Delta variant effect on the clinical course of adolescent COVID-19 patients

The clinical course of new COVID-19 variants in adolescents is still unknown. The aim of this study is to evaluate the clinical characteristics of COVID-19 in adolescents and compare the differences between the original version and the delta variant.

The medical records of patients aged 10-18 years treated for COVID-19 between April 1, 2020 and March 31, 2022 were retrospectively reviewed. Patients were divided into four groups (asymptomatic, mild, moderate, and severe) for COVID-19 severity and into two groups according to the diagnosis date (first-second year). The primary endpoint of the study was hospital admission.

The mean age of patients was 171.81 ± 29.5 months, and most of them were males (n: 435, 53.3%). While the patient number was 296 (43.52%) in the first year of pandemic, it raised to 520 (54.11%) in the second year (p < 0.01). The severity of COVID-19 was mild in 667 (81.7%) patients. In the comparison of patients according to the diagnosis date (first-second years); the parameters of anosmia, ageusia, weakness, muscle pain, vomiting, hospital admission, and length of stay in hospital were statistically different (p < 0.05). In the comparison of hospitalized patients between years, the necessity of oxygen support (p < 0.001), endotracheal intubation rates (p < 0.05), length of stay in the hospital (p < 0.001), and the severity of COVID-19 (p < 0.05) was significantly higher in the second year.

The clinical course for adolescents diagnosed with COVID-19 has linearly changed with the delta variant. Our results confirmed that the delta variant is more transmissible, requires more oxygen support, increases endotracheal intubation, and prolongs the length of stay in the hospital.