Temporal trends in reported vector-borne diseases in China before and after the onset of COVID-19 from 2004 to 2023
- 1School of Nursing and Health Management, Institute of Biomedicine, Wuhan Donghu University, Wuhan, Hubei, China
- 2School of NextMed Science and Technology, Hubei Key Laboratory of Nanomedicine for Neurodegenerative Disease, Institute of WUT-AMU, Wuhan University of Technology, Wuhan, China
- 3Hubei Key Laboratory of Gynecologic Oncology and Reproductive Health, Hubei Provincial Clinical Research Center for Cervical Lesions, Xiangyang, Hubei, China
Abstract
Background: Vector-borne diseases (VBDs) continue to pose a public health burden in China. However, changes in the reported incidence and mortality of VBDs during the COVID-19 period remain insufficiently characterized. Methods: We analyzed five major VBDs—typhus, dengue, leishmaniasis, malaria, and epidemic encephalitis B (EEB)—in China from 2004 to 2023. Province- and age-specific surveillance data for 2004–2020 were obtained from the Chinese Center for Disease Control and Prevention, whereas national aggregate data for 2021–2023 were obtained from the National Health Commission. Accordingly, spatial and age-specific analyses were restricted to 2004–2020, while national trend analyses were extended through 2023. Annual trends were evaluated using Joinpoint regression, monthly seasonal patterns were assessed using STL decomposition, monthly changes after January 2020 were evaluated using interrupted time-series analysis, and expected monthly trajectories for 2020–2023 were estimated using SARIMA models trained on pre-COVID data. Results: From 2004 to 2020, incidence and mortality of VBDs declined significantly, especially for malaria, dengue, and EEB, and spatial hotspots were concentrated mainly in southern provinces. Compared with 2013–2019, overall incidence and mortality during 2020–2023 were 59.86% lower (95% CI: –60.36 to –59.36; P < 0.001) and 83.72% lower (95% CI: –87.86 to –78.18; P < 0.001), respectively. Malaria and EEB showed the largest reductions, whereas typhus and leishmaniasis changed less markedly. However, these declines should be interpreted cautiously because they may reflect a combination of COVID-19-era public health measures, pre-existing long-term trends, disease-specific control programs, and possible surveillance disruption. Conclusions: During the COVID-19 period in China, reported VBD incidence and mortality decreased substantially. However, it would be overly simplistic to attribute these changes entirely to COVID-19-related interventions, as other factors were also likely involved. These findings highlight the need for reliable surveillance and reporting during public health emergencies, together with forecasting tools that can be adapted to changing conditions, to support future vector-borne disease control. Author summary: Vector-borne diseases, such as dengue, malaria, typhus, leishmaniasis, and Japanese encephalitis, remain important public health problems because their spread is shaped by insects, human movement, climate, and health services. In this study, we examined how these diseases changed in China over two decades, with particular attention to the years affected by COVID-19. We found that reported cases and deaths decreased substantially over time, and that several diseases were reported less often during 2020–2023 than would have been expected from earlier patterns. The largest decreases were seen for malaria and Japanese encephalitis, while typhus and leishmaniasis changed less clearly. We also found that disease patterns differed by region and age group, with higher burdens in several southern and western areas. These findings are important because they show that large public health emergencies can affect the reporting and apparent burden of diseases beyond the emergency itself. We caution that the observed declines may reflect several factors, including long-term control programs, changes in travel and behavior, and possible disruption of routine surveillance. Reliable disease monitoring remains essential during future emergencies.
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BibTeX
@article{lei2026temporal,
title = {{Temporal trends in reported vector-borne diseases in China before and after the onset of COVID-19 from 2004 to 2023}},
author = {Zhiqun Lei and Qianying Liu and Zhixin Lei},
journal = {PLOS Neglected Tropical Diseases},
year = {2026},
month = oct,
doi = {10.1371/journal.pntd.0014745},
url = {https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014745},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Temporal trends in reported vector-borne diseases in China before and after the onset of COVID-19 from 2004 to 2023
AU - Zhiqun Lei
AU - Qianying Liu
AU - Zhixin Lei
PY - 2026
DA - 2026/10/21
JO - PLOS Neglected Tropical Diseases
DO - 10.1371/journal.pntd.0014745
UR - https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014745
AB - Background: Vector-borne diseases (VBDs) continue to pose a public health burden in China. However, changes in the reported incidence and mortality of VBDs during the COVID-19 period remain insufficiently characterized. Methods: We analyzed five major VBDs—typhus, dengue, leishmaniasis, malaria, and epidemic encephalitis B (EEB)—in China from 2004 to 2023. Province- and age-specific surveillance data for 2004–2020 were obtained from the Chinese Center for Disease Control and Prevention, whereas national aggregate data for 2021–2023 were obtained from the National Health Commission. Accordingly, spatial and age-specific analyses were restricted to 2004–2020, while national trend analyses were extended through 2023. Annual trends were evaluated using Joinpoint regression, monthly seasonal patterns were assessed using STL decomposition, monthly changes after January 2020 were evaluated using interrupted time-series analysis, and expected monthly trajectories for 2020–2023 were estimated using SARIMA models trained on pre-COVID data. Results: From 2004 to 2020, incidence and mortality of VBDs declined significantly, especially for malaria, dengue, and EEB, and spatial hotspots were concentrated mainly in southern provinces. Compared with 2013–2019, overall incidence and mortality during 2020–2023 were 59.86% lower (95% CI: –60.36 to –59.36; P < 0.001) and 83.72% lower (95% CI: –87.86 to –78.18; P < 0.001), respectively. Malaria and EEB showed the largest reductions, whereas typhus and leishmaniasis changed less markedly. However, these declines should be interpreted cautiously because they may reflect a combination of COVID-19-era public health measures, pre-existing long-term trends, disease-specific control programs, and possible surveillance disruption. Conclusions: During the COVID-19 period in China, reported VBD incidence and mortality decreased substantially. However, it would be overly simplistic to attribute these changes entirely to COVID-19-related interventions, as other factors were also likely involved. These findings highlight the need for reliable surveillance and reporting during public health emergencies, together with forecasting tools that can be adapted to changing conditions, to support future vector-borne disease control. Author summary: Vector-borne diseases, such as dengue, malaria, typhus, leishmaniasis, and Japanese encephalitis, remain important public health problems because their spread is shaped by insects, human movement, climate, and health services. In this study, we examined how these diseases changed in China over two decades, with particular attention to the years affected by COVID-19. We found that reported cases and deaths decreased substantially over time, and that several diseases were reported less often during 2020–2023 than would have been expected from earlier patterns. The largest decreases were seen for malaria and Japanese encephalitis, while typhus and leishmaniasis changed less clearly. We also found that disease patterns differed by region and age group, with higher burdens in several southern and western areas. These findings are important because they show that large public health emergencies can affect the reporting and apparent burden of diseases beyond the emergency itself. We caution that the observed declines may reflect several factors, including long-term control programs, changes in travel and behavior, and possible disruption of routine surveillance. Reliable disease monitoring remains essential during future emergencies.
SN - 1935-2735
ER -