Assessing the influence of the COVID-19 pandemic on the incidence, clinical presentation, and clindamycin resistance rates of Streptococcus pyogenes infections

Objectives

Streptococcus pyogenes (group A Streptococcus [GAS]) is a prevalent cause of community-acquired bacterial infections, with invasive GAS (iGAS) infections presenting severe morbimortality. Clindamycin is generally used based on its antitoxin effect. This study investigates changes in iGAS incidence, clinical presentation, outcomes, and clindamycin resistance in an adult cohort.

Methods

This is a retrospective analysis of S. pyogenes episodes from a tertiary adult hospital in Barcelona (Spain) between 2015 and 2023. The pre-pandemic period includes data from 2015-2019. The pandemic period, from 2020-2021, and post-pandemic period comprised 2022 to the first semester of 2023.

Results

The global incidence of GAS infections in the pre-pandemic and post-pandemic periods were 2.62 and 2.92 cases per 10.000 hospital admissions, whereas for iGAS cases, they were 1.85 and 2.34. However, a transient decrease was observed during the pandemic period: 1.07 and 0.78 per 10.000 hospital admissions. There was a significant decrease in GAS and iGAS infections during the pandemic period compared with the pre-pandemic incidence (P <0.001 for GAS infections and P = 0.001 for iGAS cases) and the post-pandemic incidence (P = 0.032 for GAS infections and P = 0.037 for iGAS cases). The most common source of infection was skin and soft tissue infections with 264 (54%) cases. Skin and soft tissue infections and cases of necrotizing fasciitis increased during the pandemic. Clindamycin resistance occurred in 13.5% of isolations during the pre-pandemic and 17.5% in post-pandemic period (P = 0.05).

Conclusions

Our study revealed a temporary reduction in iGAS infections, followed by resurgence in the post-pandemic period. The observed rise in clindamycin resistance emphasizes the importance of monitoring local resistance patterns for tailored treatment.