Respiratory Syncytial Virus (RSV)

Medically Reviewed on 10/27/2022

Things to know about respiratory syncytial virus (RSV) infection

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  • RSV is a highly contagious viral infection that is most prevalent during the winter season.
  • Both respiratory syncytial virus (RSV) and COVID-19 are highly contagious respiratory infections, but they are unrelated.
  • Respiratory syncytial virus (RSV) can infect people of any age. Serious infections can occur in people who are young or old or who have weakened immune systems:
    • Premature infants and all infants less than 1 year of age
    • Children 2 years old with cardiac disease or chronic lung disease
    • Adults aged 65 years and older
  • Most children who develop an RSV infection have mild symptoms of fever, nasal congestion, nasal discharge, and cough.
  • High-risk groups are more likely to have a more severe disease process, including wheezing (bronchiolitis in infants) and/or pneumonia. Such high-risk groups include premature infants, those children with a compromised immune system, or those with chronic pulmonary disease or congenital/acquired cardiac disease.
  • There is no RSV vaccine.
  • Supportive care is the mainstay of therapy. For high-risk patients, palivizumab (Synagis) preventative therapy is available.

What is respiratory syncytial virus (RSV)?

The respiratory syncytial virus (RSV), discovered in 1956, is capable of causing a broad spectrum of illnesses. Older children and adults will commonly experience a "bad cold" lasting 1-2 weeks. Fever, nasal congestion, and cough are their most common complaints. However, in babies and toddlers, RSV can produce severe pulmonary diseases, including bronchiolitis (inflammation of the terminal airways that produces wheezing) and pneumonia (infection of these terminal airways).

What are the common symptoms of RSV infection?

  • The symptoms in most infants are similar to those of a bad cold. These include fever, prominent runny nose, cough, and nasal congestion.
  • The duration of these symptoms is 1-2 weeks. During their first RSV infection, some babies and young children also have signs and symptoms of bronchiolitis or pneumonia.
  • Bronchiolitis is a clinical state of infants (by definition) during which inflammation of the terminal airways restricts airflow and may produce wheezing.
  • The majority of children hospitalized for RSV infection are under 6 months of age. The need for supplemental oxygen, IV fluids, and pulmonary inhalation therapy are the most common indicators for hospitalization. If wheezing causes an infant's respiratory rate to increase substantially, they may have a difficult time taking in adequate fluids and become dehydrated.
  • Following childhood, RSV may cause repeated infections with moderate-to-severe cold-like symptoms although severe lower respiratory tract disease (pneumonia and/or wheezing) may occur with RSV at any age.

What are the severe symptoms of a respiratory syncytial virus infection?

Respiratory syncytial virus (RSV) is a serious virus that affects children. This is because severe infections in children can cause respiratory problems that require hospitalization. RSV is one of the leading causes of death in children younger than one year worldwide. Symptoms appear 2-8 days after exposure and are similar to those of a common cold, including:

When the virus spreads to the lower respiratory tract, coughing becomes more severe and is accompanied by wheezing due to inflammation of the small airways in the lungs. Severe symptoms of RSV include:

  • Severe or frequent cough
  • Worsening croupy cough
  • Wheezing
  • Lung congestion
  • Lung inflammation
  • Nasal flaring
  • Loss of appetite
  • Low energy
  • Tiredness
  • Irritability, fussiness, or crankiness
  • Decreased activity
  • Otitis media (middle ear infections)
  • Apnea and tachypnea (short, shallow, and rapid breathing)
  • Difficulty breathing
  • Gasping for breath
  • Rattling in the chest that may be felt over an infant's back or chest
  • Mouth, lips, and fingernails may turn bluish due to lack of oxygen
  • Signs of dehydration, such as a dry mouth, crying without tears, and urinating less often

RSV can cause lower respiratory tract diseases like bronchiolitis or pneumonia and respiratory failure in severe cases. These symptoms are usually very rare and only seen in more severe infections, such as pneumonia or bronchiolitis. If your child exhibits any of these symptoms, you should see a doctor immediately. An RSV infection can be particularly dangerous in premature infants or those with heart, lung, or immune system problems. RSV-related bronchiolitis can coexist with a urinary tract infection in newborns, so blood and urine tests may be required.

Most children recover in 1-2 weeks, though some may experience intermittent wheezing. Infections that are severe or life-threatening necessitate an extended hospital stay.


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Is RSV infection contagious? What is the incubation period for RSV? How does RSV infection spread?

Respiratory syncytial virus (RSV) infection is highly contagious. Annually 100,000-120,000 babies less than 1 year old require hospitalization.

  • The RSV incubation period (time between exposure and development of symptoms) is 2-8 days.
  • It spreads via respiratory secretions through close contact with infected people or contact with contaminated surfaces or objects.
  • Infection can occur when infectious particles contact mucous membranes of the eyes, mouth, or nose, and possibly through the inhalation of droplets generated by a sneeze or cough.
  • Those who develop RSV are contagious during the first 3-8 days of their illness.
  • RSV can live for many hours on common household objects such as furniture and tabletops.
  • As such, disease transmission may be indirect by hand to mouth after touching such contaminated surfaces.
  • This mode of transmission is especially common between infants and toddlers.

When does RSV infection occur, and who gets it?

Infection with RSV is seasonal. In temperate climates, RSV infections usually occur during the late fall, winter, or early spring months.

  • Annual community outbreaks of RSV infection often last 4-5 months.
  • The winter season (November through April) tends to be most likely to experience RSV epidemic disease.
  • For unknown reasons, the severity of illness and frequency of disease often alternate on an annual basis. For example, a "bad" year (a large number of patients with moderately severe disease) is followed by a "good" year (fewer number of patients with less severe disease).

More than half of all infants are exposed to RSV by their first birthday. Many have few or mild symptoms. However, some babies with RSV become very ill. RSV is the most common cause of bronchiolitis and pneumonia among infants and children under 1 year of age.

Since an initial RSV infection does not trigger a robust long-term immune system response, after childhood, RSV may cause repeated infections throughout life.

  • These infections are usually associated with cold-like symptoms.
  • However, severe lower respiratory tract disease (for example, wheezing and/or pneumonia) may occur at any age, especially among the elderly or among those with compromised cardiac, pulmonary, or immune systems.
  • An RSV infection may exacerbate conditions such as asthma, COPD, and congestive heart failure.

Who is at risk for severe disease?

Several broad categories of patients are most vulnerable to RSV infection. These include

  • premature infants and all infants less than 1 year of age,
  • children 2 years old with cardiac disease or chronic lung disease (for example, asthma, cystic fibrosis, etc.),
  • those of any age with a compromised immune system, and
  • those 65 years of age or older.

Can adults get respiratory syncytial virus infection?

Respiratory syncytial virus (RSV) can infect people of any age. Serious infections can occur in people who are young or old or who have weakened immune systems. However, healthy adults may only have minor or no symptoms. The infection usually lasts less than 5 days in healthy adults, and the symptoms are similar to upper respiratory tract infections. RSV symptoms in adults may include:

However, some adults at an even greater risk for severe illness from RSV include:

These high-risk adults may experience more severe symptoms due to lower respiratory tract involvement. However, an RSV infection can lead to hospitalization in adults older than 50 years and in people who have underlying medical conditions. Although it is commonly thought of as a disease in children, RSV infections cause significant illness and death in older adults every year.

  • RSV is becoming more widely recognized as a cause of serious lower respiratory tract infections in the elderly. RSV-related respiratory infections affect 3 to 10 percent of adults in the United States each winter. These infections are frequently more severe and prolonged than a common cold.
  • In the United States, one to two adults per 1000 of 65 years and older are hospitalized with RSV-associated pneumonia or aggravation of an underlying medical condition.
  • The incidences of RSV-associated illness and death among adults rise with advancing age and the prevalence of coexisting conditions. As per CDC, RSV causes 177,000 hospitalizations and 14,000 fatalities in older adults each year.

RSV infections are most common in the fall and winter months in the United States. Although people develop antibodies (immune defenses) against the virus after an infection, it appears the virus can reinfect people throughout their lives. Symptoms of reinfection are usually milder than those of the initial infection.

An RSV infection will usually clear up in 1-2 weeks, and symptoms can be managed by drinking plenty of fluids, resting, and taking over-the-counter medications such as ibuprofen or acetaminophen. However, if you or someone you care for is having difficulty breathing, has a high fever, is dehydrated, or is experiencing worsening symptoms, please contact your doctor without delay.

How do health care professionals diagnose RSV infection?

Health care professionals make a diagnosis of RSV infection using a number of different laboratory tests, including

  • isolation of the virus, detection of viral antigens,
  • detection of viral RNA,
  • demonstration of a rise in serum antibodies, or
  • a combination of these approaches.

Most clinical laboratories today use nasal swab tests based on antigen detection to diagnose RSV infection. This technique is 80%-90% reliable. A newer test protocol (RT-PCR) is more reliable and is replacing the antigen-detecting test in many hospitals and community laboratories.

What is the treatment for an RSV infection?

For children with mild RSV disease, no specific treatment is necessary other than the treatment of symptoms (such as acetaminophen [Tylenol] to reduce fever). RSV infection is a viral illness and antibiotic therapy will not be helpful.

Children with more severe disease may require supplemental oxygen and sometimes mechanical ventilation (respiratory support via a breathing machine). Health care providers may use ribavirin aerosol (Virazole) in the treatment of some hospitalized patients with severe disease. Some investigators have used a combination of intravenous immune globulin (IVIG) with high titers of neutralizing RSV antibody (RSV-IVIG) and ribavirin to treat patients with compromised immune systems.

The American Academy of Pediatrics has recently published guidelines for children from one month of age through 23 months of age dealing with bronchiolitis (most commonly caused by RVS). Previous recommendations were updated and recommend against nebulizer (inhalation) therapy employing albuterol, steroids, or hypertonic (highly concentrated) saline.

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Is it possible to prevent RSV infection?

Frequent hand washing and not sharing items such as cups, glasses, and utensils with people who have RSV illness should decrease the spread of virus to others.

Excluding children with colds or other respiratory illnesses (without fever) who are well enough to attend child care or school settings will probably not decrease the transmission of RSV, since it is often spread in the early stages of illness prior to the development of more severe symptoms.

In a hospital setting, RSV transmission can and should be prevented by strict attention to contact precautions, such as hand washing and wearing gowns, facemasks, and gloves.

In 1998, a new product called palivizumab (Synagis) was licensed to help prevent severe RSV disease in certain high-risk infants with predisposing factors such as moderate/severe prematurity, chronic lung disease, congenital heart disease, etc. Palivizumab is not a treatment for RSV but rather a tool to help prevent RSV infection. Those receiving Synagis receive a monthly injection during the RSV season. Synagis is quite expensive, and insurance companies often have strict guidelines limiting those for whom they will pay this medication.

Is there an RSV vaccine?

Unfortunately, there is no RSV vaccine yet, although development of one is a high research priority.

Effective immunity against RSV requires a continuous solid level of antibodies against the virus. There is particular concern for RSV in premature babies because of their lack of maturity and lack of protective antibodies. There is a similar concern about RSV in people of all ages with immunodeficiency. Most people's immune system loses its protective capability a few months following exposure to RSV. This enables individuals to experience repeated episodes of illness during each RSV season.

What is the prognosis of an RSV infection?

Most babies and toddlers tolerate an RSV infection well. Unless they require supplemental oxygen or are at risk for dehydration, they can receive any necessary respiratory support from their parents in their home. Unfortunately, no current vaccination is available to prevent RSV infection. Hopefully, current research in this area will soon be successful.

Is respiratory syncytial virus related to COVID-19?

Both respiratory syncytial virus (RSV) and COVID-19 are highly contagious respiratory infections, but they are unrelated. The COVID-19 pandemic in the United States has altered the timing and severity of reemerging RSV epidemics. Like other respiratory infections, RSV was heavily suppressed during its regular season due to lockdown measures implemented during the pandemic. The lifting of COVID-19 restrictions has resulted in an increase in RSV cases in the United States. COVID-19, like RSV, is a respiratory illness caused by a different virus.

Symptoms of COVID-19 include:

An estimated 58,000 children younger than five years are hospitalized in the United States each year, as a result of RSV infections. Infants and young children are most vulnerable to severe RSV, making them more likely to develop serious complications if infected. Early symptoms of RSV include:

  • Runny nose
  • Cough, which may progress to wheezing
  • Irritability
  • Decreased activity
  • Decreased appetite
  • Apnea (pauses while breathing)

RSV infects nearly all children by the age of 2. The majority of RSV cases result in a mild, cold-like illness, but it can also result in severe illnesses such as bronchiolitis and pneumonia.

Although RSV and COVID-19 are caused by different viruses, they share some symptoms. Their symptoms, however, begin in a different way. 

  • RSV typically begins with cold symptoms. Children with COVID-19 frequently have mild symptoms or none at all, but they may also have a fever, vomiting, or diarrhea
  • While the symptoms of the two infections are similar in many ways (fatigue, fever, shortness of breath, dry cough, etc.), some are specific to each. 
  • RSV is more likely to affect a child with cold-like symptoms who also experiences appetite loss and irritability. 
  • Meanwhile, COVID-19 may cause vomiting, diarrhea, and a rash which is not seen in RSV. 
  • COVID-19 symptoms are usually more severe than RSV symptoms in adults. 

It may appear strange, but your child can have these two different respiratory illnesses simultaneously. It's not common, but it's very possible. 

  • Having both illnesses at the same time can cause them to be sick for a longer period of time. 
  • Young children, especially those younger than 2 years, are at a higher risk of complications if they receive both at the same time. 
  • Because RSV and COVID-19 have similar symptoms, asking your pediatrician to test your child for both viruses is the simplest way to determine what's causing a cough or fever. 

If a child tests positive for RSV, COVID-19, or both, their pediatrician can assist them with quarantine and any subsequent steps, such as returning to school.

Another similarity between the two viruses is how they spread. The good news is that by taking many of the same precautions, you can protect yourself against both COVID-19 and RSV. Pediatric departments must be on the lookout for sizable RSV outbreaks in the upcoming seasons, with the severity of these epidemics seen during spring and summer. It is advised to use increased surveillance for managing hospital capacity and administering prophylaxis for both these respiratory diseases.

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Medically Reviewed on 10/27/2022
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Coronavirus and RSV

RSV in Older Adults and Adults with Chronic Medical Conditions

United States. Centers for Disease Control and Prevention. "Respiratory Syncytial Virus Infection (RSV)." Dec. 18, 2020. <>.

United States. National Institute of Allergy and Infectious Diseases. "Respiratory Syncytial Virus (RSV)." July 22, 2022. <>.

What Is Respiratory Syncytial Virus (RSV)?