A wide variety of viral infections – enteroviruses, herpesviruses, hepatitis infections – have been implicated in precipitating Chronic Fatigue Syndrome (CFS)/ME. Among the less common causes is parvovirus B19 – an infection which is of growing interest to researchers as it can produce complications which include anaemia (the virus can replicate in the bone marrow), nerve damage (peripheral neuropathy and encephalitis), and miscarriage.
Although parvovirus infection tends to affect small children (causing ‘slapped cheek syndrome’) it can also cause a febrile illness with a rash and widespread joint pains (especially in the small joints of the hands, knees, and ankles) in adults. And it’s something (along with certain other infections and lupus/SLE) which should always be considered in the differential diagnostic assessment of an adult with ME/CFS who starts their illness with this type of infective picture followed by persisting joint pains in addition to fatigue. Blood tests, which detect virus-specific IgG and IgM antibodies, can help to confirm the diagnosis of parvovirus B19.
Of equal importance is the fact that parvovirus B19-associated ME/CFS appears to respond to treatment. Using a form of immunological treatment known as intravenous immunoglobulin, doctors at London’s Brompton Hospital have recently reported on the cases of three ME/CFS patients with parvovirus B19 infection who improved significantly after this form of treatment (400 mg/kg/day).
There have also been several clinical trials reported involving the use of iv immunoglobulin in people with ME/CFS where no specific precipitating viral infection has been identified. However, the results have been conflicting and the role of iv immunoglobulin in treating non-parvovirus B19 ME/CFS remains the subject of debate.
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The doctors who treated the parvovirus B19 patients speculate that the treatment may work by helping to stabilize cytokine (immune system
chemicals) dysregulation which occurs in response to acute and ongoing infections. The recovered patients also had evidence of a considerably reduced viral load (i.e., clearance of their viraemia) after treatment.
Overall, these are interesting results which suggest that further assessment of immunoglobulin therapy in other sub-groups, where there is a clear post-infectious onset to ME/CFS, is warranted. This small but important study also emphasizes why I believe the MRC have got it so wrong when they conclude that research into causal factors (including the role of infection and the immunological response to infection) should not be given any high priority.
Source: Clinical Infectious Diseases, 2003,36,E100-106
NB: Other infections which can precipitate an arthralgia/joint pain and fatigue syndrome include brucellosis, leptospirosis, Lyme disease, and yersinia – some of which can be treated with drugs (ref: ‘Living with ME’, p41: ‘The post-infectious arthralgia and myalgia fatigue syndrome’).
Dr. Charles Shepherd