Respiratory syncytial virus (RSV) infection causes mild symptoms in most people and clears up in 1–2 weeks. However, more serious illness can occur in young children and older adults who may require hospitalization.

RSV can affect the upper or lower respiratory tract. It is a common virus, particularly among children — nearly all of who will contract it by the age of 2 years.

RSV usually causes mild symptoms similar to a common cold, but it can be serious and require hospitalization in certain populations. RSV can be dangerous in infants, toddlers, adults over 65 years, and people with weakened immune systems.

According to the Centers for Disease Control and Prevention (CDC), in the United States, RSV causes over 58,000 hospitalizations in children aged 5 years or younger and at least 60,000 hospitalizations in older adults.

RSV transmits through respiratory droplets released into the air when a person with the virus sneezes or coughs. A person can also contract RSV by touching a contaminated surface, such as a doorknob, or having direct contact with the virus, such as by kissing a person with RSV.

RSV can live on hard surfaces such as tables or doorknobs for several hours.

Older research from 1980 found the virus could be recovered from hard surfaces, such as countertops, for up to 6 hours and soft surfaces, such as tissues, for up to 45 minutes. The virus remained active on a person’s hands for up to 25 minutes.

Once a person encounters RSV, the virus rapidly spreads into the respiratory tract, where it begins to replicate.

Incubation period

The period between exposure to an infection and the appearance of the first symptoms — the incubation period — ranges from 2–8 days, with an average incubation period of 4–6 days.

When symptoms start showing

On average, symptoms typically start within 4–6 days after contact with the virus.

Symptoms of RSV infection are similar to a common cold and may include:

  • fever
  • runny nose
  • congestion
  • sneezing
  • sore throat
  • cough

Healthy adults may only have a few mild symptoms or not experience any symptoms at all.

Infants with RSV almost always show symptoms. In young infants, these may start as:

  • irritability
  • decreased activity
  • difficulty breathing

After a few days, symptoms may also move into the lungs and cause coughing and wheezing.

In high-risk infants and older adults, RSV can lead to more serious conditions, including bronchiolitis — inflammation of the small airways in the lungs — and pneumonia, a lung infection.

These can cause additional symptoms, such as:

  • difficult, short, or fast breathing
  • wheezing
  • bluish skin — note that this may not be visible on darker skin tones

These issues could indicate a serious medical emergency and may require hospitalization.

Transmission period

People with RSV may transmit the virus a day or two before symptoms start. In total, people can usually transmit the virus for 3–8 days.

Infants and people with weakened immune systems may be able to transmit RSV for up to 4 weeks.

Recovery

Symptoms often worsen before they improve and peak between days 4 and 6.

It can take 1–2 weeks for symptoms to fully improve. A cough can persist for about 4 weeks.

Children who experience a severe infection and require hospitalization are typically able to go home within 3–4 days. High risk infants may require longer stays and admission to the intensive care unit (ICU).

Anyone with RSV can pass the virus on to others, but young infants and people with compromised or weakened immune systems tend to be able to transmit the virus for longer periods.

People at the highest risk for severe disease include:

  • infants born prematurely
  • infants and young children with underlying conditions, such as heart or lung disease
  • infants and young children with compromised immune systems
  • adults with compromised immune systems
  • adults aged 65 years and older, especially those with an underlying heart or lung disease

Anyone experiencing lower respiratory disease symptoms should avoid interaction with children and adults at high risk of severe RSV illness. A vaccine is not currently available to prevent RSV infection in adults or children, but several promising vaccine candidates are in development and may be available soon.

A person can help prevent the transmission of RSV by:

  • covering coughs and sneezes with a tissue or shirt — not hands
  • washing hands often
  • avoiding close contact with sick people
  • disinfecting high-touch surfaces such as countertops and doorknobs
  • staying home while sick
  • avoiding crowds during fall and winter — the peak RSV season

Adults and children not at a high risk of severe illness should stay home and rest. Treatment for RSV is supportive and may include:

  • over-the-counter (OTC) medications to relieve pain and reduce fevers, such as ibuprofen (Aleve, Motrin) or acetaminophen (Tylenol)
  • fluids to prevent dehydration
  • OTC cold medicines

Caregivers should consult with a doctor before giving medications to children. In addition, they should avoid giving aspirin to a child.

Older adults, infants, and young children require medical care if they have difficulty breathing or become dehydrated. In the most severe cases, a person may require IV fluids, oxygen, or mechanical ventilation to help them breathe.

To prevent cases of RSV in high risk infants, a doctor can prescribe an antiviral drug called palivizumab. This drug is limited and is not for use after the disease has already progressed. A medical professional can administer palivizumab via a monthly intramuscular injection during the RSV season.

Most people with RSV experience a mild illness and make a full recovery in 1–2 weeks without treatment.

Infants, older adults, and people with weakened immune systems or underlying heart and lung conditions are at risk of more severe illness requiring hospitalization.

A person with RSV experiencing difficulty breathing or worsening symptoms or an infant showing signs of labored, shallow, or rapid breathing requires immediate medical care.