# Mortality Associated With Viral Bronchiolitis in a Pediatric Department: A Retrospective Analysis

## TL;DR

This study examines the causes of death from viral bronchiolitis in infants in Morocco, highlighting the need for better prevention in high-risk groups.

## Contribution

The study identifies specific risk factors and comorbidities associated with fatal viral bronchiolitis in infants, emphasizing the importance of RSV prophylaxis.

## Key findings

- 32 infant deaths due to viral bronchiolitis were recorded over 11 years, with an average age of five months and 15 days.
- Congenital heart diseases were the primary cause of death, with conditions like ventricular septal defect and dilated cardiomyopathy being most common.
- Lack of intensive care unit availability contributed to mortality, as patients could not be transferred for specialized care.

## Abstract

Introduction: In Morocco, acute viral bronchiolitis remains a major public health problem, and its incidence continues to rise. Acute viral bronchiolitis can be severe and even fatal, especially in vulnerable populations. The objectives of this study were to analyze the causes of death due to viral bronchiolitis and to highlight the importance of prophylaxis in high-risk groups.

Methods: This was a retrospective, descriptive study spanning 11 years and 11 months, from January 1, 2013, to December 10, 2024. We included all cases of acute bronchiolitis complicated by infant death. The study focused on infants aged one to 24 months who presented with acute bronchitis.

Results: During the study period, 32 cases of viral bronchiolitis resulted in death during hospitalization. The average age of patients was five months and 15 days, with a male predominance. The average duration between the onset of symptoms and death was seven days, ranging from 24 hours to 30 days. The risk factors included male sex (n=20, 62.5%), passive smoking (n=17, 53.1%), young age (n=16, 50%), and preterm infancy (n=4, 12.5%). Comorbidities were found in 25 (78%) cases, including 19 (59.4%) of congenital heart disease, one (3.12%) of bronchopulmonary dysplasia, one (3.12%) of spinal muscular atrophy, one (3.12%) of hypopituitarism, one (3.12%) of ichthyosis, and one (3.12%) of polymalformative syndrome. The primary causes of death were congenital heart diseases, including ventricular septal defect (n=5, 15.62%), dilated cardiomyopathy (n=3, 9.37%), complex congenital heart disease (n=1, 3.12%), double outlet right ventricle (n=1, 3.12%), and tetralogy of Fallot (n=1, 3.12%). The average duration of hospitalization was five days, ranging from one hour to 15 days. All patients required intensive care, but they could not be transferred due to the lack of available beds, leading to mortality.

Conclusion: Infants born prematurely with chronic lung disease or with decompensated congenital heart disease are at increased risk of severe acute bronchiolitis, particularly due to respiratory syncytial virus (RSV). This risk underscores the importance of prophylaxis with anti-RSV monoclonal antibodies.