Scientists reveal secrets of infectious childhood hea...( Researchers have discovered important ...)

Researchers have discovered important clues as to why a common bacterium can sometimes lead to a dangerous heart infection in children.

The bacterium, group A Streptococcus (GAS), causes acute rheumatic fever, the most common infectious cause of childhood heart disease in the world. In the United States, it has appeared in several localized outbreaks, and in 1999 the infection and its subsequent heart damage were responsible for 3,600 deaths.

But GAS bacteria are relatively common and also cause a range of other diseases ranging from sore throats to toxic shock and "flesh-eating" disease. What makes different GAS strains invade different parts of the body, however, remains largely unknown. In addition, researcher have not known if different rheumatic fever outbreaks are caused by genetically similar bacteria or if different strains can emerge to cause the disease.

By isolating GAS bacteria from a person with the disease, scientists from the National Institute of Allergy and Infectious Diseases (NIAID) have discovered several genes that are unique to those bacteria. Their discovery also reveals that two rheumatic fever outbreaks occurring 12 years apart in the area around Salt Lake City, Utah, were caused by virtually identical GAS strains.

"We have made enormous strides in understanding the biology of infectious diseases, yet much remains to be learned about relatively common bacteria like group A Streptococcus," says Anthony S. Fauci, M.D., NIAID director. "This research reveals some of the secrets of group A Strep and is a major accomplishment in our quest to understand an important childhood disease."

The study was directed by James Musser, Ph.D., chief of the laboratory of human bacterial pathogenesis at NIAID's Rocky Mountain Laboratories in Hamilton, Mont. Dr. Musser and his colleagues from several institutions determined the genetic blueprint of a GAS strain taken from a patient with rheumatic fever. All GA
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Contact: Sam Perdue
sp189u@nih.gov
301-402-1663
NIH/National Institute of Allergy and Infectious Diseases
25-Mar-2002