New Blood Test May Rapidly and Accurately Diagnose Flu
Aubrey Clark
September 21, 2010
The flu strikes 25-50 million individuals annually in the US and results in approximately 30,000-40,000 deaths each year. Distinguishing the flu from other viral infections that produce headache, muscle ache, and fever, can be tough, even for doctors. If a doctor can distinguish the flu from other viruses within 48 hours of showing symptoms, antivirals can be prescribed which will reduce the severity of the flu symptoms early on.
Rapid tests to diagnose influenza typically require a doctor to collect a specimen by swabbing the patient´s nasal passages or throat. While results can be provided in 30 minutes, these tests can miss 30% of patients who are positive for the illness. Moreover, the tests can also indicate a person has the flu when another virus is responsible for their symptoms. Scientists are on the lookout for fast, more accurate tests to distinguish the flu from other viruses.
A team led by Dr. Aimee Zaas, an infectious disease specialist at Duke University (Durham, NC) has reported that simply looking at a patient´s blood may allow health care professionals to quickly diagnose and treat patients with viral infections.
In her latest study, 57 healthy volunteers were exposed to either a live cold virus, respiratory syncytial virus or influenza A virus. The scientists then waited to see who got sick. Dr. Zaas and colleagues observed that the viruses caused a very, specific and unique immune response only in subjects who were ill. This immune response can be detected by looking at gene expression in a subject´s blood sample.
The team was able to identify 30 genes whose expression patterns differed only in these sick subjects. Scientists were able to document the distinct blood signatures for each virus in a database and compare the results to the blood samples of patients who were ill with influenza A. Using these genomic "signatures," they were accurately able to distinguish all patients who had influenza A from those who did not.
The genomic signature could even determine if the infection was viral or bacterial. This important because the symptoms of a cold or flu, which are caused by viruses, can be resemble a pneumonia, which is caused by bacteria.
To date, there is no rapid method for doctors to determine whether the infection is viral or bacterial; existing diagnostic tools take days to provide results. This new method can rapidly distinguish between a viral and bacterial infection. If a patient is suffering from a viral infection, they can receive antiviral therapy early on when it is of most benefit.
Moreover, the speed and accuracy of this new method may help in preventing the further development of resistant bacteria. Cautious health care professionals who are unsure of the cause of the infection may prescribe antibiotics just in cause. Antibiotics do not work for colds and other viral illnesses, and taking them for viral infections has helped create bacteria that are difficult to kill.
While not ready widespread commercial use just yet, this test is more accurate than traditional testing and performed using routine blood collection; the team at Duke is optimistic these results along with further studies may change the way infections are diagnosed. If you´re interested in helping to advance science in the detection and treatment of infectious diseases, there are a number of clinical trials regarding the study of the common cold, flu, or pneumonia which are actively recruiting.
Aubrey Clark is an editor and writer for PaidClinicalTrials.org, a registry of federally and privately supported paid clinical trials conducted in the United States and around the world.
Rapid tests to diagnose influenza typically require a doctor to collect a specimen by swabbing the patient´s nasal passages or throat. While results can be provided in 30 minutes, these tests can miss 30% of patients who are positive for the illness. Moreover, the tests can also indicate a person has the flu when another virus is responsible for their symptoms. Scientists are on the lookout for fast, more accurate tests to distinguish the flu from other viruses.
A team led by Dr. Aimee Zaas, an infectious disease specialist at Duke University (Durham, NC) has reported that simply looking at a patient´s blood may allow health care professionals to quickly diagnose and treat patients with viral infections.
In her latest study, 57 healthy volunteers were exposed to either a live cold virus, respiratory syncytial virus or influenza A virus. The scientists then waited to see who got sick. Dr. Zaas and colleagues observed that the viruses caused a very, specific and unique immune response only in subjects who were ill. This immune response can be detected by looking at gene expression in a subject´s blood sample.
The team was able to identify 30 genes whose expression patterns differed only in these sick subjects. Scientists were able to document the distinct blood signatures for each virus in a database and compare the results to the blood samples of patients who were ill with influenza A. Using these genomic "signatures," they were accurately able to distinguish all patients who had influenza A from those who did not.
The genomic signature could even determine if the infection was viral or bacterial. This important because the symptoms of a cold or flu, which are caused by viruses, can be resemble a pneumonia, which is caused by bacteria.
To date, there is no rapid method for doctors to determine whether the infection is viral or bacterial; existing diagnostic tools take days to provide results. This new method can rapidly distinguish between a viral and bacterial infection. If a patient is suffering from a viral infection, they can receive antiviral therapy early on when it is of most benefit.
Moreover, the speed and accuracy of this new method may help in preventing the further development of resistant bacteria. Cautious health care professionals who are unsure of the cause of the infection may prescribe antibiotics just in cause. Antibiotics do not work for colds and other viral illnesses, and taking them for viral infections has helped create bacteria that are difficult to kill.
While not ready widespread commercial use just yet, this test is more accurate than traditional testing and performed using routine blood collection; the team at Duke is optimistic these results along with further studies may change the way infections are diagnosed. If you´re interested in helping to advance science in the detection and treatment of infectious diseases, there are a number of clinical trials regarding the study of the common cold, flu, or pneumonia which are actively recruiting.
Aubrey Clark is an editor and writer for PaidClinicalTrials.org, a registry of federally and privately supported paid clinical trials conducted in the United States and around the world.
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