What is respiratory syncytial virus

Respiratory syncytial virus (RSV) is a common respiratory virus that infects your airways and lungs that usually causes mild, cold-like symptoms. Most people recover in a week or two, but RSV can be serious, especially for infants and older adults. Respiratory syncytial virus can cause breathing problems and lung infections in children younger than 1 year of age in the United States, such as bronchiolitis (inflammation of the small airways in the lung) and pneumonia (infection of the lungs). Older people and people who have problems with their heart, lungs or immune system are also at risk of respiratory syncytial virus respiratory illness.

Respiratory syncytial virus is highly contagious and spreads easily. The main treatment for respiratory syncytial virus is rest and plenty of fluids. Regular handwashing and good personal hygiene can stop respiratory syncytial virus from spreading.

Respiratory syncytial virus symptoms usually start with fever, runny nose, coughing and wheezing. Ear infections are also common. Symptoms may progress to pneumonia and bronchiolitis, especially in infants.

Children with asthma or breathing problems will find these get worse when they have RSV.

People of any age can get another respiratory syncytial virus infection, but infections later in life are generally less severe. People at highest risk for severe disease include:

• premature infants
• young children with congenital (from birth) heart or chronic lung disease
• young children with compromised (weakened) immune systems due to a medical condition or medical treatment
• adults with compromised immune systems
• older adults, especially those with underlying heart or lung disease

In the United States and other areas with similar climates, respiratory syncytial virus infections generally occur during fall, winter, and spring. The timing and severity of respiratory syncytial virus circulation in a given community can vary from year to year.

Most cases of respiratory syncytial virus are mild and the main treatment is to get lots of rest and drink lots of fluids. Babies with respiratory syncytial virus need small amounts of water regularly. You can manage fever and pain with over-the-counter fever reducers and pain relievers, such as acetaminophen or ibuprofen, but never give aspirin to children under 12. Antibiotics don’t work against respiratory syncytial virus. Most people recover from respiratory syncytial virus in about 10 days. Children take around 8 to 15 days to recover but some will need to go to hospital, especially if they are babies younger than 6 months.

Respiratory syncytial virus transmission

Respiratory syncytial virus spreads between people if an infected person produces small water droplets while talking, coughing and sneezing. These droplets are then breathed in by others nearby. You can get infected if you get droplets from the cough or sneeze in your eyes, nose, or mouth, or if you touch a surface that has the virus on it, like a doorknob, and then touch your face before washing your hands. Additionally, it can spread through direct contact with the virus, like kissing the face of a child with respiratory syncytial virus.

Respiratory syncytial virus is also spreads through hand-to-hand contact, or through contact with items (for example, tissues) that contain mucus from the nose or throat of an infected person.

You can also pick up respiratory syncytial virus from hard surfaces, such as door handles, that have been touched by infected people. respiratory syncytial virus survives for longer on hard surfaces than softer surfaces like tissues and hands.

People infected with respiratory syncytial virus are usually contagious for 3 to 8 days. However, some infants, and people with weakened immune systems, can continue to spread the virus even after they stop showing symptoms, for as long as 4 weeks. Children are often exposed to and infected with respiratory syncytial virus outside the home, such as in school or child-care centers. They can then transmit the virus to other members of the family.

Respiratory syncytial virus can survive for many hours on hard surfaces such as tables and crib rails. It typically lives on soft surfaces such as tissues and hands for shorter amounts of time.

Respiratory syncytial virus prevention

Respiratory syncytial virus can be prevented by:

• washing your hands – soap and water kills the virus
• keeping infected people away from others, especially babies and older people
• not sharing cups, glasses or cutlery with people who have colds
• covering your nose and mouth if you need to sneeze or cough
• throwing out tissues as soon as you’ve used them

There are steps you can take to help prevent the spread of respiratory syncytial virus. Specifically, if you have cold-like symptoms you should:

• Cover your coughs and sneezes with a tissue or your upper shirt sleeve, not your hands
• Wash your hands often with soap and water for 20 seconds
• Avoid close contact, such as kissing, shaking hands, and sharing cups and eating utensils, with others

In addition, cleaning contaminated surfaces (such as doorknobs) may help stop the spread of respiratory syncytial virus.

Ideally, people with cold-like symptoms should not interact with children at high risk for severe respiratory syncytial virus disease, including premature infants, children younger than 2 years of age with chronic lung or heart conditions, and children with weakened immune systems. If this is not possible, they should carefully follow the prevention steps mentioned above and wash their hands before interacting with such children. They should also refrain from kissing high-risk children while they have cold-like symptoms.

Parents of children at high risk for developing severe respiratory syncytial virus disease should help their child, when possible, do the following:

• Avoid close contact with sick people
• Wash their hands often with soap and water
• Avoid touching their face with unwashed hands
• Limit the time they spend in child-care centers or other potentially contagious settings, especially during fall, winter, and spring. This may help prevent infection and spread of the virus during the respiratory syncytial virus season.

Respiratory syncytial virus vaccine

Researchers are working to develop respiratory syncytial virus vaccines, but none are available yet. A drug called palivizumab is available to prevent severe respiratory syncytial virus illness in certain infants and children who are at high risk for severe disease. For example, infants born prematurely or with congenital (from birth) heart disease or chronic lung disease. The palivizumab drug can help prevent serious respiratory syncytial virus disease, but it cannot help cure or treat children already suffering from serious respiratory syncytial virus disease, and palivizumab cannot prevent infection with respiratory syncytial virus. If your child is at high risk for severe respiratory syncytial virus disease, talk to your healthcare provider to see if palivizumab can be used as a preventive measure.

Palivizumab is a monoclonal antibody recommended by the American Academy of Pediatrics ¹ to be administered to high-risk infants and young children likely to benefit from immunoprophylaxis based on gestational age and certain underlying medical conditions. It is given in monthly intramuscular injections during the RSV season, which generally occurs during fall, winter, and spring in most locations in the United States.

Respiratory syncytial virus symptoms

Symptoms of respiratory syncytial virus infection usually include:

• Runny nose
• Decrease in appetite
• Coughing
• Sneezing
• Fever
• Wheezing

These symptoms usually appear in stages and not all at once. In very young infants with respiratory syncytial virus, the only symptoms may be irritability, decreased activity, and breathing difficulties.

Respiratory syncytial virus can also cause more severe infections such as bronchiolitis, an inflammation of the small airways in the lung, and pneumonia, an infection of the lungs. It is the most common cause of bronchiolitis and pneumonia in children younger than 1 year of age.

Almost all children will have had an respiratory syncytial virus infection by their second birthday. People infected with respiratory syncytial virus usually show symptoms within 4 to 6 days after getting infected.

In Infants and Young Children

Respiratory syncytial virus infection can cause a variety of respiratory illnesses in infants and young children. Respiratory syncytial virus most commonly causes a cold-like illness but can also cause lower respiratory infections like bronchiolitis and pneumonia. One to two percent of children younger than 6 months of age with respiratory syncytial virus infection may need to be hospitalized. Severe disease most commonly occurs in very young infants. Additionally, children with any of the following underlying conditions are considered at especially high risk:

• premature infants
• very young infants, especially those 6 months and younger
• children younger than 2 years old with chronic lung or heart disease
• children with suppressed immune systems
• children who have neuromuscular disorders, including those who have difficulty swallowing or clearing mucus secretions

Infants and young children with respiratory syncytial virus infection may have rhinorrhea and a decrease in appetite before any other symptoms appear. Cough usually develops one to three days later. Soon after the cough develops, sneezing, fever, and wheezing may occur. In very young infants, irritability, decreased activity, and apnea may be the only symptoms of infection.

Most otherwise healthy infants and young children who are infected with respiratory syncytial virus do not need hospitalization. Those who are hospitalized may require oxygen, intubation, and/or mechanical ventilation. Most improve with supportive care and are discharged in a few days.

In Older Adults and Adults with Chronic Medical Conditions

Older children and adults who get infected with respiratory syncytial virus usually have mild or no symptoms. Symptoms are usually consistent with an upper respiratory tract infection which can include rhinorrhea, pharyngitis, cough, headache, fatigue, and fever. Disease usually lasts less than five days.

Some adults, however, may have more severe symptoms consistent with a lower respiratory tract infection, such as pneumonia. Those at high risk for severe illness from respiratory syncytial virus include:

• older adults, especially those 65 years and older
• adults with chronic lung or heart disease
• adults with weakened immune systems

Respiratory syncytial virus can sometimes also lead to exacerbation of serious conditions such as:

• asthma
• chronic obstructive pulmonary disease (COPD)
• congestive heart failure

Respiratory syncytial virus diagnosis

Clinical symptoms of respiratory syncytial virus are nonspecific and can overlap with other viral respiratory infections, as well as some bacterial infections. Several types of laboratory tests are available for confirming respiratory syncytial virus infection. Respiratory syncytial virus is diagnosed through blood tests or through tests of the mucus from your airways or nasal passages. These tests may be performed on upper and lower respiratory specimens.

The most commonly used types of respiratory syncytial virus clinical laboratory tests are:

• Real-time reverse transcriptase-polymerase chain reaction (rRT-PCR), which is more sensitive than culture and antigen testing
• antigen testing, which is highly sensitive in children but not sensitive in adults

Less commonly used tests include:

• viral culture
• serology, which is usually only used for research and surveillance studies

Some tests can differentiate between respiratory syncytial virus subtypes (A and B), but the clinical significance of these subtypes is unclear. Consult your laboratorian for information on what type of respiratory specimen is most appropriate to use.

For Infants and Young Children

Both reverse transcriptase-polymerase chain reaction (rRT-PCR) and antigen detection tests are effective methods for diagnosing respiratory syncytial virus infection in infants and young children. The respiratory syncytial virus sensitivity of antigen detection tests generally ranges from 80% to 90% in this age group. Healthcare professionals should consult experienced laboratorians for more information on interpretation of results.

For Older Children, Adolescents, and Adults

Healthcare professionals should use highly sensitive reverse transcriptase-polymerase chain reaction (rRT-PCR) assays when testing older children and adults for respiratory syncytial virus. Reverse transcriptase-polymerase chain reaction (rRT-PCR) assays are now commercially available for respiratory syncytial virus. The sensitivity of these assays often exceeds the sensitivity of virus isolation and antigen detection methods. Antigen tests are not sensitive for older children and adults because they may have lower viral loads in their respiratory specimens. Healthcare professionals should consult experienced laboratorians for more information on interpretation of results.

Respiratory syncytial virus treatment

Most respiratory syncytial virus infections go away on their own in a week or two. And most cases of respiratory syncytial virus are mild and the main treatment is to get lots of rest and drink lots of fluids. Babies with respiratory syncytial virus need small amounts of water regularly.

You can manage fever and pain with over-the-counter fever reducers and pain relievers, such as acetaminophen or ibuprofen, but never give aspirin to children under 12. Antibiotics don’t work against respiratory syncytial virus.

Talk to your healthcare provider before giving your child nonprescription cold medicines, since some medicines contain ingredients that are not recommended for children. It is important for people with respiratory syncytial virus infection to drink enough fluids to prevent dehydration (loss of body fluids).

Healthy infants and adults infected with respiratory syncytial virus do not usually need to be hospitalized. But some people with respiratory syncytial virus infection, especially infants younger than 6 months of age and older adults, may need to be hospitalized if they are having trouble breathing or are dehydrated. In most of these cases, hospitalization only lasts a few days.

Visits to a healthcare provider for an respiratory syncytial virus infection are very common. During such visits, the healthcare provider will evaluate how severe the person’s respiratory syncytial virus infection is to determine if the patient should be hospitalized. In the most severe cases, a person may require additional oxygen or intubation (have a breathing tube inserted through the mouth and down to the airway) with mechanical ventilation (a machine to help a person breathe).

There is no specific treatment for respiratory syncytial virus infection, though researchers are working to develop vaccines and antivirals (medicines that fight viruses).

1. Updated Guidance for Palivizumab Prophylaxis Among Infants and Young Children at Increased Risk of Hospitalization for Respiratory Syncytial Virus Infection. COMMITTEE ON INFECTIOUS DISEASES AND BRONCHIOLITIS GUIDELINES COMMITTEE. Pediatrics Aug 2014, 134 (2) 415-420; DOI: 10.1542/peds.2014-1665 https://pediatrics.aappublications.org/content/pediatrics/134/2/415.full-text.pdf[↩]