By Ethan Covey
A substantial increase in invasive group A streptococcal (GAS) infections among people who inject drugs (PWID) seeking care at the University of Vermont Medical Center (UVMMC) has highlighted the need for wound care services among this group of patients.
Forty-five cases of GAS bacteremia were identified during the first 10 months of 2023, and 19 were reported during 2022, compared with three cases during 2020 and four in 2021 (MMWR Morb Mortal Wkly Rep2024;73[16]:382-384).
Among the 64 cases of GAS identified during 2022-2023, 70% occurred among 38 patients who are known to inject drugs. In 62% of these cases, the individuals reported experiencing homelessness at the time of GAS bacteremia diagnosis.
“Our findings support other researchers that intravenous illicit drug use and homelessness are risk factors for invasive Streptococcus pyogenes infection,” said Lindsay M. Smith, MD, an assistant professor of medicine, Larner College of Medicine at the University of Vermont, in Burlington. “Illicit drug use and homelessness should be modifiable community risk factors.”
Most patients included in the study had skin and soft tissue wounds at the time of S. pyogenes bacteremia, and most had sought care in the emergency department for wound care before becoming bacteremic.
“This suggests that a one-time visit for wound care is not sufficient in preventing invasive infections,” Dr. Smith said.
In addition, known exposure to xylazine was self-reported in 27% of the cases, and suspected by a clinician in an additional 16%. Xylazine is a common adulterant in illegal drug mixtures, and has been associated with necrosis at both injection sites and noninjection sites.
“Our data only show a temporal overlap of the increase in S. pyogenes bacteremia and the introduction of xylazine into the local illicit drug supply,” Dr. Smith said. “We have not shown causation, and further study is warranted to explore a possible link.”
According to Dr. Smith, the report raised more questions than it provided answers, including whether there is a new circulating strain or em type of S. pyogenes, and whether antimicrobial susceptibility patterns have changed to non–beta-lactam antibiotics.
Dr. Smith hopes these, and other questions, will be clarified by future research.
Overall, Dr. Smith said the report showed the importance of real-time surveillance of patients admitted to the hospital with bacteremia to capture new trends, and showcased key collaboration among teams working at UVMMC.
“This report highlights the importance of collaboration between infection prevention and antimicrobial stewardship teams,” she said. “Both teams approach the problem from different vantage points, with IP looking at transmission and risk factors for transmission and ASP looking at antibiotic optimization.”
