THE RESPIRATORY SYNCYTIAL VIRUS (RSV) SEASON IS APPROACHING…

What is the respiratory syncytial virus (RSV)?

Respiratory syncytial virus (RSV) is the second most common cause of respiratory infections in infants and young children, following the influenza virus.

RSV is the primary cause of lower respiratory tract infections in infants under 1 year of age.

RSV infection affects 95% of children up to the age of 2, with most of them recovering quickly from it.

When do children suffer from RSV?
Is there a time of year when it is more likely for a baby to be infected with RSV?
The RSV season is the time of year when the respiratory syncytial virus, known as RSV, is most active. The infection exhibits seasonality, and the RSV season in Bulgaria is from October to April.

Data for Europe show that RSV is the cause of 42-45% of hospital admissions for lower respiratory tract infections in children under 2 years of age.

What can be the consequences for the baby when infected with RSV?
How dangerous can RSV be for the baby?
RSV is a virus that causes acute respiratory infections accompanied by high fever, cough, or sneezing. The illness at the beginning may resemble a common cold.

In infants under 1 year of age, premature babies, and children with underlying health problems (heart, lung, metabolic), the virus can lead to severe lung infections such as bronchiolitis (inflammation of the bronchi and small airways in the lungs) and pneumonia, resulting in high fever, severe cough, wheezing during breathing, frequent or difficult breathing. These conditions may require hospitalization and can sometimes be life-threatening.

Premature babies are a risk group for a more severe course of RSV infection.

In babies born before the 36th gestational week, the risk of hospitalization for RSV is three times higher than in those born at full term. For very premature babies born before the 32nd week, this risk is nearly 7 times higher.

Premature babies have underdeveloped lungs, making them a risk group for a more severe course of RSV infection.

Compare their lungs to those of a full-term baby…

In preterm birth, the alveoli (small branches of the airways in the lungs) are underdeveloped. By the 36th week, alveoli have already begun to form, although sometimes they may be observed earlier, at the 30th or 32nd gestational week. Babies born at 36 weeks come into the world in the midst of this transitional process. As a result, even relatively healthy preterm babies may have incompletely functioning lungs, which may pose a risk factor for frequent respiratory infections in early childhood.

Even babies born at the end of pregnancy, between the 34th and 37th weeks, are at risk. These babies, who appear physically healthy, may have underdeveloped lungs.

When a baby is born at full term, its lungs have developed to a point where the baby can breathe independently.

The lungs function, allowing the baby to inhale to take in oxygen and exhale to release carbon dioxide. At birth, there are about 50 million alveoli, and their number continues to increase after birth.

How is the infection transmitted?
RSV is easily transmitted by touching infected surfaces or through airborne droplets when inhaling particles during sneezing or coughing.

Your child can become infected with RSV by touching, kissing, and any close contact with people who have RSV. Contact with coughing and sneezing sick individuals is particularly dangerous.

Premature babies do not receive the full set of maternal antibodies that pass through the placenta.

Premature babies do not extract the antibacterial substances contained in the amniotic fluid, whose antibacterial activity improves with advancing pregnancy.

Most babies born before 34 weeks cannot feed through their mouths—lacking the coordinated ability to suck and swallow—so the baby may not receive antibodies through maternal milk that could help it cope with the infection.

Underdeveloped immunity (RSV infection immunity transmitted from the mother to the preterm baby) is a serious risk, especially in the first months, before and during the RSV season.

The RSV season is the time of year when RSV is most active, and for Bulgaria, it is from October to April.

Babies born at full term may have a better ability to defend themselves against RSV infection.

RSV does not act selectively…

RSV infects both babies born at full term and premature babies. However, in babies born at full term, with well-developed lungs and an immune system, RSV infection may pass as a mild cold, and they may recover quickly.

In premature babies, however, RSV can cause severe complications, requiring hospitalization. Sometimes these conditions can be life-threatening.

RSV can be easily transmitted by touch, sneezing, coughing, or contact with people infected with RSV.

Make sure you are prepared for this RSV season!
How can you reduce the risk of RSV infection for your baby?
• Wash your hands with soap and water or alcohol-based hand sanitizer before touching the baby.
• Frequently clean children’s toys, preferably individually.
• Children and adults with colds should stay away from the baby.
• Keep the baby away from crowded places, such as daycare centers, shopping malls, and family gatherings.
• Do not smoke around the baby.

Simple precautions like these can help protect your premature baby from RSV.

Consult your doctor/neonatologist for more information on how to protect your baby from RSV infection!
The material provides general information for educational purposes only and should not be considered as personal medical advice.