A new test can identify whether viral infections are causing a patient’s respiratory illness by measuring RNA or protein molecules in their cells, according to a new study.
Performed with a simple nasal swab, the test could prove to be a quicker, cheaper way to diagnose respiratory viral illnesses than current methods, researchers say.
“It’s a simpler test and more cost-effective for looking at viral infection,” says author Ellen Foxman, assistant professor of laboratory medicine at Yale University School of Medicine.
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, or indicators, of viral infection applicable to many different respiratory viruses, Foxman and coauthor Marie Landry first tested human nasal cells in the laboratory. With genetic sequencing techniques, they screened the cells for RNAs and proteins that increase when a virus is present.
Foxman and Landry identified three RNAs, and two proteins, that viruses “turn on.” They then investigated whether measuring the expression of the genes, or levels of the proteins, could predict the presence of a viral infection.
The researchers found that the RNAs and proteins are both accurate predictors of respiratory viral infection, which they confirmed by subsequent testing for common viruses. The RNAs predicted viral infection with 97% accuracy. The method also picked up viruses that are not identified by many current lab tests, they say.
“Instead of looking for individual viruses, our test asks the question: ‘Is the body fighting a virus?'” says Foxman. “We found we can answer that question very well.”
The researchers 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 researchers say.
The test could be particularly useful for assessing very sick patients or young children, they add, 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,” says Foxman. “The other reason is to make a decision about whether people who are not that sick should get antibiotics.”
The research team’s goal is to create a gene- or protein-based test available for general use within one to five years, Foxman says.
The researchers report their findings in the Journal of Infectious Diseases.
The National Institutes of Health, Biomedical Advanced Research and Development Authority, and the laboratory medicine department of Yale University provided funding for the study. Foxman and Landry have a patent pending.
Source: Yale University