Certain infections can trigger chronic fatigue syndromes (CFS) in a minority of people infected, but the reason is unknown. In a study in this week's issue of THE LANCET, Peter White and colleagues from St Bartholomews Hospital and the London School of Medicine, Queen Mary, University of London, UK, describe factors that predict or are associated with prolonged fatigue after glandular fever (infectious mononucleosis) and contrast these factors with those that predicted mood disorders after the same infection.
The investigators prospectively studied 250 primary-care patients with glandular fever or ordinary upper-respiratory-tract infections until 6 months after clinical onset. They sought predictors of both acute and chronic fatigue syndromes and mood disorders from clinical, laboratory, and psychosocial measures.
Patients who had glandular fever (diagnosed by a positive Monospot blood test) were twice as likely to experience fatigue syndrome six months later than patients with a negative Monospot. Patients with lower physical fitness measured two months after onset were more than twice as likely to have a fatigue syndrome four months later. Swelling of the lymph nodes in the neck (cervical lymphadenopathy) and initial bed-rest were associated with, or predicted, a fatigue syndrome up to 2 months after infection onset. By contrast, mood disorders were predicted by a premorbid psychiatric history, an emotional personality, and social adversity. Definitions of CFS that included concurrent mood disorders were predicted by a mixture of those factors that predicted either the fatigue syndrome or mood disorders.
Peter White comments: "The predictors of a CFS after an infection differ with how CFS is defined and when it is studied, depending particularly on whether the patient also has a mood disorder. The particular virus causing the infection and the body's immune reaction to it may play an early role, but physical deconditioning may also be important. By contrast, mood disorders are predicted by factors that predict mood disorders in general. More work is needed to understand how early post-infectious fatigue is caused by immune factors. This study also implies that CFS after infectious mononucleosis might be partially prevented or treated with an early and graded return to appropriate physical activity in order to prevent or treat physical deconditioning. It also suggests that "post-viral" mood disorders should be treated in the same way as any other mood disorder."
Contact: Dr Peter D White, Department of Psychiatry, St Bartholomews Hospital,William Harvey House,West Smithfield,London EC1A 7BE,UK;T) + 44 (0) 20 7601 8108;Mobile 07050 132328;F) + 44 (0) 20 7601 7969; E) email@example.com