Impact of COVID-19 on the epidemiology of severe sinogenic and otogenic infections and their intracranial complications.

This study aims to evaluate the impact of COVID-19 pandemic on the incidence, microbiological characteristics, management, and outcomes of mastoiditis and orbital cellulitis and their intracranial complications in pediatric patients. A retrospective observational study was conducted at the major pediatric hospital of Athens from 1/2018 to 12/2023. Pediatric patients (0-16 years) diagnosed with mastoiditis, orbital cellulitis, and related complications were included. Data were collected across three periods: pre-pandemic (1/2018-3/2020), during the pandemic (4/2020-6/2021), and post-pandemic (7/2021-12/2023). Statistical analyses compared demographic, clinical, and microbiological characteristics between the periods. A total of 176 cases were included (76 mastoiditis and 100 orbital cellulitis cases). The in-hospital incidence of both infections increased significantly post-pandemic compared to the period before the pandemic (mastoiditis: 5.5 vs.13.6 per 1000 admissions; orbital cellulitis: 4.8 vs. 21.8 per 1000 admissions, P < 0.001). Streptococcus and Staphylococcus species predominated across the three periods. Median (IQR) age was not significantly different between the two periods among patients with mastoiditis (pre-pandemic: 5.6 (3.5) years vs. post-pandemic: 3.3 (3.4) years, P = 0.12) and among patients with orbital cellulitis (pre-pandemic: 9.2 (6.6) years vs. post-pandemic: 8 (9.2) years, P = 0.50). Regarding the complications, the rate of intracranial empyema/abscess development among patients with orbital cellulitis, but not mastoiditis, was lower post-pandemic compared to pre-pandemic (30% vs. 10.1%, P = 0.03).

Conclusion: The study findings demonstrate a significant rise in the post-COVID-19 in-hospital incidence of mastoiditis and orbital cellulitis in children. Future epidemiological surveillance of these complications and pathogen-specific dynamics, are important to develop prevention strategies for these severe pediatric infections.

What is known: • The COVID-19 pandemic shifted the epidemiology of severe upper respiratory tract infections. • Data on the epidemiology of severe sinogenic and otogenic infections and their intracranial complications during and after the acute phase of the COVID-19 pandemic are limited in Europe.

What is new: • This study highlights a notable increase in the in-hospital incidence of mastoiditis and orbital cellulitis during the post-COVID-19 pandemic era, likely associated with immunity debt and alterations in respiratory microbiota. • Despite the increase in pediatric mastoiditis and orbital cellulitis cases, the rates of complications and surgical management remained stable throughout the study period.