By monitoring the sewage system in Heilongjiang province from 2013 to 2016, this study aimed to analyze the epidemiological tendency and genetic mutation of poliovirus (PV) found in the environment in order to setup a warning system for vaccine-derived poliovirus (VDPV) and the spread of wild poliovirus. In this study, we collected 139 sewage samples from 8 regions in Heilongjiang province. Poliovirus was identified from 72 samples, and the positivity rate was 51%. A total of 263 PV strains were isolated, including 22 strains of type 1 PV, 104 strains of type 2 PV, and 137 strains of type 3 PV. As a result of intratypic differentiation, using real-time PCR and nucleotide sequencing, 3 type 1 pre-VDPV, one type 2 VDPV, and 2 type 3 pre-VDPV strains were isolated. Interestingly, one type 1 strain with 5 nucleotide deletions and one type 3 recombinant on VP1 were isolated. By continuously monitoring the poliovirus in the environment, we aimed to recognize the VDPV or wild poliovirus with high neurovirulence from large-scale circulation and set up a warning system to avoid morbidity and virus transmission.
Keywords: Genetic Mutation; Poliovirus; VP1; monitoring.