RSV

Four-month-old Milo has had a fever and cough for three days. So far, the fever has been easily reduced, and he has continued to drink well, but during the night, his breathing became increasingly labored, and his parents noticed a faint wheezing sound. Milo's sister is three and already attends daycare. She currently has a mild infection with a runny nose and a slight cough. The parents take the infant to the pediatrician.

After the physical examination and oxygen saturation measurement, it is clear: Milo needs to be hospitalized because he requires oxygen. He has an acute RSV infection.

We frequently see cases like this in pediatricians' offices during the winter months.

What is RSV?

RSV stands for Respiratory Syncytial Virus, an RNA virus that only occurs in humans and is transmitted via droplet infection. Approximately 20-30% of all children contract RSV during their first year of life. This infection often manifests as bronchiolitis (inflammation of the small airways) or pneumonia (lung inflammation). In slightly older children, obstructive bronchitis (blockage of the small airways with difficulty exhaling) is more common. Rhinoviruses can also cause these illnesses.

The peak incidence occurs between the 3rd and 6th month of life. An RSV infection usually progresses like a common respiratory infection: After an incubation period of 3-6 days, cold-like symptoms (cough, runny nose, fever) initially appear, followed by impaired breathing or apnea (prolonged pauses in breathing). In approximately 2-3% of cases, the symptoms are so severe that hospitalization is necessary. In the winter of 2022/23, around 7,000 newborns required intensive care due to RSV infection.

Affected babies typically have a severe cough, poor feeding, sometimes fever, and exhibit symptoms of respiratory distress, such as labored or wheezing breathing or nasal flaring.

Premature infants and babies with pre-existing conditions (chronic lung diseases, immunocompromised children, children with Down syndrome) are at higher risk of developing severe RSV infections. Exposure to tobacco smoke can also worsen the course of an RSV infection. Breastfeeding has been shown to be protective.

The diagnosis is usually made clinically, meaning that the physical examination, based on the breathing pattern and the child's overall condition, usually reveals clear indications of the infection. A nasal or throat swab can detect the pathogen, but this is usually omitted in outpatient settings. If the child is very ill, a blood sample may be taken; this is decided by the treatment team. In addition to a physical examination, a blood test can provide information about the body's acid-base balance and the extent of the infection.

Generally, an RSV infection can be managed at home by the parents. Treatment is purely symptomatic; it's important to ensure adequate fluid intake, reduce fever if necessary, use decongestant nasal drops if needed, and sometimes babies need to inhale steam. However, some children require more respiratory support or are so poor at drinking that hospitalization becomes necessary. In such cases, they receive respiratory support and fluid therapy in the hospital.

Because it is a viral infection, antibiotics are ineffective in treating symptoms or influencing the course of the illness, even in severe cases.

In the hospital, the concept of "minimal handling" is followed: this means the child should undergo as few procedures as possible and be left undisturbed to allow for optimal recovery. In some cases, inhalations with salbutamol are helpful because salbutamol dilates the airways and counteracts the airway congestion described above.

An RSV infection usually heals without complications. Unfortunately, having had the infection does not protect against reinfection; however, older children are less likely to become seriously ill, and parents often only notice mild cold-like symptoms.

For high-risk patients, such as premature infants or babies with pre-existing conditions, there is a prophylactic option in the form of passive immunization. The different RSV vaccines are discussed in a separate blog post.