摘要
目的对山东省1997～2004年急性弛缓性麻痹(AFP)病例中疫苗变异脊髓灰质炎(脊灰)病毒的分子生物学性状进行分析,以提高对疫苗衍生脊灰病毒(VDPV)的认识,从而增加AFP病例监测系统检出VDPV的灵敏度.方法分离的脊灰病毒血清定型采用中和试验的方法,型内鉴定采用酶联免疫吸附试验(ELISA)和聚合酶链反应-限制性酶切片段长度多态性分析(PCR-RFLP)两种方法,疫苗变异脊灰病毒分子生物学性状分析采用VP1区序列测定的方法.结果山东省1997～2004年未分离到脊灰野病毒,分离到的脊灰疫苗病毒以Ⅱ型为主(173株),接近Ⅰ型和Ⅲ型之和.其中疫苗变异脊灰病毒10株,仍以Ⅱ型为主(8株),且有1株(CHN1025)VP1区变异率达到1%,为VDPV,但该毒株无2代病例发生.结论在山东省连续多年的口服脊灰疫苗免疫已经阻断了脊灰野病毒在人群中的传播,但从AFP病例中曾分离到1株VDPV,结合流行病学分析发现,局部地区仍存在免疫空白,因此存在着VDPV以及发生循环的VDPV潜在的可能,应引起相关部门的关注.
Objective In order to acquire more knowledge of vaccine-derived polioviruses （VDPV）, increase the sensitivity of detecting VDPV of Shandong AFP surveillance system, we analyzed the molecular character of the vaccine-variant polioviruses isolated from AFP cases in Shandong Province during 1997-2004. Methods Neutralization test was used to identity the sera-type of poliovirus isolates; ELISA and PCR-RFLP methods were used to intratypic differentiation and VP1 genomic sequencing technique was used to analyze the molecular character of vaccine-variant polioviruses. Results No wild polioviruses were found during 1997-2004, and as the preponderant strains, 173 of polioviruses type 2 （P2） strains were the most frequently isolated among the isolated Sabin-like PV strains, the number of P2 strains nearly equals to the summation of poliovirus type Ⅰ strains （P1） and type 3 strains （P3）;Totally 10 strains were identified as vaccine-variant polioviruses, and 8 were P2 strains that were still preponderant strain among the vaccine-variant polioviruses. Another 1 should be classified as VDPV for its variant rate of VP1 sequence reached 1% , fortunately there were no secondary cases occurred. Conclusion Continuous immunizations of OPV executed every year had interdicted the transmission of wild polioviruses in population in Shandong Province, but 1 VDPV has been isolated in an AFP case before, and combine with the epidemiology data in Shandong Province, potential VDPV emergence and cVDPVs circulation still possibly occur because the gaps in OPV coverage still exist in some special areas, which should be pay more attention by related departments.
出处
《中国计划免疫》
2005年第4期268-272,共5页
Chinese Journal of Vaccines and Immunization
