Epidemiological survey of a case caused by highly variant vaccine-derived poliovirus in Hubei

Objective To understand the epidemiological characteristics of a case caused by highly variant vaccine derived poliovirus in Hanchuan, Hubei province, in May 2013. Methods The case survey, virus excretion monitoring, laboratory examination and transmission risk assessment were conducted and the case was isolated and followed up. Results The isolate from the case was identified as highly variant vaccine-derived poliovirus type Ⅲ(8nt, 0.88%) by nucleotide sequencing in provincial and national polio laboratory, respectively. The case had received irregular 2 dose oral polio vaccine (OPV) immunization. Conclusion The case was finally diagnosed with non-acute flaccid paralysis (AFP) and no further transmission occurred due to strict prevention and control measures, including active search for AFP cases and supplementary immunization of OPV among the local children.