Researcher calls for gene mapping of disease germs

June 24, 1995|By Douglas Birch | Douglas Birch,Sun Staff Writer

WASHINGTON -- A tuberculosis researcher yesterday called on the United States to launch a $100 million program to create detailed genetic blueprints for 25 of the world's most dangerous microbes.

Mapping the genomes of the pathogens that cause tuberculosis, cholera, plague and other illnesses would help scientists design urgently needed diagnostic techniques, treatments and vaccines, said Dr. Barry Bloom of the Albert Einstein College of Medicine in New York.

Infectious diseases remain the "No. 1 killer in the world," causing more deaths than either cancer or heart disease on a global scale, he told members of the Congressional Biomedical Caucus at a regular monthly meeting.

"Give the National Institutes of Health just $10 million to $20 million a year" for the next five to 10 years, he said, "and we would have the genome of every major human pathogen sequenced, for all history."

Dr. Bloom admitted that the chance that Washington will launch such a project is "close to zero," given the budget-cutting mood of Congress. But he warned that the price of ignoring new infectious disease threats could be steep.

Though disease-causing microbes now are a much bigger problem in poor countries, Dr. Bloom said, the United States is not immune. The AIDS virus, he pointed out, has already caused "an astoundingly rapid rise" in deaths among men 25 to 44.

Microbes move swiftly across the globe, he noted. Cholera bacteria in the bilge water of a single ship from Southeast Asia caused an epidemic in Peru in 1990 that infected 4 million people and killed 4,000.

Dengue hemorrhagic fever, a newly emergent and more dangerous form of dengue or "breakbone" fever, has appeared in the Caribbean. Epidemiologists fear that the mosquito-borne illness could easily make the leap to mainland North America.

Humans, under assault from diseases such as AIDS and the Ebola virus that recently erupted, also face renewed assaults by new, drug-resistant forms of diseases once thought to be under control, such as new strains of tuberculosis.

Common hospital infections, which kill 20,000 people a year in the United States, are controlled with penicillin and other antibiotics, Dr. Bloom said. But the heavy use of these antibiotics has helped speed the development of strains that are drug-resistant.

"Everything we throw at them only leaves those that can survive," he said. "By throwing drugs at people, we create resistance."

Some strains of staph infection appear to be resistant to all antibiotics used in this country, including the most powerful, vancomycin. If vancomycin-resistant staph gains a secure foothold, Dr. Bloom said, "it will be devastating. Once it's here, surgery as we know it will end."

The United States is poorly prepared to respond to new disease threats, he said. When tuberculosis cases started to rise again in the mid-1980s, he said, policy-makers showed "an extraordinary lack of responsiveness to the world's single largest cause of death from infectious disease."

It took three years for the federal government to formally commit funds to combating the outbreak. He said the number of tuberculosis cases diagnosed annually has fallen to about 26,000 -- what it was in 1980. But there is still no vaccine.

One promising avenue of research into a tuberculosis vaccine, he said, uses a genetically engineered form of the bacteria that, when injected into mice, triggers an immune response. But the altered bacteria don't appear to thrive or cause the disease.

More detailed knowledge of the genes of other microbes would make it easier for scientists to come up with similar strategies in combating them, he said.

Some work is already being done on mapping the genes of infectious disease agents. The Wellcome Trust, a nonprofit foundation, is financing an effort to sequence the genome of the parasite that causes malaria.

Baltimore Sun Articles
Please note the green-lined linked article text has been applied commercially without any involvement from our newsroom editors, reporters or any other editorial staff.