Influenza Virus Type A and Type B, Molecular Detection, PCR
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Rapid detection of influenza virus types A and B in upper respiratory tract specimens.
Real-Time Polymerase Chain Reaction (PCR)/RNA Probe Hybridization
(PCR is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Influenza A/B Virus PCR
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Specimen source is required.
Submit only 1 of the following specimens:
Nasopharyngeal Aspirate or Washing
Container/Tube: Sterile container
Specimen Volume: >1.5 mL
Nasopharyngeal Swab (Rayon Mini-Tip Swab) or Throat Swab
Container/Tube: Nasopharyngeal swab (rayon mini-tip swab) or throat swab
Specimen Volume: Swab
Additional Information: Swab may be placed in M5 media for transport.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Nasopharyngeal Aspirate or Washing: 0.5 mL
Calcium alginate-tipped swab, wood swab, or transport swab containing gel
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Influenza is usually a mild illness of the upper respiratory tract resulting in malaise and headache, followed by abrupt onset of fever, severe myalgia, and usually a nonproductive cough. Influenza virus infection can lead to more serious complications such as:
-Combined influenza and bacterial pneumonia
-Primary influenza virus pneumonia
-Severe complications in patients with pre-existing conditions such as rheumatic heart disease, bronchopulmonary disease, impaired renal function, and immunocompromised patients
-Serious illness during the first 2 years of life, with croup, bronchitis, and pneumonia
Type A viruses are typically associated with the most serious influenza epidemics, while type B viruses typically cause milder infections than type A.
The prevalence of influenza varies from year to year, with outbreaks typically occurring during the fall and winter months.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Negative for influenza A nucleic acid
If positive, reported as influenza A nucleic acid detected
Negative for influenza B nucleic acid
If positive, reported as influenza B nucleic acid detected
Positive results are diagnostic of influenza A or influenza B.
Negative results do not rule out infection with influenza virus.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Results will vary depending on socioeconomic status, age of population, geographic location, time of year, and specimen collection/handling.
The sensitivity of the assay is very dependent upon the quality of the specimen submitted.
The test is specific for influenza A and B; therefore, the results do not eliminate the possibility of infection with other respiratory viruses.
A negative test does not exclude infection with influenza A or influenza B virus. Therefore, the results obtained should be used in conjunction with clinical findings to make an accurate diagnosis.
This assay detects both viable and non-viable virus. Test performance depends on viral load in the specimen and may not correlate with cell culture performed on the same specimen.
Performance of the assay has not been established for monitoring antiviral treatment of influenza.
Use of transport media will result in dilution of samples, which may lower overall test sensitivity.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Pachucki CT: The diagnosis of influenza. Semin Resp Infect 1992;7:46-53
2. Wendt CH: Community respiratory viruses: organ transplant recipients. Am J Med 1997;102:31-36; 42-43
Method Description Describes how the test is performed and provides a method-specific reference
The LightCycler PCR has been optimized to detect common conserved sequences in the matrix genes of influenza virus type A and influenza virus type B. Viral nucleic acid is extracted by the MagNA Pure automated instrument (Roche Applied Science) from respiratory specimens. Primers directed to the matrix gene amplify a specific sequence of the virus. For the test, influenza virus type A and influenza virus type B genomic RNA is transcribed to cDNA. The LightCycler instrument (Roche Applied Science) amplifies and monitors the development of target nucleic acid sequences after the annealing step during PCR cycling by fluorescence assay. This automated PCR system can rapidly (about 1 hour) detect amplicon development through stringent air-controlled temperature cycling and capillary cuvettes. The detection of amplified products is based on the fluorescence resonance energy transfer (FRET) principle. For FRET product detection, a hybridization probe with a donor fluorophore, fluorescein, on the 3'-end is excited by an external light source and emits light that is absorbed by a second hybridization probe with an acceptor fluorophore, LC-Red 640, at the 5'-end. The acceptor fluorophore then emits a light of a different wavelength that can be measured with a signal that is proportional to the amount of specific PCR product. Analysis of the PCR amplification and probe melting curves is accomplished through the use of LightCycler software. (Cockerill FR III, Uhl JR: Applications and challenges of real-time PCR for the clinical microbiology laboratory. In Rapid Cycle Real-Time PCR Methods and Applications. Edited by U Reischel, C Wittwer, F Cockerill. Berlin, Germany, Springer-Verlag; 2002, pp 3-30)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Saturday
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Same day/1 day
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
87798 x 2
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|800167||Influenza A/B Virus PCR||48509-4|