# Etiology and Clinical Correlates of Pediatric Pneumonia in Lebanon in the Era Following COVID-19 Vaccine Availability: A Multicenter Retrospective Study

## TL;DR

This study examines the causes and clinical features of pediatric pneumonia in Lebanon after the availability of the COVID-19 vaccine, finding that most cases have an unknown cause and confirmed infections are more severe.

## Contribution

The study provides contemporary data on pediatric pneumonia etiology and severity in Lebanon post-COVID-19 vaccine rollout.

## Key findings

- Most pediatric pneumonia cases (75.8%) had an unknown etiology.
- Bacterial pneumonia was linked to higher severity, including longer hospital stays and ICU admissions.
- Gram-negative bacteria were the most common cause of bacteremia in confirmed cases.

## Abstract

Background: The COVID-19 pandemic has significantly altered the global epidemiology of respiratory infections. In Lebanon, a country facing a complex socio-economic crisis, data on the contemporary microbiological etiology and clinical characteristics of pediatric pneumonia following the widespread availability of COVID-19 vaccines are critically scarce.

Methodology: A multicenter, retrospective study was conducted from January 2022 to February 2023. Children aged one month to 13 years admitted with radiologically confirmed pneumonia to three hospitals were included. Patients were categorized into those with an identified pathogen (bacterial, viral, or mixed) and those with an unknown etiology. Data on demographics, clinical presentation, laboratory results, radiological findings, and treatment were analyzed using IBM SPSS Statistics for Windows, Version 26.0 (IBM Corp., Armonk, NY).

Results: Among 157 children, the etiology was unknown in 75.8% (n=119) of cases. Confirmed bacterial pneumonia accounted for 13.4% (n=21), viral pneumonia for 9.6% (n=15), and mixed (bacterial-viral) infections for 1.3% (n=2). Only 13.3% (n=2) of viral cases were SARS-CoV-2 positive. Bacterial pneumonia was characterized by a high rate of bacteremia (76.2%, n=16), predominantly with Gram-negative organisms. Children with an identified pathogen had significantly higher heart rates (141.3 vs. 130.8 beats per minute (bpm), p=0.026), lower oxygen saturation (93.8% vs. 95.6%, p=0.002), longer hospital stays (9.1 vs. 5.5 days, p<0.001), and higher ICU admission rates (23.7%, n=9 vs. 5.0%, n=6; p=0.001). Pulmonary consolidation on X-ray was more common in the identified group (39.5%, n=15 vs. 17.6%, n=21; p=0.005).

Conclusions: A significant majority of pediatric pneumonia cases in this contemporary Lebanese cohort are of unknown etiology, underscoring persistent diagnostic challenges. Microbiologically confirmed pneumonia, particularly with Gram-negative bacteria, is associated with greater clinical severity. These findings highlight an urgent need for enhanced diagnostic strategies and tailored antimicrobial stewardship programs in the post-pandemic era to optimize patient care and combat antimicrobial resistance.