How many days does a respiratory virus typically last in an infant?

Duration of Respiratory Viral Infections in Infants

Respiratory viral infections in infants typically last 7-14 days, with symptoms peaking around days 3-5 and gradually improving thereafter. 1, 2

Common Course of Respiratory Viral Infections

• Most respiratory infections, particularly RSV (respiratory syncytial virus), begin with 2-4 days of upper respiratory tract symptoms such as fever, rhinorrhea, and congestion 2
• These initial symptoms are followed by lower respiratory tract symptoms including increasing cough, wheezing, and increased respiratory effort 2
• The most severe symptoms typically occur around days 3-5 of illness 1, 2
• Gradual improvement begins after the peak, but complete resolution may take up to two weeks 1, 3

Factors Affecting Duration and Severity

• Age: Younger infants, particularly those under 3 months, often experience more prolonged symptoms 1, 2
• Prematurity: Infants born prematurely may have more severe and longer-lasting symptoms 1, 4
• Underlying conditions: Infants with chronic lung disease, congenital heart disease, or immunodeficiency typically experience more prolonged and severe illness 1, 4
• Type of virus: RSV infections tend to last longer than some other respiratory viruses, with symptoms potentially persisting for up to 2 weeks 1, 2

Warning Signs Requiring Medical Attention

• Poor feeding or decreased fluid intake leading to signs of dehydration 2, 5
• Increased work of breathing (retractions, nasal flaring, grunting) 2
• Lethargy or significant irritability 3, 2
• Apnea (pauses in breathing), particularly in very young infants 3, 2
• Persistent high fever or fever that returns after initially improving 2
• Oxygen saturation below 90% (if measured) 2

Home Management

• Ensure adequate hydration with frequent small feedings 2, 5
• Use nasal saline drops and gentle suctioning to clear nasal passages 5
• Humidification of room air may help loosen secretions 5
• Avoid exposure to tobacco smoke and other irritants 1, 4
• Acetaminophen or ibuprofen (if older than 6 months) for fever and discomfort 2

Prevention Strategies

• Hand hygiene is critical for preventing transmission 1, 4
• Limit exposure to crowded settings during respiratory virus season 1, 4
• Breastfeeding provides some protection against severe respiratory infections 1, 5
• For high-risk infants (premature, chronic lung disease, congenital heart disease), palivizumab prophylaxis may be recommended during RSV season 4, 2

Common Pitfalls

• Expecting too rapid recovery; respiratory symptoms often persist for 1-2 weeks even with appropriate care 1, 2
• Overuse of over-the-counter cold medications, which are not recommended for infants and young children 2
• Assuming antibiotics will help; most respiratory infections in infants are viral and do not respond to antibiotics 2, 6
• Failing to recognize signs of dehydration, which can develop quickly in infants with respiratory distress 2, 5