Respiratory Syncytial Virus
Author: Jodi Neuens, RN
Objectives: Upon the completion of this CNE article, the reader will be able to
- Discuss the impact of and pathophysiology of a respiratory syncytial virus infection.
- Describe the transmission of respiratory syncytial virus, its clinical presentation, and prevention.
- Discuss how to diagnose a respiratory syncytial virus infection and the various treatment options that are currently available.
Overview and Healthcare Impact
Respiratory syncytial virus (RSV) is the leading cause of lower respiratory infections in infants and children. Most reported cases of bronchiolitis and pneumonia in the pediatric population can be attributed to RSV. According to the Centers for Disease Control (CDC), nearly 100% of children in childcare contract the virus within the first two years of life. Infants who are born prematurely and/or suffer from a cardiac condition or have chronic lung disease have a higher likelihood of suffering severe or even life-threatening complications resulting from the viral infection. RSV can also pose a threat for adults who are immuno-compromised and/or suffer from chronic cardiac or pulmonary complications.
The Centers for Disease Control has a system to track outbreaks through the use of a laboratory based tracking device known as the National Respiratory and Enteric Virus Surveillance System (NREVSS). This surveillance system has the capability to report trends of RSV activity throughout the United States. Figure 1 below summarizes the percentages of RSV detection from the Northeastern, Southern, Midwestern and Western regions detailing from January 1999 to May 2002. Public health laboratories in 47 states report weekly to the CDC the number of RSV tests performed including the number of positive results for respiratory and enteric viral infections through antigen detection and virus isolation methods. Because RSV is so highly contagious and poses a threat to infants, children and persons who are immuno-compromised, NREVSS is a promising tool that may aid in alerting healthcare providers the approximate onsets of RSV outbreaks for a specific region.
RSV is highly contagious and is spread through contact with respiratory secretions. The virus is known to live on environmental surfaces (such as furniture and clothing) for several hours. Inoculation occurs either by the route of infected droplets or self-inoculation after contact with RSV infected surfaces. To date, no effective treatment exists, supportive and preventive measures are still the best modes of defense. Due to the nature of RSV transmission, diligent hand washing remains the number one intervention for reducing the rate of infection. RSV related illnesses seem to be highest between the months of November and May. When a person is infected with RSV, symptoms can last anywhere from 8 to 15 days, however the individual can be infectious anywhere from 1 to 3 weeks, even after symptoms have stopped. Once a child becomes infected with RSV the virus can spread quickly.
As defined in the article by Park and Barnett, the typical abnormalities seen within the respiratory tract of those infected with RSV are "necrosis of the respiratory epithelium of the small airways, peribronchiolar mononuclear infiltration, plugging of the lumens, and hyperinflation with atelectasis". Laboratory results have shown elevated levels of histamine and leukotriene C4 in the secretions of those individuals with lower airway infections. Leukotriene C4 and histamine are also responsible for inducing bronchospasm in patients with asthma.
When increased amounts of nucleated protoplasm develop, the process causes severe swelling of the bronchioles along with the production of large amounts of mucus and exudate. As a result, the massive amounts of mucus can cause airway obstruction making it difficult to breathe. A serious complication that can occur in infants and young children is an increased risk for obstruction because of the smaller lumens of their airway. To compound the problem, upon expiration, the airway lumen can narrow even more from positive expiratory pressure causing outflow obstruction. This results in hyperinflation caused by air trapping in partially occluded sites and in turn can promote the development of atelectasis.
The incubation period for RSV is approximately 2 to 5 days and re-infection is not uncommon. This process, when unsupported, can lead to altered gas exchange, labored breathing, and hypoxemia. In some cases, symptoms can become so severe that hospitalization is necessary. High-risk populations for developing complications from RSV infection that may require hospitalization include:
- Infants and children (primarily under 2 years of age)
- Children within the day care setting
- Immuno-compromised populations (children & adult)
- Individuals with underlying cardiac/pulmonary disease
- Premature infants
Premature infants have a high risk for developing life-threatening complications related to RSV. Data have shown that premature infants (under 35 weeks gestation), who were exposed to long periods of oxygen therapy, had a higher incidence of re-hospitalization due to an RSV related illness.
A retrospective cohort study done through Kaiser Permanente in Northern California aimed to identify predisposing risk factors associated with severe RSV disease requiring hospitalization in premature infants. The study consisted of 1,721 premature infants born at 23 to 36 weeks who were discharged from a neonatal intensive care nursery (NICU) within 12 months before the December to March RSV season. The secondary analysis included 769 infants discharged during the RSV season. The findings suggested that overall, most preterm infants are at a lower risk of rehospitalization than previously believed. Three factors, however, were shown to increase the likelihood of infants developing severe RSV infections, which were:
- Gestational age (< 32 weeks)
- Prolonged oxygen requirement (> 28 days)
- NICU discharge (< 3 months) before the onset of RSV season
It is important to note that the peak seasons for RSV are open to interpretation dependent upon regional activity.
A child’s first RSV infection is usually symptomatic and could be severe. By six months of age, 98% of infants have already been exposed and/or treated for RSV related complications (bronchiolitis or pneumonia). The younger the child is when contracting RSV, the greater the risk of developing severe lower respiratory complications. Clinical signs and symptoms associated with an RSV infection include:
- Intermittent fever
- Labored breathing/wheezing/crackles
In young infants, apnea usually precedes other symptoms. Infants, six weeks and younger, are at the greatest risk for developing apnea; especially if they have a history of prematurity, pulmonary, or cardiac complications. The child that experiences a more severe case may elicit a more pronounced clinical picture and may require aggressive medical management. However, most children present with a runny nose and a fever that occurs within the first 2 to 4 days of infection. Temperatures can range anywhere from 100.40F to 1040F but usually will subside within the first few days, though lower respiratory complications can continue to escalate. It is often difficult to distinguish pneumonia from bronchiolitis. In many cases, the child will present with labored breathing accompanied by tachypnea, retractions, and at times the use of accessory muscles. By chest x-ray, both bronchiolitis and pneumonia show infiltrates making it difficult to determine the underlying cause. According to Van Stralen & Perkin, two classic signs characteristic of bronchiolitis include wheezing and lung hyper-expansion. At this point treatment measures include admitting the child to the pediatric floor to undergo intravenous hydration and antibiotic therapy (if the underlying diagnosis is pneumonia). Pulse-oximetry monitoring is almost always indicated.
Monitoring oxygenation saturation remains the number one best predictor of progression of the illness. In these cases, the child often remains on the pediatric unit for a couple of days for closer monitoring and to receive bronchodilating treatments and/or humidified oxygen before being discharged from the hospital. If these signs and symptoms go untreated the infection can progress and the clinical manifestations may be profound. In some instances, the child may continue to have a persistent cough accompanied by labored breathing and increasing tachypnea. Sub-sternal and intercostal retractions become more marked and the use of excessory muscles becomes more pronounced. Upon physical assessment, the child may exhibit circumoral cyanosis. In addition, nail beds and mucous membranes may be discolored due to lack of adequate oxygenation. Upon auscultation, the examiner may hear rales and wheezes. Pulse-oximetry should be initiated at this point. If findings reveal bradycardia and an oxygenation saturation <93%, immediate medical intervention is necessary to avoid impending respiratory arrest. In cases like this, the child should be admitted for supportive therapy such as intravenous fluid maintenance, arterial blood gas analysis and O2 therapy that may include intubation and mechanical ventilation. Standard precautions and contact isolation should be initiated until a definitive diagnosis has been made.
Health care providers, whether in the hospital setting or clinic setting, must be able to identify signs and symptoms that require intervention. In the article by Stralen & Perkin, five parameters for assessment of respiratory distress and failure in infants offers the clinical team a guideline to gauge their management approach. These parameters include:
1. Level of Consciousness
- Glasgow coma scale
- Social interactive / attentiveness
- Pulse-oximetry and/or response to supplemental oxygen
3. Respiratory rate and rhythm
4. Visual assessment of illness and work of breathing
- Intercostal, sub-sternal retraction
- Nasal flaring
- Use of accessory muscles
- Estimation of tidal volume
- Equality of breath sounds
- Wheezing / stridor / grunting
- Assessment of the duration of the inspiratory and expiratory phase of respiration
Treatment, Diagnosis & Prevention
The number one intervention to break the mode of transmission is diligent hand washing. In the healthcare environment, hand washing along with contact isolation precautions is necessary to reduce the risk of infecting other children on the unit. Because RSV is so highly contagious and poses severe health risks to children, implications for nursing care should focus heavily on prevention and education of the family about tactics that reduce the risk of infecting other children or re-infection. Nurses need to teach families about basic prevention strategies such as good hand washing practices and keeping clothing and surfaces clean that are in contact with their child or children. Parents with premature infants or hospitalized children should be educated about the use of humidifiers and nasal washes for blocked passages, and be told of the importance of maintaining adequate fluid intake for their child. They should also receive information about the potential risks associated with second-hand smoke and the importance of adhering to the Palivizumab treatment protocol (if the child is receiving this treatment – discussed below).
In the event of an outbreak on a specific clinical unit where patients share a room, it may be beneficial to cohabitate those children already infected to minimize exposure to susceptible pediatric patients who are otherwise RSV negative. This also holds true if a child is admitted to the unit to rule out a possible RSV infection; these children should be isolated until a diagnosis is confirmed. Currently the most widely used method for diagnosing RSV is through rapid diagnostic testing either by enzyme-linked immunosorbent assay (ELISA) or by direct fluorescent antibody technique. Accuracy of the results relies heavily on how the sample was obtained. A nasal wash with 5mL of isotonic solution is the desired method over a nasal smear.
Since there is no treatment available for RSV to date, measures remain supportive. As of January 2002, the third phase of a long-term safety trial for palivizumab was begun. Palivizumab is a humanized monoclonal antibody approved for use in prevention against lower respiratory infections related to RSV. The drug is available for the group of pediatric patients that are considered to be at high risk for contracting the virus. Palivizumab is administered as a 15 mg/kg intramuscular injection given once a month during the peak RSV season.
The paper by Park & Barnett analyzed the different treatment modalities that have been used in the management of RSV, which should be given case specific consideration before treatment is initiated because of the evidence that is available, related to their beneficial properties:
- "Bronchodilators" have been shown to only offer short-term benefits and should not be considered as part of routine management in the care of infants and children.
- "Corticosteroids" have not been shown to be very effective in treating bronchiolitis related to RSV infection.
- "Antibiotics" have little impact as a treatment option unless the lower respiratory tract infection is also complicated by a bacterial source. This should be established prior to beginning antibiotic therapy. Antibiotics have no affect on viral illnesses.
- "RespiGam" is a hyperimmnue polyclonal globulin that was approved by the Food and Drug Administration (FDA) in 1996. However, concerns surrounding the risks associated with the administration method (IV infusion lasting several hours; the potential transmission of blood-borne pathogens; and the potential for interference with an immune response to vaccination) led to the development of Palivizumab as the preferred prevention plan.
Every year RSV is responsible for a large number of mild to severe respiratory related illnesses in children. Today defense measures against the virus still remain supportive and the focus of healthcare providers relies heavily on prevention. Within the last year there has been significant progress made in the development of Palivizumab for populations at high risk for contracting RSV. The NREVSS tracking device operated by the CDC offers the medical community insight into the trends related to RSV outbreaks throughout the country. The major responsibility for healthcare providers in both the acute care setting and primary care setting is to educate patients and their families along with the community at large about the spread of RSV and the importance of being familiar with signs and symptoms associated with the infection. Families, who have children that fall into the high-risk category, need to be monitored closely along with consistent follow-up, to ensure compliance and in turn reduce the risk for developing severe or even life threatening complications related to RSV.
Through research and dedication significant developments have been made to better understand the etiology and clinical characteristics associated with RSV. Technology has offered healthcare professionals an array of supportive treatment options; however, educating the community remains at the forefront of prevention.
- Respiratory Syncytial Virus: Regional Trends:
Weekly laboratory test result data are collected on a voluntary basis. Because there is often a delay in reporting for some laboratories, data collection is less complete for the more recent weeks shown. Data from past years' surveillance seasons (January 1999 - June 2001) are complete. In the United States, RSV infections typically occur during annual community outbreaks, during late fall, winter, and early spring. There may be a variation in the timing of outbreaks between regions and between communities in the same region.
References or Suggested Reading:
- American Academy of Pediatrics. (1998, November) Prevention of respiratory syncytial virus infections: Indications for the use of Palivizumab and update on the use of RSV-IGIV(RE9839) Policy Statement, 102, pp. 1211-1216.
- Center for Disease Control. (2002, April) Issues in child care settings. Retrieved from:
- Center for Disease Control. (2002, May). Respiratory syncytial virus regional trends.
Retrieved from: www.cdc.gov/ncidod
- Cooper KE The effectiveness of ribavirin in the treatment of rsv. Pediatric
- Glidden C. RSV and the infant. Home Care Provider 2000;5:10-11.
- Immunotherapy Weekly. (2000, Jan). Clinical trial for synagis and siplizumab
completed. Retrieved from: www.NewsRX.com
- Joffe S, Escobar GJ. Rehospitalization for respiratory syncytial virus among premature infants. Pediatrics 1999;104:894.
- Morbidity & Mortality Weekly Report. (2002, Jan) Respiratory syncytial virus activity
United States, 2000-01 season. Volume 51 p. 26.
- Park JW, Barnett DW. Respiratory syncytial virus infection and the primary care physician. Southern Medical Journal 2002;95:353-357.
- Tobias JD. Caffeine in the treatment of apnea associated with respiratory syncytial virus infection in neonates and infants. Southern Medical Journal 2000;93:294.
- Van Stralen D, Perkin RM. RSV: not the common cold: signs and symptoms of respiratory syncytial virus. Journal of Emergency Medical Services 2000;25:72-81.
- Wagner C. Care of the pediatric patient with RSV infection. Airmed 1999;5:10-11.
Jodi L. Neuens, RN, BSN is currently a part of the adjunct faculty for Pediatrics at Maricopa Community College District in Arizona and is a resource nurse in Pediatrics, Neonatal ICU, and Pediatric ICU at Desert Samaritan Medical Center in Mesa Arizona, while she is completing her Masters Degree in Nursing (August 2002) through the University of Phoenix, Phoenix Arizona. She obtained her BSN at Lewis University in Romeoville, Illinois.
Her clinical background includes Neonatal ICU, Level II nursery, and couplet care. She has also taught community child-care classes for John C. Lincoln North Mountain Hospital in Phoenix, Arizona. She is a member of the National Honor Society of Nursing and The Academy of Neonatal Nurses.