2023 Highlights
- According to the Centers for Disease Control and Prevention (CDC), the number of serious group A strep infections in the United States have been increasing over the past decade. In 2023, the number of serious infections reached a 20-year high. This is consistent with Minnesota’s data. The increase can be seen across all age levels, including among pediatric cases.
- In 2023, long-term care facilities and their residents were impacted by the increase in group A strep transmission in Minnesota. The majority of long-term care facilities outbreaks are associated with lapses in infection prevention, staff turnover, and wound care. CDC released a decision tool for investigating and controlling GAS infections in long-term care to better guide those involved in the response.
- While group A strep bacteria circulate year-round, infection is more common in December through April (“high season”). In Minnesota, an increase was first noticed in the fall of 2022 and was sustained through August 2023 demonstrating a departure from typical seasonality.
There were 625 cases (11.0 cases per 100,000 population), including 55 deaths, reported in 2023, compared to 310 cases and 29 deaths in 2022. The median age of cases was 58 years (range, 25 days to 97 years). Sixty-one percent of cases were residents of the metropolitan area. Allowing for multiple presentations per patient, 300 (48%) had cellulitis, 169 (27%) septic shock, 93 (15%) septic arthritis and/or osteomyelitis, 89 (14%) bacteremia without another focus of infection, 84 (13%) pneumonia, 53 (8%) abscess (not skin), 44 (7%) necrotizing fasciitis, and 40 (6%) STSS. Twenty-seven (4%) cases were injection drug users in 2023 compared to 27 cases (9%) in 2022. There were two deaths in 2023 compared to no deaths in 2022. Forty-two (7%) cases were residents of long-term care facilities (LTCFs). Among 2023 LTCF-associated invasive GAS cases only, twelve facilities had a single case, four facilities had two cases, and six facilities had more than two cases.
Allowing for multiple infection types per patient, the 55 deaths included 43 that were diagnosed with septic shock, 18 with cellulitis, 12 with STSS, 11 with pneumonia, 7 with necrotizing fasciitis, and 6 with septic arthritis and/or osteomyelitis. Of the 55 deaths, the most frequently reported underlying conditions were obesity (21), diabetes (17), chronic kidney disease (13), chronic skin breakdown (13) (e.g. psoriasis, chronic ulcers), heart failure (13), current tobacco smoker (12), atherosclerotic cardiovascular disease (9), solid organ malignancy (8), and seizure disorder (7). Thirty-four fatal cases had two or more underlying conditions, and eight had none reported.