Intro: The epidemiology of invasive group A Streptococcus (iGAS) has been previously documented in Alberta, Canada, however, coinfections with respiratory viral infections (VRI) and associated emm types remains unclear. Here, we aimed to 1) evaluate number of iGAS-VRI coinfections from 2018 to 2024, 2) identify emm types found in iGAS-VRI coinfections, and 3) analyze temporal trends of coinfection within iGAS cases.

Methods: iGAS and VRI data between January 1^st, 2018 and December 31^st, 2024 was obtained from the Public Health Laboratory and patient results reviewed. An iGAS-VRI coinfection was considered to be a VRI case ± 28 days of an iGAS case. Using R, statistical testing with Fishers exact test was conducted on emm type and age while a Cochran Armitage trend test was used to access coinfection trends. 

Results: Of 2126 iGAS cases, 254 coinfections (11.9%) were observed with emm1, 12, 49, 74, and 81 having the highest prevalence. For individual viral analysis, iGAS-SARS-CoV2 coinfections were most prevalent followed by entero/rhino virus (ERV) and influenza. In addition, ages 4 and under were disproportionally affected by coinfection while coinfection cases were disproportionally affected by emm1. While the overall number of coinfection cases had increased, its proportion relative to iGAS infection is trending negatively.

Conclusion: We observed iGAS-VRI coinfections in Alberta occur in 11.9% of iGAS cases. Statistical analysis revealed that emm1 and ages under 4 were disproportionally represented in coinfection cases. Also, the occurrence of coinfections within iGAS infections are trending negatively.