2021年昆明市手足口病流行病学和肠道病毒病原谱特征

Epidemiology and enterovirus spectrum of hand,foot,and mouth disease in Kunming city,2021

目的了解昆明市手足口病(Hand,foot and mouth disease,HFMD)流行病学和肠道病毒(Enterovirus,EV)病原谱特征。方法通过中国传染病报告信息管理系统收集2021年昆明市HFMD病例信息进行描述性流行病学分析;采集部分HFMD病例标本,采用荧光定量PCR检测肠道病毒71型(Enterovirus 71,EV71)、柯萨奇病毒A16型(Coxsackievirus A16,CVA16)、CVA6和其他EV,采用一步法RT-PCR对其他EV进行扩增和基因型鉴定;构建各基因型EV与参考株的VP1区全基因序列系统进化树,分析亲缘性。结果2021年昆明市HFMD报告发病率为103.72/10万(8804例),其中0-4岁、5-9岁、10-14岁、≥15岁分别为8724.75/10万、1649.25/10万、29.08/10万、9.35/10万,主城区、郊县分别为524.10/10万、965.68/10万。HFMD病例标本的EV检测阳性率为63.15%(538/852);在538株EV中,CVA16、CVA6、EV71、CVA4、CVA2、CVA10、埃可病毒18型(Echovirus 18,E18)、CVA9、E30、CVA5、CVA12、E21、未分型EV分别占38.66%(208株)、30.86%(166株)、2.97%(16株)、2.97%(16株)、1.30%(7株)、1.12%(6株)、0.74%(4株)、0.37%(2株)、0.37%(2株)、0.19%(1株)、0.19%(1株)、0.19%(1株)、20.07%(108株)。CVA16、CVA6、EV71和CVA4的优势亚型分别为B1a、D3a、C4a和C2亚型,其中CVA16 B1a亚型、EV71与东南亚国家流行株的亲缘关系密切,CVA6、CVA4与中国其他地区流行株的亲缘关系密切。结论2021年昆明市<5岁儿童和郊县HFMD发病率高;HFMD的EV病原谱呈多样性,优势基因型从既往的EV71转变为CVA16、CVA6和CVA4。

Objective To determine the epidemiology and pathogenic spectrum of hand,foot,and mouth disease(HFMD)in Kunming city.Methods We obtained data from HFMD cases reported in 2021 in Kunming from the Chinese Infectious Disease Reporting System for a descriptive analysis.We collected samples from a subset of HFMD cases and used real-time RT-PCR to test for enterovirus 71(EV71),coxsackievirus A16(CVA16),CVA6,and other EVs,which were further amplified and genotyped using one step RT-PCR.We constructed a phylogenetic tree of the VP1 genes of the isolates and reference strains to determine genetic relationships.Results The overall incidence per 100000 population of reported HFMD was 103.72(8804 cases)in 2021 in Kunming,with age-specific incidences of 8724.75,1649.25,29.08,and 9.35 among 0-4-,5-9-,10-14-,and≥15-year-olds;and incidences of 524.10 and 965.68 in urban and suburban areas.Among 852 tested samples,538(63.15%)were positive for an EV,and among these,CVA16,CVA6,EV71,CVA4,CVA2,CVA10,echovirus 18(E18),CVA9,E30,CVA5,CVA12,E21,and non-genotyped EV accounted for 38.66%(208 strains),30.86%(166 strains),2.97%(16 strains),2.97%(16 strains),1.30%(7 strains),1.12%(6 strains),0.74%(4 strains),0.37%(2 strains),0.37%(2 strains),0.19%(1 strain),0.19%(1 strain),0.19%(1 strain),and 20.07%(108 strains).Dominant sub-genotypes of CVA16,CVA6,EV71,and CVA4 were B1a,D3a,C4a,and C2;CVA16 B1a and EV71 strains were genetically close to corresponding strains in Southeast Asian countries,while CVA6 and CVA4 strains were close to corresponding strains in other areas of China.Conclusions The HFMD incidence was high among children under 5 years of age and in suburban areas of Kunming in 2021.The EV spectrum of HFMD was diverse,with dominant genotypes changing from EV71 to CVA16,CVA6,and CVA4.