Should you need urgent health advice please contact your GP or call NHS 111. In an emergency please visit A&E or call 999

We offer tailored content specific to your area. Check below to find your local area.

Choose your location for articles and services where your live:

Respiratory syncytial virus (RSV) and bronchiolitis in infants

What is RSV?

Respiratory syncytial virus (RSV) is one of the common viruses that cause coughs and colds in winter.

It’s a common seasonal winter virus which causes mild respiratory infection in adults and children, but it can be severe in infants who are at increased risk of acute lower respiratory tract infection. During the last year there has been a large reduction in respiratory viral infections other than COVID-19, this means that there is an increasing number of young children who have never been exposed to these common viruses.

The RSV/bronchiolitis season in the UK typically begins in the autumn, earlier than the adult flu season, and runs through winter. Around the world, evidence of unseasonal outbreaks of these infections has emerged as measures such as social distancing and mask wearing are relaxed.

Complications in infants

RSV is the most common cause of bronchiolitis in children aged under 2 years, this can make the airways inflamed and fill with mucus, making it harder to breathe.

The early symptoms of bronchiolitis are similar to those of a common cold, such as a runny nose and a cough.

Further symptoms can develop over the next few days, and may include:

  • a slight high temperature (fever)
  • a dry and persistent cough
  • difficulty feeding
  • rapid or noisy breathing (wheezing)

You should seek emergency medical care if your child becomes breathless – this is the most common symptom of severe RSV.

Most cases of bronchiolitis are not serious, but you should contact your GP or call NHS 111 if:

  • you’re worried about your child
  • your child has taken less than half their usual amount during the last 2 or 3 feeds, or they have had a dry nappy for 12 hours or more
  • your child has a persistent high temperature of 38C or above
  • your child seems very tired or irritable.

Dial 999 for an ambulance if:

  • your baby is having difficulty breathing.
  • your baby’s tongue or lips are blue.
  • there are long pauses in your baby’s breathing.

Most cases are not serious and clear up within 2 to 3 weeks, but the symptoms can be very worrying for parents. RSV is a virus, so antibiotics may not be an effective treatment. For some infants and babies, such as those born prematurely or with a heart condition, bronchiolitis can be more severe. If you have any concerns, contact your health visitor or GP.

Take a look at this PDF for more information about bronchiolitis symptoms in children under one year old.

Preventing infection

Good hygiene can reduce the spread of these infections. Make sure you carry tissues and use them to catch coughs or sneezes, bin the used tissues as soon as possible and wash your hands with soap and warm water for twenty seconds to kill the germs.

Children with flu or bronchiolitis symptoms should stay home and reduce contacts where possible.

It is perfectly okay for parents to ask people with colds to keep away from newborn babies, especially those born prematurely, particularly in the first two months.

Page last reviewed: 25-08-2021

Next review due: 25-08-2024