Protracted cluster of Group A Streptococcal infection among individuals receiving wound care in the community, North East England, 2022: An outbreak report

Background: Outbreaks of Group A Streptococcal (GAS) infection are difficult to detect in community healthcare settings and present unique challenges for infection prevention and control (IPC). We describe investigation of a cluster of GAS among individuals receiving wound care from the same community integrated care team (CIT) and associated complexities. Methods: Prospective and retrospective surveillance for cases of invasive and noninvasive GAS infection linked to the CIT was undertaken with the local NHS trust IPC team. Screening samples were requested from staff working in the CIT (n = 191) and from staff and residents (n = 73) in care home A where several cases resided. Clinical isolates were sent to the UKHSA reference laboratory for emm typing and whole genome sequencing (WGS). Results: Twenty-two cases were identified over a five-month period. Eighteen had isolates available for typing, 11 of which were emm type 108.1 and 0-2SNPs apart on WGS. Six were different emm types and one emm type 108.1 but 9-13SNPs apart from other isolates and so excluded from the investigation. No staff infected or colonized with emm 108.1 were identified, and no single healthcare worker had attended all cases. GAS was isolated in the room of a case resident in care home A and found to be closely genetically related to clinical isolates. Conclusions: WGS was integral in identifying outbreak cases and a multiagency approach essential to the investigation. Unfortunately, despite this no clear source or route of transmission was identified. Further research is required to determine the most effective IPC strategies for community healthcare.