The Surveillance and Running Status of Poliomyelitis Laboratory Network in 2002 in China

We analyzed the running status of poliomyelitis laboratory network in China in 2002 There were 5308 stool specimens collected from AFP cases by31 provincial laboratory staff,and all the viruses isolated were typed by the neutralization test.Of the viruses tested,55 were type I poliovirus,181 were type Ⅱ,97 were type Ⅲ,83 were mixed polioviruses,27 were mixture of poliovirus with other enterovirus,and 458 were non-polio enteroviruses (NPEV) 31 provincial polio laboratories except the Tibet polio laboratory (because they sent data late)had passed the proficiency test,even 11 laboratories got credit from experts autoptically 503 viral isolates sent to National Laboratory for Poliomyelitis were intratypically identified by PCR-RFLP test,among these,451 isolates were from AFP cases We found no wild-type poliovirus,but 64 type Ⅰ,170 type Ⅱ,99 type Ⅲ vaccine-like viruses,82 type-mixed viruses,and 3,19,5 polio vaccine mutant viruses of type Ⅰ,Ⅱ,Ⅲ respectively We also made ELISA test according to WHO’s requirements,among total 609 single type viruses,575 were Sabin-like viruses(SL),3 were non-Sabin-like viruses(NSL),28 were double-reaction viruses(DRV) After that,we selected 68 viruses to determine the VP1 gene sequene,2 vaccine-derived polioviruses (VDPV) were identified (from Sichuan and Anhui Provoinces each),but no residue paralysis in patients was found and no evidence showed that the VDPV spread among the communities