大连市1例脊髓灰质炎疫苗高变株病例的流行病学调查

Epidemiological investigation on a case caused by vaccine hypervariable poliovirus in Dalian City

目的阐述大连市1例脊髓灰质炎疫苗高变异株病例的流行病学调查与分析。方法按照相关要求,对疫情开展病例个案调查、病毒传播风险评估、应急处置等相关工作,由省级AEFI调查诊断专家组对病例进行诊断。结果 2016年,大连市发现1例口服第1剂二价脊髓灰质炎减毒活疫苗后高变异株病例,国家脊灰实验室对病例所分离到的脊灰病毒进行核苷酸序列测定时发现,与Sabin株相比变异数为7。结论该病例诊断为疫苗相关麻痹型脊髓灰质炎病例,按照相关要求采取措施,有效地控制了疫情的扩大和蔓延。

[Objective]To elaborate the epidemiological investigation and analysis on a case caused by vaccine hypervariable poliovirus in Dalian City.[Methods]Related work including case investigation,assessment of virus transmission risks and emergency response was conducted following related requirements,and the case was diagnosed by the provincial AEFI investigation and diagnosis expert group.[Results]The case was reported in Dalian City in 2016,which occurred after receiving 1 dose of bivalent oral polio vaccine immunization. The isolate from the case was identified as highly variant vaccine-derived poliovirus typeⅢ（7 nt）by nucleotide sequencing in the National Polio Laboratory,and there were 7 variations number as compared with Sabin.[Conclusion]The case is finally diagnosed with vaccine-associated paralytic poliomyelitis and no further transmission has occurred due to strict prevention and control measures.