A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
Rabies was diagnosed in Cape fur seals by using direct fluorescent antibody testing in South Africa, 2024. We investigated the origin of rabies virus in this species. Phylogenetic analysis revealed virus introduction from jackals into seals, followed by sustained viral transmission within the seal population and spillover into a domestic dog.
Rabies is a viral encephalitis caused by members of the Lyssavirus genus within the Rhabdoviridae family ( 1 ). Rabies virus (RABV) is a prototype species of the Lyssavirus genus and has a wide host range, including various Chiroptera and terrestrial Carnivora species ( 2 ). In southern Africa, RABV is maintained by domestic dogs and wildlife species such as black-backed jackals ( Lupulella mesomelas ), bat-eared foxes ( Otocyon megalotis ), aardwolves ( Proteles cristatus ), and yellow mongooses ( Cynictis penicillata ) ( 3 ).
In 2021, reports of unusually aggressive Cape fur seals ( Arctocephalus pusillus pusillus ) surfaced in South Africa; the behavior was attributed to domoic acid toxicity ( 4 , 5 ). On May 20, 2024, an unvaccinated domestic dog, henceforth referred to by its sample reference number, 170/24WC, from a walled suburban home in Cape Town was diagnosed with rabies using direct fluorescent antibody test (dFAT) on a brain tissue sample at the Agricultural Research Council–Onderstepoort Veterinary Research (Pretoria, South Africa). The owner suspected that a Cape fur seal had bitten the dog because the dog had a habit of approaching seals and sustained a bite wound while out of sight during an off-leash beach walk with the owner 2 weeks before the onset of clinical signs.
As part of the ensuing investigation, stakeholders in Cape Town were contacted to determine if any seals showing aggression or abnormal behavior had been observed or removed from beaches in the preceding month. A report stated that a Cape fur seal had been in a fight with dogs on Big Bay Beach in Cape Town on May 22, 2024, and suffered several injuries. The seal was captured by authorities and died in transit to a veterinary facility. A brain sample from this seal (sample reference 186/24WC) was obtained and tested positive for rabies by dFAT.
The Cape fur seal is the only resident pinniped species in southern Africa; an estimated 2 million animals are distributed from Baía dos Tigres in Angola to Algoa Bay, South Africa. The seals breed in colonies on land, where they frequently encounter people and face predation from terrestrial hunters such as the brown hyena ( Hyaena brunnea ) and the black-backed jackal ( 6 ). To our knowledge, the only previous confirmed case of rabies in a pinniped occurred in a ringed seal ( Pusa hispida ) in Svalbard, Norway in 1980 ( 7 ). We investigated to determine the origin and geographic spread of rabies virus infection in Cape fur seals in South Africa.
Figure 1 . Sampling locations for study of emergence of rabies in Cape fur seals, South Africa. Numbers next to circles indicate no. positive/total no. samples. Inset map shows location of study area...
Rabies is a notifiable disease in South Africa, and all suspected animal cases must be reported t…