What is RSV?

Introduction

The Respiratory Syncytial Virus (RSV) causes cold-like symptoms; but, there is new research showing that there may be more damage done than we previously knew. Scientists are finding that there is a correlation between children who become infected with RSV and later in life are diagnosed with asthma and reoccurring respiratory infections.

The virus was discovered first in adolescent monkeys.1 Soon after, the virus was found in bronchiole and nasal secretions in human infants. The virus tends to target the upper respiratory track and then moves into the lower airways; and, the virus makes syncytial in cultures; therefore, they named the virus Respiratory Syncytial Virus, RSV.

The RSV virus presents itself with cold or flu-like symptoms and in infants sometimes more serious symptoms. Coughing, sneezing, low-grade fever, and muscle aches are among the most common symptoms. Most people have an immune system that will fight off the virus and the person gets over the illness in about one to two weeks. However, newborn infants may not have a strong immune system to fight it off and they come down with more serious symptoms such as an increase work of breathing, decreased saturation levels due to inflammation, mucus production thickening the alveolar/capillary membrane, and in severe cases, cyanosis can occur.

Definition

The Respiratory Syncytial Virus (RSV) is in the paramyxoviridae family. There are two strains Subtype A and Subtype B. Subtype A is the strain that shows the symptoms -subtype B is asymptomatic. RSV occurs as a quasi species, which means the virus can mutate. The virus has an average diameter of 120 and 300 nm.(2) RSV replicates in the upper respiratory track then spreads to the lower airways manifesting as bronchiolitis or pneumonia. The virus causes inflammation, edema of the airways, increased mucus production, and breakdown of respiratory epithelium.

The virus has a tendency to target certain patients. RSV is the most common cause of bronchiolitis and pneumonia in infants under the age of one years old, premature infants under the age of six months, and those with compromised cardiac, pulmonary, and/or immune systems, infants who have other siblings living in the same house, and infants who live in a house where someone smokes.(2) In healthy individuals, the virus causes cold or flu-like symptoms. On average 25% to 40% of infants show signs of bronchiolitis and/or pneumonia, of that percentage, 0.5% to 2% requires a hospital stay.

Symptoms

The symptoms of RSV vary according to severity of the disease process. Cold-like symptoms such as rhinorrhea, sore throat, low grade fever, cough, and sneezing are among the common symptoms. The patient may have tachypnea (fast breathing) due to the infection. Wheezing or decreased breath sounds may be present due a possible secondary diagnosis, bronchiolitis, that causes bronchoconstriction. Since the infant is having problems breathing, the infant may have difficulty with feeding and dehydration. Infants may have accessory muscle use while breathing. In infants, retractions while breathing may be present.(3) Mild hypoxemia may occur due to the thickening of the alveolar/capillary membrane (excessive secretions) and usually responds well to oxygen therapy.(4) If the disease process is severe enough, and if cyanosis is present, the patient may have to be put on mechanical ventilation. Symptoms last between three to fifteen days.(2,3)

There are only three main treatments for RSV. Bronchodilators to help the bronchospasm that occurs with the RSV on occasions. There is an antiviral drug that stops the virus from replicating, and an injection of RSV-IGIV, which are only used in severe cases. Since RSV is a virus, antibiotic use is not a treatment option unless there is an underlying bacterial infection.

For those with mild to moderate symptoms the treatments of a humidifier and nasal decongestants can be given at home. Patients are usually instructed to drink more fluids in order to maintain hydration. The parents of these infants are encouraged to use a bulb suction to frequently suction the nose and or pharynx to clear secretions.(6)

Bronchodilators

Bronchodilators can be used for RSV; however, if the treatment does not show any improvement of symptoms, the treatment should stop. Beta-2 agonists may help the work of breathing and bronchospasm that may occur by relaxing the smooth muscle along the airways. This is also used as a trial, since childhood asthma has similar symptoms. This does not help the inflammation caused by the virus; therefore, the treatment should be stopped if there is no improvement.

Since RSV is spread through close contact with someone who is infected, the only real way to prevent the spread of RSV is hygiene. RSV is inactivated with soap, water, and/or disinfectants.2 Frequent hand washing, of adults and children, is the most efficient way of keeping infection to a minimum. If a child does indeed catch RSV parents can help the child get better by drinking a lot of liquids, sleep, and comfort.8

Conclusion

RSV is a strand of RNA that causes cold/flu-like symptoms in children who are at risk or premature neonates. Symptoms can range from mild cold-like symptoms (coughing, sneezing, low grade fever, muscle aches) to severe symptoms such as tachypnea, wheezing, caused by bronchospasm, can cause a difficulty breathing and cyanosis

One subject that should be addressed is parental education. When children get sick the tendency is to let the child get so sick there is not much medical personal can do. If parents know when their child needs serious medical attention, children could be saved from a life of pulmonary problems. Researchers are finding that infants who catch RSV have a greater chance of developing childhood asthma and other recurrent respiratory infections that could possibly cause more damage to the respiratory system.

References

1. Prober C, Sullender, W: Advances In Prevention of Respiratory Syncytial Virus. Mosby Inc, 1999.

2. Respiratory Syncytial Virus. CDC, Respiratory and Enteric Viruses Branch. 2003.

3. Hay W, Hayward A, Groothuis J, Levin M: CURRENT Pediatric Diagnosis and Treatment. Appleton & Lange, 1995

4. Scanlon C, Wilkins R, Stoller J: Egan's Fundamentals of Respiratory Care, 7^th edition. Mosby, 1999.

5. Burton G, Hodgkin J, Ward J: Respiratory Care, A Guide to Clinical Practice. Lippincott Williams& Wilkins, 1997.

6. Respiratory Information Center. http://www.rsvinfo.com/managing/treatmild_b.html.

7. Palivizumab (Systemic). MedlinePlus Drug Information, 2004. http://www.nlm.nih.gov/medlineplus/druginfo/uspdi/203646.html.

8. Respiratory Syncytial Virus -- A Guide for Parents. Channing L. Bete Co, 2001.