• Open Access

Multiple versus single virus respiratory infections: viral load and clinical disease severity in hospitalized children

Authors

  • Emily T. Martin,

    1. Department of Pharmacy Practice, Wayne State University, Detroit, MI, USA.
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  • Jane Kuypers,

    1. Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
    2. Department of Laboratory Medicine, University of Washington, Seattle, WA, USA.
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  • Anna Wald,

    1. Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
    2. Department of Laboratory Medicine, University of Washington, Seattle, WA, USA.
    3. Department of Epidemiology, University of Washington, Seattle, WA, USA.
    4. Department of Medicine, University of Washington, Seattle, WA, USA.
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  • Janet A. Englund

    1. Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
    2. Department of Pediatrics, University of Washington, Seattle, WA, USA.
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Emily T. Martin, MPH, PhD, Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences, 259 Mack Ave, Detroit, MI 48201, USA. E-mail: etmartin@wayne.edu

Abstract

Please cite this paper as: Martin et al. (2012) Multiple versus single virus respiratory infections: viral load and clinical disease severity in hospitalized children. Influenza and Other Respiratory Viruses 6(1), 71–77.

Background  Molecular testing for viral pathogens has resulted in increasing detection of multiple viruses in respiratory secretions of ill children. The clinical impact of multiple virus infections on clinical presentation and outcome is unclear.

Objectives  To compare clinical characteristics and viral load between children with multiple virus versus single virus illnesses.

Patients/methods  Eight hundred and ninety-three residual nasal wash samples from children treated for respiratory illness at Children’s Hospital, Seattle, from September 2003 to September 2004 were evaluated by quantitative PCR for respiratory syncytial virus (RSV), human metapneumovirus (hMPV), influenza (Flu), parainfluenza, adenoviruses, and coronaviruses (CoV). Illness severity and patient characteristics were abstracted from medical charts.

Results  Coinfections were identified in 103 (18%) of 566 virus-positive samples. Adenovirus was most commonly detected in coinfections (52%), followed by CoV (50%). Illnesses with a single virus had increased risk of oxygen requirement (P = 0·02), extended hospital stays (P = 0·002), and admissions to the inpatient (P = 0·02) or intensive care units (P = 0·04). For Adv and PIV-1, multiple virus illnesses had a significantly lower viral load (log10 copies/ml) than single virus illnesses (4·2 versus 5·6, P = 0·007 and 4·2 versus 6·9, P < 0·001, respectively). RSV, Flu-A, PIV-3, and hMPV viral loads were consistently high whether or not another virus was detected.

Conclusions  Illnesses with multiple virus detections were correlated with less severe disease. The relationship between viral load and multiple virus infections was virus specific, and this may serve as a way to differentiate viruses in multiple virus infections.

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