Epidemiologic characteristics of dengue fever in Ruili City at the China-Myanmar border in late 2023
10.3969/j.issn.1002-2694.2025.00.093
- VernacularTitle:中缅边境瑞丽市2023年后期登革热流行特征分析
- Author:
Lirong YUAN
1
;
Wenzhi YANG
;
Yue OUYANG
;
Tang LIU
;
Hongmei ZHAN
;
Run CHEN
;
Junyu ZHANG
;
Hongning ZHOU
Author Information
1. 昆明理工大学生命科学与技术学院,昆明 650500
- Publication Type:Journal Article
- Keywords:
dengue virus;
genetic evolutionary analysis;
dengue vector;
Ruili City,China-Myanmar border
- From:
Chinese Journal of Zoonoses
2025;41(7):735-741
- CountryChina
- Language:Chinese
-
Abstract:
This study was aimed atanalyzing the epidemic characteristics of dengue fever in Ruili City atthe China-Myanmar bor-der in late 2023,to provide evidence for local dengue fever prevention and control measures.Adult Aedes mosquitoes were collected from Ruili City with a backpack type mosquito sucking machine in October of 2023.Serum samples frompatients with suspected den-gue were collected in acutephase,in November of 2023.Detection ofdengue virus(DENV)nucleic acids in Aedesmosquitoes and acute phase serum samples from suspected dengue fever patients using reverse transcription-polymerase chain reaction,and nucleic acid positive samples were inoculated into Vero cells for viral culture.After three consecutive blind passage,samples with cytopathic effect(CPE)were collected for be sequencingand analysisof genetic and evolutionary information.Dengue case characteristics were analyzed through descriptive epidemiological methods.Among the 109 cases of dengue fever,the ratio of males to females was 1.27∶1.The youngest patient was 1 year old,the oldest patient was 84 years old,the age group of 20～59 years accounted for 73.39%,and the major-ity of occupations were freelancer(40.37%).A total of 827 female Aedes albopictus and 312 Aedes aegypti were collected,all of which tested negative for DENV nucleic acid.109 serum samples tested positive for DENV nucleic acid,including 49 DENV-1 and 60 DENV-2.Moreover,five DENV-1 and nine DENV-2 samples were obtainedthrough third-generation blind passaging with CPE.The E gene sequences of these five DENV-1 strains were detected,all were found to belong to DENV-1 genotype I,and had same evolu-tionary branch as the 2023 Guangzhou,China(PP563911),the 2019 Myanmar(MW793710),and 2019 Attapeu,Laos(MW559046).The nucleotide and amino acid sequence similarityamong the five DENV-1 genotype was 99.4%-99.9%and 99.8%-100.0%.Compared with the aforementioned epidemic strains,their nucleotide similarities were 99.5%-100.0%,99.4%-99.6%and 99.3%-99.5%,respec-tively,and amino acid similarity was 99.8%-100.0%.Nine DENV-2 E gene sequences were of Asian genotype I and belonged to the same evolutionary branch as the 2018 Myanmar(MW788982),2019 Hangzhou(OP684212)and 2019 Ruili(OQ928150).The nucleotide and amino acid similarities of the nine samples were 99.5%-100.0%and 99.8%-100.0%,respectively.Compared with the aforementioned epidemic strains,their nucleotide similarities were 99.7%-100.0%,99.3%-99.7%and 99.3%-99.7%,respectively,and the amino acid similarity was 99.8%-100%,99.8%-100.0%and 99.4%-99.6%,respectively.Two dengue vectors,Aedes albopictus and Aedes aegypti,were present in Ruili city,and the dengue outbreak was caused primarily by DENV-1 genotype I and DENV-2 Asian genotype I in later 2023.The sources of DENV-1 were probably the same as those of DENV-1 with Guangzhou(2023),and the sources of DENV-2 were probably from Myanmar.Dengue cases were found primarilyin the 20-59 year age group and freelancers,thus suggesting that relevant local departments should strengthen surveillance of dengue imported case and vector.
