The wound care team: a new source of group a streptococcal nosocomial transmission

In August 2001, the Centers for Disease Control and Prevention (CDC) notified the Texas Department of Health (TDH) of an unusually high number of wounds infected with group A streptococci (GAS) in an acute care facility. The TDH initiated an investigation, ultimately identifying 28 cases of non-pharyngeal, non-community-acquired GAS that had occurred between December 2000 and August 2001 and resulted in 3 deaths and 4 nonfatal cases of invasive disease. Ten specimens were sent to the CDC for emm typing; all isolates were emm type 114. However, the source of the outbreak could not be confirmed through laboratory testing at that time.

A case-control study was conducted comparing the 10 case-patients with 52 control-patients with wounds that were not infected with GAS. Age, gender, type of wound, underlying medical conditions, and treatment by the wound care team were examined for association with GAS infection.

The odds of having wound care team treatment versus not having it were 424.2 (95% confidence interval, 19.0 to 9,495.2) among case-patients when compared with control-patients. No other risk factor showed this magnitude of association.

This study provided overwhelming epidemiologic evidence that the wound care team was the means of transmission. One year later, when two patients receiving wound care were concurrently diagnosed as having GAS, a member of the wound care team was found to be GAS positive for the matching emm type. This is the first report of a GAS hospital outbreak linked to a wound care team.