Poliomyelitis epidemic in the Netherlands, 1978

Some provisional data are given of the polio-epidemic in The Netherlands in 1978. Contrary to previous outbreaks, the present epidemic did not only affect areas with low vaccination acceptance rates, cases were also reported from many municipalities with acceptance rates of 90% and over. The epidemic caused by type 1 started mid-April 1978 in the centre of the country. Up to 1st November 110 cases were reported from a belt running from South-West (Zeeland) to North-East (Overijssel). Only one death occurred among the 80 paralyzed cases. The epidemic exclusively struck a population of some Protestant denominations which mostly reject vaccination on religious grounds. The majority of the cases belong to a population of about 66,000 individuals under the age of 27, who were not vaccinated on religious grounds. No case of polio, however, was found in about 384,000 individuals under the age of 27 who has not been vaccinated on other than religious grounds. No case of polio occurred in the vaccinated (inactivated poliovaccine) population. The exclusive spread of the epidemic in a poorly vaccinated but coherent population, whose members are thoroughy mixed in an extremely well vaccinated population (annual acceptance rate about 95%) is discussed.