Epidemiological survey of case caused by highly variant vaccine derived poliovirus in Beijing

Objective To understand the epidemiological characteristics of a case caused by highly variant vaccine-derived poliovirus in Beijing. Methods The case survey, virus excretion monitoring and transmission risk assessment were conducted and the case was isolated according to Survey guideline of high risk and clustering AFP cases. Results In July 2010,polio virus was isolated from a AFP case from Jiangxi province to Beijing for medical care seeking, the isolate was identified as highly variant vaccine derived poliovirus type Ⅲ by nucleotide sequencing in state polio laboratory. The case had received irregular 1 dose OPV immunization. Conclusion The case was finally diagnosed with vaccine-associated paralytic poliomyelitis (VAPP) and no further transmission occurred due to strict prevention and control measures.