Respiratory Syncytial Virus (RSV)

Introduction

It is winter and your baby has been running a low-grade fever for a couple of days. She has been coughing and her nose has been stuffy. She seems irritable and has been crying excessively. You call her pediatrician hoping to get the same pink, liquid antibiotic that cured your baby the last time she was sick. However, the pediatrician refuses to call your baby's prescription into the pharmacy. Instead, the pediatrician asks you to bring your baby into the office right away. The pediatrician says that your baby may have a common cold, ear infection, or Respiratory Syncytial Virus (RSV). You have never heard of RSV before. What is it?

What is it?

Respiratory Syncytial Virus (RSV) is the most common cause of respiratory tract infections in young children less than 2 years of age, especially infants between the ages of 2 and 10 months. In most children, the virus manifests itself as a mild respiratory infection with symptoms similar to a cold. If the infection worsens, the infection can interfere with the child's breathing. Most RSV infections occur between the months of November and May, with the peak infections occurring in January and February. While it commonly occurs in young children, RSV can affect adults and the ederly as well.

What causes it?

Respiratory Syncytial Virus (RSV) infection is caused by a virus that can enter into the body through the nose, eyes, or mouth. RSV attaches itself to the upper portion of the respiratory tract, including the nose, mouth, throat, pharynx or larynx. The virus can then move to the lower respiratory tract, the lungs. RSV is highly contagious. The virus can be spread through physical contact such as touching, kissing, or any other close contact with an infected individual. When infected individuals cough or sneeze, RSV can be emitted and travel in the air to infect other individuals as they breathe in the same air. The virus can also land on objects such as tables, toys, or drinking cups or glasses and live on the surface for 4 to 7 hours. If you touch or use those objects within this time frame, RSV can then enter your body through your eyes, nose and mouth.

Who has it?

Almost all children have had an RSV infection by the time they are 2 to 3 years old, with the peak occurrence at age 2 months to 8 months. It is possible to develop RSV after you have already had it once before, however the severity tends to decrease with age and occurance. According to the Centers for Disease Control and Prevention (CDC), 31 of 1000 children under the age of 1 year are hospitalized each year because of RSV. The CDC has also reported that hospitalizations due to RSV infections are higher in children of American Indian or Alaska Native descent, which is thought to be due to an increased prevalence of risk factors for RSV in these populations. Although, RSV is primarily known as a children's virus, adults may also become infected with RSV. RSV in adults is much less recognized because many other respiratory infections have similar clinical manifestations to RSV. In adults, the signs and symptoms of RSV typically mimic the common cold.

What are the risk factors?

Risk factors are characteristics that can predispose you to developing a condition. The following are common risk factors for becoming infected with RSV:

  • Exposure to tobacco smoke
  • Birth within 6 months before onset of RSV season
  • Living in crowded conditions (for example, more than 2 children per bedroom or more than 4 per household)
  • Day care attendance
  • Older siblings in preschool or school
  • Being in a multiple birth set (for example, twin, triplet)

There are also risk factors for developing severe RSV infections. The following are common risk factors for developing severe RSV that may require hospitalization:

  • Age younger than 3 months at time of infection
  • Premature birth
  • Chronic lung disease (for example, asthma, chronic obstructive lung disease, bronchopulmonary dysplasia [a chronic lung disease often seen in premature infants], or cystic fibrosis)
  • Congenital heart disease
  • Weakened immune system (for example HIV infection, diabetes, no spleen, cancer, kidney disease, liver disease, or blood disorders)
  • Lower socioeconomic status
  • Male sex

What are the symptoms?

Symptoms of RSV vary depending on the severity of the infection and where the virus is located in the respiratory tract. Initially, RSV typically affects the upper respiratory tract causing symptoms such as:

  • fever
  • runny nose that usually has a clear discharge
  • nasal congestion
  • cough
  • sore throat
  • decreased appetite
  • irritability
  • rapid breathing

As the infection worsens-meaning the virus travels down to the lower respiratory tract and to the smaller airways of the lungs - it can cause swelling or inflammation of the lungs and more severe symptoms such as coughing, wheezing, difficulty breathing, and rapid breathing. As the infection worsens, the child may begin to wheeze (a high-pitched noise when exhaling). The child may not want to eat or drink as usual, and they may appear more tired.

In the most severe RSV infections, the lips and nails may appear pale or blue along with the child's rapid or difficult breathing. If the infection becomes severe enough, the child may even experience short pauses (10-15 seconds in length or longer) in breathing. If you notice that your child experiences any of these more severe symptoms such as pale or blue lip and nail coloring, fast breathing, difficulty breathing, or pauses in breathing, the child needs to be taken to the Emergency Room immediately.

It is important to note that the symptoms of cough and wheezing associated with RSV infection may linger for about 4 to 8 weeks following the infection. However, wheezing generally lasts for about 7 days, and coughing usually lasts for 14 days.

How is it treated?

Respiratory syncytial virus (RSV) is a viral infection. Unfortunately, there are no medications available to cure the viral infection and treatment is individualized based on the severity of the infection. Because RSV is a virus, antibiotics, which are commonly used to treat bacterial infections, are not effective. The treatment of RSV is aimed mainly at relieving symptoms.

RSV infections that are mild are usually self-limiting. This means that once an infection occurs, it must "run its course". RSV infections in infants and children are generally mild in nature and can be treated at home. For mild infections, treatment focuses on alleviating the symptoms such as fever, cough, and congestion. It is important to be sure that the infant is able to breath, drink, eat and sleep comfortably. More severe RSV infections that compromise a child's breathing may require hospitalization. Read on to learn more about how to help alleviate RSV symptoms.

Treating a Fever
If the child has a fever, medications may be used to reduce the fever. Even though fever is the body's natural defense to fight off bacteria and viruses, it is important to reduce a fever because it can be uncomfortable and a prolonged high fever can lead to complications such as febrile seizures. A non-aspirin medication should be used to reduce fever in children. Examples of non-aspirin medications that reduce fever are acetaminophen (Tylenol or Panadol) and Nonsteroidal Anti-inflammatory Drugs (NSAIDs) such as ibuprofen (Motrin or Advil). Aspirin should be avoided in children less than 15 years of age because it has been associated with a rare, but serious and sometimes fatal, condition called Reye's syndrome when given to children with viral infections.

Preventing Dehydration
Keeping your child well hydrated is also very important when the child is infected with RSV. Adequate hydration can prevent dehydration, which often occurs because child is unwilling to eat or drink when infected with RSV. Dehydration can also accompany fever. Encouraging your child to drink plenty of fluids, such as water or juices, can prevent dehydration. If your child has a severe infection and is hospitalized, fluids may be provided through an intravenous (IV) line.

Relieving Congestion
Infants and young children with RSV may require bulb suctioning of the nose to remove excess mucus. Removal of the mucus should make it easier for the infant or child to breath. Bulb suctioning may even make the infant or child more comfortable when performed before napping or bedtime or before eating, thus encouraging the infant to sleep or eat better.

Breathing Treatments
Children who have difficulty breathing and require hospitalization may also require supplemental oxygen therapy. Oxygen is frequently supplied through a mask or nasal prongs.

Breathing treatments are commonly used to help open the airways. An instrument called a nebulizer may be used to help deliver medication deep into the lungs. Medications most frequently used for breathing treatments are beta-2 agonists (such as albuterol). Beta-2 agonists work by helping open the airways in the lungs allowing for more oxygen to enter the lungs, thereby enabling the child to breath easier.

Corticosteroids are also frequently used to treat RSV. They are used to reduce the inflammation in the lungs that leads to difficulty breathing. However, most clinical studies failed to show consistent evidence of clinical improvement after their use. Older children and children with a history of airway disease are more likely to benefit from corticosteroids, and it is recommended that corticosteroids only be used in such individuals.

Ribavirin, an antiviral, may also be given as a breathing treatment; however, ribavirin is only approved for hospitalized infants infected with RSV. Even though ribavirin is approved for hospitalized infants with RSV, the use of ribavirin has been limited because it is expensive and the overall benefit has yet to be proven. Researchers are currently investigating its role in RSV treatment.

Nasal products that contain sodium chloride, such as ocean nasal drops, or lubricant, such as polyethylene glycol (Rhinaris Lubricating Mist), may be used to keep nasal passageways moist when they are dried and irritated. A cool mist vaporizer may also help keep nasal passageways moist.

Preventing RSV in High-Risk Patients
In instances when children are at extremely high risk for developing RSV, there are medications such as palivizumab (Synagis) or RSV immune globulin (RespiGam) that may be used to prevent these individuals from becoming infected with RSV. Click on the link below to learn more about these preventative medications.

Preventative Medications

Usually, babies receive natural substances to help fight RSV and other viruses, called antibodies, from their mothers. If a baby is born prematurely, the baby does not get enough of these virus-fighting antibodies before birth. Synagis and RespiGam provide the natural antibodies that specifically target RSV. Synagis is recommended for prevention of serious RSV infections in infants with bronchopulmonary dysplasia (BPD - a chronic lung disease often seen in premature infants) and infants with a history of premature birth (birth before 35 weeks gestation). RespiGam is recommended for prevention of serious RSV infections in infants less than 24 months of age with BPD and infants with a history of prematurity. Synagis and RespiGam are injections, typically given once a month during the RSV season (November through May). One injection protects the baby for one month, so an injection is needed every month during the RSV season to be fully protected.

Helping Yourself

Preventing the spread of RSV to other infants, children and adults is very important. If your child is in the hospital, healthcare professionals will take proper precautions to ensure that others do not become infected with the virus. If your child is at home and is infected with RSV, proper and frequent hand washing can help prevent the spread of RSV to others. Make sure that anyone who touches the child washes his or her hands with soap and warm water. The infected baby or child should not be exposed to second-hand smoke because tobacco smoke can worsen RSV symptoms.

Other simple actions parents can take to help their children avoid being infected with RSV include the following:

  • Use a tissue when you cough or sneeze, and dispose of it right away
  • If possible, try to keep your baby away from people with coughs or colds, especially during the winter months.
  • Wash toys used by children who have symptoms of a cold.

What is on the horizon?

Even though RSV is an infection that affects a great portion of children population, there is only one FDA-approved medication available for halting the growth of RSV (ribavirin). Currently no treatment is available to completely eradicate or cure viral infections of any kind including RSV. However, there are many current clinical studies on medications for RSV prevention. Researchers are pursuing the possibility of an RSV vaccine.

Numax Anti-RSV Mab is an antibody against RSV, which is similar to Synagis. However, Numax is proposed to be at least ten times more effective than Synagis. Synagis is only available in injection formulation, but Numax will be available in an inhaled formulation. Furthermore, Numax will be indicated for both children and elderly, while Synagis is only indicated for children. This product is under investigation and has not been approved by the FDA.

Another study currently underway is looking at Motavizumab for the treatment of RSV. Motavizumab is a monoclonal antibody that researchers believe could potentially neutralize RSV. So far, studies in animal models have been fairly successful, and investigators have moved on to include human subjects in their research. Motavizumab is still under review and has not been approved by the FDA.

New drugs are being looked at daily for RSV, many drugs that are currently being researched are so new they are not even named yet, however, the outlook for RSV is looking up each day.

References

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Respiratory Syncytial Virus (RSV) Health Condition Last Updated: October 2007

Note: The above information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist, or other healthcare professional. It is not intended to diagnose a health condition, but it can be used as a guide to help you decide if you should seek professional treatment or to help you learn more about your condition once it has been diagnosed.

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