Abstract
Case definitions in disease surveillance and conservation medicine allow wildlife professionals and conservation organizations to have a common language in what signs they are looking for when it comes to wildlife disease investigations, as well as their research. An evidence-based standardized case definition framework was created for a common marine mammal disease, Brucella ceti, to further improve the proper classification of “suspected”,
“probable”, and “confirmed” cases. This was created in collaboration with the National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service, Marine Mammal and Turtle Division’s Marine Mammal Branch, along with other stranding organizations. This report included background information on Brucella ceti through an extensive literature review, as well as standard case definition criteria, including signalment (sex, age class, etc.), clinical signs, diagnostic tests, and epidemiological criteria for diagnosis. Through this research, bacterial culture, PCR/qPCR, and sequencing provided the strongest confirmatory result, while histopathology and immunofluorescence were best suited for detecting a connection between a Brucella ceti infection and disease lesions. Serological evidence was best utilized as a supportive diagnostic method for exposure. In addition, neurological signs and poor body condition were noted as the most common clinical signs involved with a B. ceti infection, which can also be attributed to neurobrucellosis as a primary infection. These tools can be used to assist stranding organizations to help properly identify Brucella ceti, following set guidelines shown by clinical and physiological observations on a case-by-case basis.