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Research Project: Detection and Characterization of Arboviruses and Environmental Influences on Transmission at the U.S. Wildlife and Livestock Interface

Location: Research Programs

Project Number: 3022-32000-018-001-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 1, 2021
End Date: Aug 31, 2024

The transmission of pathogens between wildlife and domestic animals represents a poorly understood threat to the mitigation and control of both endemic and foreign animal diseases, including zoonoses. The objective of this agreement is to develop new systems to better understand the maintenance and transmission of arboviruses at the interface of wildlife and livestock in the United States (U.S.). Specific objectives include: 1) developing new in vitro systems to study the susceptibility of wildlife to arboviral diseases, 2) developing surveillance methods to detect arboviral infections in animals at the wildlife-livestock interface, and 3) developing a repository for geo-referenced environmental data and samples resulting from field surveillance of arthropod vectors and wildlife associated with enzootic foci of arboviruses near livestock operations. These efforts will support early detection and warning for viral pathogens and provide baseline information on circulating viruses, as well as historic reference information to inform predictive models that asses the risk of arbovirus emergence and resurgence.

This agreement combines the investigators’ expertise in arboviruses, molecular biology, microbiology, virology, immunology, medical and veterinary entomology, wildlife diseases, and biosafety/biosecurity to advance the mutual goal of understanding the risk of emerging pathogen transmission between U.S. wildlife and livestock. Three primary approaches will use samples from U.S. wildlife, principally feral swine, as well as arthropod populations that are potential vectors of viruses of concern to generate new knowledge towards this goal. In the first approach, immune cells will be isolated from feral swine samples and maintained in culture with the aim of developing cell lines for in vitro studies of wildlife host responses to infectious diseases. The cells/cell lines will be characterized for aspects of phenotype and then will then be used to determine host susceptibly to arboviruses such as Japanese encephalitis virus (JEV) and Rift Valley fever virus (RVFV). Indicators of pathogenicity such as cytopathology will be examined and the kinetics of virus replication will be determined. In the second approach, pan-arbovirus RT-qPCR assays will be designed to detect the presence of bunyaviruses, flaviviruses, and other relevant arboviruses in biological samples from wildlife. Different sample types (e.g., tissues, blood, serum) will be used to determine the most suitable samples for virus detection. Following initial development and validation with standard laboratory real-time thermocyclers, assays will be adapted and equivalency validated on a field-based system. Unbiased metagenomic sequencing will be further used on positive samples. Alternatively, family-specific targeted sequencing approaches may be developed. The third approach will focus on identifying biotic and abiotic environmental factors that influence arbovirus vector and wildlife reservoir host populations, and the potential for transmission of arboviruses at the wildlife-livestock interface. A repository for these field-based geo-referenced datasets and samples will be established, maintained and made available to collaborating investigators. Dedicated ultra-cold freezers and a secure local area network (LAN) server for data storage will be utilized to ensure biosecurity of both datasets and samples.