Characteristics of COVID-19 Infections and Severe Outcomes in a Multinational Study in Latin America During the Circulation Period of the Delta Variant in the Pediatric Population
Authors: Gutiérrez Tobar Iván F , Homsi Maysam R , VAsquez Milka , Caniza Miguela A , Londoño Juan P , Ruiz Alejandra Nava , Arteaga Maribel Baquera , Muriel Verónica Elena González , Fuentes Valeria Margarita Mejía , Molina Sara Eloísa Rivera , Bejarano José Iván Castillo , De la Mora Hernández Marie Ann Cosette , Robles Martha Avilés , Riosvelasco Fernando Ortega , Gutierrez Valentina , Esposto Sofía 
Published: November 2023

Abstract

Background
SARS-CoV-2 infection had specific characteristics in the pediatric population described in previous studies. These clinical features included specific COVID-19 presentation, antibiotic usage, and predictors of disease severity. In addition to patient related factors, external influences could affect COVID-19 outcomes. The features of children with COVID-19 of five Latin American countries were described. Study participants were members of the Prevencionistas e Infectólogos para Cáncer Pediátrico en América Latina (PRINCIPAL) Network of the Global Infectious Diseases Program at St Jude Children's Research Hospital. This study aims to analyze the differences between patients with non-severe and severe disease when the circulation of the Delta variant was predominant, and few children had received SARS-CoV-2 vaccines.

Methods
This is a retrospective, observational, multinational study that included children with a confirmed diagnosis of COVID-19 between January 2021 and January 2022. Epidemiological, clinical, and treatment characteristics are described and compared between patients with severe and non-severe disease. Frequencies and percentages are presented as well as median and interquartile ranges (IQR). Comparisons were made using the chi-squared test for proportions and the Wilcoxon test for nonparametric quantitative variables.

Results
745 patients were included. Patients had a median age of 51 (13-139) months, 194 (26%) had comorbidities, and 701 (94%) presented with symptomatic disease. Fever was present in 524 (74.8%) patients, respiratory symptoms in 550 (78.5%), followed by gastrointestinal manifestations in 218 (31.1%). X-ray findings were abnormal in 175/362 patients, with interstitial infiltrates being the most common finding, 123 (70.7%). Almost a third of patients (29%) received an antibiotic; ceftriaxone was most frequently prescribed in 123/216 cases. Of 745 patients, 526 (70.8%) were hospitalized, of which 165 (31.4%) required PICU admission. Patients presenting with severe disease and requiring PICU admission we more likely to have a comorbidity, 128 (22%) vs. 66 (40%), p&lt;0.001. Mucocutaneous findings or adenitis were more frequently described in severe cases, 19 (11.5) vs. 18 (5.0%), p=0.007. Regarding laboratory results, low lymphocytes 2445 vs. 1676 (p&lt;0.001) and low platelets 294,000 vs. 250,000 (p=0.0002) were most common in patients with severe disease. The proportion of patients with lymphocytopenia was also higher in those with severe disease, 39% vs. 52% p= 0.010. Not surprisingly, antibiotic usage (broad and narrow spectrum) was higher in patients admitted to the PICU (32 vs. 16.5%) p=0.001, despite no significant difference in the frequency of bacterial coinfection (5.56% vs. 9.7% p=0.081) when compared to patients with non-severe disease. Specific treatment strategies were more frequent in PICU patients (39.1% vs. 72.1%) p&lt;0.001, and steroids were the most frequently used drug, 35.2% vs. 70.7% (p&lt;0.001). Table 1.

Conclusions
Regardless of the variant, COVID-19 is an important cause of hospitalization in children. Fever, respiratory and gastrointestinal symptoms are the most frequent manifestations in children. Despite the low frequency of bacterial coinfection, a high proportion of antibiotic usage is described. Compared to recent publications, mucocutaneous involvement, lower lymphocyte and platelet counts, and higher inflammatory markers were more frequently found in admissions to the PICU. Currently, with higher vaccine coverage and more comprehensive knowledge of the disease, optimization of pediatric COVID-19 management is expected, especially concerning antibiotic use. It is essential to continue multicenter surveillance of the behavior of COVID-19 in the pediatric population.