Beginning in late October, the virology laboratory at St. Louis Children’s Hospital (SLCH) will be offering polymerase chain reaction (PCR) detection of influenza virus nucleic acid in respiratory specimens. PCR has been shown by numerous studies to be the most sensitive test available for the detection of influenza viruses; therefore, it is possible to have specimens that are negative for influenza by rapid influenza diagnostic tests (RIDTs), direct fluorescent antibody stain and/or culture, but positive by PCR. The test will initially be run once per day, Monday – Friday. Specimen cutoff is 10 p.m. for testing the following day.
The test is comprised of two PCR reactions that are run simultaneously. The first reaction is formulated to detect all strains of Influenza A and B viruses, including the 2009 H1N1 strain. The second reaction is specific for the detection of the 2009 swine H1N1 Influenza A virus.
Results of testing will include a result for each virus:
Influenza A virus: detected or not detected
Influenza B virus: detected or not detected
2009 swine H1N1 influenza A virus: detected or not detected
A result of Influenza A virus detected and 2009 swine H1N1 virus detected indicates the presence of 2009 swine H1N1 influenza A virus in the specimen. A result of Influenza A virus detected and 2009 swine H1N1 influenza A virus not detected indicates the presence of a seasonal H3N2, seasonal H1N1, or a new novel influenza A virus in the specimen. For questions regarding this test, contact the SLCH virology laboratory at 314.454.2036.