A rise in severe necrotizing fasciitis- another consequence of the COVID-19 pandemic?

Purpose: During the COVID-19 pandemic restrictions such as social distancing, lockdowns and mask mandates were imposed by Germany's government. After these interventions were abolished, an increase in group A streptococcal infections, including necrotizing fasciitis, was observed in our Level 1 trauma center. The aim of this study was to evaluate the incidence of type I and type II necrotizing fasciitis (NF) before, during and after the COVID-19 pandemic.

Methods: 165 patients with severe NF, treated in our Level 1 trauma center, were included between 2010 and 2023. Patients were categorized into a pre-mask, mask and post-mask group, according to their date of admission relative to the COVID-19 pandemic. Clinical parameters and patient characteristics were assessed between groups.

Results: In the pre-mask group, type I NF (69%) was more common than type II NF (31%). In the mask group 95% of patients had type I NF. In the post-mask group, Streptococcus pyogenes triggered type II NF dominated with 74% of all cases. There was a significant increase in NF type II cases in the post-mask group compared to the pre-mask and mask-group (p < 0.001). Patients with NF in the post-mask group appeared significantly healthier and tended to be younger than patients before and during the COVID-19 pandemic.

Conclusion: This study supports the hypothesis that the general population has acquired an "immune debt" following the COVID-19 pandemic, resulting in an increase in necrotizing fasciitis incidence, especially triggered by Streptococcus pyogenes, after restrictions such as mask mandates and social distancing were lifted.