Impact of the COVID-19 pandemic on the incidence of acute mastoiditis in a tertiary reference children's hospital in Brazil.

Many countries implemented mitigation strategies during the COVID-19 pandemic. Consequently, studies conducted between 2020 and 2022 reported changes in respiratory tract infection incidence and seasonality patterns, alongside a reduction in associated illnesses such as acute otitis media (AOM). Following the pandemic, a resurgence in AOM and acute mastoiditis (AM) cases has been observed.

Objectives: To compare the incidence of AM hospitalizations and complications across three periods: pre-pandemic, pandemic, and post-pandemic. Additionally, the study aims to evaluate associations with patient age, need for surgical intervention, antibiotic therapy, and isolated etiological agents.

Methods: This retrospective cohort study reviewed pediatric charts from three 22-month periods: pre-pandemic (P1), pandemic (P2), and post-pandemic (P3). These periods were compared in terms of case numbers, presence and severity of AM complications, patient demographics (age and sex), and treatment approaches.

Results: A total of 9 AM cases were recorded in (P1), 5 in the (P2), and 25 in (P3). This represents a 25.5 % reduction in AM incidence during the pandemic compared to the pre-pandemic period, though this was not statistically significant (p = 0.8027). However, a significant 103.3 % increase in AM incidence was noted between the pre- and post-pandemic periods (p = 0.0322). No significant differences were found among periods regarding age, sex, complications, case severity, surgical intervention, antibiotic duration, or length of hospitalization.

Conclusion: Although AM incidence slightly declined during the pandemic, the post-pandemic period showed a significant rise in the incidence of cases compared to pre-pandemic values.