ETIOLOGICAL SURVEILLANCE ON ACUTE FLACCID PARALYSIS (AFP) CASES AND HEALTHY CROWDS FROM 2000 TO 2009 IN QINGHAI PROVINCE

[Objective] To provide the laboratory basis for maintaining polio-free status through the etiological surveillance of stool specimens of acute flaccid paralysis (AFP) cases and healthy crowds. [Methods] Virus isolation and identification were used, and the strains were determined by intratypic differentiation of poliovirus. [Results] 1 613 stool specimens of AFP cases and healthy crowds were detected from 2000 to 2009 in Qinghai Province, and 22 strains of poliovirus were isolated, the isolation rate was 1.36% , including 3 strains of poliovirus type I vaccine strain, 2 strains of poliovirus type II vaccine strain, 9 strains of poliovirus type III vaccine strain, 8 strains of hybrid poliovirus vaccine strain, and no wild poliovirus strain. Furthermore, 187 strains of non-polio enteroviruses (NPEV) were isolated, and the isolation rate was 11.59%. [Conclusion] There is no prevalence of local wild poliovirus from 2000 to 2009 in Qinghai Province, which illustrates that we block the spread of local wild poliovirus effectively, and maintain polio-free status.