Epidemiological implications of the isolations and intratypic serodifferentiation of poliovirus strains in the Netherlands.

From the results of virus isolation and serological studies it can be concluded that poliovirus does not occur endemically in the Netherlands. On the other hand continual importation of poliovirus is demonstrated among children of foreign workers, refugees and adoptive children. A certain part of these imported poliovirus strains appear to be wild type as shown by intratypic serodifferentiation with monospecific antisera. These strains are a continuous danger to non-immunized persons lacking neutralizing antibodies. The intratypic serodifferentiation with monospecific antisera also appears to be applicable for the differentiation of wild poliovirus strains and may therefore be a useful tool in epidemiological studies.