Increased Cardiorespiratory Illness Linked to Influenza Outbreaks in Pediatric Population

Benoit Morel, MD

A new study from France found that cardiorespiratory decompensation and bed occupancy for adult emergency departments were significantly increased following bronchiolitis and pediatric influenza outbreaks.

Investigators suggested that prediction tools such as the decision-making support tool PREDAFLU could be used to provide early warnings of increased activity during these visits.

Respiratory pathogens such as respiratory syncytial virus (RSV) and influenza are commonly cited reasons for increased activity in pediatric ED visits and are also associated with CRD in adult populations.

Given the seasonal nature of these viruses, Benoit Morel, MD, University Hospital of Saint Etienne, and fellow investigators believed it would be advantageous to predict their variations.

As such, Morel and colleagues evaluated the increased burden of CRD in adult Eds during flu and bronchiolitis outbreaks in pediatric populations in Grenoble.

The Methods

The team based their ecological study on a retrospective review of data related to admissions to the adult ED. The study was conducted from June 29, 2015 to March 22, 2020.

University Hospital Center (CHU) in Grenoble is located in the center of the city that is home to 450,000 people.

All the admissions to the EDs of CHU Saint Etienne and Grenoble from June 29, 2015 to March 22, 2020 were included in the study.

In 2019 alone, the adult ED of CHU had 59,546 admissions while the pediatric ED had 33,000 admissions. Patients were managed in a similar manner in both facilities.

Morel and investigators defined the outbreak periods for bronchiolitis and flu in the pediatric population with PREDAFLU.

From there, a Kruskal-Wallus variance analysis and a Spearman monotone dependency were performed to study the relationship between the number of adult ED admissions for the International Classification of Diseases (ICD)-10 codes related to cardiorespiratory diagnoses and the presence of an epidemic outbreak as defined with the support tool.

The Findings

Based on the identified ICD-10 diagnostic codes, investigators observed that the number of weekly adult ED visits increased during the outbreak periods of flue and bronchiolitis in the pediatric population during in the 5 years studied.

A similar increase was noted in CHU SaintEtienne and CHU Grenoble.

The increase in ED occupancy for these pathologies was also significantly related to the pediatric respiratory infection outbreaks, and these criteria gave an idea of the increased workload in the ED due to CRD during the bronchiolitis and flu outbreaks in the pediatric population.

Notably, the period of cocirculation of bronchiolitis and flue was considerably shorter in the winter of 2015-2016 when compared to other years.

However, for the winters of 2016-2017, 2017-2018, 2018-2019, and 2019-2020, the peak of weekly visits was similar in magnitude and occurred mainly during the cocirculation period.

Data for CHU Saint Etienne indicated that the median number of ED visits during the outbreak period was 56 (95% CI 54-61) compared with 44 (95% CI 42-46) outside the outbreak periods (ie, a median increase of 12 ED visits per week for CRD pathologies), which was deemed significant based on the Kruskal-Wallis test (χ 2 3=102.7, P<.001).

Regarding total occupancy in the ED for CRD, the difference between the outbreak periods based on the Kruskal-Wallis test, was significant for CHU Saint-Etienne (χ 2 3=75.071, P<.001).

“This study demonstrated that it is possible to extend the usage of a surveillance tool like PREDAFLU, used to forecast outbreaks of bronchiolitis and flu in the pediatric population, to provide an early warning for an increase in ED visits for CRD in the adult population,” the team wrote.

The study, "Evaluating the Increased Burden of Cardiorespiratory Illness Visits to Adult Emergency Departments During Flu and Bronchiolitis Outbreaks in the Pediatric Population: Retrospective Multicentric Time Series Analysis," was published online in JMIR Publications.