Blog
Testing for multiple Respiratory Viruses
- By: Maureen Carland
- On: 07/21/2026 07:34:15
- In: Infection Control
A frequent question I get during respiratory virus season is: "Should I test for multiple viruses at once (parallel testing) or test one virus first and only test further if the first result is negative (series testing)?" A new JAMA Internal Medicine randomized trial and accompanying editorial help answer that question for long-term care.
The study found that nursing homes using point-of-care multiplex PCR (testing simultaneously for COVID-19, influenza, and RSV) did not reduce the number of outbreaks, but they did identify more cases earlier, started influenza antivirals sooner, and reduced hospital transfers by about 11% (4 fewer ED transfers per 100 beds each respiratory season). Importantly, facilities with multiplex PCR tested residents with mild or atypical symptoms more readily because they could quickly rule in or rule out multiple respiratory viruses with one test.
So how would I use this information to direct my testing strategy?
If I know that one virus is overwhelmingly circulating in our community (for example, influenza activity is very high while COVID-19 and RSV activity are low), testing in series may be a reasonable and cost-effective approach. However, one must keep in mind the false-negative rate of the test you are using. Rapid antigen tests, particularly for influenza, have ok but not great sensitivity. A negative result should not be used to rule out infection in a resident with compatible symptoms. If clinical suspicion remains high, continue appropriate transmission-based precautions and obtain PCR testing when available.
When multiple respiratory viruses are circulating simultaneously or when rapid diagnosis will change treatment or infection prevention decisions, parallel testing with a multiplex PCR would be the preferred strategy. The evidence suggests that earlier, more accurate diagnosis helps make better clinical decisions for anti-viral treatment and avoid unnecessary hospital transfers.
Staff contact: mcarland[at]mehca.org