# SARS-CoV-2 Variants and Their Impact on Pediatric COVID-19: Clinical Manifestations and Hematological Profiles

## TL;DR

This study examines how different SARS-CoV-2 variants affect children's symptoms and blood profiles, finding fever as a common symptom and longer hospital stays for Omicron cases.

## Contribution

The study provides insights into the clinical and hematological differences in pediatric patients based on SARS-CoV-2 strain and age group.

## Key findings

- Fever was the most consistent symptom across all age groups and virus strains.
- Neutropenia (30%) and lymphopenia (23%) were the most common hematological manifestations.
- The Omicron strain was associated with the longest hospital stay compared to other strains.

## Abstract

Background: The aim of this study was to analyze data on pediatric cases of COVID-19 admitted to a tertiary referral hospital in northwest Greece. Methods: A retrospective analysis was conducted on the most common clinical manifestations and laboratory findings, stratified by age group and SARS-CoV-2 strain. Results: A total of 254 children were hospitalized, with a mean age of 4.5 years. Underlying conditions were present in 10.2% of cases; two children required pediatric intensive care unit (PICU) admission, and one child died. The most common hematological manifestations, in general, were neutropenia (30%) and lymphopenia (23%), whereas the findings varied when the children were stratified by age group. Eight children developed multisystem inflammatory syndrome (MIS-C), with the most common findings being anemia (75%), lymphopenia (50%), and thrombocytopenia (25%). Analysis of the SARS-CoV-2 strains revealed the proportions of the dominant strain over time. Fever was the predominant symptom across all strains, particularly in the Omicron group, which also had a high incidence of gastrointestinal symptoms. The longest hospital admission occurred in children with the Omicron strain, followed by the Wuhan, Alpha, and Delta strains. Conclusions: Fever was the most consistent symptom across all age groups and virus strains. The most common hematological manifestations were neutropenia (30%) and lymphopenia (23%). The Omicron strain was associated with the longest hospital stay.