Bronchiolitis, a disease affecting children under 2 years of age

Acute bronchiolitis is an epidemic respiratory illness caused primarily by the respiratory syncytial virus (RSV). It mainly affects children under the age of 2. In the vast majority of cases, bronchiolitis is mild and resolves spontaneously with a favorable outcome. In rare cases, bronchiolitis requires hospitalization or even admission to the intensive care unit. Deaths attributable to acute bronchiolitis are very rare (less than 1%).

Bronchiolitis most frequently occurs during seasonal outbreaks. The outbreak generally begins in mid-October, peaks in December, and ends by the end of winter.

In France, it is estimated that bronchiolitis affects nearly 30% of infants under 2 years of age each winter, representing approximately 480,000 cases per year. An estimated 2–3% of infants under 1 year of age are hospitalized for more severe bronchiolitis each year.

A highly contagious viral infection

Bronchiolitis is highly contagious and is primarily caused by the respiratory syncytial virus (RSV). Other causative agents include parainfluenza viruses, adenoviruses, and others. The virus spreads through saliva, sneezing, coughing, and contact with hands. The virus also remains on contaminated objects (such as toys, pacifiers, and “comfort blankets”). Thus, a cold in a child or adult can cause bronchiolitis in an infant.

Hygiene measures to prevent bronchiolitis

Currently, prevention relies mainly on hygiene measures:

• Wash your hands before approaching an infant. This should take 30 seconds, using soap and water or an alcohol-based hand sanitizer if washing hands is not possible

• Avoid, whenever possible, taking your child to crowded public places (public transportation, shopping malls, etc.), where they might come into contact with people who have colds

• Do not share unwashed bottles, pacifiers, or utensils

• Ventilate the room by opening the windows for at least 10 minutes a day

• Do not smoke near babies and children

• Regularly clean objects that the infant comes into contact with (toys, pacifiers, etc.).

Variable symptoms

Symptoms of RSV infections vary depending on the person affected. Nasal congestion with a mild cough and moderate or no fever are the most common signs. The infection may be limited to a simple cold or nasopharyngitis. Within 2 to 3 days, a lower respiratory tract infection may develop, characterized by a cough and increased mucus production, which can lead to breathing difficulties.

In infants and children under 2 years of age, the cough may become more frequent, accompanied by breathing difficulties that manifest as rapid, wheezing breathing. At this stage of the illness, the child may have trouble eating and sleeping. They may have a fever.

In most cases, bronchiolitis resolves on its own within 5 to 10 days, but the cough may persist for 2 to 4 weeks.

Bronchiolitis, which is easily recognized by a doctor or pediatrician, is managed in the community in the vast majority of cases. Visits to the emergency room and hospitalization are rarely necessary.
Antibiotics are not indicated initially, as bronchiolitis is viral in origin. Antibiotic therapy may be considered later if a secondary bacterial infection develops.

It is important to ensure infants stay well-hydrated to help thin secretions.

• nasal rinses to clear the nasopharyngeal passages

• dietary advice: dividing meals into smaller portions to ensure proper hydration

• medications to treat fever, if necessary.

In any case, children’s respiratory condition must be monitored: any worsening requires a doctor’s visit or even hospitalization.