This case demonstrates the possibility of rabies translocation by human movement of captive mammals, including species in which rabies has not been previously reported. In the United States, multiple RVVs exist in wild mammalian reservoir populations. Except for bat RVVs, distinct variants associated with major animal reservoir species occur in geographically distinct regions where transmission is mainly among members of the same species.[3,4] The complete genome sequence of rabies virus isolated from this tamandua was similar to that of the eastern raccoon RVV reference sequences from Virginia, which is consistent with the presence of native wildlife (including raccoons) inside the fencing perimeter at the Virginia zoo. The eastern raccoon RVV is enzootic in 18 states and the District of Columbia. Washington County, Tennessee, has enzootic north-central skunk RVV, but this raccoon RVV is not considered enzootic in the county; no cases of the raccoon RVV have been reported in the county during the previous 5 years. Phylogenetic data and epidemiologic evidence were used to rule out local transmission and expansion of raccoon RVV into this Tennessee county, which confirmed that extensive mitigation actions were not required. Although the National Association of State Public Health Veterinarians recommends that dogs, cats, ferrets, and horses be vaccinated against rabies before interstate movement, no similar recommendations for vaccination of other captive animals are in effect. Expansion of rabies zones in the United States through translocation has substantial adverse public health implications, including threatening the health of humans, domestic animals, and other wildlife; and potentially requiring changes in wildlife rabies control measures.
Rabies detection in animals in the United States is dependent on the public health and veterinary laboratories that routinely perform rabies testing with standardized methods. The national case definition for animal rabies requires laboratory confirmation with either a positive result for the direct fluorescent antibody test or isolation of rabies virus. Timely action is required when rabies is suspected and an animal or human rabies exposure has occurred. In this situation, >1 month had lapsed between the necropsy and confirmatory diagnosis performed by CDC. Delays in appropriate diagnostic testing for rabies after necropsy caused delays in administering rPEP and inadvertently placed persons at increased risk for rabies.
Captive mammals maintained in exhibits or zoological parks typically are not completely excluded from rabies host species and can become infected. All employees who work with animals in areas where rabies is endemic should receive preexposure rabies vaccination in accordance with recommendations of the Advisory Committee on Immunization Practices.[2,9] Three employees at the Tennessee zoo and veterinary staff members in this case had not received rabies preexposure vaccination, despite living in a skunk rabies reservoir area and routinely working with animals. These persons were recommended to receive rabies immune globulin and the 4-dose rPEP vaccination series after risk assessment. This case also highlights the importance of continued public health efforts to expand awareness and education about rabies prevention and control, responsible animal ownership, routine rabies vaccination, appropriate personal protective equipment for barrier protection when performing laboratory procedures with potentially infected animals, and consistent interdisciplinary communication.
Morbidity and Mortality Weekly Report. 2022;71(15):533-537. © 2022 Centers for Disease Control and Prevention (CDC)