Related Experiment Video

Updated: Mar 13, 2026

Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels

Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels

Published on: August 7, 2017

Etiology of Acute Respiratory Infections in Infants: A Prospective Birth Cohort Study

Prawin Kumar¹, Guruprasad R Medigeshi, Vishnu S Mishra

¹From the *Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India; †Department of Biotechnology, Vaccine and Infectious Disease Research Center, Translational Health Science and Technology Institute (THSTI), Faridabad, India; and ‡Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.

The Pediatric Infectious Disease Journal

|October 19, 2016

Insights

Acute respiratory infections (ARIs) in infants occur frequently, with rhinovirus being the most common cause. This study highlights the viral etiology and incidence of ARIs in infants, crucial for understanding pediatric respiratory health.

Area of Science:

Pediatric Infectious Diseases
Respiratory Virology
Epidemiology

Background:

Limited studies exist on the causes of acute respiratory infections (ARIs) in infants.
Understanding ARI etiology is crucial for developing effective prevention and treatment strategies in this vulnerable population.

Purpose of the Study:

To determine the incidence and etiology of ARIs in infants during their first year of life.
To analyze the seasonal patterns of ARI occurrence.
To investigate the association between clinical presentation and the identified causes of ARI.

Main Methods:

A birth cohort of infants was followed for one year.
Nasopharyngeal aspirates were collected for multiplex real-time PCR to identify respiratory viruses.
Additional tests for bacterial pathogens and inflammatory markers were performed for lower respiratory tract infections.

Main Results:

A total of 503 ARI episodes were recorded in 310 infants, with an incidence of 1.8 episodes per infant per year.
Viruses were detected in 63.3% of ARI episodes, with coinfections in 18.2%.
Rhinovirus was the most prevalent virus (42%), followed by respiratory syncytial virus (20%), coronavirus (17.6%), and parainfluenza virus (16.8%). Bacterial and mixed infections were common in lower respiratory tract infections.

Conclusions:

Infants experience a high incidence of ARIs, predominantly upper respiratory tract infections.
Viral pathogens, particularly rhinovirus, are the primary cause of ARIs in infants.
The findings underscore the importance of viral surveillance and targeted interventions for infant respiratory health.

Read full analysis

Abstract

Background:

There is paucity of studies on etiology of acute respiratory infections (ARI) in infants. The objective of this study is to document incidence and etiology of ARI in infants, their seasonal variability and association of clinical profile with etiology.

Methods:

A birth cohort was followed for the first year of life; for each episode of ARI, nasopharyngeal aspirates were collected to identify the causative respiratory virus(es) using multiplex real-time polymerase chain reaction assay. For lower respiratory tract infections blood culture, serum procalcitonin, serum antibodies to Mycoplasma and Chlamydia and urinary Streptococcus pneumoniae antigen were also assayed.

Results:

A total of 503 ARI episodes were documented in 310 infants for an incidence rate of 1.8 episodes per infant per year. Of these, samples were processed in 395 episodes (upper respiratory tract infection: 377; lower respiratory tract infection: 18). One or more viruses were detected in 250 (63.3%) episodes and viral coinfections in 72 (18.2%) episodes. Rhinovirus was the most common virus [105 (42%)] followed by respiratory syncytial virus [50 (20%)], parainfluenza virus [42 (16.8%)] and coronavirus [44 (17.6%)]. In lower respiratory tract infections, viral infections were detected in 12 (66.7%) episodes, bacterial infections in 17 (94.4%) episodes and mixed bacterial-viral infections in 8 (44.4%) episodes. Peak incidence of viruses was observed during February-March and September-November. There was no significant difference in symptom duration with virus types.

Conclusion:

In this cohort of infants, ARI incidence was 1.8 episodes per year per infant; 95% were upper respiratory tract infections. Viruses were identified in 63.3% episodes, and the most common viruses detected were rhinovirus, respiratory syncytial virus and parainfluenza virus.

More Related Videos

An In vitro Model to Study Immune Responses of Human Peripheral Blood Mononuclear Cells to Human Respiratory Syncytial Virus Infection

An In vitro Model to Study Immune Responses of Human Peripheral Blood Mononuclear Cells to Human Respiratory Syncytial Virus Infection

Published on: December 10, 2013

Generation, Amplification, and Titration of Recombinant Respiratory Syncytial Viruses

Generation, Amplification, and Titration of Recombinant Respiratory Syncytial Viruses

Published on: April 4, 2019

Related Concept Videos

Pneumonia I: Introduction

Pneumonia I: Introduction

Pneumonia is an acute respiratory infection that targets the lungs, specifically the alveoli. These tiny air sacs, essential for oxygen exchange, become engorged with pus and fluid, severely hindering breathing, decreasing oxygen absorption, and causing significant pain and discomfort during respiration.
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...

Acute Respiratory Failure-I

Acute Respiratory Failure-I

Acute respiratory failure is a condition characterized by the inability of the lungs to perform their primary function: gas exchange. This failure leads to insufficient oxygen levels (hypoxemia) in the blood, elevated carbon dioxide levels (hypercapnia), or both, causing critical impairment in organ function.
Definition: It is defined by specific criteria based on blood gas measurements. Hypoxemia happens when the partial pressure of oxygen (PaO2) falls below 60 mmHg. At the same time,...

Acute Respiratory Failure-V

Acute Respiratory Failure-V

The treatment for acute respiratory failure varies based on factors like the underlying cause, overall health, and severity. A collaborative healthcare team is essential for early detection, often through arterial blood gas analysis. Identifying the cause is the primary goal, with treatment strategies adjusted for ventilation/perfusion (V/Q) mismatch, shunting, or diffusion impairment.
Ensure that patients are monitored continuously for their response to therapy, including changes in...

Acute Respiratory Failure-II

Acute Respiratory Failure-II

Type I Respiratory Failure, or hypoxemic respiratory failure, occurs when the partial pressure of oxygen (PaO2) in arterial blood falls below 60 mmHg while breathing room air without a corresponding increase in arterial carbon dioxide levels (PaCO2). This condition highlights a significant impairment in the lungs' capacity to oxygenate the blood.
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:

Acute Respiratory Failure-III

Acute Respiratory Failure-III

Hypercapnic respiratory failure, also known as Type 2 or ventilatory respiratory failure, is a severe condition characterized by the body's inability to effectively remove carbon dioxide (CO2) from the bloodstream. It leads to an arterial CO2 pressure (PaCO2) exceeding 45 mmHg and a blood pH above 7.35. This situation indicates that the body's ventilatory demand, or the ventilation needed to maintain normal PaCO2 levels, surpasses its supply or the maximum gas flow achievable without...

Pulmonary Cycle: Exhalation

Pulmonary Cycle: Exhalation

In terms of human respiration, the act of expelling air, known as exhalation (or expiration), operates on the principle of pressure gradients. During expiration, the pressure within the lungs exceeds that of the surrounding atmosphere. Under normal conditions, quiet breathing involves passive exhalation and is free of muscular contractions. This is because the exhalation process is driven by the natural elastic recoil of the lungs and chest wall, both of which have an inherent tendency to...

Articles linked to this work by shared authors, journal, and citation graph.

A review of potential health risks of radiofrequency electromagnetic field exposure from mobile phones and base stations in children and pregnant women.

Frontiers in public health·2026

Public health interventions for the prevention and management of overweight and obesity in children and adolescents: a rapid review.

Frontiers in public health·2026

Correction: A state wise analysis of the socioeconomic and health impacts of the COVID-19 pandemic in India: lessons for future health system preparedness.

Frontiers in public health·2026

A Phase IIa, Double Blind, Randomized, Placebo Controlled, Parallel, Multicentre, Proof-of-Concept Study to Evaluate the Efficacy and Safety of Desidustat Oral Tablet for Treatment of Sickle Cell Disease.

European journal of haematology·2026

A state wise analysis of the socioeconomic and health impacts of the COVID-19 pandemic in India: lessons for future health system preparedness.

Frontiers in public health·2026

A Phase IIa, Proof-of-Concept, Placebo-Controlled, Randomised Trial to Investigate the Efficacy and Safety of Oxfendazole as a Macrofilaricidal Drug in Adults Harbouring Lymphatic Filarial Worms.

Infectious diseases and therapy·2026

See all related articles