An Overview of RSV

A highly contagious viral illness in infants and young children

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Respiratory syncytial virus, or RSV, is a common, highly contagious illness in children that often causes mild cold symptoms. However, in infants and older adults, RSV can cause serious lower respiratory illnesses (pneumonia and bronchiolitis).

The diagnosis of RSV is generally clinical, meaning it is made through a medical history and physical examination. There is no cure for RSV; rather, treatment involves managing the symptoms (e.g., drinking fluids and lowering fever), as well as monitoring closely for breathing problems, which may warrant hospitalization.

RSV infection occurs most commonly from December through March. The vast majority of children have been infected with RSV at least once by the age of two.


The symptoms of RSV usually appear within four to six days of becoming infected, and they usually develop in stages, meaning they do not all appear at the same time.

Generally speaking, the symptoms usually start off mild. For example, a child may develop simple cold symptoms like a clear runny nose followed by a cough a couple of days later. This may then be soon followed by sneezing, a low-grade fever, and wheezing. Other symptoms may include a sore throat, mild headache, and decreased appetite. Very young infants may become irritable or exhibit decreased activity.

Infants and children under the age of two years, especially those under six months of age, are most likely to develop severe symptoms of RSV, such as a very high fever, sleep apnea, and signs of pneumonia or bronchiolitis.

Both pneumonia and bronchiolitis can cause coughing, wheezing, chest tightness, and difficulties breathing. If severe enough, hospitalization may be required.

Besides young children, other groups considered at high risk for developing severe symptoms of RSV include:

  • Premature babies
  • Children with weakened immune systems
  • Children with neuromuscular disease, congenital heart disease or lung malformations, or chronic lung disease

Older adults, too, especially those over 65 years of age and adults with a chronic lung or heart disease or a weakened immune system, are also at risk for developing a severe RSV infection.

When to Seek Immediate Medical Attention

These symptoms are indications that your child needs medical attention right away, and you should call 911 immediately.

  • Appearance of blue lips, fingernails, or skin (called cyanosis)
  • Difficulty breathing, including breathing very fast
  • Severe coughing
  • Retractions (the skin around the ribcage is sucked in with each breath)
  • Nasal flaring (wide flaring of the nostrils with each breath)
  • Excessive congestion (it may seem like an infant is choking or gagging on their secretions)
  • Difficulty sucking may indicate breathing problems in an infant
  • Becoming pale, anxious, agitated, grunting, or struggling/tiring to breath
  • Becoming very drowsy or stopping breathing


RSV is a common respiratory virus that usually causes cold symptoms. But in severe cases, the virus may cause pneumonia (inflammation of the lung) or most notably in children, bronchiolitis (inflammation of the tiny airways that connect to your lungs).

Experts suspect that bronchiolitis develops as a result of RSV-induced cell death within the bronchioles. These dead cells (along with any associated mucous and swelling) plug up the airways, leading to wheezing and breathing difficulties.

RSV is a contagious virus and is spread through contact and droplet transmission. This means that anyone who comes into contact with the nasal or oral secretions of someone infected with RSV can become infected. For example, you may become infected if someone with RSV sneezes or coughs and the virus particles go into your eyes, nose, or mouth.

Touching a toy (or another object like a crib rail or doorknob) that a child sick with RSV has touched can also lead to transmission of RSV. Direct contact, such as kissing a child with RSV, can spread the virus, as well.


The diagnosis of RSV is made by a medical history and physical examination. If RSV-induced bronchiolitis is suspected, a test of nasal or cough secretions can confirm the infection.

Confirming the diagnosis of RSV-induced bronchiolitis may be important in some cases, as many viruses may cause bronchiolitis, but when RSV is the culprit, the illness tends to be more severe.

Imaging tests, like a chest X-ray, are reserved for severe cases of breathing problems, like those that warrant a potential intensive care unit (ICU) admission.

Disease Severity and Risk Factors

It's important to keep in mind that during the diagnostic process, your child's doctor will use the history and physical examination to access the severity of the illness, as this will impact the treatment plan and whether hospitalization may be necessary.

For instance, your child's doctor will likely inquire about worrisome symptoms like a high fever or decreased activity, eating, or urination at home. Your doctor will also check your child for the presence of nasal flaring, an increased breathing rate, and/or low oxygen saturation.

In addition to the severity of the illness, your child's doctor will ask about underlying health problems like a history of heart or lung disease or prematurity. This is because certain health conditions are associated with an increased risk of progressing to a more severe illness.


For most children and adults, RSV infection causes only cold symptoms, so the treatment is no different than treating any other cold at home.

However, in some people, especially babies, RSV can cause difficulty breathing which requires hospitalization.

Home Care

There is no medication to cure RSV—rather, the treatment is supportive, meaning managing symptoms until the virus runs its course. In addition to supportive care (e.g., fever reduction and drinking ample fluids), it's important to closely monitor your child for worsening symptoms and to contact your doctor with any concerns.

Fever Reduction

Be sure to also ask your doctor about the specifics of when and how to treat your child's fever. Remember to never give aspirin to any child under the age of 18 to avoid the risk of developing a serious illness called Reye's syndrome.

Hospital Care

In the hospital, besides close monitoring, supportive treatments may include oxygen therapy, nasogastric (through the nose) or intravenous (through the vein) fluid administration, and in severe cases, mechanical ventilation (a breathing machine).


There is no vaccine against RSV, although researchers are hard at work trying to develop one. At this time, the best way to prevent RSV infection is to use good hand hygiene.

Here are some important things you can do to help protect your child against RSV infection:

  • Make sure anyone who touches your child washes his or her hands first.
  • Keep your child away from anyone who is sick, especially with cold symptoms or a fever.
  • Keep your child away from crowds and large groups.
  • Do not share your child's cups or eating utensils with anyone
  • Clean potentially contaminated surfaces (for example, doorknobs and toys)
  • Keep your child away from tobacco smoke and secondhand smoke.
  • Whenever possible, especially if your baby is at high risk for RSV infection, limit his or her participation in childcare during flu season.
  • Everyone in your household, including infants 6 months old and older, should get a flu shot every year as soon as they are available.

Other tips for preventing common illnesses, such as covering your mouth when you cough or sneeze, and not touching your face, also help minimize others' risk of catching or spreading RSV. Of course, this is most important for those at highest risk.

Synagis (Palivizumab)

Synagis is an intramuscular (injected into the muscle) monoclonal antibody that is available to help prevent severe RSV illness in premature babies and children at high risk for RSV. It's typically given once a month during RSV season for a maximum of five months.

Synagis is not a vaccine, and it cannot cure or treat a child who is already diagnosed with RSV. If your child is at very high risk for RSV infection, your pediatrician may discuss this option with you.

A Word From Verywell

The bottom line here is that while RSV is a common illness that usually causes run-of-the-mill, cold symptoms, it can be very serious in certain individuals, especially infants and older adults.

In the end, educating yourself about this illness can help you be on the alert if you or a loved one contracts it. Let's hope too that with more research, scientists can develop a safe and effective RSV vaccine.

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Article Sources
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