West Michigan influenza infections peaked mid-March 2022 and have been declining in the weeks that followed. Now with a low prevalence of circulating influenza, using the most sensitive diagnostic test is recommended in order to obtain accurate and actionable results. Influenza antigen testing (e.g. Sofia instrument) is no longer appropriate at this time and Influenza PCR testing should be ordered when clinically indicated.
More detailed information can be found as published by the CDC:
Algorithm to assist in the interpretation of influenza testing results and clinical decision-making during periods when influenza viruses are NOT circulating in the community, and in previous lab newsletters: Influenza Diagnosis and Test Utilization
To provide efficient and safe testing for patient specimens, please review the following information when sending COVID-19 PCR and Influenza A/B PCR testing in the same encounter to Spectrum Health Laboratories.
Two labels will be available for this testing. Labels must be fixed so that
• The test and patient information are shown
• The barcode may be easily scanned by Lab staff or instruments
When this is not done correctly, Laboratory staff removes the labels and re-fixes or re-prints it, which obstructs workflow, causes delays, and could result in patient information being peeled off. With patient safety and efficient testing being two of the Lab’s top priorities, it is vital that specimens arrive in such a way as to best accomplish both.
The mitigation strategies enacted during the COVID-19 pandemic to reduce the spread of this virus led to essentially non-existent influenza prevalence during the 2020-2021 winter season. However, influenza has now returned and case numbers are increasing throughout West Michigan.
Influenza prevalence guides the most appropriate testing approach and sufficient prevalence has now been reached for influenza rapid antigen testing (e.g. Sofia instrument) to have improved performance. The use of rapid antigen testing as a screening method during high prevalence reduces both the cost to the patient and turn-around-time as compared to lab-based molecular methods. Rapid antigen tests generally have high analytical specificity, but lack the sensitivity of nucleic acid amplification methods (e.g. PCR). For this reason, PCR testing is still recommended for hospitalized patients and for outpatients with a negative antigen result if influenza is still suspected and if the result will impact clinical decision making.
Spectrum Health Lab has noticed an increase in outpatient orders for Respiratory Pathogens by Film Array [LAB3359]. This may be due to a shortage of supplies for some Point of Care (POC) testing platforms. Film Array is typically used for emergency and high acuity patients and therefore has a high cost that may not be covered by most patients’ insurance. To lesson out of pocket costs for your patients, please order the below for RSV, COVID, or Flu testing.
The mitigation strategies enacted during the COVID-19 pandemic to reduce the spread of this virus have also impacted the transmission of other respiratory viruses. Influenza is typically prevalent during the winter months (December through March), however, influenza cases were essentially non-existent during the 2020-2021 season and influenza is not currently circulating in our community.
In the absence of circulating influenza activity, it is recommended to use the most sensitive diagnostic test in order to obtain accurate and actionable results. Influenza antigen testing (e.g. Sofia instrument) is not appropriate at this time. More detailed information can be found as published by the CDC: Algorithm to assist in the interpretation of influenza testing results and clinical decision-making during periods when influenza viruses are NOT circulating in the community
At this time when Influenza prevalence is not widespread in the community, please order “Influenza A/B PCR” [LAB3255] when testing is needed. This applies to patients at all Grand Rapids and regional hospitals, and also system wide ambulatory patients.
Influenza is currently widespread throughout the nation at epidemic proportions. During influenza epidemics, clinical assessment predicts the presence of influenza infection virtually as well as laboratory testing. Therefore, it is no longer necessary to perform viral testing on ambulatory patients who present with illness consistent with influenza before beginning antiviral treatment. Antiviral treatment for Influenza should be started as soon as possible to have a beneficial effect.
Shortages of supplies and medications frequently occur during Influenza epidemics. However, diagnosis of specific viral respiratory infection remains important for hospitalized patients.
Please follow the current recommendations:
- Limit availability of viral transport media at ambulatory sites.
- Emergency departments are to limit viral respiratory testing to patients expected to be admitted.
- Do not perform testing for test of cure.
Thank you for your support during this time. Please direct any questions to Laboratory Services via the “contact us” link above.