Stomach Virus Associated with Chronic Fatigue Syndrome

LOMITA, Calif., Sept. 14 -- Enterovirus, a common pathogen that can cause acute respiratory or gastrointestinal infections, may be a factor in chronic fatigue syndrome, according to researchers here.

Eighty-two percent of stomach biopsy samples from 165 chronic fatigue syndrome (CFS) patients tested positive for enterovirus infection versus 7% of samples from controls (P<0.001), John K.S. Chia, M.D., and Andrew Chia, of EV Med Research, reported in the Journal of Clinical Pathology.

"Finding enterovirus [viral capsid protein 1] protein in 82% of stomach biopsy samples seems to correlate with the high percentage of CFS patients with GI complaints," Dr. Chia wrote.

Moreover there was evidence that enterovirus infection was chronic in a subset of CFS patients. In paired biopsies obtained from six patients -- the initial biopsies were done at the time of initial GI infection and the follow-up biopsies were done two to eight years later as GI symptoms persisted -- results of viral staining were the same, he wrote.

Those paired biopsies provided evidence of a "strong association between enteroviral infection persistence/infection and CFS."

The 165 patients all had gastrointestinal complaints as part of their CFS presentation. All patients underwent upper GI endoscopies and antrum biopsies. Immunoperoxidase staining was performed using enterovirus-specific monoclonal antibody or a control monoclonal antibody specific for cytomegalovirus. Samples were compared with stomach samples from 22 normal volunteers.

There was no evidence of cytomegalovirus infection in patients or controls.

• There was microscopic evidence of mild chronic inflammation in 157 of the 165 specimens from CFS patients.
• Eight of 165 specimens showed presence of H. pylori.
• 27% of patients with 2+ staining for enterovirus were able to work in a sedentary job for six to eight hours a day versus 54% of patients who had 1+ staining (P=0.016).
• Enterovirus RNA was detected in 37% of paraffin-embedded samples from CFS patients versus 0.05% of paraffin-embedded samples from controls (P<0.01).

Published studies have linked persistent enterovirus infections with "chronic myocarditis, type 1 diabetes, and neuromuscular diseases" but the authors wrote that "the concept of enteroviral persistence remains controversial."

Nonetheless, they concluded that if their findings are confirmed "stomach biopsies could be used as a test to document viral persistence, and serve as an objective means to follow the response to antiviral therapy, in addition to quantitation of subjective complaints."