Respiratory syncytial virus, or RSV, is a common virus that affects the lungs and breathing passages. It usually causes cold-like symptoms but can sometimes lead to more serious illnesses, especially in infants, young children, and older adults. Most people recover in a week or two, but for some, especially babies under six months, RSV can become severe and require medical care.
RSV is very contagious and spreads easily in households, schools, and daycare centers. It tends to appear more often in fall, winter, and early spring. Understanding how it spreads, what symptoms to look for, and how to treat it can help you protect your child and prevent complications.
What Causes Respiratory Syncytial Virus And How It Spreads
RSV is caused by a virus that infects the respiratory tract. It spreads through droplets from a cough or sneeze and by touching infected surfaces, such as toys, doorknobs, or hands. Once someone is infected, they can easily pass the virus to others—even before they show symptoms.
The virus enters the body through the nose, mouth, or eyes and settles in the lining of the respiratory system. In most healthy children and adults, RSV causes a mild infection similar to the common cold. But for infants, especially those born early or with other health problems, RSV can lead to conditions like bronchiolitis (inflammation of the small airways) or pneumonia.
RSV can reinfect people, even if they’ve had it before. Immunity to RSV is not strong, which means someone can catch it more than once in their lifetime.
Different Types of RSV Infections
There is only one RSV virus, but it can cause different types of illnesses depending on the person’s age and health. In general, RSV infections fall into two main categories:
-
Mild RSV infection: This is the most common type and usually looks like a cold. It causes sneezing, coughing, a runny nose, and sometimes a low fever. Most children experience this kind of Respiratory Syncytial Virus at least once by age two.
-
Severe RSV infection: In some cases, RSV moves deeper into the lungs, causing bronchiolitis or pneumonia. This type is more likely in babies, especially those younger than six months, or in children with weak immune systems, heart disease, or lung conditions like asthma.
RSV can also be serious for older adults, especially those with heart or lung disease or weakened immune systems.
Symptoms You Should Watch For
The symptoms of Respiratory Syncytial Virus usually start about four to six days after a person is exposed to the virus. At first, the signs may look just like a regular cold. You might notice a runny nose, sneezing, coughing, or a low-grade fever. But in babies, symptoms can become more serious after a few days. Common symptoms include:
-
Runny nose and nasal congestion
-
Cough that may get worse over time
-
Sneezing and sore throat
-
Decreased appetite or difficulty feeding
-
Fever (mild to moderate)
-
Tiredness or irritability
In more serious cases, especially in infants, RSV can lead to:
-
Fast or shallow breathing
-
Wheezing or noisy breathing
-
Blue lips or fingernails
-
Flaring nostrils or sucking in the chest while breathing
-
Pauses in breathing (apnea), especially in very young infants
Because RSV can cause dehydration, especially in babies who are not feeding well, it’s important to watch for signs like fewer wet diapers, dry mouth, or crying without tears. If your child has trouble breathing, is very sleepy, or shows signs of dehydration, it’s important to seek medical help right away.
How Respiratory Syncytial Virus Is Diagnosed
Doctors usually diagnose RSV based on symptoms and a physical exam. They will ask about your child’s breathing, feeding, and general behavior. In many cases, no tests are needed to confirm RSV.
However, if the child is very young or at risk for complications, the doctor may do a nasal swab test to detect the virus. This involves gently taking a sample of mucus from the nose and testing it for Respiratory Syncytial Virus.
Other tests may include a chest X-ray or oxygen level check (using a pulse oximeter) if the doctor suspects pneumonia or trouble with breathing. These tests help decide whether the child needs treatment at home or in the hospital.
Treatment Options And How To Care at Home
There is no cure for RSV, and antibiotics do not work against viruses like Respiratory Syncytial Virus. Most RSV infections get better with rest, fluids, and careful attention to symptoms. The goal of treatment is to keep the child comfortable and manage any breathing problems or dehydration. Home care for mild cases usually includes:
-
Keeping the child hydrated: Offer breast milk, formula, or water more often than usual.
-
Using a humidifier: Moist air can help ease breathing and reduce coughing.
-
Suctioning the nose: Use a bulb syringe and saline drops to remove mucus, especially before feeding or sleeping.
-
Fever control: Use acetaminophen or ibuprofen if needed for fever, but only if approved for your child’s age.
In more severe cases, hospitalization may be needed. This can involve:
-
Oxygen therapy: To help with breathing if oxygen levels are too low
-
IV fluids: If the child is too tired or sick to eat or drink
-
Monitoring: In the hospital, staff can watch the child’s breathing and help if symptoms get worse
There are no widely used antiviral medicines for Respiratory Syncytial Virus in healthy children, but in certain high-risk infants, doctors may recommend a preventive injection called palivizumab during RSV season. This medication doesn’t cure RSV, but it can reduce the risk of severe illness in babies who qualify.
Preventing RSV Infections
Respiratory Syncytial Virus is very contagious, but there are simple steps you can take to reduce the chance of infection:
-
Wash hands often, especially before feeding your baby
-
Avoid close contact with people who have cold symptoms
-
Keep babies away from crowded places during RSV season
-
Don’t let people kiss your baby if they’re feeling sick
-
Clean toys, surfaces, and doorknobs regularly
-
Keep your child home from daycare or school if they have a fever or severe cough
Vaccines for RSV are being developed, and one was recently approved for certain adults and infants through maternal vaccination. These options may become more common in the coming years.
