Objective: To study national pediatric acute rhinosinusitis (ARS) burden fluctuations before and during the first 2 coronavirus-19 (COVID) years, characterized by alternating lockdown and relaxation periods, the introduction of COVID vaccines, and the emergence of nonalpha COVID variants. Methods: This was a cross-sectional, population-based study covering the 3 pre-COVID years and the first 2 COVID years from a big database of the largest Israeli Health Maintenance Organization. For comparison purposes, we explored ARS burden trends with those of urinary tract infection (UTI), which is unrelated to viral diseases. We identified children <15 years presenting with ARS and UTI episodes and categorized them according to their age and presentation date. The average ARS and UTI episodes of the 3 pre-COVID years were used to calculate the incidence rate ratios (IRRs) of the 2 COVID years, analyzed separately. Seasonal variations were explored. Results: We identified 44,483 ARS and 121,263 UTI episodes. There was a substantial reduction in ARS episodes during the COVID years (IRR 0.36, 95% CI: 0.24–0.56, P < 0.001). Although UTI episode rates also decreased during COVID (IRR 0.79, 95% CI: 0.72–0.86, P < 0.001), the reduction in ARS burden was 3-fold higher. The dominant pediatric ARS age group was between 5 and 15 years. The largest decrease in ARS burden was during the first COVID year. ARS episode distribution showed a seasonal fluctuation, with a peak during the summer months during the COVID years. Conclusions: Pediatric ARS burden decreased during the first 2 COVID years. Episode distribution was noted to be year-round.

To evaluate the impact of the pneumococcal conjugate vaccines (PCVs) introduction on the orbital complications of acute rhino-sinusitis (OC-ARS). A retrospective cohort study of all pediatric patients with OC-ARS during the period 2002-2019. Data included clinical, demographic, laboratory, and microbiology findings. Patients were divided into three groups: before PCV7 introduction (group 1), after PCV7 and before PCV13 (group 2), and after PCV13 (group 3). Of 265 enrolled patients, 117, 39, and 109 were assigned to groups 1, 2, and 3. During the study period, a significant decrease was recorded in the percentages of patients in Chandler classification severity category 1, with an increase in patients in category 3 (P = 0.011). The yearly incidence of OC-ARS decreased from 12.64 cases per 100,000 population in 2002 to 5.56 per 100,000 in 2008, and 2.99 per 100,000 in 2019 (P < 0.001). Patients aged 0-4 years showed a dramatic decrease from 29 cases per 100,000 population in 2002 to 4.27 per 100,000 in 2019 (P < 0.001). The pathogens retrieved from all cultures performed were Streptococcus pneumoniae (32.5%), non-typeable Haemophilus influenzae (27.5%), Streptococcus Species, (12.5%), and Staphylococcus aureus (20%), with no changes in distribution during the study periods. Surgery was performed in 28 (10.6%) patients. A significant decrease was seen in the overall incidence of OC-ARS, mainly attributable to the decrease in patients aged 0-4 years. An increase was recorded in the severity of the disease following PCVs introduction.