Vesicular stomatitis virus transmission dynamics in cattle ranches located in an enzootic region within its endemic range in Chiapas, Mexico

Authors: ZHOU, LAWRENCE - New Mexico State University; VALDEZ, FEDERICO - Oak Ridge Institute For Science And Education (ORISE); LOPEZ-GONZALEZ, IRENE - Senasica; URBINA-FREYSSER, WILLIAN - The Inter-American Institute For Cooperation On Agriculture; OCANA, ARIADNA - The Inter-American Institute For Cooperation On Agriculture; TAPIA, CRISTELL - The Inter-American Institute For Cooperation On Agriculture; ZAMBRANO, ARMANDO - The Inter-American Institute For Cooperation On Agriculture; HERNANDEX-SOLIS, EDILBERTO - The Inter-American Institute For Cooperation On Agriculture; PETERS, DEBRA - Retired ARS Employee; Mire, Chad; NAVARRO, ROBERTO - Senasica; RODRIGUEZ, LUIS - Retired ARS Employee; HANLEY, KATHRYN - New Mexico State University

Submitted to: Viruses
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/31/2024
Publication Date: 11/6/2024
Citation: Zhou, L.H., Valdez, F., Lopez-Gonzalez, I., Urbina-Freysser, W., Ocana, A., Tapia, C., Zambrano, A., Hernandex-Solis, E., Peters, D.P., Mire, C.E., Navarro, R., Rodriguez, L.L., Hanley, K.A. 2024. Vesicular stomatitis virus transmission dynamics in cattle ranches located in an enzootic region within its endemic range in Chiapas, Mexico. Viruses. 16(11). Article 1742. https://doi.org/10.3390/v16111742.
DOI: https://doi.org/10.3390/v16111742

Interpretive Summary: Vesicular Stomatitis Virus (VSV) is an insect-transmitted livestock disease that that occurs yearly in southern Mexico and Central America, but also causes sporadic outbreaks in the United States. We conducted a study at cattle ranches located in Chiapas, Mexico to investigate why VSV is commonly detected in the area. We recorded cases of VSV in cattle and detected VSV antibodies in the majority of cattle. This suggests high levels of VSV transmission occur in the area, similar to previous VSV studies in cattle. We also collected a suite of insects that are believed to be involved in VSV transmission and detected the virus in a subset of insects collected throughout the year. Additionally, our study identified other insect species that may be responsible for transmitting and maintaining the virus. We found that VSV transmission in cattle is correlated with precipitation, but the virus is maintained in insects throughout the year. This suggests that insects play a role in maintaining the virus during non-rainy seasons, and that the environment in Chiapas, Mexico allows for this to occur. Our study supports findings from previous livestock studies in the area while also providing further insight into how the virus might be maintained when cattle cases are absent.

Technical Abstract: Vesicular stomatitis virus (VSV), comprising the viruses Vesiculovirus New Jersey (VSNJV) and Vesiculovirus Indiana (VSIV), emerges from its focus of endemic transmission in southern Mexico to cause sporadic livestock epizootics in northern Mexico and the western US. A dearth of information on the role of potential arthropod vectors and reservoir hosts in the endemic region hampers efforts to predict future incursions into the US. We conducted a longitudinal study at five cattle ranches in a VSV-endemic region in Chiapas, Mexico from 2021 to 2022. We monitored livestock cases at each ranch using surveys and screened sera of juveniles and adults for anti-VSNJV antibodies via neutralization assay. We also sampled haematophagous insects during the rainy, post-rainy, and dry seasons and screened a subset for VSNJV and VSIV via qRT-PCR. Livestock cases were reported during the rainy and post-rainy seasons, and seroprevalence against VSNJV in adult cattle ranged from 75-100%. All four putative VSV vector taxa (blackflies, sandflies, biting midges and mosquitoes) were present on ranches, but the abundance of blackflies was significantly lower. We detected VSNJV in all four insect taxa throughout the year, while VSIV was only detected in mosquitoes in the rainy season. Intriguingly, no livestock cases were reported in Chiapas during the dry season, but VSNJV was detected in insects in all five ranches during this period.