'Clustering' of multiple sclerosis cases by date and place of birth.
G. A. Ashitey, Gilbert MacKenzie · Journal of Epidemiology & Community Health · 1970
IT has been suggested that a 'slow virus' may cause multiple sclerosis, and experiments on the possibility of transmitting the agent are continuing (Campbell, Norman, and Sandry, 1963; Dick, McAlister, McKeown, and Campbell, 1965; Field, 1966, 1968, 1969).Further, some circumstantial evidence sug- gests that the disease may be acquired in infancy even though the clinical manifestations appear much later (Millar, 1966; Dean, 1967; Kurtzke, 1968).These two suggestions could be combined into a single, simple, and testable hypothesis which, if true, should logically result in the 'clustering' (i.e.groups of cases closely associated in time and place) of cases by date and place of birth simultaneously.This paper reports the results of an investigation of the temporal-spatial distribution of multiple sclerosis in Northern Ireland.The statistical techniques used are basically those described by Ederer, Myers and Mantel (1964) and by David and Barton (1966).