Streptococcal Invasive Disease Group A, 2018

Invasive Group A streptococcal disease (GAS) is defined as GAS isolated from a usually sterile site such as blood, cerebrospinal fluid, or a wound when accompanied with necrotizing fasciitis or streptococcal toxic shock syndrome (STSS). Three hundred sixty-seven cases (6.6 cases per 100,000 population), including 37 deaths, were reported in 2018, compared to 359 cases and 34 deaths in 2017. The median age of cases was 60 years (range, newborn to 99 years). Fifty-five percent of cases were residents of the metropolitan area. Allowing for multiple presentations per patient, 140 (38%) had cellulitis, 71 (19%) bacteremia without another focus of infection, 83 (23%) septic shock, 51 (14%) pneumonia, 25 (7%) abscess, 33 (9%) septic arthritis and/or osteomyelitis, 25 (7%) necrotizing fasciitis, and 11 (3%) had STSS. Twenty-three cases (6%) were injection drug users in 2018, compared to 10 (3%) in 2017. Forty-four (12%) cases were residents of long-term care facilities. Eighteen facilities had a single case, nine facilities had 2 or more cases including one facility that had 5 cases. A cluster of isolates from 53 cases from the west metropolitan area were determined to be indistinguishable from one another using whole genome sequencing. A review of the cases revealed that these cases were primarily residents of 19 different long term care facilities and had underlying wounds. An investigation of shared services between these facilities revealed that this cluster was associated with a single wound care provider who was contracted by these facilities.

The 37 deaths included 25 that presented with just septic shock, 7 bacteremia without another focus of infection, 8 cellulitis, and 12 pneumonia (individuals could have more than one infection type). Of the 34 deaths, the most frequently reported underlying conditions were obesity (10), current tobacco smoker (8), diabetes (7), chronic kidney disease (7), heart failure (7), atherosclerotic cardiovascular disease (7), chronic obstructive pulmonary disease (4), asthma (4), current alcohol abuse (3), dementia (3), peripheral vascular disease (3), cirrhosis (2), and chronic skin breakdown (2). Twenty-one fatal cases had two or more underlying conditions, and 5 had none reported.

• For up to date information see>> Group A Streptococcus (GAS)
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2018