A new research shows that an infection changes the behavior of the patient's genes, and the host response differs depending on whether bacteria or a virus is doing the damage. The findings could help doctors distinguish between viral infection and bacterial infection. Thus, they are able to choose the proper treatment, such as antibiotics, antiviral drugs or just chicken soup and sleep.
In order to find the viral fingerprints, the researchers analyzed diverse datasets, including information about how human genes behaved after an infection of influenza, human rhinovirus and respiratory syncytial virus, or RSV. Finaly, they pinpointed a consistent viral calling card — a list of nearly 400 genes, each of which grew either more or less active during a viral attack. Many of those genes make proteins known to be involved in virus responses and inflammation. Secondly, they tested whether the behavior of these genes could distinguish viral infections from bacterial infections, or no infection at all.
By analyzing other separate datasets, the scientists discovered that the virus signature could predict whether a person was infected with a virus. Because the signature was consistent across a wide array of studies, the host response is very solid signature.
Further studies could tell whether the virus was flu. The behavior of just 11 genes served as a signature of flu, revealing whether a person was infected with influenza as opposed to other viruses. The researchers found that the viral signature showed up hours before symptoms appeared. The study even found an asymptomatic carrier — someone who didn't feel ill but was shedding virus.
The study provides clues about how well the flu vaccine worked. The body's response to vaccines was similar to the response to an actual flu infection: The behavior of the 11 genes reliably changed in both cases, a result that could allow doctors to track the effectiveness of the flu shot.
The researchers have found an interesting difference between men and women. In men, the influenza signature peaked in response to a flu vaccine the first day after the shot, while women's responses peaked three days later. Some vaccine studies have waited several days to look for an immune response, and concluded that men have weaker reactions. However, a simple difference in timing may explain those observations.
Before the new approach could be useful in clinics, it will need to be tested in a large prospective trial, one designed to capture changes in gene behavior in people over time.
CUSABIO aims to serve researchers in life science and healthcare. http://www.cusabio.com/
