By Sean Henahan, Access Excellence

BETHESDA, MD- The National Institute of Allergy and Infectious Diseases (NIAID) is tracking a number of new and re-emerging deadly diseases caused by a host of infectious bacteria and viruses throughout the world. NIAID researchers hope to improve detection, treatment and prevention of such diseases, several of which are expected to intensify in the next few years.

Dengue fever is at the top of the list of diseases being tracked by the NIAID. Dengue is an acute infectious disease is caused by the flavivirus which is transmitted by infected mosquitoes. The disease causes headache, fever, muscle pain and rash, but is rarely fatal. However, a more severe form of the disease seen mostly in children, dengue hemorrhagic fever, causes severe symptoms including fever, shock, hemorrhaging from the nose and mouth, respiratory distress and death

Dengue is most common in Southeast Asia, but has also caused outbreaks in Puerto Rico, the Caribbean, Central America and South America. In Asian countries, 1.5 billion people, including 600 million children, live in areas where the virus is common. Dengue infects 35 to 60 million people and kills up to 20,000 people annually. NIAID officials are concerned that mosquitoes feeding on infected people traveling within the United States could be potential sources to spread dengue in this country.

Yellow fever, another mosquito-borne disease, is caused by the arbovirus. Symptoms include swollen tongue, gastric distress and hematemesis (black vomit). It continues to be a serious problem in Africa, but successful mosquito control programs have limited the virus spread in the Americas. However, the mosquito that carries the virus has reinfested most South American countries, leading to concerns the virus may soon re-emerge on that continent. From 1986 to 1988, more than 5,300 people worldwide developed the disease and 58 percent died--the most severe three-year outbreak since yellow fever reporting began in 1948. The WHO estimates that at least 10 cases occur for each reported case.

Cholera is also a growing concern. Cholera, a disease caused by the Vibrio cholerae bacteria strikes an estimated half million people in Asia each year, killing 100,000. A new strain that emerged in India in 1992 and has spread throughout Southeast Asia appears to pose an even greater threat. The bacteria recently caused outbreaks in Somalia and among Rwandan refugees in Zaire. Another epidemic has ravaged Central and South America since 1991, affecting more than 1 million people. No safe, effective vaccine exists for this disease.

Mycobacterium tuberculosis (TB) causes more deaths worldwide than any other infectious disease. The bacteria responsible for TB infect one-third of the world's population, including 10 million Americans, but not all develop active disease. Eight million people in the world are infected each year, and the number may rise to 12.1 million by 2005. Thirty million people are expected to die from TB during the present decade.

John La Montagne, Ph.D., director of the NIAID Division of Microbiology and Infectious Diseases, reviewed the institute's research efforts in this area at the annual meeting of the American Association for the Advancement of Science in Atlanta recently.

The NIAID has several research programs dedicated to the study of new and re-emerging diseases. One program supports tropical disease research units in leading U.S. universities. The program emphasizes an interdisciplinary approach to research combining the latest biotechnology techniques to investigate the basic biology of parasites and their interactions with hosts.

Another NIAID program supports international collaborations in infectious diseases research. U.S. research institutions collaborate on research in other countries where tropical diseases are common. The major portion of the research is conducted in the foreign country and focuses on native health problems.

The NIAID is one of 17 institutes of the National Institutes of Health (NIH), the federal focal point for biomedical research. Many other NIH branches are also studying new and re-emergent diseases at home and abroad. Other branches of the federal government, notably the U.S. Army, are also conducting ongoing research in this area.

Transmitted: 95-03-14 21:32:29 EST

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