Respiratory syncytial virus (RSV) is a common respiratory virus. It can cause a viral respiratory infection that affects the lungs and respiratory tract in adults and children, resulting in cold-like symptoms.

RSV is common, and the infection tends to clear up in a week or two. “Syncytial” is pronounced “sin-SISH-ul.”

The infection can cause mild symptoms similar to those of a common cold. However, severe cases may require hospitalization.

Serious cases are more common in very young children, older adults, and people with compromised immune systems. In the United States, RSV is a common cause of bronchiolitis and pneumonia in children under 1 year old. However, RSV seldom develops into pneumonia.

Fast facts about RSV

Here are some key points about the virus:

  • Most children have the infection 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 the infection usually takes 1–2 weeks.
  • Treatment typically involves relieving the symptoms.

RSV is a contagious virus that affects the respiratory system.

The Centers for Disease Control and Prevention (CDC) report that most children have exposure to RSV before they turn 2 years old. Among adults, the infection is most likely to affect older people and people with weakened immune systems.

The symptoms can be mild, like those of a common cold, but some people may have more severe symptoms. Bronchiolitis and pneumonia can develop from severe cases of RSV.

According to the CDC, 1–2% of infants with RSV who are younger than 6 months need to spend time in a hospital for treatment.

Seasonality

In the U.S. and other countries with similar climates and seasons, RSV infections usually occur during the fall, winter, and spring.

However, this can vary from year to year. Also, the seasonality and severity may vary among different communities.

RSV can infect anyone, and it is even possible for a person to get it more than once throughout their life.

According to the CDC, most children get RSV by the age of 2, but it can also infect adults. Symptoms typically resemble a common cold. It may take up to two weeks to recover from the virus.

High-risk groups may become very sick and develop pneumonia or bronchiolitis.

There are two groups of people who doctors consider to be at high risk of serious or severe RSV: Infants and young children, and older adults.

Children who are at risk include:

  • premature babies
  • infants under 6 months of age
  • children under 2 who have chronic lung disease or congenital heart disease
  • those with weakened immune systems
  • children who have neuromuscular conditions

Adults who are at risk include those:

  • over 65 years of age
  • with chronic heart or lung disease
  • with weakened immune systems

Sometimes, RSV can lead to other conditions worsening, including asthma, congestive heart failure, and chronic obstructive pulmonary disease.

Adults who experience severe cases of RSV may need to receive treatment in a hospital. For adults over 65, a weakened immune system places them at high risk of complications.

RSV is a contagious virus that spreads through droplets in the air or on surfaces. When a person with the infection coughs or sneezes, respiratory tract secretions containing the virus pass into the air.

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

People may develop symptoms of the infection 4–6 days after exposure to RSV.

According to the CDC, early symptoms of RSV infection in children include:

  • runny nose
  • reduced appetite
  • a cough that may turn into wheezing

Very young infants may have different symptoms from older children and adults, including:

  • irritability
  • reduced activity
  • apnea, or pausing for breath while sleeping

However, most infants recover from RSV infections before the age of 2 years without any serious problems.

Early symptoms of RSV infection in adults include:

  • cough
  • runny nose
  • fever
  • sore throat
  • fatigue

Children commonly come into contact with RSV at school or daycare centers. They may then pass it on to family members.

Adults who are in close contact with someone who has RSV can contract the virus. The virus can transmit through kissing, coughing, and sneezing as infected droplets pass from one person to another.

In addition, a person can get RSV by touching surfaces that contain these droplets and then touching their face.

RSV infections are usually contagious for around 3–8 days. In infants under 6 months and people with weakened immune systems, the virus may continue to be contagious for up to 4 weeks, even when symptoms are no longer present.

People with no underlying medical conditions usually recover within 1–2 weeks.

Possible complications of RSV include:

In severe cases, people may require treatment in a hospital. This enables health professionals to:

  • monitor the symptoms, especially breathing problems
  • treat any dehydration
  • if necessary, offer advanced forms of treatment and medical support, such as additional oxygen

Hospitalization for RSV usually only lasts a few days.

If RSV symptoms are mild, a doctor does not usually use testing to distinguish between it and viruses such as other common colds.

If the symptoms are severe or the associated risks are high, a doctor may use diagnostic tests.

If testing is necessary, a doctor will take a full medical history and do a physical examination. The doctor may also take a mouth swab or order a blood test to check for the virus. They may also need a white blood cell count.

If RSV is severe, a doctor may request a CT scan, chest X-ray, or other tests to assess the person’s lung health. In infants, the doctor may take urine or blood samples to check for bronchiolitis or a urinary tract infection.

Most cases of RSV resolve without treatment in 1–2 weeks. In mild cases, the treatment aims to relieve the symptoms.

Self-care strategies include:

  • staying home to avoid spreading the virus
  • staying comfortable and resting
  • drinking plenty of fluids
  • using a nasal suction bulb to relieve nasal stuffiness
  • using nasal saline drops
  • using a cool mist humidifier
  • taking pain relief medication, such as ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) for a fever

In severe cases of RSV, hospital treatment may include:

  • oxygen supplementation
  • breathing tubes in cases of respiratory failure or severe apnea
  • intravenous fluids for hydration

There have been several vaccines approved by the Food and Drug Administration (FDA) to help prevent RSV in adults and children. Recommendations for who can receive the RSV vaccine are based on age and other risk factors.

The RSV vaccine is currently not an annual vaccine, but for infants with a higher risk of complications from RSV, doctors may recommend monthly RSV antibody injections involving the drug palivizumab during the peak seasons.

RSV is spread through microscopic droplets released into the air or on surfaces.

The CDC recommends practicing good hygiene to help reduce the spread of RSV, including:

  • frequent handwashing
  • avoiding touching the face with the hands
  • avoiding close contact with people who have a cold or cold-like symptoms
  • covering the nose and mouth when sneezing or coughing
  • regularly cleaning and disinfecting surfaces
  • staying home when sick

Other tips include not sharing cups and utensils and limiting time spent in areas where RSV may be especially contagious. This is particularly important in the fall, winter, and spring, which are peak RSV seasons in the U.S.

RSV is common, especially in young children. It is a respiratory virus that can infect the throat, nose, lungs, and breathing passages. The virus can spread through droplets from coughing and sneezing.

Most people with the infection have mild symptoms similar to those of a common cold. They usually recover within 2 weeks. However, it can be more dangerous for infants, older adults, and anyone with a weakened immune system.