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 2023, 2) identify emm types found in iGAS-VRI coinfections, and 3) analyze trends in coinfection before, during, and after the emergence of COVID-19.
Methods: iGAS and VRI data between January 5, 2018, to October 30, 2023, was obtained from the Public Health Laboratory and patient results reviewed. A positive iGAS test ± 28 days of a positive VRI test was considered an iGAS-VRI coinfection. For analysis of emm types and individual viruses, cases with 2 or more VRI infections were considered as separate cases. Trends before, during, and after COVID-19 were analyzed with Mann-Kendall Trent Test and emm types were graphed using R.
Results: Of the 1583 iGAS cases, 186 coinfections (13.3%) were observed and associated with emm1, 12, 49, 74, and 81. Seven cases had 3 concurrent VRI infections and 23 had 2. For individual viral analysis, iGAS-COVID-19 coinfections were most prevalent followed by entero/rhino virus (ERV) and influenza. In addition, emm1 was predominant for ERV and influenza while emm74 was predominant for COVID-19 followed closely by emm1. Lastly, coinfections in pre-COVID, COVID, and post-COVID periods displayed no significant increase (p=0.098).
Conclusion: We observed iGAS-VRI coinfections in Alberta occur for over 10% of iGAS cases. Also, the emm types associated with coinfections are similar to iGAS-only infections.