tetano
Editor, Senior Moderator
J Clin Microbiol. 2014 Jul 23. pii: JCM.01523-14. [Epub ahead of print]
Detection of Respiratory Viruses in Sputum from Adults Using Automated Multiplex Polymerase Chain Reaction (PCR).
Branche AR1, Walsh EE2, Formica MA3, Falsey AR2.
Author information
Abstract
BACKGROUND:
Respiratory tract infections (RTI) frequently cause hospital admissions among adults. Diagnostic viral RT-PCR of nose and throat swabs (NTS) is useful for patient care by informing antiviral use and appropriate isolation. However, automated RT-PCR systems are not amenable to utilizing sputum due to its viscosity. We evaluated a simple method of processing sputum in a fully automated Respiratory Viral Panel RT-PCR assay (FilmArray).
METHODS:
Archived sputum and NTS samples collected 2008-2012 from hospitalized adults with RTI were evaluated. A subset of sputum samples positive for 10 common viruses by uniplex RT-PCR was selected. A sterile cotton tip swab was dunked in sputum, swirled in 700uL of sterile water (dunk and swirl method) and tested by FilmArray. Quantitative RT-PCR was performed on "dunked" sputum and NTS samples for Flu A, RSV, OC43 and HMPV.
RESULTS:
Virus was identified in 31% of 965 illnesses using uniplex RT-PCR. Sputum was the only sample positive for 105 subjects, including 35% (22/64) of influenza cases and significantly increased the diagnostic yield of NTS alone (302/965 [31%] vs. 197/965 [20%]; p=.0001). Of 108 sputum samples evaluated by FilmArray using the dunk and swirl method, 99 (92%) were positive. Quantitative RT-PCR revealed higher mean viral loads in dunked sputum compared to NTS samples for Flu A, RSV and HMPV (p=0.0001, p=0.006, p=0.011).
CONCLUSION:
The dunk and swirl method is a simple and practical method for reliably processing sputum in a fully automated PCR system. Higher viral loads in sputum may increase detection over NTS testing alone.
Copyright ? 2014, American Society for Microbiology. All Rights Reserved.
PMID:
25056335
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/25056335
Detection of Respiratory Viruses in Sputum from Adults Using Automated Multiplex Polymerase Chain Reaction (PCR).
Branche AR1, Walsh EE2, Formica MA3, Falsey AR2.
Author information
Abstract
BACKGROUND:
Respiratory tract infections (RTI) frequently cause hospital admissions among adults. Diagnostic viral RT-PCR of nose and throat swabs (NTS) is useful for patient care by informing antiviral use and appropriate isolation. However, automated RT-PCR systems are not amenable to utilizing sputum due to its viscosity. We evaluated a simple method of processing sputum in a fully automated Respiratory Viral Panel RT-PCR assay (FilmArray).
METHODS:
Archived sputum and NTS samples collected 2008-2012 from hospitalized adults with RTI were evaluated. A subset of sputum samples positive for 10 common viruses by uniplex RT-PCR was selected. A sterile cotton tip swab was dunked in sputum, swirled in 700uL of sterile water (dunk and swirl method) and tested by FilmArray. Quantitative RT-PCR was performed on "dunked" sputum and NTS samples for Flu A, RSV, OC43 and HMPV.
RESULTS:
Virus was identified in 31% of 965 illnesses using uniplex RT-PCR. Sputum was the only sample positive for 105 subjects, including 35% (22/64) of influenza cases and significantly increased the diagnostic yield of NTS alone (302/965 [31%] vs. 197/965 [20%]; p=.0001). Of 108 sputum samples evaluated by FilmArray using the dunk and swirl method, 99 (92%) were positive. Quantitative RT-PCR revealed higher mean viral loads in dunked sputum compared to NTS samples for Flu A, RSV and HMPV (p=0.0001, p=0.006, p=0.011).
CONCLUSION:
The dunk and swirl method is a simple and practical method for reliably processing sputum in a fully automated PCR system. Higher viral loads in sputum may increase detection over NTS testing alone.
Copyright ? 2014, American Society for Microbiology. All Rights Reserved.
PMID:
25056335
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/25056335