With tuberculosis the leading cause of death worldwide among people with AIDS, a leading charity has awarded $44.7 million to a consortium led by Johns Hopkins scientists that aims to find the best way to combat the twin epidemics in developing nations.
The Bill & Melinda Gates Foundation announced the grant yesterday at the XV International Conference on AIDS in Bangkok, Thailand. The money will pay for projects in South America and Africa, including one that will deliver anti-TB medications to thousands of coal miners across South Africa.
Scientists will dispense the drug isoniazid, which has been used for 50 years in Western nations - but rarely in the Third World - to keep people who have been exposed to TB from getting sick with the active disease.
"There has been a belief that giving preventive therapies is not effective for controlling the disease," said Dr. Richard Chaisson, a Hopkins professor of infectious diseases who is heading the effort. "I think there is very good evidence that's not correct."
As examples, he noted a program in which Hopkins researchers virtually eliminated the threat of tuberculosis among hundreds of Baltimore drug addicts who had been exposed to the disease. Such exposure is measured by a person's reaction in skin tests.
In another instance, researchers stopped an epidemic of TB in Alaska by treating everyone in a community with the medication, regardless of their exposure.
The Gates money goes to the Hopkins-led group Consortium to Respond Effectively to the AIDS-TB Epidemics. Joining Hopkins are scientists in London, South Africa and Brazil, and others with the World Health Organization and the U.S. Centers for Disease Control and Prevention.
People with acquired immune deficiency syndrome are particularly vulnerable to tuberculosis because of their weakened immune systems. When tuberculosis takes hold among people infected with the AIDS virus, it also threatens to break out among the broader population, experts say.
"Anyone concerned about HIV/AIDS must also be concerned about TB because the two diseases go hand in hand," Dr. Helene Gayle, an official with the Gates Foundation, said in a statement.
"I'm optimistic that researchers, policymakers and funders around the world will recognize the need to alleviate the tremendous burden of these linked epidemics."
Chaisson said the presence of each disease amplifies the other, particularly in developing nations where medications and primary health care are scarce.
