The impact of social restrictions on the incidence and microbiology of severe acute tonsillitis.

Introduction: We aimed to explore the impact of social distancing on the incidence, severity and microbiology of patients with acute tonsillitis (AT).

Methods: In this single-centre study, we retrospectively included all patients with AT referred to the Ear-Nose-Throat Department, Aarhus University Hospital, Denmark, in the two years preceding versus the two years after the COVID-19 lockdown in Denmark (11 March 2020).

Results: In total, 425 patients were included. The incidence of AT was significantly lower in the post-lockdown period (n = 128) than in the pre-lockdown period (n = 297) (p less-than 0.001). Reduced incidence was observed across all age groups. No significant differences were found in patient characteristics between periods. The proportion of hospitalised patients was significantly lower in the post- than in the pre-lockdown period (36% versus 25%, p = 0.032). Prevalent culture findings were Streptococcus pyogenes (15%), S. anginosus group (11%) and Fusobacterium necrophorum (5%). No statistically significant differences in the relative prevalence of individual bacteria were found between periods.

Conclusions: The incidence of patients with AT referred to hospital decreased by 57% in the two-year period after the COVID-19 lockdown compared with the period leading up to the lockdown. Our findings suggest that this decrease mirrored a general decline in AT incidence rather than altered referral patterns.

Funding: None.

Trial registration: The study was approved by the Danish Data Protection Agency (#1-16-02-134-23) and the Danish Patient Safety Authority (#1-45-70-41-23).