid Heifets of the National Jewish Medical and Research Center in Denver said developing nations would need to set up controls to prevent bacteria from spreading through the air outside labs before adopting the new testing method.

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To contact the reporter on this story: Catherine Larkin in Washington at clarkin4@bloomberg.net.

Last Updated: October 11, 2006 17:00 EDT