Laboratory Surveillance of Acute Flaccid Paralysis in Hebei Province

Objective To study the surveillance indicators in polio laboratory of Hebei,so as to surveillance VDPV or wild-type poliovirus in time.Methods According to WHO's normal method to isolate virus by L20B,RD and Hep-2 cells,and then the neutralization test,intratypic differentiation test were carried out to all poliovirus isolated using PCR-RFLP and ELISA methods.Results All the surveillance indicators in polio laboratory of Hebei met the requirements of WHO and MOH.There were 1 199 stool samples collected in 2003-2005. 86 polioviruses were isolated from AFP cases,and 115 of non-polio enteroviruses(NPEV) were also isolated from AFP cases.Among 100 positive isolates,12 of type 1 vaccine-like viruses,29 of type 2 vaccine-like viruses,23 of type 3 vaccine-like viruses,23 of mixed viruses,8 of vaccine-like viruses mixed with enteroviruses,and 5 of mutant viruses were identified by PCR-RFLP method.Then ELISA test was conducted according to WHO manual,and among total 138 single serotype viruses,132(95.7%) of sabin-like viruses(SL),5(3.8%) of double reaction viruses(DRV),1(0.7%) of non-sobilike viruses(NSL) were identified.Conclusion No wild polioviruses or VDPVs were found in Hebei.maintaining a nopolio wild-type virus status in Hebei.