广州市2010-2019年4型登革热病例流行特征及其病毒E基因

  目的  了解2010-2019年广州市4型登革热病例的流行病学特征和4型登革病毒的分子生物学特征。  方法  2010-2019年，收集广州市登革热病例相关资料及血清标本，使用RT-PCR法检测血清标本并分型，对4型登革热病例标本进行登革病毒包膜(envelope, E)蛋白基因序列测定，并进行进化树构建及基因重组分析。  结果  2010-2019年，广州市共报告43 174例登革热病例，其中23例为4型登革热病例。4型登革热病例仅分布在5个区，曾在2010年出现本地流行。广州市的4型登革热输入病例主要来自东南亚国家，病毒E基因序列与东南亚国家的序列有较高相似性，病毒基因型归属于印度尼西亚基因型和东南亚基因型，未检测到基因重组。  结论  应加强对广州市4型登革热病例流行状况和输入病例的监测和关注，并进一步加强对东南亚回国人员登革热常识和个人防护的健康宣传。某些区需要预防出现4型登革病毒的扩散和蔓延。登革病毒基因型转换并未引起登革热在广州市流行强度的变化，有待进一步的观察和研究其是否会发生重组。

Epidemiology of dengue virus serotype 4 cases and E gene analysis of dengue virus in Guangzhou Province from 2010 to 2019

  Objective  Investigate epidemiology of dengue virus serotype 4 cases, and molecular biological characteristics of dengue virus serotype 4 circulating in Guangzhou from 2010 to 2019.  Methods  Information and serum samples of dengue patients were collected. Serotypes were confirmed by real-time PCR. Envelope (E) gene of dengue virus serotype 4 was sequenced. Phylogenetic tree was constructed, and recombination was analyzed.  Results  A total of 43 174 dengue cases were reported in Guangzhou between 2010 and 2019, of which 23 cases were confirmed as serotype 4. Serotype 4 cases can only be detected in 5 districts. An endemic of dengue virus serotype 4 broke out in 2010. The imported cases were mainly from Southeast Asia. Sequences of E gene had a high similarity with sequences from Southeast Asia. Sequences acquired in Guangzhou clustered into Indonesia genotype and Southeast Asia genotype. No recombination has been detected.  Conclusions  Supervision on dengue virus serotype 4 cases and imported cases should be enforced. Conduct propaganda of knowledge about dengue fever and personal protection should be further done among people coming back from Southeast Asia. Dengue virus serotype 4 must be prevented from spreading, especially in some districts. The genotype shift didn't cause any change of epidemic. Although there was no sign of recombination, further research is needed.