Respiratory syncytial virus (RSV)

Symptoms

• Cold symptoms (stuffy/runny nose, sore throat, chills, fatigue)
• Fever
• Cough
• Poorer appetite and less energy than usual
• Breathing that’s rapid, laboured, or noisy; in babies, you may notice their skin sinking in around their ribs and collar bone when they inhale
• Irritability, especially in babies
• Difficulty eating or drinking
• Nostrils that flare on inhalation, especially in babies

• Has had a fever for more than 48 hours
• Is vomiting or not eating
• Refuses to drink
• Isn’t wetting their diaper
• Coughs to the point of choking or vomiting
• Has symptoms other than fever that last at least 72 hours, especially if they are vomiting, not eating, or refusing to drink

• Has difficulty breathing or has bluish lips and fingertips, especially in babies
• Refuses or is unable to drink and shows signs of dehydration: decreased quantity and frequency of urine (less than 3 or 4 times in 24 hours), absence of tears, dry mouth
• Is less than 3 months old and has a fever (rectal temperature of 38.1°C or higher)
• Is 3 months or older and has a rectal temperature of 38.5°C or higher
• Atypical behaviours: excessive crying, lethargy, difficulty waking up, agitation (which can be a sign that breathing difficulties are worsening), etc.

What is the respiratory syncytial virus?

Respiratory syncytial virus (RSV) is a relatively harmless but highly contagious virus that mainly infects the lungs and respiratory tract. RSV is usually most active between early autumn and early spring.

It’s very common in children; in fact, it’s the most frequent cause of respiratory infection in young children. Most toddlers are infected at least once before they turn 2. A person can contract RSV more than once, but symptoms and possible complications are generally less severe with subsequent infections.

RSV resolves fully and in most cases, has no significant health consequences. However, complications can occur in some babies, such as:

• Severe dehydration
• Difficulty breathing
• Bronchiolitis, especially in children under 2. Around 75% of bronchiolitis cases are caused by RSV.

Treatment

Generally speaking, RSV doesn’t require treatment, and most children recover quickly. Because this infection is caused by a virus, antibiotics are not effective in treating it.

Some babies may need to be hospitalized if they have trouble breathing, in order to receive supplemental oxygen. This is more common in babies who are under 6 months, born prematurely, or have heart or lung disease or a weakened immune system.

Severely dehydrated children who have difficulty drinking and eating and children who develop bronchiolitis may also need to be hospitalized to receive fluids or oxygen.

Care and practical advice

Here are some things you can do to help your child:

• Prop up the head of your child’s bed to about 30 degrees (semi-seated position) to make it easier for them to breathe. To do this, place pillows or cushions under the mattress.
• Hold your baby in a semi-upright position when breastfeeding or bottle-feeding.
• Give your child small amounts of fluids throughout the day to prevent dehydration (e.g., breast milk, formula, water, soup).
• If your child has a fever, you can give them acetaminophen (e.g., Tylenol^®, Tempra^®) or ibuprofen (e.g., Advil^®, Motrin^®) as indicated and in the doses recommended for their age and weight. Don’t give ibuprofen to babies under 6 months, and never give acetylsalicylic acid (Aspirin^®, ASA, etc.) to a child or teenager, as this drug is associated with certain serious complications (Reye’s syndrome).
• Regularly clear your child’s nose with a saline solution (which you can buy from the pharmacy or make at home). This solution will soften secretions and help them drain. Only if necessary, you can remove your baby’s secretions with a bulb syringe or nasal aspirator.
• Don’t give cough syrup or decongestants to children under 6. Although these drugs are widely available without a prescription, they can cause potentially serious side effects in young children.
• Avoid exposing your child to secondhand smoke or allergens such as dust or pet dander.

Prevention

Because RSV spreads so easily, follow these preventive measures during its active season, between early fall and early spring.

• Keep your baby as far away as possible from people with colds, especially if they’re under 6 months old. Because RSV is often mistaken for a cold, a person with cold symptoms could have RSV without knowing it.
• Don’t kiss your child if you have cold symptoms.
• Avoid taking your baby to crowded places like shopping malls or parties.
• Wash your hands and your child’s hands often with soap and water to reduce the transmission of germs.
• Avoid sharing toys that may have been handled by people who are ill (colds, flu, etc.).
• In wintertime, regularly clear your child’s nose with a saline solution.

Preventing complications

To reduce the risk of RSV complications, we recommend the following:

• Breastfeed your baby if you can, as breast milk contains antibodies that help fight disease.
• Don’t expose your child to secondhand smoke. Smoke irritates their nose, sinuses, and lungs, making them more vulnerable to complications from RSV.
• Follow the recommended vaccination schedule. Vaccines won’t prevent RSV, but they will protect your child from complications. Currently, there is no pediatric vaccine for RSV. However, a vaccine for pregnant women, designed to protect newborns from RSV, was approved by Health Canada in January 2024.

Medication to prevent RSV complications

A drug called nirsevimab (Beyfortus^TM) is available to prevent serious complications of RSV in babies. One dose of this drug provides protection for at least 5 months. As of fall 2024, nirsevimab will be available free of charge during the RSV season for the following children:

• Babies born on or after October 1 of the current year
• Babies who are less than 6 months old on October 1 of the current year
• Babies born at less than 37 weeks gestation and who are less than 8 months old on October 1 of the current year
• Babies with health problems that could increase the risk of RSV complications (e.g., chronic lung disease, congenital heart disease, cystic fibrosis), if they are under 19 months old on October 1 of the current year

If your baby is born during RSV season, they can receive the medication at the hospital or birthing centre. If your child is eligible and was born before then, you can book an appointment through Clic Santé during RSV season.

Scientific review: Dr. Anne-Claude Bernard-Bonnin, pediatrician Research and copywriting:The Naître et grandir team Updated: September 2024

Photo : GettyImages/LSOphoto