The ecological and etiological investigation of ticks and rodents in China: results from an ongoing surveillance study in Zhejiang Province

Jinna Wang; Mingyu Luo; Tianqi Li; Ying Liu; Guoqin Jiang; Yuyan Wu; Qinmei Liu; Zhenyu Gong; Jimin Sun

doi:10.3389/fvets.2023.1268440

The ecological and etiological investigation of ticks and rodents in China: results from an ongoing surveillance study in Zhejiang Province

Front Vet Sci. 2023 Nov 28:10:1268440. doi: 10.3389/fvets.2023.1268440. eCollection 2023.

Authors

Jinna Wang^#¹, Mingyu Luo^#¹, Tianqi Li¹, Ying Liu¹, Guoqin Jiang², Yuyan Wu¹, Qinmei Liu¹, Zhenyu Gong¹, Jimin Sun¹

Affiliations

¹ Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China.
² Shaoxing Center for Disease Control and Prevention, Shaoxing, China.

^# Contributed equally.

Abstract

Objectives: This study aimed to analyze the population density of vector ticks and reservoir hosts rodents, and to investigate the relevant pathogen infection in Zhejiang Province, China.

Methods: In this surveillance study, the data of ticks density were collected with the tick picking method on animal body surface and the drag-flag method, while the rodent density with the night trapping method. The samples of ticks were examined for the severe fever with thrombocytopenia syndrome virus (SFTSV), and blood serum and organs from rodents were subjected for SFTSV, hantavirus, Leptospira, Orientia tsutsugamushi (O. tsutsugamushi) and Yersinia pestis (Y. pestis) screening in the laboratory.

Results: From 2017 to 2022 in Zhejiang Province, 16,230 parasitic ticks were found in 1848 positive animals, with the density of parasitic ticks of 1.29 ticks per host animal, and a total of 5,201 questing ticks were captured from 1,140,910 meters of vegetation distance with the questing tick density of 0.46 ticks/flag·100 m. Haemaphysalis longicornis (H. longicornis) was the major species. A total of 2,187,739 mousetraps were distributed and 12,705 rodents were trapped, with the density of 0.58 per 100 trap-nights. Rattus norvegicus was the major species. For SFTSV screening, two groups nymphal ticks of H. longicornis were tested to be positive. For the rodents samples, the Leptospira had a positive rate of 12.28% (197/1604), the hantavirus was 1.00% (16/1604), and the O. tsutsugamushi was 0.15% (2/1332). No positive results were found with SFTSV and Y. pestis in the rodents samples.

Conclusion: Findings from this study indicated that the ticks and rodents were widely distributed in Zhejiang Province. Particularly, the positive detection of SFTSV, Leptospira, hantavirus and O. tsutsugamushi in ticks or rodents from this area suggested that more attention should be paid to the possibilities of relevant vector-borne diseases occurrence.

Keywords: Leptospira; Orientia tsutsugamushi; SFTS; Yersinia pestis; density; hantavirus; rodent; tick.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the Zhejiang Medical and Health Technology Project (nos. 2021KY119, 2024KY889, 2023KY638, and 2022RC281).