Flu Testing Changes

Date: 10/01/2018

Please read carefully the message below from Dr. Sarah Buss, Director, Clinical Microbiology regarding changes to Flu testing beginning October 1st

Beginning October 1st, Respiratory Virus PCR (RVPCR) will be utilized as the primary method for direct detection and discrimination of influenza A/B and RSV at ALI. RVPCR is performed on NP swabs received in UTM and results are typically available the same day that the sample is received in the laboratory.

The RVPCR only detects influenza A/B and RSV. If testing for other respiratory viruses is indicated, please order a respiratory virus culture (C RV) and note on the requisition which virus is suspected. A respiratory viral culture (C RV) includes testing for influenza A, influenza B, RSV, adenovirus, parainfluenza 1-3 and rhinovirus. Enterovirus culture is a separately orderable procedure. The turn-around-time for a C RV is 48-72 hours, and they are setup Monday through Saturday. Acceptable specimens for C RV include NP swabs +/- throat swabs, bronchial washes, or nasal washes. If you would like to order a C RV on a RVPCR negative sample, please do so within 3 days of sample collection.
Historically, the laboratory waited until culture results from our patient population demonstrated positivity for influenza or RSV before implementing RVPCR as the primary respiratory virus testing method. This typically led to a switch from culture to PCR in November. We have not yet identified influenza or RSV in viral cultures this season: adenovirus, rhinovirus and enterovirus have been the predominant viruses isolated. We will be making the shift from culture to PCR on October 1st this year because influenza has already been detected in the state, and we want to ensure that turnaround times for influenza and RSV testing meet our clients’ expectations. 

The differences in testing are highlighted in the chart below:
Orderable: Respiratory Virus PCR (RVPCR)    Respiratory Virus Culture (C RV)
Turn-Around-Time: Typically same day or within 24 hours         Preliminary result in 48-72 hours;
            Final report issued at 10 days
Tests Included: Influenza A                             Influenza A
  Influenza B                             Influenza B
  RSV                                  RSV
                            Parainfluenza 1
                            Parainfluenza 2
                            Parainfluenza 3
If you have any questions please contact the Clinical Microbiology department at 973-6980 or Dr. Sarah Buss at 973-6971.