Laboratory Studies

Laboratory studies generally are not indicated in the infant with bronchiolitis who is comfortable in room air, well hydrated, and feeding adequately.

Nonspecific laboratory studies may include a complete blood count (CBC), assessment of serum electrolyte concentrations, urinalysis, and measurement of oxygen saturation. The CBC may reveal a normal or mildly elevated white blood cell (WBC) count and an elevated percentage of band forms. Blood cultures, although frequently obtained, are rarely positive for pathogenic bacteria. Arterial blood gas analysis may be indicated if carbon dioxide retention is a concern.

Specific diagnostic tests for confirmation of respiratory syncytial virus (RSV) infection are readily available. These tests can be performed on samples of secretions obtained by washing, suctioning, or swabbing the nasopharynx. Secretions can be analyzed for virus in the laboratory by means of culture, antigen-revealing techniques, or polymerase chain reaction (PCR). Molecular probes for revealing RSV in clinical specimens may be more sensitive than the aforementioned assays and are becoming clinically available, but they presently are more expensive. There are 6 commercially available multiplex PCR assays (nested PCR), with sensitivity and specificity of 100% and 89% respectively with some variability in performance.

The antigen detection methods offer the potential for diagnosis within hours and may be obtained reliably in the absence of a sophisticated virology laboratory. However, monitoring of test performance is critical for maintaining appropriate sensitivity and specificity. Specific tests for RSV may be indicated for therapeutic decision making (eg, withdrawal of unnecessary antibiotics), isolation of patients, and educating parents and staff about the nature of RSV disease.

Chest radiography

Chest radiography is frequently obtained in children with severe RSV infection. Typically, it reveals hyperinflated lung fields with a diffuse increase in interstitial markings. In 20-25% of cases, focal areas of atelectasis or pulmonary infiltrates are also noted. Generally, these findings are neither specific to RSV infection nor predictive of the course or outcome, except for the observation that infants who have the additional findings of atelectasis or pneumonia may have a more severe disease course.

Histologic findings

In infants who have died of RSV bronchiolitis, histologic study of lung tissue demonstrates mononuclear cell and neutrophil infiltration of the peribronchiolar areas, necrosis of the small airway epithelium, plugging of the lumens with exudate and edema, and atelectasis and hyperinflation.

Treatment & Management

Respiratory Syncytial Virus Infection (RSV): Trends and Surveillance. Centers for Disease Control and Prevention. Available at https://www.cdc.gov/rsv/research/us-surveillance.html. June 26, 2018; Accessed: February 14, 2019.
Bont L, Checchia PA, Fauroux B, Figueras-Aloy J, Manzoni P, Paes B, et al. Defining the Epidemiology and Burden of Severe Respiratory Syncytial Virus Infection Among Infants and Children in Western Countries. Infect Dis Ther. 2016 Sep. 5 (3):271-98. [QxMD MEDLINE Link].
American Academy of Pediatrics Committee on Infectious Diseases, American Academy of Pediatrics Bronchiolitis Guidelines Committee. Updated guidance for palivizumab prophylaxis among infants and young children at increased risk of hospitalization for respiratory syncytial virus infection. Pediatrics. 2014 Aug. 134 (2):415-20. [QxMD MEDLINE Link].
Perez-Yarza EG, Moreno A, Lazaro P, Mejias A, Ramilo O. The association between respiratory syncytial virus infection and the development of childhood asthma: a systematic review of the literature. Pediatr Infect Dis J. 2007 Aug. 26(8):733-9. [QxMD MEDLINE Link].
Welliver RC. Bronchiolitis and infectious asthma. Feigin RD, Cherry JD, Demmler-Harrison G J, Kaplan SLeds. Textbook of Pediatric Infectious Diseases. 6th edition. Philadelphia, PA: Saunders Elsevier; 2009. 277-288.
Oray-Schrom P, Phoenix C, St Martin D, Amoateng-Adjepong Y. Sepsis workup in febrile infants 0-90 days of age with respiratory syncytial virus infection. Pediatr Emerg Care. 2003 Oct. 19(5):314-9. [QxMD MEDLINE Link].
Falsey AR, Hennessey PA, Formica MA, Cox C, Walsh EE. Respiratory syncytial virus infection in elderly and high-risk adults. N Engl J Med. 2005 Apr 28. 352(17):1749-59. [QxMD MEDLINE Link].
Kong AM, Krilov LR, Fergie J, Goldstein M, Diakun D, Wade SW, et al. The 2014-2015 National Impact of the 2014 American Academy of Pediatrics Guidance for Respiratory Syncytial Virus Immunoprophylaxis on Preterm Infants Born in the United States. Am J Perinatol. 2018 Jan. 35 (2):192-200. [QxMD MEDLINE Link].
Anderson EJ, Krilov LR, DeVincenzo JP, Checchia PA, Halasa N, Simões EA, et al. SENTINEL1: An Observational Study of Respiratory Syncytial Virus Hospitalizations among U.S. Infants Born at 29 to 35 Weeks' Gestational Age Not Receiving Immunoprophylaxis. Am J Perinatol. 2017 Jan. 34 (1):51-61. [QxMD MEDLINE Link].
Olsen SJ, Winn AK, Budd AP, et al. Changes in Influenza and Other Respiratory Virus Activity During the COVID-19 Pandemic - United States, 2020-2021. MMWR Morb Mortal Wkly Rep. 2021 Jul 23. 70 (29):1013-9. [QxMD MEDLINE Link]. [Full Text].
Frellick M. RSV Kills 100,000 Kids Under Age 5 a Year Worldwide. Medscape Medical News. 2022 May 19. Available at https://www.medscape.com/viewarticle/974323.
Li Y, Wang X, Blau DM, et al. Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in children younger than 5 years in 2019: a systematic analysis. Lancet. 2022 May 28. 399 (10340):2047-64. [QxMD MEDLINE Link]. [Full Text].
Leader S, Kohlhase K. Recent trends in severe respiratory syncytial virus (RSV) among US infants, 1997 to 2000. J Pediatr. 2003 Nov. 143(5 Suppl):S127-32. [QxMD MEDLINE Link].
Thompson WW, Shay DK, Weintraub E, et al. Mortality associated with influenza and respiratory syncytial virus in the United States. JAMA. 2003 Jan 8. 289(2):179-86. [QxMD MEDLINE Link].
Hall CB, Weinberg GA, Iwane MK, Blumkin AK, Edwards KM, Staat MA. The burden of respiratory syncytial virus infection in young children. N Engl J Med. 2009 Feb 5. 360(6):588-98. [QxMD MEDLINE Link].
Paes B, Mitchell I, Li A, Lanctôt KL, CARESS Investigators. A comparative study of respiratory syncytial virus (RSV) prophylaxis in premature infants within the Canadian Registry of Palivizumab (CARESS). Eur J Clin Microbiol Infect Dis. 2012 Oct. 31 (10):2703-11. [QxMD MEDLINE Link].
Winterstein AG, Hampp C, Saidi A. Effectiveness of palivizumab prophylaxis in infants and children in Florida. Pharmacoepidemiol Drug Saf. 2012 Jan. 21(1):53-60. [QxMD MEDLINE Link].
Kitsantas P, Nirmalraj L. Effects of Respiratory Syncytial Virus Infection in Infancy on Asthma and Respiratory Allergy in 6-Year-Old Children. South Med J. 2018 Nov. 111 (11):698-702. [QxMD MEDLINE Link].
Yi H, Lanctôt KL, Bont L, et al. Respiratory syncytial virus prophylaxis in Down syndrome: a prospective cohort study. Pediatrics. 2014 Jun. 133 (6):1031-7. [QxMD MEDLINE Link].
Impact-RSV Study Group. Palivizumab, a humanized respiratory syncytial virus monoclonal antibody, reduces hospitalization from respiratory syncytial virus infection in high-risk infants. Pediatrics. 1998 Sep. 102(3 Pt 1):531-7. [QxMD MEDLINE Link].
Hall CB, Douglas RG Jr. Modes of transmission of respiratory syncytial virus. J Pediatr. 1981 Jul. 99(1):100-3. [QxMD MEDLINE Link].
Feltes TF, Cabalka AK, Meissner HC, et al. Palivizumab prophylaxis reduces hospitalization due to respiratory syncytialvirus in young children with hemodynamically significant congenital heart disease. J Pediatr. 2003 Oct. 143(4):532-40. [QxMD MEDLINE Link].
Kimberlin DW, Barnett ED, Lynfield R, Sawyer MH. Red Book 2021-2024: Report of the Committee on Infectious Diseases. 2021-2024.
[Guideline] American Academy of Pediatrics. Updated Guidance: Use of palivizumab prophylaxis to prevent hospitalization from severe respiratory syncytial virus infection during the 2022-2023 RSV season. Pediatrics. 2022 Nov 17. [Full Text].
AAP Issues Guidelines to Combat Rise in Respiratory Illness. Medscape Medical News. Available at https://www.medscape.com/viewarticle/984378. 2022 Nov 21; Accessed: November 21, 2022.
Rietveld E, Steyerberg EW, Polder JJ, et al. Passive immunisation against respiratory syncytial virus: a cost-effectiveness analysis. Arch Dis Child. 2010 Jul. 95(7):493-8. [QxMD MEDLINE Link].
Simoes EA, Groothuis JR, Carbonell-Estrany X, et al. Palivizumab prophylaxis, respiratory syncytial virus, and subsequent recurrent wheezing. J Pediatr. 2007 Jul. 151(1):34-42, 42.e1. [QxMD MEDLINE Link].
Carbonell-Estrany X, Simoes EA, Dagan R, et al. Motavizumab for prophylaxis of respiratory syncytial virus in high-risk children: a noninferiority trial. Pediatrics. 2010 Jan. 125(1):e35-51. [QxMD MEDLINE Link].
Gillespie L. EU Panel Backs New Drug for Infant Immunization of RSV. Medscape Medical News. 2022 Sep 16. Available at https://www.medscape.com/viewarticle/980967.
Hammitt LL, Dagan R, Yuan Y, et al. Nirsevimab for Prevention of RSV in Healthy Late-Preterm and Term Infants. N Engl J Med. 2022 Mar 3. 386 (9):837-46. [QxMD MEDLINE Link]. [Full Text].
Boyce TG, Mellen BG, Mitchel EF, et al. Rates of hospitalization for respiratory syncytial virus infection among children in medicaid. J Pediatr. 2000 Dec. 137(6):865-70. [QxMD MEDLINE Link].
Harding A. Spreading Out Palivizumab Shots Improves RSV Protection. Reuters Health Information. Available at http://www.medscape.com/viewarticle/840348. February 25, 2015; Accessed: June 26, 2015.
Belderbos ME, Houben ML, Wilbrink B, et al. Cord blood vitamin d deficiency is associated with respiratory syncytial virus bronchiolitis. Pediatrics. 2011 Jun. 127(6):e1513-20. [QxMD MEDLINE Link].
Hall CB, Dougla RG, Geiman JM, Messner MK. Nosocomial respiratory syncytial virus infections. N Engl J Med. 1975. 293:1343-6. [QxMD MEDLINE Link].
Gutfraind A, Galvani AP, Meyers LA. Efficacy and optimization of palivizumab injection regimens against respiratory syncytial virus infection. JAMA Pediatr. 2015 Apr. 169 (4):341-8. [QxMD MEDLINE Link].
Lavoie PM, Solimano A, Taylor R, Kwan E, Claydon J, Turvey SE, et al. Outcomes of Respiratory Syncytial Virus Immunoprophylaxis in Infants Using an Abbreviated Dosing Regimen of Palivizumab. JAMA Pediatr. 2016 Feb. 170 (2):174-6. [QxMD MEDLINE Link].

Media Gallery

Respiratory syncytial virus infection season, United States, by region and Florida. Image courtesy of Centers for Disease Control and Prevention.
Electron micrograph of respiratory syncytial virus (RSV). RSV is most common cause of bronchiolitis and pneumonia in children younger than 1 year. Image courtesy of Centers for Disease Control and Prevention.

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Author

Leonard R Krilov, MD Chief of Pediatric Infectious Diseases and International Adoption, Vice Chair, Department of Pediatrics, Winthrop University Hospital; Professor of Pediatrics, Stony Brook University School of Medicine

Leonard R Krilov, MD is a member of the following medical societies: American Academy of Pediatrics, American Pediatric Society, Infectious Diseases Society of America, Pediatric Infectious Diseases Society, Society for Pediatric Research

Disclosure: Nothing to disclose.

Coauthor(s)

Asif Noor, MD Assistant Professor of Pediatric Infectious Diseases, NYU Long Island School of Medicine

Asif Noor, MD is a member of the following medical societies: American Academy of Pediatrics, Pediatric Infectious Diseases Society

Disclosure: Nothing to disclose.

Chief Editor

Russell W Steele, MD Clinical Professor, Tulane University School of Medicine; Staff Physician, Ochsner Clinic Foundation

Russell W Steele, MD is a member of the following medical societies: American Academy of Pediatrics, American Association of Immunologists, American Pediatric Society, American Society for Microbiology, Infectious Diseases Society of America, Louisiana State Medical Society, Pediatric Infectious Diseases Society, Society for Pediatric Research, Southern Medical Association

Disclosure: Nothing to disclose.

Acknowledgements

Ashir Kumar, MD, MB Professor Emeritus, Department of Pediatrics and Human Development, Michigan State University College of Human Medicine

Ashir Kumar, MD, MB is a member of the following medical societies: American Association of Physicians of Indian Origin and Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Larry I Lutwick, MD Professor of Medicine, State University of New York Downstate Medical School; Director, Infectious Diseases, Veterans Affairs New York Harbor Health Care System, Brooklyn Campus

Larry I Lutwick, MD is a member of the following medical societies: American College of Physicians and Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.