You are in: eMedicine Specialties > Pediatrics: General Medicine > Infectious Disease Human MetapneumovirusArticle Last Updated: May 21, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 10
  Author: Joseph Domachowske, MD, Associate Professor, Department of Pediatrics, Division of Infectious Diseases, State University of New York-Upstate Medical University Joseph Domachowske is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American Society for Microbiology, Infectious Diseases Society of America, Pediatric Infectious Diseases Society, and Phi Beta Kappa Editors: Itzhak Brook, MD, MSc, Professor, Department of Pediatrics, Georgetown University School of Medicine; Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc; Leslie L Barton, MD, Professor, Program Director, Department of Pediatrics, University of Arizona School of Medicine; Daniel Rauch, MD, FAAP, Director, Pediatric Hospitalist Program, Associate Professor, Department of Pediatrics, New York University School of Medicine; Russell W Steele, MD, Professor and Vice Chairman, Department of Pediatrics, Head, Division of Infectious Diseases, Louisiana State University Health Sciences Center Author and Editor Disclosure Synonyms and related keywords: human metapneumovirus, hMPV, common cold, bronchiolitis, respiratory failure, respiratory tract infection, respiratory syncytial virus, rhinorrhea, congestion, cough, dyspnea, tachypnea, wheezing, rales, RSV, human respiratory syncytial virus, human pneumovirus INTRODUCTIONSection 2 of 10
  BackgroundHuman metapneumovirus (hMPV) is a respiratory viral pathogen that causes a spectrum of illnesses that range from asymptomatic infection to severe bronchiolitis. In 2001, van den Hoogen et al described the identification of this new human viral pathogen from respiratory samples submitted for viral culture during the winter season.1 Half of the initial 28 hMPV isolates were cultured from patients younger than 1 year, and 96% were isolated from children younger than 6 years. Seroprevalence studies revealed that 25% of all children aged 6-12 months who were tested in the Netherlands had detectable antibodies to hMPV; by age 5 years, 100% of patients showed evidence of past infection. Separate reports from all areas of the world support the early contention that this newly discovered virus is ubiquitous, and, like human respiratory syncytial virus (RSV) infection, is seasonal in nature. PathophysiologyThe pathophysiology of hMPV infection is thought to be closely related to the other common human pneumovirus, RSV. Like RSV, hMPV has a tropism for the respiratory epithelium. The patient may be asymptomatic, or symptoms may range from mild upper respiratory tract symptoms to severe bronchiolitis and pneumonia. Viremia from hMPV infection has not yet been demonstrated, but a 2005 reported case of hMPV encephalitis with concurrent lung disease supports the possibility that the virus may (rarely) enter the bloodstream. FrequencyUnited StateshMPV infection is very common. Estimates suggest that this virus is the causative agent of infant bronchiolitis in 5-15% of cases. InternationalSeroprevalence studies revealed that 25% of all children aged 6-12 months who were tested in the Netherlands had detectable antibodies to hMPV; by age 5 years, 100% of patients showed evidence of past infection. In Australia, 3 of 200 (1.5%) randomly chosen respiratory samples with negative results for the presence of known respiratory pathogens had positive results for hMPV on culture, polymerase chain reaction, or both. RaceTo date, no racial predilection has been described. SexFemales accounted for 31% of the patients originally described to have hMPV infection. AgehMPV infection is prevalent during infancy and early childhood. By age 5 years, seroprevalence data suggest infection in all (or nearly all) individuals. Available demographic data are limited to the CLINICALSection 3 of 10
HistoryPatient history should focus on respiratory symptoms, such as rhinorrhea, congestion, cough, dyspnea, and tachypnea. PhysicalA complete physical examination may reveal rhinorrhea, congestion, cough, tachypnea, wheezing, or rales. A high fever with myalgias has been described in some patients. Respiratory failure may ensue, requiring mechanical ventilation. Causes
DIFFERENTIALSSection 4 of 10
Bronchiolitis Parainfluenza Virus Infections Respiratory Syncytial Virus Infection Rhinovirus Infection WORKUPSection 5 of 10
Lab Studies
Imaging StudiesChest radiography is appropriate in patients who present with symptoms of lower respiratory tract disease. Histologic FindingsCurrently, histologic findings are unknown. TREATMENTSection 6 of 10
Medical CareTreatment is supportive. Maintain hydration and provide supplemental oxygen if necessary. Supplemental oxygen may be required in patients with moderate-to-severe infection. In patients with respiratory failure, mechanical ventilation is necessary. Clinical trials of anti–human metapneumovirus (hMPV) monoclonal antibodies for the prevention of hMPV infection in high risk infants are planned but not yet open for enrollment. ConsultationsPatients with severe bronchiolitis or pneumonia may require admission to an intensive care unit. Consultation with a pediatric infectious disease specialist or pulmonologist may also be necessary. MEDICATIONSection 7 of 10
Drug therapy is not currently a treatment component. See Treatment. FOLLOW-UPSection 8 of 10
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Article Last Updated: May 21, 2007 |
