ISOLATION OF EPIDEMIC POLIOVIRUS FROM SEWAGE DURING THE 1992-3 TYPE-3OUTBREAK IN THE NETHERLANDS

To examine the extent of wild poliovirus circulation during the 1992-3 epidemic in the Netherlands caused by poliovirus type 3, 269 samples from sewage pipelines at 120 locations were examined for the presence of poliovirus. The epidemic virus strain was found in 23 samples, all from locations inside the risk area which contained communities that r efuse vaccination for religious reasons. By sewage investigation, the wildtype virus was shown to be present in the early phase of the epide mic at two locations, one week before patients were reported from that area. The wild type 3 poliovirus was also detected retrospectively in a river water sample collected for other reasons three weeks before n otification of the first poliomyelitis case, at a site a few kilometre s upstream the home village of this patient. Oral poliovirus vaccine ( OPV) virus was found at 28 locations inside or at the border of the ri sk area. Trivalent OPV was offered to unvaccinated or incompletely-vac cinated persons living in this region as part of the measures to contr ol the epidemic.