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Updated: May 17, 2026

Mosquito-Associated Virus Isolation from Field-Collected Mosquitoes
Published on: August 31, 2022
Shifting dengue virus imports into Yunnan, China, 2017-2019: epidemic lineages sparking local outbreaks
Mengyuan Zheng1, Wei Chang1, Gaowen Liu2
1Faculty of Life Science and Technology & Yunnan Provincial Key Laboratory of Public Health and Biosafety, Kunming University of Science and Technology, Kunming, China.
Objectives:
This study examines the genotypic diversity and transmission patterns of dengue virus (DENV) among imported cases in Yunnan.
Methods:
A total of 351 suspected imported dengue cases were studied, with infections confirmed by DENV NS1 antigen and Pan-qPCR. Serotype typing was performed through specific qPCR. Genetic and phylogeographic analyses were conducted on 228 newly obtained and 1747 publicly available DENV E gene sequences.
Results:
DENV infection was confirmed in 262 specimens (74.6%, 262/351). Genotypic analysis of 228 DENV E region sequences revealed all four DENV serotypes, categorized into eight genotypes and 24 unique lineages. Notably, DENV-1 (n = 143) was primarily classified as lineage 1I_E.1 (80.4%). DENV-2 (n = 52) was assigned principally to lineages 2II_F.1.1 and 2V_A.1.2. The number of lineages increased from three in 2014 to 22 in 2019, contributing to local outbreaks, especially those linked to lineage 1I_E.1. Additionally, lineages 1I_K.1.2 and 2II_F.1.1 established ongoing transmission chains. Geographic analysis identified 60 key transmission routes. Cambodia contributed to the regional transmission of DENV-1, while Yunnan and Guangdong served as important domestic hubs.
Conclusions:
The introduction of diverse DENV strains has reshaped local transmission dynamics, underscoring the critical need to control imported cases to effectively prevent outbreaks.
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