Monitoring of Polio Vaccine Virus Strains in Hebei Province in 2008

Objective To study the surveillance indicators in polio laboratory of Hebei Province,and to monitor vaccine-derived poliovirus(VDPV) or wild-type poliovirus in time.Methods According to WHO's standard method to isolate virus,then the neutralization test and intratypic differentiation test were carried out to all polioviruses isolated using PCR-RFLP methods.Results All the surveillance indicators in polio laboratory of Hebei met the requirements of WHO and MOH.24 strains of polioviruses were isolated from 407 AFP cases,and the isolation rate was 5.90%.The 39 strains of single serotype PVs were performed VP1 sequencing,and no VDPV or wild-type poliovirus was found.Conclusions Polio-free status was maintained in 2008 in Hebei Province.The laboratory surveillance system was sensitive and laboratory data were provided for maintaining the polio-free status in Hebei Province.