Long Term Impact of Adeno-tonsillectomy on Immunity Against Respiratory Viral Infections; Evidence Deduced During COVID-19 Pandemic

To evaluate the risk of acquiring COVID-19 infection in patients who have undergone adeno-tonsillectomy (AT) as compared to their siblings. In this bidirectional cohort control study, 36 cohorts, younger than 18 y, who underwent AT, and 27 controls (siblings of the enrolled cohorts, younger than 18 y) were recruited. Incidence of COVID-19 was analyzed by symptoms suggestive of COVID-19 infection, COVID-19 testing, and SARS-CoV-2 specific antibody measurement. In the cohort group, the overall COVID-19 positivity rate was 80.5% (n = 29/36) and symptomatic COVID-19 positivity rate was 68.9% (n = 20/29). Among the controls, the overall COVID-19 positivity rate was 44% (n = 12/27) and symptomatic COVID-19 positivity rate was 16% (n = 2/12). The cohorts had 1.8 times higher risk of contracting COVID-19 infection and the relative risk of symptomatic COVID-19 infections as compared to controls was 4.14. This pilot study indicates that adeno-tonsillectomy poses children at a significantly higher risk of COVID-19 infections and likely other viral upper respiratory tract infections.