What is respiratory syncytial virus (RSV)?

What is respiratory syncytial virus (RSV)?

Respiratory syncytial virus can cause both adults and children to have a viral respiratory infection that affects the lungs and respiratory tract.

The disease caused by this virus, pronounced “sin-SISH-ul,” can be as mild as a common cold but hospitalization may be needed in serious cases.

Serious cases are most likely to occur in children very young and those with a compromised immune system or other chronic diseases.

Important facts about respiratory syncytial virus

Here are some key points about respiratory syncytial virus.

  • Most children experience respiratory syncytial virus by the age of 2 years.
  • The virus can spread through both direct and indirect contact with secretions from people with the infection.
  • It can survive on hard surfaces, such as tabletops and toys, for several hours.
  • Full recovery from infection usually takes 1 to 2 weeks.
  • Treatment typically involves relieving the symptoms.

What is it?

Doctor and her patient with a child
Most children will experience RSV before the age of 2 years.

Respiratory syncytial virus (RSV) is a highly infectious, respiratory system-affected virus.

By the time they reach 2 years old, most children would have been exposed to RSV.

This is most likely to affect older adults among adults

The virus is one common cause of multiple breathing problems.

Symptoms, like those of a cold, can be mild. However it can develop bronchiolitis and pneumonia if it affects the lower respiratory tract.

In 1 to 2 percent of infants under the age of 6 months with RSV will need to stay in hospital for time.


RSV is highly contagious, and spreads through transmission of droplets. Secretions from their respiratory tract containing the virus are passed out into the air when a person with the infection coughs or sneezes.

RSV can survive on surfaces such as tabletops, hands and clothing for hours , making the virus easy to transmit from person to person.

An individual is normally infectious for 3 to 8 days but even after their symptoms have vanished, young children and those with a compromised immune system may still be able to pass it on for up to 4 weeks.

Those that are at the greatest risk of complications or severe symptoms include:

  • infants who were born preterm
  • those aged younger than 2 years
  • older adults
  • adults or children with a weakened immune system
  • people with congenital heart or chronic lung diseases
  • those with other existing medical conditions, such as asthma

Infection is more likely among those who have a child or sibling in daycare or school.

In infants

Early symptoms in children and infants include:

  • a runny nose
  • reduced appetite
  • a cough which may be followed by wheezing

Very young infants may show different symptoms from older children or adults, including:

  • irritability
  • lack of activity
  • reduce appetite
  • apnea, or pausing for breath while sleeping

RSV can be dangerous in infants, especially in:

  • those born pre-term
  • infants under the age of 6 months
  • those under 2 years with lung, heart, or neuromuscular problems
  • children with a weakened immune system

Many babies, however, develop an RSV before they are 2 years old without having any serious problems.


Symptoms usually occur 3 to 8 days after the virus has been released.

Children and babies will normally recover within 1 to 2 weeks, but in those under 6 months of age and individuals with a compromised immune system, RSV will continue to spread for longer.

Symptoms of RSV include:

  • runny nose
  • coughing
  • sneezing
  • sore throat
  • mild headache
  • decreased appetite
  • fever
  • wheezing, rapid breathing and other breathing difficulties
  • irritability and decreased activity in infants
  • short, shallow and rapid breathing in infants
  • blue color to skin (cyanosis).

Possible complications include:

  • pneumonia
  • bronchiolitis
  • middle ear infection
  • asthma
  • recurrent RSV infections

Occasional RSV recurrences following an initial infection are normal.

In serious cases, hospitalisation can be needed. This allows health care workers to:

  • monitor symptoms, especially breathing problems
  • offer advanced forms of treatment and medical support, if needed


Bronchiolitis is a smaller infection of the respiratory tract that may result from RSV. It commonly affects those below the age of 2.

The airways are inflamed and become contaminated. The following symptoms may occur:

  • fever
  • dry, persistent cough
  • feeding problems
  • wheezing

Most cases aren’t serious, but you should call a doctor if your child has difficulty breathing or feeding, if they have a high temperature, or if they appear tired or irritable.


A doctor will perform a medical history obtaining and perform a physical exam. This will include an assessment of the lung and possibly oxygenation, using pulse oximetry.

The doctor generally doesn’t need to differentiate between RSV and other viruses, including other common cold viruses.

However, if a child is very young, is likely to be hospitalized, or has other health conditions, they may decide to make a particular diagnosis and arrange for additional testing to rule out other infections.

This may include laboratory blood checks, chest X-rays, and possibly laboratory nasal secretion examination.


Cool mist humidifiers can be used for humidifying the air and relieving RSV symptoms.
Cool mist humidifiers can be used to moisten the air and relieve the symptoms of RSV.

Treatment will aim, in mild cases, to relieve symptoms.

Comfort-enhancing steps may include:

  • using a cool mist humidifier
  • using bulb suction for mucus
  • providing increased fluid intake
  • maintaining an upright position
  • administering nasal saline drops
  • possibly, offering acetaminophen, if there is a fever

In severe cases, hospital treatment may include:

  • oxygen supplementation
  • the removal of mucus from the respiratory tract
  • intubation in cases of respiratory failure or severe apnea

In rare cases, inhaled drugs like nebulised bronchodilators may also be used. Such medications, including bronchiolitis, are of minimal use in the treatment of RSV infection and are not widely used.

These medications may include:

  • ribavirin (Virazole), an antiviral
  • epinephrine, either inhaled or injected, to help relieve symptoms

Infections with RSV tend to resolve within 1 to 2 weeks, even in severe cases requiring hospitalisation.


Taking good hygiene practices is the only way to avoid the spread of RSV.

Handwashing: Wash your hands always after you come in contact with someone with cold-like symptoms and before coming in contact with a child. This could also help kids understand the value of washing their hands.

Keeping surfaces clean: Cleaning surfaces such as toys, tables, and handles will reduce the risk of spreading RSV.

Coughs and sneezes: when coughing or sneezing, children should be advised to cover the mouth, preferably with a handkerchief, or to sneeze into the elbow to prevent droplets on the hand.

Other tips include:

  • discouraging sharing of cups and other utensils
  • limiting contact with those who have cold-like symptoms
  • avoiding smoking and exposure to second-hand smoke

In the RSV season, which appears to be in the U.S. during the winter months, monthly RSV antibody injections (palivizumab) may be prescribed for children at a higher risk of complications if they contract RSV.