Molecular epidemiological characteristics of dengue virus serotype 3 in Yunnan Province, China, 2014-2020: A cross-sectional study

Peng Cheng; Kok KengTee; Zaili Feng; Anzhou Tao; Yinzhu Tao; Yandaijiu Wang; Taif Shah; Qi Liu; Zongbo An; Binghui Wang; Xueshan Xia

doi:10.1016/j.jiph.2026.103283

Molecular epidemiological characteristics of dengue virus serotype 3 in Yunnan Province, China, 2014-2020: A cross-sectional study

J Infect Public Health. 2026 Jun 5;19(8):103283. doi: 10.1016/j.jiph.2026.103283. Online ahead of print.

Authors

Peng Cheng¹, Kok KengTee¹, Zaili Feng², Anzhou Tao², Yinzhu Tao¹, Yandaijiu Wang¹, Taif Shah¹, Qi Liu¹, Zongbo An¹, Binghui Wang³, Xueshan Xia⁴

Affiliations

¹ Yunnan Province Key Laboratory of Public Health and Biosafety, School of Public Health, Kunming Medical University, Kunming, China.
² The People's Hospital of Dehong Prefecture, Mangshi, China.
³ Yunnan Province Key Laboratory of Public Health and Biosafety, School of Public Health, Kunming Medical University, Kunming, China. Electronic address: binghuiwang@aliyun.com.
⁴ Yunnan Province Key Laboratory of Public Health and Biosafety, School of Public Health, Kunming Medical University, Kunming, China. Electronic address: oliverxia2000@aliyun.com.

PMID: 42247806
DOI: 10.1016/j.jiph.2026.103283

Abstract

Background: Dengue fever, caused by dengue virus serotype 3, has represented a significant public health challenge in Yunnan Province, China, for nearly a decade. The frequent movement of individuals across neighboring countries continuously threatens local outbreaks. Nevertheless, there remains a considerable gap in research regarding the genetic evolution and migration pathways of DENV-3.

Methods: This study collected 161 DENV-3 E gene sequences from patients with indigenous and imported dengue fever from Myanmar in Yunnan Province between 2014 and 2020. The maximum likelihood method was employed to construct a phylogenetic tree for identifying genotype subtypes. Additionally, the Bayesian phylogeographic reconstruction method was utilized to infer the spatial migration patterns and ancestral geographic origins of the virus. A molecular transmission network was also established based on genetic distances between sequences to identify and characterize high-risk transmission clusters.

Results: The phylogenetic analysis indicated the presence of a co-circulating epidemic of genotype I and genotype III in Yunnan. The Bayesian skyline plot demonstrated that the effective virus population size of DENV-3 underwent significant expansion from 2016 to 2018. Phylogeographic analysis identified Myanmar and Laos as the primary source hubs for DENV-3 transmission in Yunnan (Bayes factor >100). The molecular transmission network revealed four major high-risk transmission clusters, highlighting the mutual transmission of DENV-3 among Yunnan, Myanmar, and Laos.

Conclusion: The frequent cross-border movement of individuals is the principal driver of DENV-3 importation into Yunnan and the maintenance of local circulation. Enhanced surveillance of dengue virus genotypes and importation pathways within the cross-border human is essential for mitigating dengue virus transmission.

Keywords: Bayesian phylogeography; Cross-border transmission; Dengue virus serotype 3 (DENV-3); Molecular transmission network.