This winter, West Michigan influenza infections peaked in December 2022 and significantly declined throughout February and March 2023. 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.
Test Utilization
Inform: RSV Testing – Age Restrictions
Respiratory syncytial virus (RSV) primarily infects pediatric patients, but occasionally infects adults and may be of particular concern for the elderly and immunocompromised. Corewell Health Laboratories offers two tests for RSV. A rapid antigen test may be used to confirm RSV diagnosis in pediatric patients. This test is not approved by the FDA for testing adult patients, so tests will be cancelled if ordered on an off-label age group. There are no age restrictions for RSV testing by way of a molecular panel that also includes COVID and influenza as viruses with overlapping symptoms.
Test name | Epic Test ID | Methodology | Specimen | Age restriction |
RSV Rapid | LAB495 | Antigen | Nasopharyngeal (NP) swab | Approved for patients 0 – 18 years of age |
COVID, Influenza, RSV PCR | LAB1230746 | Molecular/PCR | Nasopharyngeal (NP) swab | No age restriction |
Influenza cases numbers are currently 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.
The Enteric Pathogens PCR test performed by Spectrum Health Laboratory may be used to detect common pathogenic bacteria and viruses in stool collected from individuals with symptoms of gastrointestinal infection. Specifically, this test detects Campylobacter, Salmonella, Shigella, Vibrio, Yersinia enterocolitica, Norovirus, Rotavirus, and the Shiga toxin virulence factor. Effective August 17, 2022, Spectrum Health’s Epic EMR will contain new ask-at-order questions to help improve the clinical decision support and appropriate utilization of this testing.
Specimen Collection and Test Updates – June 2022
The following information was updated in the Lab Catalog.
Specimen Collection and Test Updates – April 2022
The following information was updated in the Lab Catalog.
Discontinuation of Placenta Microbiology Cultures
As of April 12, 2022, Spectrum Health Laboratory will no longer add microbiology cultures to placental tissues received based on paper requisition forms.
Viral and bacterial cultures from placental tissue are rarely clinically beneficial and are no longer the gold standard diagnostic approach due to the relative insensitivity of culture methods.
If viral studies are desired (possible indications could include known CMV exposure with positive IgM or intrauterine fetal demise at < 28 weeks), then molecular testing is the recommended diagnostic approach. HSV and CMV PCR tests may be ordered in Epic.
• Herpes Simplex 1/2 Qualitative PCR, Tissue (LAB1230413)
• Cytomegalovirus (CMV) Qualitative PCR, Tissue (LAB1230291)
Bacterial cultures are challenging to interpret since they typically grow normal genital flora and histopathological analysis used to diagnose acute chorioamnionitis correlates poorly with growth from bacterial placenta cultures. If indicated, culture and PCR tests may be ordered in Epic.
• Metamycoplasma hominis, Molecular Detection, PCR, Varies (LAB848)
• Ureaplasma species, Molecular Detection, PCR, Varies (LAB848)
Placenta tissues sent to the lab in formalin are not acceptable for PCR or culture orders.
Specimen Collection and Test Updates – March 2022
The following information was updated in the Lab Catalog.
Specimen Collection and Test Updates – February 2022
The following information was updated in the Lab Catalog.