Characterization of a Novel Reassortant Epizootic Hemorrhagic Disease Virus Serotype 6 Strain Isolated from Diseased White-Tailed Deer (<i>Odocoileus virginianus</i>) on a Florida Farm
Thaís C. S. Rodrigues,
Pedro H. O. Viadanna,
Kuttichantran Subramaniam,
Ian K. Hawkins,
Albert B. Jeon,
Julia C. Loeb,
Juan M. C. Krauer,
John A. Lednicky,
Samantha M. Wisely,
Thomas B. Waltzek
Affiliations
Thaís C. S. Rodrigues
Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
Pedro H. O. Viadanna
Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
Kuttichantran Subramaniam
Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
Ian K. Hawkins
Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
Albert B. Jeon
Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
Julia C. Loeb
Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, USA
Juan M. C. Krauer
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
John A. Lednicky
Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, USA
Samantha M. Wisely
Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, USA
Thomas B. Waltzek
Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
We report an outbreak of a novel reassortant epizootic hemorrhagic disease virus serotype 6 (EHDV-6) in white-tailed deer (WTD) on a Florida farm in 2019. At necropsy, most animals exhibited hemorrhagic lesions in the lung and heart, and congestion in the lung, liver, and spleen. Histopathology revealed multi-organ hemorrhage and congestion, and renal tubular necrosis. Tissues were screened by RT-qPCR and all animals tested positive for EHDV. Tissues were processed for virus isolation and next-generation sequencing was performed on cDNA libraries generated from the RNA extracts of cultures displaying cytopathic effects. Six isolates yielded nearly identical complete genome sequences of a novel U.S. EHDV-6 strain. Genetic and phylogenetic analyses revealed the novel strain to be most closely related to a reassortant EHDV-6 strain isolated from cattle in Trinidad and both strains received segment 4 from an Australian EHDV-2 strain. The novel U.S. EHDV-6 strain is unique in that it acquired segment 8 from an Australian EHDV-8 strain. An RNAscope® in situ hybridization assay was developed against the novel U.S. EHDV-6 strain and labeling was detected within lesions of the heart, kidney, liver, and lung. These data support the novel U.S. reassortant EHDV-6 strain as the cause of disease in the farmed WTD.