Abstract
The hypothesis that a virus might in some way be involved in the causation of type 1 diabetes has a long history, but decades of research have failed to resolve the issue beyond reasonable doubt. Viruses could potentially play a primary role in the pathogenesis of type 1 diabetes by initiating autoimmunity, a secondary role by promoting established immune responses, or a tertiary role by precipitating the onset of hyperglycaemia. There is currently little evidence to suggest that viruses play a primary role in the causation of type 1 diabetes, let alone a necessary or sufficient role. Secondary or tertiary roles remain possible, but have yet to be confirmed in prospective studies.