The effect of a mass poliomyelitis vaccination program on the occurrence of enteroviruses in seawater.

A mass poliomyelitis immunization program undertaken in a coastal city correlated with a significant increase in the levels of vaccinal-type strains of poliovirus recovered in the surrounding seawater. These vaccinal strains were detected together with other wild strains regularly isolated that did not exceed the levels usually detected. The need for a serious monitoring of uncontrolled sewage discharges into the sea is discussed.