Post-viral fatigue syndrome. Epidemiology: lessons from the past

This chapter outlines the recorded epidemiological history of PVFS (including the early epidemics of myalgic encephalomyelitis) and the development of the concept, including the realisation that endemic cases also occur. Cases of PVFS are still not recorded by the Surveillance Centre for Communicable Diseases, so it is very difficult to detect and monitor any outbreak in the community, since each GP may only have two or three such patients and would, therefore, not be aware of an epidemic in the community as a whole if it occurred. Epidemiological issues raised by the early epidemics, including the delineation of the syndrome, the question of bias, the role of hysteria and the role of depression; the issue of symptom distribution, and its implications for aetiology; and a multiaxial framework for understanding the association with psychological symptoms are discussed. The value of a future multidisciplinary research programme designed to disentangle direct and predisposing causes of PVFS is emphasised.