Sept. 13, 2007 - A group of viruses known to cause respiratory and gut
infections may also be a major trigger for chronic
fatigue syndrome (CFS).
In a newly published study, four out of five CFS patients showed evidence of
chronic enterovirus infection in stomach tissue biopsies, compared with just
one in five healthy people.
Enteroviruses are very common,
second only to the common cold viruses as the most
common viral infections in humans, according to the CDC. Most people who are
infected with an enterovirus have no symptoms at all.
California infectious disease specialist John Chia, MD, says his findings
point to chronic infection with the virus as a possible cause of chronic fatigue syndrome in a large percentage of patients.
But a longtime CFS researcher says the complex disorder is not likely to be
so easily explained.
James Jones, MD, of the CDC’s chronic viral diseases branch, says despite
extensive research, no cause-and-effect relationship between an active
infectious agent and chronic fatigue syndrome has been established.
“This is an illness with a lot of different origins, and to assume that its
cause is due to an infection because the symptoms are similar to an infection
is a great leap,” Jones tells WebMD.
Early this summer, CDC researchers reported that the prevalence of chronic
fatigue syndrome may be between six and 10 times higher in the U.S. than
The major symptom of the disease is severe fatigue -- not relieved with rest
-- that persists for at least six months. But patients also often complain of
symptoms such as muscle and joint pain, memory and concentration problems,
depression, sleep problems, headaches, sore
lymph nodes, and/or gastrointestinal problems.
Chia, who practices medicine in Torrance, Calif., says he began researching
chronic fatigue syndrome soon after his son Andrew became sick with the
condition in 1997 at age 14.
“It took us a year to find out what he had,” he says.
Early efforts to find a cause for CFS focused on viruses. Jones was among
the first to suggest that chronic infection with the virus that causes
mononucleosis, the Epstein-Barr virus, might explain the disease.
But the failure to find persistent evidence of Epstein-Barr or any other
virus in the blood of CFS patients led most researchers, including Jones, to
look elsewhere for causes.
The lack of a diagnostic test for chronic fatigue syndrome also led many to
dismiss it as an imaginary disorder, but recent research by CDC and others have
proven that it is both real and common.
Other Conditions Lead to CFS
In previous research, Chia reported finding evidence of chronic infection in
the muscles of CFS patients.
In the new study, he looked for similar evidence in stomach tissue taken
from CFS patients who had the diagnostic procedure known as endoscopy, in which
a long tube with a camera is inserted via the mouth into the stomach and
biopsies of tissue are taken.