RSV virus without secrets. Who is most at risk?

A runny nose, cough, slight fever does not necessarily mean the first symptoms of influenza or Covid-19. It could be the RSV virus. Especially in the fall and winter when we see a rapid increase in illnesses. Although it usually causes harmless respiratory infections, it can also be very dangerous.

We talk to Dr. Agnieszka Sikora-Wiórkowska, a pediatrician and family medicine specialist, about what RSV actually is and who is most at risk for the severe form.

Bronchiolitis is an acute infectious disease of the lower respiratory tract caused by viral infection. The most common etiologic agent is respiratory syncytial virus (RSV). RSV infects the epithelial cells lining the small airways. The infection leads to swelling, increased mucus production, and eventually necrosis and regeneration of these cells.

In children under 2 years of age, viral bronchiolitis is the most common infectious disease of the lower respiratory tract.

How does infection occur in children?

Infection occurs via the droplet route. The source of infection is mainly older siblings attending kindergarten or school, less often adults.

Most cases of bronchiolitis are diagnosed in autumn and winter.

For most previously healthy children, bronchiolitis is a mild, self-limiting disease and can be effectively treated at home. Only 1-2% of children require a hospital stay, and a small percentage of them develop respiratory failure.

We know that parents of the smallest children should be most careful. What should they pay attention to?

The risk factor that is the most common indication for hospitalization is age. The majority of children admitted to the hospital for bronchiolitis are under1 year of age, and in infants under 3 months of age, the disease can progress with apnea and respiratory failure. Another important risk factor for severe bronchiolitis is prematurity.

Other risk factors for a more severe course of bronchiolitis include chronic respiratory diseases, congenital heart defects, neurological diseases, immune disorders, breastfeeding for less than 2 months, attending a nursery, contact with preschool- and school-age siblings, and exposure to tobacco smoke.

Doctor, and what does an RSV infection look like in a child?

Bronchiolitis develops about 5 days after contact with the virus. The course of bronchiolitis is characteristic. Usually at the beginning of the disease there are mild features of upper respiratory tract infection, runny nose, dry cough accompanied by an unremitting fever. Symptoms increase gradually, usually reaching their greatest intensity on day 3-4 of the disease. The cough intensifies, becoming wet, which is directly related to the appearance of thick, difficult to expectorate secretions. Most often, the symptoms are accompanied by shortness of breath and accelerated, wheezing. The child moves the wings of the nose, fasts, gets tired when eating, interrupts feeding.

How do you diagnose RSV infection? Are laboratory tests necessary?

On physical examination, one can find rhinorrhea and impaired patency
of the nose, coughing, accelerated breathing and increased respiratory effort, as indicated by movement of the nasal wings, fasting, retraction of the intercostal, supraclavicular pits and diaphragm. On auscultation, features of airway narrowing in the form of generalized bilateral wheezing, furling, crackling are found.

Usually, a medical history and symptoms found on physical examination are sufficient to diagnose and assess indications for hospitalization. During the visit, vital signs such as respiratory rate, heart rate and blood oxygen saturation are measured.

In some cases, a chest X-ray is taken and blood is drawn for testing. It is also possible to perform a rapid test for RSV in the respiratory tract after collecting nasal secretions.

For the virus, antibiotics do not work, how then do you treat toddlers suffering from RSV?

There is no causal treatment - antiviral. Symptomatic treatment, hydration, oxygen therapy in case of drops in saturation are used.

In some cases, bronchodilators are used, but the indications for such treatment depend on the specific case. Inhaled or systemic corticosteroids are not routinely recommended. Antibiotic therapy is used for infants with bacterial complications, such as otitis media.

All infants with bronchiolitis need to be evaluated for dehydration. Accelerated breathing, production of large amounts of respiratory secretions, fever and decreased appetite all contribute to dehydration.

Respiratory physiotherapy should not be used in the treatment of bronchiolitis. Infection of the endothelial cells lining the narrow airways plays an important role in the pathogenesis of bronchiolitis. It is a diffuse process that disrupts the balance between perfusion and ventilation, so kinesitherapy has no effect.

Suctioning upper airway secretions improves the patient's comfort and improves appetite. However, intensive suctioning can cause swelling of the nasal mucosa and exacerbate airway obstruction. It is wise to suction the secretions before meals and when there is a lot of it.

In the prevention of RS virus infection, a monoclonal antibody directed directly against the virus is used. Indications for such treatment include only children born prematurely, with bronchopulmonary dysplasia or with a congenital cardiovascular defect that causes hemodynamic abnormalities.

It is therefore crucial to quickly identify the cause of the infection. We know what the treatment is, and how to protect ourselves from infection?

Because of the route of infection, preventing the spread of infection includes avoiding sick people, large gatherings of people, and washing hands thoroughly. Breastfeeding is a natural method of preventing respiratory infections. In addition, infants and young children must not be exposed to tobacco smoke, as the harmful substances in it reduce immunity.

Most infants pass the infection mildly and recover in about 2-3 weeks. Keep in mind the possibility of developing further infections caused by the RS virus.