Life or Death: Immune genes determine outcome of strep infection
By John Travis
Think of it as Russian roulette with a bacterium instead of a gun. Most people infected with group A streptococcal bacteria notice no symptoms or simply develop a sore throat. Sometimes, however, a strep infection erupts into a life-threatening illness, causing failure of several organs and shock. On even rarer occasions, the infection devours a person’s flesh at a remarkable rate.
Subtle variations among people’s immune genes may largely account for the radically different outcomes, according to an international team of researchers led by Malak Kotb of the University of Tennessee in Memphis. Curiously, the immune-gene types that produce the strongest reaction to the strep A bacteria seem to also predispose people to the most-severe disease.