2015-2016年梧州市手足口病病原体CA6、 CA10流行特征分析

Epidemiological characteristics of hand-foot-mouth disease caused by CA6 and CA10 in Wuzhou in 2015-2016

目的分析2015-2016年CA6、CA10所致手足口病(hand foot and mouth disease,HFMD)病例的流行特征,为今后制定预防及控制防治策略提供依据。方法 2015年1月至2016年12月,在梧州市的两个城区和下辖3县1市共选取7个普通病例监测点以及8个重症病例定点救治医院,对普通和重症监测病例进行样本采集,使用RT-PCR法对其他类型肠道病毒通用核酸检测结果为阳性的样本进行CA6和CA10的分类检测。结果 688份分型样本中CA6、CA10的阳性率分别为47.67%和13.23%,两者的重症监测病例和普通监测病例阳性率间比较差异均有统计学意义(χ~2=57.22、33.59,均P<0.01);CA6流行期为每年的4~11月,CA10流行期为每年5~8月;CA6、CA10的高发年龄段均为3岁以下,两种病原体的重症和普通监测病例间在年龄分布上差异有统计学意义(χ~2=28.84,P=0.024)。CA6发病数与月平均气温、月平均降水量、月平均日照时间、人口密度的相关系数分别为0.470(P<0.01)、0.180(P=0.007)、0.390(P<0.01)、0.070(P<0.01),CA10发病数的相关系数分别为0.278(P<0.01)、0.324(P<0.01)、0.185(P=0.012)、0.280(P<0.01)。结论 CA6是影响非EV71非CA16的其他类型EV流行的重要病原体,流行期长于EV71和CA16;感染CA10后重症转化率高,CA6、CA10对于低龄儿童的危害均不容忽视;CA6、CA10发病均与气温、降水量、日照时间及人口密度存在关联,地区间分布差异较大,应寻找热点地区制订个体化的防控措施。

Objective To understand the epidemiological characteristics of hand-foot-mouth disease(HFMD)caused by Coxsackievirus A6(CA6)and Coxsackievirus A10(CA10)from 2015 to 2016 in Wuzhou,and to provide evidence for disease control and prevention.Methods From January 2015 to December 2016,clinical samples were collected from patients with HFMD in seven surveillance sites for non-severe cases and eight designated hospitals for severe cases in Wuzhou.RT-PCR was used to determine the genotype of CA6 and CA10 among EV nucleic acid positive samples.Results Among 688 EV nucleic acid positive samples,the positive rates of CA6 and CA10 genotype were 47.67%and 13.23%.The differences of positive rates of CA6 and CA10 genotype between non-severe cases and severe cases were statistically significant(χ~2=57.22,33.59,P<0.01).The epidemic season was from April to November for CA6 and from May to August for CA10.Even though children under 3 years old were the highly infected age group for both CA6 and CA10,the differences of CA6 and CA10 positive rates were statistically significant in the age group between non-severe cases and severe cases(χ~2=28.84,P=0.024).The correlation coefficients of HFMD incidence with the monthly mean temperature,monthly average precipitation,monthly average hours of sunshine and the population density were 0.470(P<0.01),0.180(P=0.007),0.390(P<0.01)and 0.07(P<0.01)for CA6,and were 0.278(P<0.01),0.324(P<0.01),0.185(P=0.012)and 0.280(P<0.01)for CA10.Conclusions CA6 is a major pathogen affecting the prevalence of non-EV71 and non-CA16 EV with longer epidemic period..Cases with CA10 infection are more likely to become severe cases.Children under 5 years are the major group of infections for both CA6 and CA10.The incidences of CA6 and CA10 are closely related to temperature,precipitation,hours of sunshine and population density.The distribution of pathogens among regions is quite different.Therefore it is suggested to search for hot spots to develop individualized prevention and control strategies.