Respiratory Syncytial Virus (RSV) Infection

Topic Overview

What is respiratory syncytial virus infection?

Respiratory syncytial virus infection, usually called RSV, is a lot like a bad cold. It causes the same symptoms. And like a cold, it is very common and very contagious. Most children have had it at least once by age 2.

RSV is usually not something to worry about. But it can lead to pneumonia or other problems in some people, especially babies. So it's important to watch the symptoms and call your doctor if they get worse.

What causes RSV infection?

A virus causes RSV infection. Like a cold virus, RSV attacks your nose, eyes, throat, and lungs. It spreads like a cold too, when you cough, sneeze, or share food or drinks.

There are many kinds of RSV, so your body never becomes immune to it. You can get it again and again throughout your life, sometimes during the same season.

What are the symptoms?

RSV usually causes the same symptoms as a bad cold, such as:

• A cough.
• A stuffy or runny nose.
• A mild sore throat.
• An earache.
• A fever.

Babies with RSV may also:

• Have no energy.
• Act fussy or cranky.
• Be less hungry than usual.

Some children have more serious symptoms, like wheezing. Call your doctor if your child is wheezing or having trouble breathing.

How is RSV diagnosed?

Doctors usually diagnose RSV by asking about your or your child's symptoms and by knowing whether there is an outbreak of the infection in your area.

There are tests for RSV, but they aren't usually needed. Your doctor may want to do testing if you or your child may be likely to have other problems. The most common test uses a sample of the drainage from your nose.

How is it treated?

RSV usually goes away on its own. For most people, home treatment is all that is needed. If your child has RSV:

• Prop up your child's head to make it easier to breathe and sleep.
• Suction your baby's nose if he or she can't breathe well enough to eat or sleep.
• Control fever with acetaminophen or ibuprofen. Never give aspirin to someone younger than 20 years, because it can cause Reye's syndrome.

When a person with RSV is otherwise healthy, symptoms usually get better in a week or two.

RSV can be serious when the symptoms are very bad or when it leads to other problems, like pneumonia. Certain people are more likely to have problems with RSV:

• Babies younger than 6 months, especially those born early (prematurely)
• People with immune system problems
• People with heart or lung problems
• Adults older than 65

These people sometimes need treatment in a hospital. So it's important to watch the symptoms and call your doctor if they get worse.

Can you prevent RSV infection?

It's very hard to keep from catching RSV, just like it's hard to keep from catching a cold. But you can lower the chances by practicing good health habits. Wash your hands often, and teach your child to do the same. See that your child gets all the vaccines your doctor recommends.

Medicines to prevent RSV may be given to babies and children who are more likely to have problems with the infection. Sometimes these medicines don't prevent RSV, but they may keep symptoms from getting serious.

Cause

Respiratory syncytial virus (RSV) is highly contagious, meaning it spreads easily from person to person. There are two main types of RSV and many subtypes (strains). For this reason, you cannot have full immunity to the virus, and you may have many RSV infections throughout life.

People with RSV infection may spread the virus through their secretions (saliva or mucus) when they cough, sneeze, or talk. You can catch the virus by:

• Touching an object or surface contaminated with the virus and then touching your nose, eyes, or mouth without first washing your hands. The virus can survive for more than 6 hours on countertops and other hard surfaces, such as doorknobs, and for 30 minutes on hands, clothing, or tissue.
• Close contact. If an infected person coughs or sneezes near you, you could breathe in RSV that's in his or her saliva or mucus.

The virus spreads easily in crowded settings, such as child care facilities, preschools, churches, and nursing homes. Children attending school often spread the virus to their parents and siblings. The incubation period-the time from exposure to RSV until you have symptoms-ranges from 2 to 8 days, but usually is 4 to 6 days.¹

You are most likely to spread the virus within the first several days after symptoms of RSV infection begin. You remain contagious for up to 8 days or longer. Babies and young children may spread the virus for at least 3 to 4 weeks. Recent research suggests that it may be possible to be a carrier of the virus 3 or 4 months or longer because parts of the virus have been found to remain in some people long after symptoms have disappeared.²

Many different viruses, such as the human metapneumovirus, can cause lower respiratory tract infections in children.³ These viruses can cause symptoms that are similar to an RSV infection.

Symptoms

When a respiratory syncytial virus (RSV) infection affects the nose and throat (upper respiratory system ), symptoms are usually mild and resemble those of the common cold. They include:

• Cough.
• Stuffy or runny nose.
• Mild sore throat.
• Earache.
• Fever, usually at the beginning of the illness. A high fever does not mean the illness is more severe.

Babies may have additional symptoms, including:

• A decreased interest in their surroundings.
• Listlessness and sleepiness.
• Fretfulness (irritability) and not sleeping well.
• Poor feeding.
• Apnea, where breathing stops for about 15 to 20 seconds. This usually occurs only in babies who were born prematurely and who also have a history of apnea.

It is difficult to distinguish between a common cold and RSV infection. Unless you or your child has an increased risk of having complications from RSV, it usually is not important to know which virus causes symptoms.

RSV infection can also lead to bronchiolitis and/or pneumonia.

Symptoms of these complications include:

• Difficulty breathing, which may include breathing more rapidly than normal.
• Wheezing.
• Coughing that is getting worse. A child may choke or vomit from intense coughing that may be dry or loose (producing mucus).
• Lethargy, increased tiredness, decreased interest in surroundings, or loss of interest in food.

What Happens

In healthy children, respiratory syncytial virus (RSV) infections tend to be mild and resemble a cold. Children who have only upper respiratory system symptoms, such as a sore throat or a runny nose, usually recover in about 10 to 14 days.

Two different types and many different subtypes (strains) of RSV exist. For this reason, you cannot have full immunity to the virus and may have many RSV infections throughout your life. A child's first RSV infection, which almost always occurs by age 2, usually is the worst. Some babies and children have an increased risk of having complications from an RSV infection because their immune system is unable to fight off the virus. In addition, babies have narrow breathing tubes that can clog easily, making breathing difficult. The most common complications for young children are bronchiolitis and pneumonia, which are lower respiratory tract infections.

Adults older than 65 have an increased risk of having complications following infection with RSV. Pneumonia is a particular risk, especially if other health problems exist, such as chronic obstructive pulmonary disease (COPD) or heart failure.

It may take older adults longer to recover from RSV infection and its complications than other age groups.

What Increases Your Risk

Respiratory syncytial virus (RSV) infects almost all children by the age of 2, and reinfection throughout life is common.¹ The first RSV infection is usually the most severe. The virus spreads easily and is extremely difficult to completely avoid. Babies and young children who are in day care centers or frequently in public places are most likely to become infected, especially during the peak season. Older brothers and sisters in school often become infected with the virus and spread it to other household members, including babies and preschoolers. Sharing food, touching objects that are contaminated with the virus, and not washing hands can lead to RSV infection. Older adults living in nursing homes or other group environments also have a higher risk of becoming infected with RSV.

Babies between 2 months and 7 months of age have the highest incidence of RSV infection affecting the lower respiratory tract . Reinfection with another type or strain of RSV can occur within weeks. But later infections are usually less severe.⁴

With RSV infections, there is an increased risk of having complications, especially in certain babies and young children and adults older than 65. The complications bronchiolitis and pneumonia occur slightly more often in boys than in girls.⁴

You can get RSV throughout your life because there are two different types and many subtypes (strains) of the virus, meaning you can never have complete immunity.

When To Call a Doctor

Call 911 or other emergency services immediately if your child is having difficulty breathing, indicated by:

• Breathing very fast (more than 60 times a minute).
• Making a grunting noise.
• Being unable to speak, cry, or make sounds, sometimes with drooling.
• Flaring nostrils or lifting the shoulders when inhaling.
• Having a gray, mottled, or blue color to the skin (look for skin color changes in the fingernail beds, lips, or earlobes).
• Wheezing that lasts over 1 hour in a baby younger than 3 months old who also appears sick.
• Breathing that stops for longer than 15 to 20 seconds.

See your doctor immediately if your baby or child has moderate difficulty breathing, indicated by:

• Breathing 40 to 60 times a minute.
• Tiring quickly during feeding. The child either stops eating or sucks in air to catch a breath. The child loses interest in eating because of the effort involved.
• Using the stomach muscles when breathing.
• Having unusual color. The child's face, hands, and feet are pale to slightly gray or lacelike purple and pale (mottled), but the tongue, gums, and lips remain pink.

See your doctor if your child shows signs of a lower respiratory infection, indicated by:

• Breathing rapidly-although keep in mind that the normal breathing rate for children is faster than for adults.
• Having difficulty breathing. Children may use muscles in the neck, chest, and stomach when taking in air. This causes the skin to retract between the ribs with each breath, making the ribs more defined than usual, a condition known as retractions. Retractions get worse (the ribs become more defined) as the degree of difficulty in breathing increases.
• Wheezing.
• Appearing extremely tired.
• Showing little interest in food or surroundings.
• Showing signs of an ear infection, such as irritability, difficulty sleeping, and tugging on or rubbing the ear. For more information, see the topic Ear Infections.
• Having a fever greater than 100.4 °F (38 °C) when younger than 3 months old.

Call a doctor if your child is:

• Breathing slightly faster than normal and seems to be getting worse. Most healthy children breathe less than 40 times a minute.
• Having cold symptoms that become severe or other problems are developing, such as signs of an ear infection.

Watchful Waiting

For an otherwise healthy child who has symptoms of an upper respiratory infection, such as a cough or runny nose, home treatment usually is all that is needed. But it is important to watch for signs and symptoms of complications, such as dehydration. For more information, see the Check Your Symptoms section of the topic Respiratory Problems, Age 11 and Younger.

Watchful waiting may not be appropriate when your child with an upper respiratory infection has an increased risk for complications. Watch your child closely if he or she has symptoms of an upper respiratory infection. If symptoms get worse or new symptoms develop, see a doctor right away.

Who To See

Respiratory syncytial virus (RSV) infection can be diagnosed and treated by a health professional such as a:

• Family physician.
• Pediatrician.
• Nurse practitioner.
• Physician assistant.

To prepare for your appointment, see the topic Making the Most of Your Appointment.

Exams and Tests

In otherwise healthy people, it is not usually necessary to distinguish respiratory syncytial virus (RSV) infection from a common cold. A doctor may suspect RSV infection as the cause of symptoms when there is evidence of a recent community outbreak. It is generally not necessary to confirm RSV infection with lab tests. But a medical history and physical exam may be done to evaluate symptoms.

A viral detection test may be done to confirm a diagnosis of RSV in symptomatic children and adults older than 65 who are at an increased risk for a severe infection or for complications. This test involves lab analysis of nasal drainage, obtained with a cotton swab or nasal wash. Testing may also be recommended for people who are hospitalized if the cause of symptoms has not already been determined and they have a high risk of developing complications.

The results of viral detection tests help determine whether precautions are needed to prevent the spread of infection. For children who have a risk of getting severe infections or complications of RSV infections, the results of these tests may help guide treatment, such as the need for medicines.

Certain tests may be needed if RSV symptoms do not improve or become worse or if complications, such as bronchiolitis or pneumonia, are suspected. These tests may include:

• A chest X-ray, which may show signs of pneumonia.
• Blood tests, such as a chemistry screening, a complete blood count, or arterial blood gases (ABGs) analysis.
• Oximetry, to measure the amount of oxygen in the blood.

Treatment Overview

Respiratory syncytial virus (RSV) infections are usually mild and seem like a common cold. In most cases, RSV infections go away on their own in about 10 to 14 days. Home treatment to ease symptoms and prevent complications is usually all that is needed.

• Watch for signs of dehydration. Make sure to replace fluids lost through rapid breathing, fever, diarrhea, or vomiting. Encourage more frequent breast- or bottle-feeding. Avoid giving your baby sports drinks, soft drinks, undiluted fruit juice, or water. These beverages may contain too much sugar, contain too few calories, or lack the proper balance of essential minerals (electrolytes).
• Make your child more comfortable by helping relieve his or her symptoms. Sometimes a child may get some relief from medicine, such as acetaminophen or ibuprofen, or from being kept in an upright position, which makes breathing easier.
• Make sure you understand whether and when antibiotics are needed. Antibiotics are not usually given for RSV infections. But if your child develops complications, such as an ear infection (otitis media), your doctor may prescribe an antibiotic. Do not stop giving antibiotic medicine when your child starts to feel better. The entire prescription must be taken to completely kill the bacteria. If you do not give your child all the medicine, the bacterial infection may return.
• Take care of yourself. Caring for a sick child can be very tiring physically and emotionally. You can best help your child when you are rested and feeling well.

Treatment for severe infection or complications

Children who develop lower respiratory infections, especially bronchiolitis, may need medicines, such as bronchodilators, in addition to home treatment. Although antibiotics are not used to treat RSV or any other viral infection, they are used when a bacterial infection, such as pneumonia, develops as a complication.

When complications develop in otherwise healthy children, corticosteroid medicines sometimes are used. But more study is needed before corticosteroids are routinely recommended for this purpose.⁵

A child who is having difficulty breathing or is dehydrated may need to be cared for in a hospital. The child may need respiratory and other medical treatments. In very rare cases, some children receive the antiviral medicine ribavirin while they are in the hospital.

• Pregnant women should avoid contact with a child who is receiving ribavirin.
• If your child is in the hospital for RSV, there are extra measures you can take to make his or her stay comfortable.

Prevention

Respiratory syncytial virus (RSV) infection is easy to catch (highly contagious). It is common for children to develop viral infections such as RSV if they are often exposed to infected people and have not built up immunity. There is no sure way to prevent respiratory illnesses in babies and children.

Sometimes, medicines are used to help prevent RSV infection in babies and children who are at risk for complications from RSV. Even if RSV infection develops, use of these medicines may result in a less severe infection.

Monoclonal antibodies, such as palivizumab (Synagis), may be used to help prevent or reduce the severity of RSV infection.

The following may help reduce your child's risk of respiratory problems:

• Wash your hands frequently, and teach your children to do the same. Also, make sure people who care for your child wash their hands and understand the importance of this habit in preventing the spread of infection.
• See that your child gets all of his or her vaccines, especially Haemophilus influenzae type b (Hib) and diphtheria, tetanus, and pertussis (DTaP). For more information, see the topic Immunizations.
• Breast-feed your baby for at least the first 6 months after birth, if possible. Breast milk seems to offer some protection against RSV infection, but more study is needed.⁶ Breast milk does not prevent RSV infection.
• Separate a child diagnosed with RSV from others in the home as much as possible.
• If you smoke, quit. If you cannot quit, do not smoke in the house or car. Secondhand smoke irritates the mucous membranes in your child's nose, sinuses, and lungs, making him or her more susceptible to infections.

Outbreaks of RSV often occur between late fall and early spring. To keep from catching the virus during this time, limit your exposure to RSV. This is most critical for babies and children who are at risk for serious RSV infections. Parents should make sure that they avoid:

• Sharing items such as cups, glasses, and utensils with others.
• People with upper respiratory infections, such as colds.
• Child care centers, malls, movie theaters, and other congested places where many people are in an enclosed area.
• Visiting children who are in the hospital.

If your child is otherwise healthy, home treatment to prevent RSV infection from becoming severe, such as ensuring your child gets plenty of rest, is usually all that is needed.

Researchers are trying to develop a vaccine to prevent infection with RSV. Currently, no vaccine is available.

Home Treatment

When to use home treatment

Most mild to moderate respiratory syncytial virus (RSV) infections in otherwise healthy people are like the common cold and can be treated at home. If your child is older than 1 year of age and is not at risk for complications from RSV infection, try home treatment. But RSV infections in people with an increased risk of complications need close monitoring.

People who have impaired immune systems need to see a doctor for coldlike symptoms because of the increased risk for developing complications. Also, babies and children with health problems and other risk factors, as well as older adults, should see a doctor at the first sign of RSV.

How to help your child with RSV infection

• Watch for signs of dehydration. Make sure to replace fluids lost through rapid breathing, fever, diarrhea, or vomiting. Encourage more frequent breast- or bottle-feeding. Avoid giving your baby sports drinks, soft drinks, undiluted fruit juice, or water. These beverages may contain too much sugar, contain too few calories, or lack the proper balance of essential minerals (electrolytes).
• Make your child more comfortable by helping relieve his or her symptoms. Sometimes a child may get some relief from medicine, such as acetaminophen or ibuprofen, or from being kept in an upright position, which makes breathing easier. Never give aspirin to someone younger than 20 years, because it can cause Reye's syndrome.
• Make sure you understand if and when antibiotics are needed. Antibiotics are not usually given for RSV infections. But if your child develops complications, such as an ear infection, your doctor may prescribe an antibiotic. Do not stop giving antibiotic medicine when your child starts to feel better. The entire prescription must be taken to completely kill the bacteria. If you do not give your child all the medicine, the bacterial infection may return.
• Take care of yourself. Caring for a sick child can be very tiring physically and emotionally. You can best help your child when you are rested and feeling well.

Medications

Most respiratory syncytial viral (RSV) infections do not require prescription medicines. But medicines may be recommended for certain people to help:

• Prevent RSV infection.
• Treat RSV infection and its complications.

Medication Choices

A medicine may be given to infants and children at high risk for complications of RSV to prevent the infection or reduce its severity. Monoclonal antibodies, such as palivizumab (Synagis), are usually given in monthly doses for the entire RSV season. This medicine can stop RSV from multiplying.

Medicines to help treat complications of RSV infection include:

• Corticosteroids. These medicines may be used if a child has an RSV infection and also has asthma or an allergic-type breathing problem. But corticosteroids are not used now as often as they were used in the past.
• Antibiotics. Antibiotics help the body destroy bacteria and may be used to help treat or prevent complications that can occur from RSV.
• Bronchodilators. They relax the muscle layer that surrounds the breathing tubes in the lung, allowing them to expand and move air more easily. This helps to reduce wheezing.

What To Think About

• High doses of vitamin A to treat symptoms of RSV have not proved effective and in fact may be harmful. For these reasons, this treatment is not recommended.
• Ribavirin (Virazole) is an antiviral medicine that is very rarely used to treat people with RSV infections who have a high risk of developing complications. Studies so far have provided conflicting evidence regarding its effectiveness. The doctor will consider the particular circumstances of the person being treated before making a recommendation about ribavirin.¹
• Bronchodilators are effective about half the time for babies.⁷ Many experts recommend that bronchodilators be tried initially for babies who are having trouble breathing. If the baby is able to breathe easier right away, the medicine can be continued.¹
• A vaccine for RSV is not currently available. Studies are ongoing.

Surgery

There is no surgical treatment for respiratory syncytial virus (RSV) infection.

Other Treatment

There is no other treatment for respiratory syncytial virus (RSV) infection.

Other Places To Get Help

Organizations

Related Information

• Bronchiolitis
• Ear Infections
• Pneumonia
• Respiratory Problems, Age 11 and Younger

References

Citations

1. American Academy of Pediatrics (2006). Respiratory syncytial virus. In LK Pickering, ed., Red Book: 2006 Report of the Committee on Infectious Diseases, 27th ed., pp. 560-566. Elk Grove Village, IL: American Academy of Pediatrics.

2. Schwarze J, et al. (2004). Latency and persistence of respiratory syncytial virus despite T cell immunity. American Journal of Respiratory and Critical Care Medicine, 169(7): 801-805.

3. Williams J, et al. (2004). Human metapneumovirus and lower respiratory tract disease in otherwise healthy infants and children. New England Journal of Medicine, 350(5): 443-450.

4. Mcintosh K (2007). Respiratory syncytial virus. In RM Kliegman et al., eds., Nelson Textbook of Pediatrics, 18th ed., chap. 257, pp. 1388-1390. Philadelphia: Saunders Elsevier.

5. Schuh S, et al. (2002). Efficacy of oral dexamethasone in outpatients with acute bronchiolitis. Journal of Pediatrics, 140: 27-32.

6. Hall CB (2004). Respiratory syncytial virus and human metapneumovirus. In RD Feigin et al., eds., Textbook of Pediatric Infectious Diseases, 5th ed., vol. 2, chap. 185A, pp. 2315-2341. Philadelphia: Saunders.

7. Horga MA, Moscona A (2006). Respiratory syncytial virus. In FD Burg et al., eds., Current Pediatric Therapy, 18th ed., pp. 793-797. Philadelphia: Saunders Elsevier.

Other Works Consulted

• Hall CB, McCarthy CA (2005). Respiratory Syncytial Virus. In GL Mandell et al., eds., Principles and Practice of Infectious Diseases, 6th ed., chap. 155, pp. 2008-2026. Philadelphia: Elsevier Churchill Livingstone.

• Hayden FG and Ison MG (2006). Respiratory viral infections. In DC Dale, DD Federman, eds., ACP Medicine, section 7, chap. 25. New York: WebMD.

• Walsh EE (2008). Respiratory syncytial virus. In L Goldman, D Ausiello, eds., Cecil Medicine, 23rd ed., chap. 385, pp. 2462-2463. Philadelphia: Saunders Elsevier.

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