Chronic fatigue linked with enterovirus infection

NEW YORK, Sep 22 (Reuters) Some patients with chronic fatigue syndrome appear to have a chronic enteroviral infection that can be detected by a stomach biopsy, according to a report in the current Online First issue of the Journal of Clinical Pathology.

''Enteroviruses are acid and bile resistant and are believed to be common causes of acute gastritis,'' the authors note.

''Most patients with chronic fatigue syndrome have persistent or intermittent, upper and/or lower gastrointestinal symptoms.'' This led Dr John K Chia and Dr. Andrew Y. Chia from Enteroviral Medical Research in Lomita, California, to look for enterovirus in the stomach biopsy specimens of 165 consecutive patients with chronic fatigue syndrome.

They found that 82 per cent of these stomach biopsy specimens tested positive for enterovirus compared with only 20 percent of stomach biopsy specimens from subjects who didn't have the syndrome (controls).

Biopsies were performed on six patients when the symptoms of chronic fatigue syndrome and/or abdominal symptoms first began, and again 2 to 8 years later. The paired specimens for all of the patients tested positive for enterovirus, the authors report.

In addition, enterovirus RNA was detected in 9 of 24 (37 percent) of the samples from patients, but in only 1 of 21 of the control samples. One of three patients had enterovirus RNA detected in two samples taken 4 years apart and samples from 5 patients could be grown in the laboratory.

This study shows that a significant group of chronic fatigue syndrome patients may have a chronic, disseminated, enteroviral infection that can be diagnosed by stomach biopsy, Chia and Chia conclude. Moreover, the study findings suggest a strong association between enteroviral infection and chronic fatigue syndrome.

However, the study could not confirm that enterovirus infection causes chronic fatigue syndrome, and it is possible that this infection is triggered by another undefined mechanism, which is responsible for the syndrome, they note.

In previous studies, patients' symptoms improved after antiviral therapy, the researchers note, which suggests that ''active, persistent viral infection is still of paramount importance.'' The primary feature of chronic fatigue syndrome is severe, incapacitating fatigue that isn't improved by bed rest. In 1994 research experts in chronic fatigue syndrome drafted a definition of the condition that would be useful to researchers and doctors who see patients, according to the US Centers of Disease Control and Prevention.

A diagnosis can be made if a patient has had severe fatigue for 6 months or longer, and other medical conditions have been excluded. The patient must also have four or more of the following symptoms: impairment in short-term memory or concentration; sore throat; tender lymph nodes; muscle pain; multiple joint pain without swelling or redness; headaches; unrefreshing sleep; and malaise after physical exertion.

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