The spread of HIV and AIDS across Africa is fueling the rise of another deadly disease that many thought was on the decline: tuberculosis. Health experts meeting at a conference on AIDS and TB in Ethiopia's capital, Addis Ababa, are calling on African nations to expand their HIV therapy to include treatment for tuberculosis.

About a third of the 25 million Africans infected with HIV, the virus that causes AIDS, will die of tuberculosis, a disease that ravages lung tissue. Tuberculosis, also known as TB, is the leading cause of death among people with AIDS. Worldwide, about 5000 people die every day from TB. Most of those deaths occur in Africa, where extreme poverty, lack of adequate health facilities and rampant HIV infection rates are exacerbating an already alarming TB crisis.

Dr. Mario Raviglione is the director of Stop TB, the World Health Organization's (WHO) program to fight the spread of tuberculosis. He is one of the speakers at the AIDS/TB conference in Addis Ababa, where he spoke to VOA by telephone.

Dr. Raviglione explains that HIV-infection makes patients vulnerable to TB.

"In Africa, at a certain age, an adult age, the majority of the population already has been exposed to tuberculosis, but is not sick with it," he says. "What happens is that once they get infected with HIV and the immune system is down, tuberculosis takes over."

As more effective antibiotics were introduced in the 1950s, cases of TB had been steadily declining for more than 30 years. Not any more, say health experts.

Today, TB infects nearly nine million people every year, and the World Health Organization estimates that one billion people could be infected with TB in the next two decades.

Less than 10 percent of those cases worldwide are attributable to HIV infection, but in some parts of Africa as many as 75 percent of new TB cases are linked to the virus.

Yet, fewer than half of those living with HIV are treated for TB, despite the fact that HIV patients respond well to TB treatments. HIV-infected people who also have untreated TB often die within months, health experts say. Even with international support, including the Global Fund to Fight AIDS and a $15 billion initiative by U.S. President George Bush to combat AIDS and other infectious diseases in Africa, the meager health budgets of most African countries are strained by growing populations of HIV-infected people. Testing and treating those infected with TB adds to the cost, especially if the treatments require months of TB drugs.

Dr. Raviglione says the WHO's "Stop TB" program is trying to encourage African governments to beef up their health care systems against the deadly one-two punch of HIV and TB.

"The point is that in certain settings, especially in the African settings, the health infrastructures are often so weak that there is not enough capacity to suspect TB, to diagnose it properly with the laboratory test that is necessary, and to place patients eventually in treatment," he adds. "That is what we are fighting against, trying to convince governments to invest in such a way that these primary services are available to pick up the patient and put them on treatment whether they are HIV positive or negative."

So far, "Stop TB" has helped expand and strengthen TB detection and treatment in eleven African countries, including six of the nine African countries listed among the world's 22 worst TB-affected nations.

The goal, Dr. Raviglione says, is to head off a growing but curable disease that seems to be riding on the back of the HIV/AIDS epidemic.