Streptococcal Invasive Disease - Group A, 2005

One hundred twenty-two cases of invasive group A streptococcal (GAS) disease (2.4 per 100,000 population), including nine deaths, were reported in 2005, compared to 146 cases and 18 deaths in 2004. Ages of case-patients ranged from 1 month to 96 years (mean, 49 years). Fifty-one percent of case-patients were residents of the Twin Cities metropolitan area. Thirty-nine (32%) case-patients had cellulitis with bacteremia and 36 (30%) case-patients had bacteremia without another focus of infection. There were 14 (12%) cases of primary pneumonia and eight (7%) cases of necrotizing fasciitis. Eight (7%) case-patients had septic arthritis and/or osteomyelitis, and two (2%) had streptococcal toxic shock syndrome (STSS) accompanied by soft tissue infections. Ten (8%) case-patients were residents of long-term care facilities. None of the facilities had more than one case-patient.

The nine deaths included five cases of bacteremia without another focus of infection and one case of pneumonia. The three remaining fatal cases had bacteremia with cellulitis. The deaths occurred in persons ranging in age from 49 to 90 years. For the eight deaths in patients with known health histories, significant underlying medical conditions were reported for all of the cases.

Isolates were available for 115 (94%) cases, all were subtyped using PFGE; 59 different molecular subtypes were identified. Thirty-eight subtypes were represented by one isolate each; other subtypes were represented by two to 17 isolates each. No epidemiologic links were noted among cases with indistinguishable subtypes.

The deaths were distributed among nine different PFGE subtypes with no two deaths attributed to the same subtype.

• For up to date information see>> Group A Streptococcus (GAS)
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2005