PARIS (AP) – A deadly drug-resistant new strain of tuberculosis on the rise this year has forced scientists to confront a new problem: old drugs and a more than century-old TB test that takes weeks to get laboratory confirmation.

Scientists, doctors and public health specialists met in Paris on Monday to discuss the urgent need for better tests, new drugs and a broadly effective vaccine. Tuberculosis will also come up later this week at the annual Union World Conference on Lung Health, also in Paris.

The TB drugs prescribed today are more than 40 years old, and they require patients to undergo a six- to nine-month treatment regimen.

Tuberculosis, a respiratory illness spread by coughing and sneezing, is the world’s deadliest curable infectious disease. The World Health Organization estimates that 1.7 million people die from TB every year.

That classifies the disease as extensively drug resistant TB, or XDR.

XDR-TB is virtually incurable with existing antibiotics. In the South African province of KwaZulu-Natal, where 53 patients were found to have the disease recently, all but one of them died within a month, health experts say. For XDR-TB patients also infected with HIV/AIDS, disease progression has been disturbingly quick, with a mortality rate approaching 100 percent. With high HIV/AIDS prevalence rates across Africa, treating XDR-TB will prove tremendously challenging.

“The problem of extensively resistant tuberculosis is a very rude wake-up call,” Kenneth G. Castro, director of the TB elimination program at the CDC, said at Monday’s conference, hosted by the Global Alliance for TB Drug Development.

“We don’t know how frequently this occurs in different parts of the world,” he said, urging rapid surveys to find out.

For more than a decade, health officials have worried about multidrug-resistant TB, which can withstand the mainline antibiotics isoniazid and rifampin.

There are probably not enough new drugs in the works, said the French aid group Medecins Sans Frontieres, known in English as Doctors Without Borders.

The group released an analysis Monday suggesting that none of the drugs currently in development will bring dramatic and rapid improvement to fighting TB, and it urged more financial support for the TB alliance and other efforts.

The group expressed concern that many drugs in development are similar to existing compounds, which may mean they are less effective in fighting resistant strains.

The number of TB drugs being developed is still “small compared to the drug pipelines for diseases of major concern to wealthy countries, such as cancer or cardiovascular disease,” the analysis said.