Epidemiological surveys revealed the risk of TAMV spill-over from ticks to hosts

Abstract

Background

Tick-borne viral diseases have become an increasingly important public health concern. Tamdy virus (TAMV) is a tick-borne virus of the genus Orthonairovirus in the family Nairoviridae. While some studies have suggested that TAMV is a pathogen associated with human febrile illness, its epidemiology and the risk of TAMV spill-over remain poorly understood.

Methods

Ticks were collected in Xinjiang, China, and grouped into pools. RT-PCR assays were used to detect TAMV RNA in these pools. The seroprevalence of TAMV was investigated using Immunofluorescence assays, Western blotting, and Luciferase immunoprecipitation system (LIPS) assays.

Results

TAMV RNA was detected in 17 out of 363 tick pools, resulting in a minimum infection rate (MIR) of 4.7%. Hyalomma asiaticum and Dermacentor nuttalli were identified as major tick vectors of TAMV. Phylogenetic analysis demonstrated that TAMV strains from Xinjiang are closely related to strains from other countries. Seroprevalence studies showed that TAMV exposure has been occurring in Xinjiang since at least 2006. Antibody responses to TAMV were detected in 1.1% (26/2296) of animals, including domestic animals and wild rodents. The seropositivity rates were as follows: sheep (1.7%), dog (2.3%), Marmota monax (0.8%), Meriones meridianus (3.5%).

Conclusions

The research findings reveal that TAMV can be transmitted by ticks to various animal species, posing a significant public health risk. The wide distribution of TAMV and its tick vectors emphasise the importance of early preparedness and control measures. This study highlights the necessity for maintaining vigilance in addressing emerging zoonotic diseases transmitted by ticks.

Keywords:

• Orthonairovirus
• Tamdy virus
• ticks
• animal sera
• epidemiology
• spill-over

Author contributions

SS and FD designed the study and analysed experimental data; YJZ, QLW, JW, JYJ, ST, and SRS provided ticks and animal serum samples. AM, YB, and SYC performed experiments. AM and SS co-wrote the manuscript and made the revisions. SS and FD conceived, led the project, and obtained funding. All authors reviewed the manuscript.

Acknowledgements

We would like to thank Prof. Linfa Wang from Duke - National University of Singapore Medical College for kindly providing the pREN2 plasmid and the technical support to establish LIPS. We would like to thank all team members of the National Virus Resource Center for their assistance.

Ethical approval

The study was reviewed and approved for ethical consideration by the institutional review board (IRB) of Wuhan Institute of Virology, CAS (Approval Number: WIVH33202102).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Key R&D Program of China (2022YFC2302700, 2021YFC2300900), the Key Deployment Projects of Chinese Academy of Sciences (KJZD-SW-L11), the National Natural Science Foundation of China (81960369), the Science Research Key Project of Xinjiang Education Department (XJEDU2019I002).