DNA test for viral infections 'highly accurate'

Researchers in the USA have developed a blood test that relies on genetic
information from patients' immune systems to distinguish between viral and
bacterial infections.

The test looks for a genetic 'signature' of activity in 30 genes that
are turned on during a viral infection. Lead researcher Dr Aimee Zaas of Duke
University told Bloomberg Businessweek the test worked like a freeze-frame to
show 'what those genes are doing at the moment in time it's captured'.

A small preliminary study of the test
in a real world setting was published in Science Translational Medicine. Among
102 people arriving at a hospital's emergency department with fever, 28 had a
viral infection, 39 had a bacterial infection and 35 were healthy controls.

The test provided true positive
identifications of viral infection for 25 of the 28 cases, and correctly ruled
out the negative cases 94 percent of the time.

Although further evaluation of
the test would be necessary before it could be considered for widespread clinical
use, Dr Zaas said her team was 'very pleased that the assay could pick out
those with viral infection with a high degree of accuracy'.

Current methods of distinguishing the two types of
infection can take several days, whereas Duke University's DNA test delivers
results in only 12 hours. Quicker
diagnosis would enable doctors to prescribe suitable treatments faster to
patients and also help avoid unnecessary antibiotic use.

Antibiotics are often
used in a trial-and-error fashion or as first-line therapy when the nature of
the infection is unclear, despite this practice being increasingly discouraged.

And over-prescription
of antibiotics can have serious public health consequences, co-senior author, Dr
Chris Woods underlined: 'One of the big global threats at the moment is the
emergence of bacterial resistance, and that is largely driven by overuse of
antibiotics'.

'A tool that
enables us to accurately identify viral infections could curb the
indiscriminate use of antibiotics and reduce the development of resistant
pathogens'.