Cold, Flu or Pneumonia? Answer May Lie in Blood Test
Gene signature detects differences in viral, bacterial infections, study finds
THURSDAY, Aug. 6, 2009 (HealthDay News) -- A genomic "signature" in blood appears able to identify people who've been exposed to common upper respiratory viruses, such as the cold or flu, even before symptoms develop.
In a study involving 60 healthy volunteers who were infected with either a live cold virus, respiratory syncytial virus or influenza A virus, the researchers identified changes in 30 genes that are activated as the body responds to infection.
The genomic signature is strong enough to reveal whether the infection is viral or bacterial and can identify who has a viral infection and who does not, according to the study.
The body's immune system responds quickly and in a specific way when exposed to a virus as opposed to bacteria, explained the study's lead author, Dr. Aimee Zaas, an infectious diseases specialist at Duke University in Durham, N.C.
"A detailed reading of that response, using gene expression data, reveals what type of pathogen the person is reacting to," Zaas explained in a news release from the university.
The study, in the August issue of Cell Host & Microbe, could lead to changes in the way doctors care for people who develop upper respiratory infections. Cold, flu and pneumonia symptoms are similar, and doctors can't confirm what a patient has without the results of laboratory tests, a process that can take days.
"Until results are in, treatment is a best guess. Knowing exactly which pathogen is involved is important because it affects the urgency of response and the type of treatment," senior author Dr. Geoffrey Ginsburg, director of Duke's Center for Genomic Medicine, said in the news release.
"This [new] approach could lead to more precise, informed and tailored therapy -- essentially, personalized care for infectious disease," he said. "That's better for the patient and better for public health in general."
The U.S. Centers for Disease Control and Prevention has more about influenza and other respiratory viruses.