广州市2019年输入与本地登革热流行特征及病毒E基因比较

Epidemiological features of dengue fever and envelope gene of dengue virus among imported and indigenous cases in Guangzhou city: a comparison analysis on registry data of 2019

目的 对广东省广州市2019年登革热输入病例和本地病例的流行病学资料和病毒E基因进行分析,评估输入病例对广州市登革热流行的影响。方法 通过中国疾病预防控制信息系统传染病报告信息管理系统收集广州市2019年登革热病例信息,统计分析病例流行病学特征,测定登革病毒E基因序列并构建最大相似度基因树。结果 广州市2019年共计报告登革热确诊病例1 655例,输入病例273例,本地病例1 382例。输入病例中男女性别比为2.85:1,86.45%的病例发病年龄集中在20~49岁,职业分布主要为商业服务、家务及待业和工人为主,全年12个月均有发生,发病高峰在6—8月,东南亚国家输入病例占境外输入病例的90.38%。本地病例中男女性比为1.07:1,89.87%的病例发病年龄集中在20~69岁,职业分布主要为家务及待业、商业服务和离退休人员,发病时间为6—12月,发病高峰在8—10月。病毒E基因显示本地病例序列与输入病例序列、东南亚国家序列亲缘关系较近。结论 广州市登革热流行受输入影响较大,2019年的本地流行是由输入病例引起的可能性更大。

Objective To assess epidemiological features of imported and indigenous dengue fever cases and phylogenetic features of dengue virus prevalent in the cases in Guangzhou, Guangdong province in 2019 and to explore the impact of imported cases on dengue fever epidemics in the city. Methods The data on all dengue fever cases registered in Guangzhou city in 2019 were extracted from the National Notifiable Infectious Disease Reporting System. The demographic and epidemiological features of the reported cases were statistically analyzed. The envelope(E) gene of the dengue viruses isolated from the cases was sequenced and analyzed to construct maximum likelihood phylogenetic trees. Results Among1 655 dengue fever incidents yearly registered in the city, 273 and 1 382 were imported and local cases. Of the imported cases with a male to female ratio of 2.85 : 1, 86.45% were aged 20 to 49 years, mainly being engaged in commercial service,housework and general industries. The imported cases occurred in every month of the year but more cases were reported during June and August. The most(90.38%) of the imported cases were from Southeast Asia. For the reported local dengue fever cases, the male to female ratio was 1.07 : 1 and 89.87% were at ages of 20-69 years;main occupations of the local cases included houseworker, unemployee, commercial service worker and retiree;the local cases were reported during June –December and more cases were reported during August-October of the year. E gene sequences of the virus isolated from the local cases displayed close associations with sequences from imported cases and with those of prevalent virus in Southeast Asia. Conclusion The epidemic of dengue fever in Guangzhou city was affected by the imported dengue fever cases and the local prevalence of dengue fever in 2019 was likely being induced by the imported cases.