An “outbreak” of group A Streptococcus

BACKGROUND: Group A Streptococcus (GAS) outbreaks rarely occur, with Pennsylvania reporting 532 non-related cases of invasive GAS between 2000 and 2003. Three fatal cases of invasive GAS that were presumed to be epidemiologically linked were identified in two geographically related but competing hospitals. All of the patients presented within 8 days of each other and resided in a small rural town in eastern Pennsylvania. An investigation of this outbreak was undertaken and an aggressive educational and infection control approach was taken. METHODS: Pulsed-field gel electrophoresis (PFGE) of the three isolates was performed by the Pennsylvania State Health Department. An intensive, collaborative investigation was initiated to determine if the GAS cases were linked. An internal and external notification system was activated in both medical systems. Extensive chart reviews and family interviews were conducted. A detailed analysis of inpatient and outpatient GAS cases was completed. Both infection control departments networked with the local and state health departments. Droplet and contact isolation precautions were enforced in the patient care areas as per the Centers for Disease Control and Prevention (CDC) recommendations. Daily educational updates were provided to the intensive care units and pre-hospital personnel. Media statements and a statewide health advisory were prepared. RESULTS: Using PFGE, all three blood isolates from the patients were identical (Emm-type 1). However, no definitive epidemiological link was identified. No healthcare worker (HCW) or household cultures were obtained and no antibiotic prophylaxis was provided. There was no secondary transmission to family members or HCWs identified. Additionally, there have been no GAS invasive cases in this Pennsylvania community 8 months after the initial patient presentations. CONCLUSIONS: Despite three cases of GAS necrotizing fasciitis being associated in time and location, these cases appear to have been independent events. Strict enforcement of droplet and contact isolation precautions prevented unnecessary exposure and possible secondary cases among HCWs. Timely communication and education helped to relieve staffʹs anxiety, and these measures contributed to preventing unnecessary cultures and prophylaxis. This experience demonstrated the ability of competing hospitals to put competition aside and collaborate while dealing with a possible public health emergency.