Reemergence of a Big Brown Bat Lyssavirus rabies Variant in Striped Skunks in Flagstaff, Arizona, USA, 2021–2023

Authors

• Amy T. Gilbert, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, National Wildlife Research Center, Fort Collins, ColoradoFollow
• Lolita I. Van Pelt, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, Phoenix, ArizonaFollow
• Lias A. Hastings, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, Phoenix, ArizonaFollow
• Crystal M. Gigante, Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Poxvirus and Rabies Branch
• Lillian A. Orciari, Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Poxvirus and Rabies Branch
• Sabrina Kelley, Coconino County Health and Human Services, Flagstaff, Arizona
• Kathryn Fitzpatrick, Arizona Department of Health Services
• René Edgar Condori, Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Poxvirus and Rabies Branch
• Yu Li, Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Poxvirus and Rabies Branch
• Scott Brunt, New York State Department of Health, Wadsworth Center Rabies Laboratory
• April Davis, New York State Department of Health, Wadsworth Center Rabies Laboratory
• Matthew W. Hopken, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, National Wildlife Research Center, Fort Collins, Colorado
• Clara C. P. Mankowski, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, National Wildlife Research Center, Fort Collins, Colorado
• Ryan M. Wallace, Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Poxvirus and Rabies Branch
• Charles E. Rupprecht, Auburn University
• Richard B. Chipman, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, National Rabies Management Program, Concord, New HampshireFollow
• David L. Bergman, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, Phoenix, ArizonaFollow

Document Type

Article

Date of this Version

2024

Citation

Vector-borne and Zoonotic Diseases (2024) 24(8): 552-

doi: 10.1089/vbz.2023.0126

Comments

United States government work

Abstract

Background

Throughout the Americas, Lyssavirus rabies (RV) perpetuates as multiple variants among bat and mesocarnivore species. Interspecific RV spillover occurs on occasion, but clusters and viral host shifts are rare. The spillover and host shift of a big brown bat (Eptesicus fuscus) RV variant Ef-W1 into mesocarnivores was reported previously on several occasions during 2001–2009 in Flagstaff, Arizona, USA, and controlled through rabies vaccination of target wildlife. During autumn 2021, a new cluster of Ef-W1 RV cases infecting striped skunks (Mephitis mephitis) was detected from United States Department of Agriculture enhanced rabies surveillance in Flagstaff. The number of Ef-W1 RV spillover cases within a short timeframe suggested the potential for transmission between skunks and an emerging host shift.

Materials and Methods

Whole and partial RV genomic sequencing was performed to evaluate the phylogenetic relationships of the 2021–2023 Ef-W1 cases infecting striped skunks with earlier outbreaks. Additionally, realtime reverse-transcriptase PCR (rtRT-PCR) was used to opportunistically compare viral RNA loads in brain and salivary gland tissues of naturally infected skunks.

Results

Genomic RV sequencing revealed that the origin of the 2021–2023 epizootic of Ef-W1 RV was distinct from the multiple outbreaks detected from 2001–2009. Naturally infected skunks with the Ef-W1 RV showed greater viral RNA loads in the brain, but equivalent viral RNA loads in the mandibular salivary glands, compared to an opportunistic sample of skunks naturally infected with a South-Central skunk RV from northern Colorado, USA.

Conclusion

Considering a high risk for onward transmission and spread of the Ef-W1 RV in Flagstaff, public outreach, enhanced rabies surveillance, and control efforts, focused on education, sample characterization, and vaccination, have been ongoing since 2021 tomitigate and prevent the spread and establishment of Ef-W1 RVin mesocarnivores.