[An epidemiologic survey of multiple sclerosis in the Szczecin province in Poland].

The possibility of a focus of the province of Szczecin (Northwestern part of Poland) was first noticed in our survey covering the period of 1960-86. Starting from 1986 the incidence of MS in this region was closely followed. Seven communes with an area of 1202 km2 and 45,231 inhabitants, had 50 MS patients on Dec. 31st, 1995 and a prevalence rate of 110,54/100,000. This is twice the prevalence more than in surrounding area (52,89/100,000). New cases appeared irregularly, with four peaks in 1960, 1967-8, 1976-7 and 1981-2. The age at onset, duration of disease, life expectancy and natural history of the disease in the focus and rest of Szczecin region were similar. We conclude, that clustering seems to be due to the influence of environmental factors, such as peat soil, coniferous forest, quality of drinking water and nearby industrial plants.