Multiple sclerosis in the Orkney and Shetland Islands. II: The search for an exogenous aetiology.

Abstract

In Orkney and Shetland, a survey of lifetime events was undertaken in multiple sclerosis patients and 2 control groups to define shared exposure to an exogenous agent or environmental insult. Analyses of demographic factors, diet, social class and occupation, housing and environment, animal exposure, schooling, travel, infectious disease and medical history disclosed a remarkable similarity in responses between patients and controls for most questions. Differences were noted for sanitation, place of residence at onset and animal exposure. The data give additional support for an exogenous etiology of multiple sclerosis.