The WHO Poliovirus Eradication Programme has renewed interest in the identification of wild and vaccine strains of poliovirus circulating in the community. One method of monitoring these strains is to study poliovirus isolates detected in sewage. To facilitate the isolation of poliovirus from sewage and eliminate the possibility of detecting the other enteroviruses, sewage was inoculated onto a transfected Mouse L cell line. This cell line contains the gene for the poliovirus receptor which allows poliovirus infection to take place but not that of other enteroviruses. This cell line is, however, too sensitive to the toxic elements of concentrated sewage to be of practical use.
Polioviruses have also been isolated from river and seawater as part of three year surveys of sewage discharges into a river system and a coastal harbour. These isolates have been characterised using PCR amplification of a region of the VP1 gene followed by restriction fragment length polymorphism (RFLP) analysis. All isolates were vaccine-like although many poliovirus type 2 isolates had distinct PCR-RFLP profiles. The RFLP typing method is an efficient system for rapidly monitoring poliovirus isolates from the environment.