Invasive Group A ''Streps and Flesh-Eating'' Syndrome
Strep infection are occupational diseases of childhood that usually follow a routine and uncomplicated. The greatest cause for concern are those few occasions when such infections erupt into far more serious ailments. One dramatic example is necrotizing fasciitis,
a complication Of S. pyogenes infaction that has been known for hundreds of years. Recent small outbreaks of the disease in England and the United States have received heavy publicity as the flesh-eating disease caused by killer bacteria. It should be emphasized that cases of this disease are rather rare, but its potential for harm is high. It can begin with an innocuous cut in the skin and spread rapidly tissue, causing severe disfigurement and even death.
There is really no mystery to the pathogenesis of necrotizing fasciitis. It begins very much like impetigo and other skin infections: Streptococci on the skin are readily introduced into small abrasions or cuts, where they begin to grow rapidly. These strains of group A streptococci have great toxigenicity and invasiveness by releasing special enzymes and toxin. Their enzymes digest the connective tissue in skin, and their toxins poison the epidermal and dermal tissue. As the flesh is killed, itseparates and sloughs off, forming a pathway for the bicteria to spread into deeper tissues such as muscle. More dangerous infections involve a mixed infection with anaerobic bacteria and/or systemic spread of the toxin to other organs. It is true that some patients have lost parts of their limbs and faces and others have suffered amputation, but earlydiagnosis and treatment can prevent these complications. Fortunately, even virulent strains of Streptococcus pyogenes are not usually drug resistant. More mysterious however is the epidemiologic pattern of these virulent new outbreaks. The incidence of aggressive infections had been gradually declining throughout the antibiotic era