Streptococcal Invasive Disease - Group A, 2003

One hundred eighty-one cases of invasive group A streptococcal (GAS) disease (3.7 per 100,000 population), including 22 deaths, were reported in 2003, compared to 147 cases and 24 deaths in 2002. Ages of case-patients ranged from one to 96 years (mean, 50 years). Fifty-four percent of case patients were residents of the Twin Cities metropolitan area. Forty-five (25%) case-patients had bacteremia without another focus of infection. There were 21 (12%) cases of primary pneumonia and 17 (9%) cases of necrotizing fasciitis. Twelve (7%) case patients had septic arthritis and/or osteomyelitis, and nine (5%) had streptococcal toxic shock syndrome (STSS). Twenty-three (13%) case patients were residents of 17 long-term care facilities. Five facilities had more than one case and each case within a facility had a matching PFGE subtype to the other case(s) in the facility.

The 22 deaths included eight (36%) cases of bacteremia without another focus of infection, two (9%) cases of pneumonia, and one (5%) case of septic arthritis. One case had STSS and one case had both peritonitis and STSS. The remaining fatal cases had bacteremia with another focus of infection, including six (27%) with cellulitis, and one (5%) each with mediastinitis, pneumonia, and one with both pharyngitis and cellulitis. The deaths occurred in persons ranging in age from one to 92 years. For the 14 deaths in patients with known health histories, significant underlying medical conditions were reported for all of the cases.

Isolates were available for 171 (94%) cases, of which 159 were subtyped using PFGE; 50 different molecular subtypes were identified. Twentyseven subtypes were represented by one isolate each; other subtypes were represented by two to 47 isolates each. No epidemiologic links were noted among cases with indistinguishable subtypes, except for the cases from the five long-term care facilities having multiple cases as described previously.

The deaths were distributed among 12 different PFGE subtypes, with eight (36%) deaths attributed to the most common PFGE subtype. No other subtype accounted for more than two deaths.

• For up to date information see>> Group A Streptococcus (GAS)
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2003