IX. Isolation of Enteroviruses from Sewage Before and After Vaccine Administration **

In conjunction with the city-wide program of oral vaccination conducted during the early months of 1961 in Middletown, Connecticut, tests were carried out on serial samples of sewage from various strategic points in the city as a means of virological surveillance. Objectives were: a) to determine the relative prevalence of polioviruses and other enteroviruses in the city sewage prior to, during, and subsequent to the vaccination campaign; b) to continue attempts to isolate enteroviruses from sewage for at least one year in an effort to determine how long the attenuated poliovirus vaccine strains might persist in sewers servicing communities of different sizes.