Bronchiolitis

Bronchiolitis is a very common viral respiratory illness that affects most babies and toddlers up to age 2, especially during the first few months of life. The illness, which is most common in the fall and winter, begins in the upper respiratory tract and can spread to the lower respiratory tract (the bronchioles, or small airways), causing partial blockage due to increased secretions.

The illness is highly contagious, not only among babies and toddlers but also among older children and adults. However, in older children and adults, it usually causes only mild symptoms, mainly in the upper respiratory tract.

Causes

Bronchiolitis is caused by various respiratory viruses, most commonly RSV, and is the most common respiratory cause of hospitalization among young babies.

How It Spreads

Bronchiolitis is highly contagious and can therefore spread quickly, both among family members and among other babies and children who come into contact with the sick child, such as at daycare.

It spreads in 2 ways:

• Through direct contact with nasal secretions and saliva from a sick person.
• Through contact with a sick person's hands or with objects contaminated with secretions, such as toys and towels.

At-Risk Groups

Babies and toddlers up to age 2 are at high risk of developing bronchiolitis. In addition, some groups are at higher risk of developing severe illness and, in some cases, complications:

• Preterm babies.
• Preterm babies with chronic lung disease of infancy (bronchopulmonary dysplasia - BPD).
• Babies up to 3 months old.
• Babies and children with chronic heart disease.
• Babies and children with weakened immune systems.
• Babies and children exposed to secondhand smoke.

Course of the Illness

During the first few days, upper respiratory symptoms such as a runny nose and sore throat will appear. Later, lower respiratory symptoms may also develop, such as coughing, wheezing, and shortness of breath. The illness peaks after 3–4 days, after which symptoms begin to improve. The illness usually lasts about 2 weeks, but the cough may continue for more than a month.

Diagnosis

In most cases, a pediatrician can diagnose the illness based on the symptoms alone. In more complex cases, such as when hospitalization is required, a nasal swab may be needed to identify the type of virus.
If symptoms do not improve after 4 days or become worse, blood tests for markers of inflammation and a chest X-ray may be needed to check for a secondary bacterial infection.

Recommended Treatment

Because bronchiolitis is a viral illness, treatment is supportive and based on the symptoms:

• Relieve nasal congestion with saline solution. A nasal aspirator can be used for babies.
• Prevent dehydration by breastfeeding frequently or offering small amounts by bottle more often.
• Avoid smoking around the sick child.

In severe cases, hospitalization may be required for observation and respiratory monitoring, oxygen as needed, fluid monitoring, and appropriate nutrition.

Prevention

Vaccination

To protect babies early in life, they can receive the RSV vaccine at the hospital after birth and before discharge, as part of the immunization schedule.

The vaccine is safe and effective. It has been approved in more than 50 countries and is given in about 25 countries, including the United States and Australia. Millions of doses have been given to babies and toddlers to date, and studies show that, on average, it reduces hospitalizations due to the illness by 83%.

In addition to vaccination, several precautions are recommended to help prevent infection, particularly among preterm babies and babies in the first few months of life:

• Handwashing: Maintain good hygiene and wash your hands with soap and water, especially when you are near or in contact with young babies. This recommendation applies not only to family members but also to daycare staff and healthcare professionals who come into direct contact with children.
• Avoiding contact with sick people: Keep babies and toddlers away from people who are sick and from items they have used, such as towels, bedding, and toys.
• Avoiding smoking: Children exposed to secondhand smoke are at higher risk of developing the illness and its complications because smoking damages the body's natural mechanism for clearing mucus.
• Breastfeeding: Breastfeeding significantly reduces the risk of various illnesses, including RSV.
• Staying home: After a viral illness such as bronchiolitis, babies should be given time to recover and rest before returning to their regular routine and daycare. When babies return to daycare too soon, before their immune system has had enough time to recover, they often become infected again.