Postviral fatigue syndrome: persistence of enterovirus RNA in muscle and elevated creatine kinase.

Enterovirus-specific probes have been prepared by reverse transcription of conserved sequences in purified Coxsackie B2 virus genomic RNA and molecular cloning techniques. These probes were used in quantitative slot blot hybridizations to test for the presence of enterovirus-specific RNA in skeletal muscle biopsy specimens from 96 patients who had suffered from the postviral fatigue syndrome myalgic encephalomyelitis for up to 20 years. Biopsy specimens from 20 patients were positive for the presence of virus-specific RNA with hybridization signals more than three standard deviations greater than the mean of the normal muscle controls. Biopsies from the remaining 76 patients were indistinguishable from the controls. These data show that enterovirus RNA is present in skeletal muscle of some patients with postviral fatigue syndrome up to 20 years after onset of disease and suggest that a persistent virus infection has an aetiological role.