According to a study published in the Journal of Infectious Diseases, a new test that measures mRNAs or proteins in human nasal epithelial cells could prove to be a quicker way to diagnose respiratory viral infections than current methods.

This transmission electron microscopic image depicts the ultrastructural details of an influenza virus particle. Image credit: Erskine L. Palmer & M.L. Martin / CDC.

This transmission electron microscopic image depicts the ultrastructural details of an influenza virus particle. Image credit: Erskine L. Palmer & M.L. Martin / CDC.

Upper respiratory illnesses are common, yet there is no rapid diagnostic test to confirm more than a handful of common viruses as the cause.

To identify biomarkers of viral infection applicable to many different respiratory viruses, Yale University researchers Dr. Ellen Foxman and Dr. Marie Landry tested human nasal cells in the laboratory.

With genetic sequencing techniques, the researchers screened the cells for mRNAs and proteins that increase when a virus is present.

They identified three mRNAs (CXCL10, IFIT2, and OASL) and two proteins (CXCL11 or CXCL10) that are ‘turned on’ by a virus.

They then investigated whether measuring the expression of the genes, or levels of the proteins, could predict the presence of a viral infection.

The team found that the mRNAs and proteins were both accurate predictors of respiratory viral infection, confirmed by subsequent testing for common viruses.

The mRNAs predicted viral infection with 97% accuracy.

“Our method also picked up viruses that are not identified by many current lab tests,” the authors noted.

“Instead of looking for individual viruses, our test asks the question: ‘Is the body fighting a virus?’” Dr. Foxman said.

“We found we can answer that question very well.”

The scientists hope to develop the method into a rapid gene or protein test that doctors could perform in their offices.

Such a test could help providers diagnose a viral infection more quickly and accurately than with routine evaluation or more time-consuming and expensive tests.

The test could be particularly useful for assessing very sick patients or young children and it could also help reduce the misuse of antibiotics to treat viral infections.

“One reason to test is to know why the patient is sick. The other reason is to make a decision about whether people who are not that sick should get antibiotics,” Dr. Foxman said.

“Our goal is to create a gene- or protein-based test available for general use within one to five years.”