Related Experiment Video

Updated: May 28, 2026

A Neonatal Imaging Model of Gram-Negative Bacterial Sepsis
08:46

A Neonatal Imaging Model of Gram-Negative Bacterial Sepsis

Published on: August 12, 2020

Seasonal and Age-Specific Patterns of Viral and Bacterial Infections in Febrile Infants ≤ 90 Days Presenting to a

Tommaso Bellini1, Giacomo Brisca2, Marcello Mariani3

  • 1Paediatric Emergency Room and Emergency Medicine Unit, Department of Emergency Medicine, Anesthesia and Critical Care, IRCCS Istituto Giannina Gaslini, Genoa, Italy.

Acta Paediatrica (Oslo, Norway : 1992)
|May 27, 2026
PubMed

Insights

Viral infections in infants show seasonal patterns, unlike bacterial infections. Viral co-infections can occur with serious bacterial infections (SBIs), so urinalysis remains crucial for febrile infants.

Area of Science:

  • Pediatrics
  • Infectious Diseases
  • Epidemiology

Background:

  • Febrile infants under 90 days face risks of serious bacterial infections (SBIs), but viral illnesses are more common.
  • Current management often focuses on bacterial risk, with less integration of viral epidemiology.
  • Understanding age-specific etiologies and trends is vital for optimizing care.

Purpose of the Study:

  • To analyze age-specific bacterial and viral causes of fever in infants.
  • To describe seasonality, temporal trends, and co-infections in febrile infants.
  • To inform management strategies by integrating epidemiological data.

Main Methods:

  • Retrospective observational study of infants ≤90 days (2018-2025).
  • Infants categorized into age groups: ≤28, 29-60, and 61-90 days.
  • Analysis of bacterial/viral etiologies, co-infections, seasonality, and trends.

Main Results:

  • Serious bacterial infections (SBIs) occurred in 15% of cases; invasive bacterial infections (IBIs) peaked in neonates ≤28 days.
  • Viral infections were predominant across all age groups.
  • Viral infections exhibited seasonality (winter respiratory, summer enterovirus), unlike non-seasonal bacterial infections. Approximately 10% of SBIs had viral co-infections. Viral detections dipped in 2020-2021, then rebounded.

Conclusions:

  • Viral infections are seasonal, while bacterial infections are not.
  • Viral positivity does not rule out SBIs; routine urinalysis is essential.
  • An epidemiology-informed approach can complement bacterial risk stratification.
Abstract

Keywords:
bacterial infectionsco‐infectionfeverinfantnewbornseasonalityurinary tract infectionsvirus diseases

Related Concept Videos

Patterns of Fever01:26

Patterns of Fever

Before understanding the types and patterns of fever, it is essential to know its phases.
Viral Meningitis01:18

Viral Meningitis

Viral meningitis is the most common form of meningitis and is often referred to as aseptic meningitis to indicate the absence of bacterial involvement. It is generally milder than bacterial meningitis, with symptoms including fever, headache, stiff neck, drowsiness, nausea, photophobia, and vomiting. Rarely, more severe manifestations or death may occur. Common causative agents include enteroviruses, particularly coxsackie A and B viruses and echoviruses, all members of the Enterovirus genus...
Encephalitis l: Introduction01:19

Encephalitis l: Introduction

Encephalitis is inflammation of the brain parenchyma, most often due to infections or autoimmune processes. It presents with neuropsychiatric features such as fever, altered mental status, behavioral changes, cognitive dysfunction, seizures, focal deficits, and sometimes autonomic instability. In some cases, the meninges are also involved, resulting in meningoencephalitis.Infectious CausesInfectious encephalitis is most commonly viral but can also result from bacterial, fungal, or parasitic...
Respiratory Syncytial Virus Disease01:29

Respiratory Syncytial Virus Disease

Human respiratory syncytial virus (RSV) is a widespread pathogen that primarily targets infants and young children but also poses a serious health risk to elderly and immunocompromised individuals. Belonging to the Pneumoviridae family, RSV is a negative-sense, single-stranded RNA virus within the Pneumovirus genus. Its global health burden is significant, with millions of cases annually resulting in hospitalizations and mortality, particularly in resource-limited settings. Although most...
Influenza01:27

Influenza

Influenza is an acute, highly communicable viral disease that affects the respiratory tract and is responsible for seasonal epidemics worldwide. Influenza A is the most prevalent type associated with widespread outbreaks and is subtyped based on two surface glycoproteins: hemagglutinin (H) and neuraminidase (N), as in H1N1. These glycoproteins are essential for viral infectivity, transmission, and immune recognition. Transmission occurs primarily through respiratory droplets and contaminated...
Infectious Diseases and Their Occurrence01:28

Infectious Diseases and Their Occurrence

Infectious diseases appear in populations through various transmission patterns, influenced by pathogen characteristics, population immunity, environmental conditions, and social behavior. Understanding these patterns is essential for effective public health surveillance and intervention. These categories—sporadic, outbreak, epidemic, pandemic, and endemic—help frame the nature and scope of disease events.Sporadic diseases occur irregularly and infrequently, without a predictable temporal or...