Zoonotic agents are defined as those microbial pathogens shared in nature by humans and lower vertebrate animals. In marine mammals there are at least 15 of these zoonotic pathogens that have been recognized. Their potential for transmission to humans and between animals is however poorly defined.

In this presentation 2 zoonotic diseases will be discussed: blastomycosis arid erysipelas. The former has been recognized clinically in pinnipeds and the hematology and pathology will be presented. The disease has also been recognized in dolphins with one instance of transmission to humans. A specific antigen of Blastomyces dermatitidis was isolated and used in the ELISA. An average of 35% wild and captive dolphins were found to be sufficiently challenged by this fungus to have elevated antibody levels.

Erysipeloid is a common zoonotic disease in fish handlers and recognized bite/abrasion wounds of marine mammal handlers. In 2 previous presentations to the IAAAM the isolation and characterization of Erysipelothrix rhusiopathiae pinnipeds and human lesions were discussed. The serological profile in many captive and wild pinnipeds and cetaceans was also presented. These antibody studies (published in Dis. Aquat. Org., Vol. 3) used as the antigen a surface, outer membrane protein. The antigen has since been found to not be related to virulence as shown in a mouse protection test. In this presentation studies on the use of a surface polysaccharide antigen and the deeper wall antigen associated with virulence as described by Vervey and White, will be presented. To determine the level of antibody associated with immunity after vaccination, mouse protect studies with different levels of antibody were used. Protection appears to be in the 01) range 0.8-1.0.