[Historical geographical epidemiology of poliomyelitis]

Poliomyelitis was considered a rare disease before it terrified Europe and North America with large-scale epidemics during the first half of the 20th century. In Africa and Asia the number of reported cases increased remarkably only after World War II. A theory which is widely accepted today assumes that infection with poliovirus 1, 2 and 3 has always been globally endemic, but that the proportion of cases with residual paralysis has increased only since 1900 as a consequence of the rise of the mean age at infection. Sabin, however, initially was convinced that virus strains with enhanced neurotropism had caused the dramatic increase in paralytic poliomyelitis. Epidemic outbreaks in anglo-american troops in Malta and in the Far East during the war played a crucial role in the discussion. Later, also Sabin sustained the theory mentioned first, which gradually assumed the position of a dogma. The present paper deals with the question of how this dogma became dominant, in spite of the weakness of its epidemiological and virological foundation.