A simple, rapid diagnostic test, the eosinophil count, which is done as part of routine complete of full blood cell count may help recognize COVID-19 in patients early enough.
Current coronavirus testing relies on a diagnostic test that uses nasopharyngeal swab PCR assay, which is often fraught with a high false-negative rate and a long turnaround time. Eosinophil count measures the amount of a type of white blood cell called eosinophil, which increase in levels in response to parasitic infections, allergies, and cancer. Scientists have found a pattern in patients with coronavirus revealing that the absence of these white blood cells or a persistently low count may suggest coronavirus infection, and may be associated with a poorer clinical outcome.
In the study, 60% of patients with COVID-19 had zero eosinophil count at presentation and a total of 88% had zero levels during hospitalization. The scientists say in areas where standard COVID-19 nasopharyngeal swab tests are unavailable, an eosinophil count test could identify who is likely to have and die of COVID-19.