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RSV Infection

Also known as Respiratory syncytial virus, Bronchiolitis

Severity: ModerateLeading cause of infant hospitalisation for lower respiratory infection

This article is general health information for the selected condition. It is not a diagnosis and does not replace clinical judgement. If you have questions or need treatment advice, please consult a qualified healthcare professional.

What is rsv infection?

Respiratory syncytial virus causes cold like illness in most people but can produce bronchiolitis and pneumonia in infants and serious disease in older adults. Almost all children are infected by age two. Preventive monoclonal antibodies for infants and vaccines for older adults and pregnant women have substantially changed prevention.

Causes

  • Respiratory syncytial virus
  • Spread by droplets and contaminated surfaces
  • Seasonal winter circulation in temperate climates
  • High transmissibility in nurseries and households

Symptoms

  • Runny nose and congestion
  • Cough
  • Fever
  • Wheeze
  • Rapid or laboured breathing in infants
  • Chest wall recession and nasal flaring
  • Poor feeding and reduced wet nappies
  • Apnoea in very young infants

Risk factors

  • Age under 6 months
  • Premature birth
  • Congenital heart or chronic lung disease
  • Age over 65
  • Immunosuppression
  • Crowded living conditions and tobacco smoke exposure

Diagnosis

  • Clinical diagnosis of bronchiolitis in infants
  • Rapid antigen or PCR testing on nasal swab
  • Pulse oximetry to assess oxygenation
  • Chest X-ray only when the picture is atypical
  • Assessment of feeding and hydration in infants

Treatment

  • Supportive care with small frequent feeds
  • Nasal suction and saline drops
  • Supplemental oxygen if saturations fall
  • Nasogastric or intravenous fluids if feeding is inadequate
  • Nirsevimab immunisation for infants
  • RSV vaccination for older adults and in pregnancy
  • Avoidance of routine bronchodilators and steroids in bronchiolitis

Self care

  • Offer small frequent feeds rather than large ones
  • Use saline drops and gentle nasal suction before feeds
  • Keep the infant upright when possible
  • Monitor wet nappies as a hydration guide
  • Avoid tobacco smoke entirely
  • Use paracetamol for fever if age appropriate
  • Do not use cough medicines in young children

When to see a doctor

Book an appointment if:

  • Feeding less than half the usual amount
  • Fewer wet nappies than normal
  • Worsening cough or noisy breathing
  • Fever lasting more than three days
  • A high risk infant with any respiratory symptoms
  • Symptoms worsening after day five

Some symptoms need emergency care rather than an appointment. See the warning signs listed above.

Prevention

  • Nirsevimab immunisation for infants where available
  • RSV vaccination in pregnancy and for older adults
  • Hand washing and avoiding crowds during peak season
  • Keep infants away from anyone with cold symptoms
  • Avoid tobacco smoke exposure
  • Breastfeeding, which offers some protection

Outlook

Most infants recover within one to two weeks, with cough sometimes lasting three weeks. Symptoms usually peak around days three to five. Hospital admission is needed for a minority, mainly for feeding support and oxygen. Some children have recurrent wheeze afterwards, and a link with later asthma is recognised though not fully understood.

Common questions

When should an infant with RSV be seen urgently?

Fast or laboured breathing, chest wall pulling in, grunting, pauses in breathing, blue lips, poor feeding with fewer wet nappies, or marked lethargy all require urgent assessment.

Do inhalers help bronchiolitis?

Generally no. Bronchodilators and steroids have not been shown to improve outcomes in typical infant bronchiolitis, and management is supportive with feeding support and oxygen when needed.

Can RSV be caught more than once?

Yes. Immunity is incomplete and reinfection occurs throughout life, usually as a common cold in healthy adults but potentially serious in older adults and those with lung disease.

References

  1. Centers for Disease Control and Prevention. Diseases and conditions.
  2. World Health Organization. Fact sheets.
  3. National Institutes of Health. Health information.

Important: Dard AI is not a medical device and does not diagnose, treat, or replace clinician judgement. This article is general information only. Always consult a qualified healthcare professional about diagnosis and treatment, and seek emergency care for severe or rapidly worsening symptoms.