Respiratory syncytial virus is a common infection of the respiratory tract that strikes virtually all children by the age of 2. More commonly known as RSV, the infection is highly contagious. It is frequently associated with epidemics that can last up to five months and that typically occur in late fall, winter or early spring.
RSV can enter the body through the eyes, nose or mouth. Children over age 3 and most adults who contract RSV usually experience symptoms that are no worse than those of a common cold. However, RSV in children younger than 3 can sometimes cause lower respiratory tract illnesses such as bronchiolitis (commonly called a "chest cold"), tracheobronchitis (croup) and pneumonia. In rare but severe cases, RSV can lead to respiratory failure.
RSV is most likely to cause more serious symptoms in babies born prematurely, older adults, and those with heart, lung or immune system problems, regardless of age.
There appears to be a link between bouts of RSV and increased incidences of asthma symptoms. However, scientists have not concluded that RSV actually causes asthma. Rather, it is thought that RSV causes swelling and narrowing of the lower airway that can trigger asthma symptoms. However, another study on RSV has also indicated that it could contribute to the development of asthma. Research is ongoing.
About respiratory syncytial virus (RSV)
Respiratory syncytial (pronounced sin–SHISH–ull) virus is a common infection of the lungs and breathing passages. It has a wide range of effects on the body, from minor to severe.
Nearly 60 percent of children are infected with respiratory syncytial virus (RSV) during the first year of life, and virtually all children have contracted the virus by age 2, according to the American Academy of Allergy, Asthma and Immunology (AAAAI).
RSV most often affects infants aged 2 months to 6 months, and is frequently transmitted from child to child in daycare centers, preschools and schools. It is often associated with epidemics that can last up to five months and typically occur in late fall, winter or early spring. However, this may vary by region. In tropical climates, for instance, outbreaks are most likely during the rainy season.
RSV usually causes symptoms very similar to those of a common cold and resolves within a week to two weeks. However, some patients display more serious symptoms. RSV is the most common cause of lower respiratory tract illnesses such as bronchiolitis (inflammation of the small airways) and pneumonia among children younger than 1 year of age, according to the Centers for Disease Control and Prevention (CDC). In rare cases, RSV infection can lead to respiratory failure and death.
There are many different strains of RSV. Therefore, the body can never develop full immunity to RSV, and it is possible to become infected with a strain of RSV just weeks after recovering from a different RSV strain. People can be infected with RSV many times throughout their lives, but symptoms tend to be most severe the first time the illness strikes. Thereafter, symptoms become milder. With each bout of RSV, a person develops greater immunity to the virus.
Some evidence suggests that young children who develop bronchiolitis during an RSV episode have higher incidences of asthma later in life. Medical experts at this time do not believe that RSV actually causes asthma, and the link between the two conditions is not completely known. However, experts do know that the RSV causes swelling and narrowing of the lower airway that can help trigger asthma attacks.
Potential causes of respiratory syncytial virus
Respiratory syncytial virus (RSV) is extremely contagious, and a person can become infected in several ways. It is passed through oral and nasal fluids such as mucus, saliva and phlegm and is easily transmitted through shaking hands, kissing and touching. It can live for 30 minutes or more on a person’s hands and can survive up to five hours on countertops, utensils, toys and other hard surfaces. The chance of spreading RSV within a family is high because it is so contagious.
People can also contract RSV through breathing in small droplets of saliva or mucus when a person coughs or sneezes. People with RSV are most contagious during the first four days of their illness, but can spread the infection for up to two weeks after symptoms begin.
Signs and symptoms of RSV
Symptoms of respiratory syncytial virus (RSV) usually appear four to six days after exposure to the virus. It can be very difficult to distinguish between RSV and a common cold, as they share many symptoms. Usually, this is not a major concern, as both RSV and common colds cause only minor health effects and tend to resolve without medical intervention.
In children older than 3 and adults, symptoms are usually those of an upper respiratory tract illness such as the common cold. Symptoms include:
RSV symptoms can be more serious for children under age 3, and the virus can trigger lower respiratory illnesses such as bronchiolitis (inflammation of the small airways) or pneumonia. Infants with RSV may appear listless, lack appetite, act irritable and sleep poorly. In very rare cases, RSV can lead to respiratory failure and death.
Severe RSV symptoms in children under age 3 include:
Severe cough
Wheezing
Brief periods when breathing stops (apnea)
Breathing difficulties, including rapid breathing (tachypnea)
Bluish tint to lips and fingernails caused by low oxygen in the blood (cyanosis)
Children most at risk for experiencing such serious symptoms include those born prematurely (due to underdeveloped lungs) and those with pre–existing lung, heart or immune system disorders.
RSV also can cause complications in adults older than 65, especially if they suffer from heart and lung disorders, such as chronic obstructive pulmonary disease (COPD) or heart failure. Older adults may experience longer recovery periods than those in other age groups.
Although most cases of RSV are not dangerous, those at high risk for complications should contact their physician when signs and symptoms of RSV develop. Children experiencing severe RSV symptoms, such as difficulty breathing and cyanosis, should receive immediate medical attention.
In general, RSV symptoms usually are most severe the first time a person contracts the virus, and tend to be milder with subsequent RSV infections.
Diagnosis methods for RSV
A physician will complete a physical examination and compile a patient medical history and list of symptoms in attempting to diagnose respiratory syncytial virus. A cotton swab or nasal wash may be used to obtain fluid from the nose so it can be tested for RSV. A physician may also use a stethoscope to listen for wheezes or other abnormal lung sounds.
Other tests sometimes used to diagnose RSV include:
Chest x-ray. Used to look for signs of pneumonia or bronchiolitis.
Arterial blood gas analysis. Helps detect decreased oxygen saturation in the blood.
Pulse oximetry. Measures the amount of oxygen in the blood.
RSV antibody tests are considered to be of limited use. While they can detect the presence of RSV antibodies – which indicates past or present infection with RSV – they cannot detect the presence of the virus itself.
Treatment options for RSV
In most cases, RSV infection requires no significant treatment. After one or two weeks, the virus runs its course and the patient recovers. During this time, patients can aid the recovery process by:
Drinking plenty of liquids.
Getting bed rest.
Running a humidifier, which may help soothe the throat and nose.
Using saline nose drops. In infants and children, use of a bulb syringe can loosen mucus in the nose.
Using nonprescription pain relievers, such as acetaminophen, can help reduce fever and ease sore throat.
In some cases infections can last up to three weeks and include more substantial symptoms. RSV symptoms are most likely to be serious in children younger than 3 who were born prematurely or who have pre–existing lung, heart or immune system conditions. Infants who contract RSV that develops into a lower respiratory tract illness may spend up to a week receiving treatment in the hospital. Treatment is likely to include:
Supplemental oxygen
Humidified air
Intravenous fluids for hydration
Respiratory support via a ventilator if necessary
Because RSV is a virus, antibiotics are not used to treat the condition. However, antibiotics may be prescribed to treat complications that can be associated with RSV, such as bacterial infections of the middle ear (otitis media) or bacterial pneumonia. The findings of a recent study suggest that infants with bronchiolitis caused by RSV may benefit from treatment with an antibiotic with anti-inflammatory effects. However, more research is needed.
Bronchodilators may be prescribed to help force open the airways in patients with RSV. Corticosteroids may be prescribed to treat RSV patients who have asthma or allergy–related breathing problems. Some physicians prescribe an antiviral medication called ribavirin for very ill children, but studies have reported conflicting evidence about whether or not such an approach is effective.
Though research continues, to date, there is no vaccine to inoculate children against RSV. In the meantime, physicians may prescribe preventative medicines for members of high–risk groups prior to the start of RSV season. The treatments provide no benefit to patients who already are in the midst of an RSV infection.
The two major preventative treatments introduce antibodies, which attach to RSV and neutralize it before it makes copies of itself. These treatments include:
Palivizumab. Contains laboratory–produced antibodies that are injected intramuscularly into patients younger than 24 months to protect them from RSV infection. It usually is given during the autumn months, when the risk of infection is particularly high. This treatment is given in five monthly doses.
Respiratory syncytial virus immune globulin intravenous (RSV–IGIV). Contains antibodies obtained from human blood donations. RSV–IGIV is given to patients intravenously, or through their veins, in five monthly doses. Because this is a blood product, children who receive RSV–IGIV must refrain from also receiving the MMR (measles, mumps and rubella) or chickenpox vaccine for nine months after the last RSV–IGIV infusion.
The American Academy of Pediatrics has established guidelines for which patients should receive antibody treatments. They include:
Children younger than 2 with chronic lung disease.
Premature infants born at less than 28 weeks who are less than 12 months old at the start of RSV season.
Premature infants born between 29 and 32 weeks who are less than six months old at the start of RSV season.
Premature infants born between 32 and 35 weeks who are less than six months old at the start of RSV season and who have other risk factors, including:
Twins and other multiple births
Attending daycare regularly
Frequent exposure to secondhand tobacco smoke and air pollution
Sharing a bedroom with a sibling
Having a sibling who attends school
Before a child is immunized for RSV parents should inform the pediatrician of any other medical conditions, especially heart disease.
Prevention methods for RSV
A number of simple steps can be taken to help reduce the odds of contracting respiratory syncytial virus (RSV) infection. These include:
Washing hands frequently. RSV often spreads when nose and throat fluids of infected people find their way onto the hands of an uninfected person, who then touches their nose, eyes or mouth. This allows RSV to enter the body. Adults can also pass RSV onto infants and children by touching the child’s nose or eyes. During RSV season all adults who come into contact with young children should wash their hands frequently.
Keeping children away from tobacco smoke. Regular exposure to smoke irritates the mucous membranes in a child’s nose, sinuses and lungs and increases the risk of contracting RSV.
Avoiding crowds during outbreaks of RSV. Because RSV is so contagious, outbreaks are often large and reported in the media. Parents should keep children away from child care centers, malls, movie theaters and other congested places until the epidemic has passed.
Frequently cleaning household surfaces and toys with disinfectant during peak RSV seasons.
Encouraging children and other family members to cover their mouths when coughing or sneezing.
Making sure children do not share cups, utensils, toys and other items with those who may be infected.
Ongoing research regarding RSV
Researchers are still trying to uncover the precise link between respiratory syncytial virus (RSV) and increased incidences of asthma attacks.
Studies indicate that certain genes may cause an increase in the immune reaction to RSV in some individuals. This may make infections more severe in those with these genes. In addition, RSV possesses a potent ability to infect and kill cells in the lungs that regulate cough and wheezing. Taken together, these factors may make the body more vulnerable to asthma symptoms.
Research also continues on a potential vaccine that would protect against RSV infections. It is hoped that such a vaccine will help prevent both infant death and increased asthma incidences associated with RSV.
Questions for your doctor regarding RSV
Preparing questions in advance can help parents to have more meaningful discussions with their child’s physicians. Parents may wish to ask their child’s doctor the following questions about respiratory syncytial virus (RSV):
Do my child’s symptoms indicate RSV?
What methods will you use to determine if my child has RSV?
Does RSV pose a danger to my child's overall health?
What are my child’s treatment options?
Is my child a candidate for antibody treatments?
When will my child’s symptoms improve?
At what point will my child no longer be contagious?
Should I isolate my child from the rest of the family?
How can I prevent RSV?
What are my child's odds of contracting the virus?
I have had the virus in the past. Is it possible to contract it again?
