Pediatric pulmonary protection for respiratory syncytial virus

Abstract

Respiratory syncytial virus (RSV) is one of the most common causes of childhood respiratory illness worldwide.1.Pediatrics. 2009; 124: 1694-1701Crossref PubMed Scopus (287) Google Scholar Nearly all children will become infected with the virus by age 2 years.1.Pediatrics. 2009; 124: 1694-1701Crossref PubMed Scopus (287) Google Scholar The majority of children who become infected with RSV will only experience acute upper respiratory symptoms (e.g., fever, congestion, runny nose); however, a small subset of "at-risk" individuals will suffer more severe disease.1.Pediatrics. 2009; 124: 1694-1701Crossref PubMed Scopus (287) Google Scholar Severe disease may lead to hospitalization and/or long-term pulmonary complications, such as recurrent wheezing or asthma.1.Pediatrics. 2009; 124: 1694-1701Crossref PubMed Scopus (287) Google Scholar In the United States alone, it is estimated that up to 125,000 children under age 1 year are hospitalized due to an RSV-associated illness each year.2.www.cdc.gov/rsv/index.html www.synagis.com/rsv-seasonality.html.Google Scholar Similar to influenza, RSV has a peak season for outbreaks. In the United States, this timeframe typically falls between November and April, but slight variations occur annually based on the geographic region of focus.2.www.cdc.gov/rsv/index.html www.synagis.com/rsv-seasonality.html.Google Scholar For example, during the 2011–12 season, initial RSV cases were identified as early as mid- August (Florida) and persisted through mid- January (Kansas City).2.www.cdc.gov/rsv/index.html www.synagis.com/rsv-seasonality.html.Google Scholar Florida and Puerto Rico have documented confirmed RSV activity year- round in past seasons.3.www.cdc.gov/rsv/index.html www.synagis.com/rsv-seasonality.html.Google Scholar Familiarization with the months associated with a specific region's RSV season is important for recommending preventive therapy to qualifying patients. An RSV infection begins once the virus attaches to and enters the superficial cells of the host's respiratory tract.4.www.synagis.com/rsv-seasonality.html.Google Scholar Viral attachment and penetration are mediated through the virus's G and F surface proteins, respectively.4.www.synagis.com/rsv-seasonality.html.Google Scholar The F protein also facilitates fusion between infected cells and their neighbors, resulting in the formation of the classic "syncytia" for which RSV is named.4.www.synagis.com/rsv-seasonality.html.Google Scholar Viral replication begins in the epithelial cells of the nasopharynx, which then may spread to the lower respiratory tract.5.Virus Res. 2011; 162: 80-99Crossref PubMed Scopus (322) Google Scholar Symptoms usually emerge between 4 and 6 days after exposure but can begin anywhere from 2 to 8 days following contact.2.www.cdc.gov/rsv/index.html www.synagis.com/rsv-seasonality.html.Google Scholar Patients often present with cold-like symptoms, with runny nose and decreased appetite typically appearing first. Coughing, sneezing, fever, and sometimes wheezing may begin approximately 1 to 3 days after initial symptom development.5.Virus Res. 2011; 162: 80-99Crossref PubMed Scopus (322) Google ScholarHIGHLIGHTS■Nearly all children will become infected with RSV by age 2 years.■In very young infants, symptoms such as grunting, nasal flaring, and intercostal retractions are typically related to a decreased ability to maintain oxygenation.■Pharmacists can serve as a resource for parents and caregivers of children at high risk for severe disease. ■Nearly all children will become infected with RSV by age 2 years.■In very young infants, symptoms such as grunting, nasal flaring, and intercostal retractions are typically related to a decreased ability to maintain oxygenation.■Pharmacists can serve as a resource for parents and caregivers of children at high risk for severe disease. These symptoms may not be so readily apparent in very young infants.5.Virus Res. 2011; 162: 80-99Crossref PubMed Scopus (322) Google Scholar In this patient population, symptoms such as grunting, nasal flaring, and intercostal retractions, which occur when the muscles of the ribs pull inward, are typically related to a decreased ability to maintain oxy- genation.5.Virus Res. 2011; 162: 80-99Crossref PubMed Scopus (322) Google Scholar In patients who are healthy at baseline, a full recovery is generally possible within 1 to 2 weeks.5.Virus Res. 2011; 162: 80-99Crossref PubMed Scopus (322) Google Scholar Diagnosis of an RSV infection is usually based on a physician's evaluation of the patient's history, symptoms, and physical examination.5.Virus Res. 2011; 162: 80-99Crossref PubMed Scopus (322) Google Scholar The use of routine chest x-rays and rapid antigen testing are not recommended, as neither have been shown to alter management approaches.5.Virus Res. 2011; 162: 80-99Crossref PubMed Scopus (322) Google Scholar Once an RSV infection has been diagnosed, treatment is generally supportive in nature.5.Virus Res. 2011; 162: 80-99Crossref PubMed Scopus (322) Google Scholar Maintenance of hydration and oxygenation status is crucial in severely ill infants and children.5.Virus Res. 2011; 162: 80-99Crossref PubMed Scopus (322) Google Scholar The routine use of bron- chodilators or corticosteroids (inhaled or systemic) for the treatment of RSV is not recommended.5.Virus Res. 2011; 162: 80-99Crossref PubMed Scopus (322) Google Scholar The development of a safe and effective vaccine for the prevention of RSV has yet to occur; however, current discussions indicate positive projections for the future.6.American Family Physician. 2011; 83: 141-146PubMed Google Scholar In the meantime, individuals caring for at-risk children should be counseled to utilize nonpharmacologic measures to prevent virus transmission. RSV is capable of surviving on hard surfaces for many hours. Under experimental conditions, studies have shown that RSV is capable of remaining viable on fomites anywhere from 2.5 to 8 hours, depending on the material examined.7.Vaccine. 2013; 31: 209-215Google Scholar Using appropriate hand hygiene techniques may help to prevent the spread of RSV. It is important to counsel parents and caregivers to handwash frequently with soap and water for at least 20 seconds before handling a child.2.www.cdc.gov/rsv/index.html www.synagis.com/rsv-seasonality.html.Google Scholar When soap and water are not readily available, consider an alcohol-based hand sanitizer with at least 60% alcohol.2.www.cdc.gov/rsv/index.html www.synagis.com/rsv-seasonality.html.Google Scholar It is also imperative to disinfect hard surfaces (e.g., doorknobs, countertops, handheld devices) and toys on a regular basis.2.www.cdc.gov/rsv/index.html www.synagis.com/rsv-seasonality.html.Google Scholar, 8.Applied and Environmental Microbiology. 2007; 73: 1687-1696Crossref PubMed Scopus (392) Google Scholar Caregivers should also keep their infants away from large crowds, individuals who are currently sick, and tobacco smoke.2.www.cdc.gov/rsv/index.html www.synagis.com/rsv-seasonality.html.Google Scholar Palivizumab (Synagis) is approved by FDA for the prevention of serious lower respiratory tract illness caused by an RSV infection in children at high risk for disease.9.www.lung.org/lung-disease/respiratorysyncytial-virus/preventing-rsv.html.Google Scholar Pavilizumab exerts its pharmacological effect by binding the F protein of RSV, preventing the fusion of the virus with the host's cell membrane.9.www.lung.org/lung-disease/respiratorysyncytial-virus/preventing-rsv.html.Google Scholar In addition, blocking the F protein also prevents cell-to-cell fusion from occurring between RSV- infected cells.9.www.lung.org/lung-disease/respiratorysyncytial-virus/preventing-rsv.html.Google ScholarPharmacists can provide education on nonpharmacologic prevention strategies and the importance of adherence to palivizumab therapy, when appropriate. The recommended dose of palivizumab is 15 mg/kg given intramuscularly at monthly intervals.9.www.lung.org/lung-disease/respiratorysyncytial-virus/preventing-rsv.html.Google Scholar Injections should be administered every 28 to 30 days during the RSV season to ensure the best possible outcomes.9.www.lung.org/lung-disease/respiratorysyncytial-virus/preventing-rsv.html.Google Scholar Table 1 outlines recommendations from the American Academy of Pediatrics on administration of palivi- zumab.1.Pediatrics. 2009; 124: 1694-1701Crossref PubMed Scopus (287) Google ScholarTable 1Palivizumab prophylaxis criteria for infants and young children1.Pediatrics. 2009; 124: 1694-1701Crossref PubMed Scopus (287) Google Scholar'10.Synagis [package insert].Google ScholarAdapted from: Pediatrics. 2009;124(6):1694–701Airway abnormalities or neuromuscular disease (maximum of 5 doses)■Children <1 year of age with congenital abnormalities of the airway or the presence of a neuromuscular disease of the lungsChronic lung disease of prematurity (maximum of 5 doses)■Children <24 months of age with chronic lung disease of prematurity who have received medical therapy within the 6 months prior to the respiratory syncytial virus (RSV) seasonHemodynamically significant congenital heart disease (CHD) (maximum of 5 doses)■Children <24 months with CHD who are receiving medical therapyPremature Infants (maximum dose varies by situation)■Infants born <31 weeks 6 days (maximum of 5 doses)■If born <28 weeks' gestation, prophylaxis may be initiated any time before the patient reaches 1 year of age. If patient reaches 1 year of age after the commencement of prophylaxis, therapy should be continued through the RSV season.■If born between 29 weeks' gestation and 31 weeks', 6 days' gestation, prophylaxis may be initiated any time before the patient reaches 6 months of age. If patient reaches 6 months of age after the commencement of prophylaxis, therapy should be continued through the RSV season.■Infants born at 32 weeks' to <34 weeks', 6 days' gestation during or 3 months before the RSV season with at least one of the following two risk factors present (maximum of three doses, and should not be administered past 3 months of age): (1) attends child care in a home or facility and/or (2) lives in the same household with an individual <5 years of age Open table in a new tab The pharmacist may play many roles in improving outcomes for young children at risk for severe RSV-related illness. Pharmacists can serve as a resource for parents and caregivers of children at high risk for severe disease. They can provide education on nonpharmacologic prevention strategies and the importance of adherence to palivizumab therapy, when appropriate. Pharmacists can also ensure that patients are receiving the appropriate dose without overutilization of the drug. Palivizumab is supplied as single-use, preservative-free vials containing either 50 mg/0.5 mL or 100 mg/1 mL.9.www.lung.org/lung-disease/respiratorysyncytial-virus/preventing-rsv.html.Google Scholar By proactively reaching out to the prescriber to verify the current weight of an infant or child, the pharmacist can quickly and accurately determine the appropriate dose of the next monthly injection for a given patient. This should be done at each monthly refill to maximize the cost-effectiveness associated with therapy. Building this process into operational procedures for all patients receiving palivizumab will help to ensure appropriate dosing and timely administration.