Abstract
A 7.9 kg female 95 percent lanugo harbour seal pup was recovered from the beach at Camp Orkila, Northwest Orcas Island, Washington State and transported to the Wolf Hollow Wildlife Rescue Center. After 6 weeks in the rehabilitation center, the pup had gained only 0.86 kg and a small raised, black verruca was observed below the left nares. Over the course of the following week, the lesion increased to approximately 3 cm diameter, was biopsied July 12, 2010 and parapoxvirus was identified. On August 4, 2010, the pup rapidly deteriorated, vomited and died acutely. On gross examination, there were 3 lingual ulcers along the dorsal and dorsolateral aspect of the tongue, mucocutaneous villonodular to lobulated proliferative lesions, and the lungs featured generalized pulmonary edema and congestion. Histopathology substantiated the clinical and molecular findings and numerous Gram positive cocci were evident along the surface, as well as interspersed within the hyperplastic foci. In this case, bacteria involvement was likely opportunistic, secondary to disruption of the epidermis and bacterial colonization. Aerobic culture of the lung, brain and small intestines yielded methicillin resistant Staphylococcus aureus.
MRSA has been found in marine mammals, pets, livestock, and birds. Several strains circulate in susceptible hosts and genotyping of isolates assists in characterizing potential origins of infection. In this case, genetic analysis revealed spa type 1 (CMRSA-5 or CMRSA 7/10 (equivalent to USA300). Aside from CMRSA-5 in horses, these clones are rarely recovered from wildlife, domestic or production animals.1 CMRSA-2, the most common human clone in the region was not identified.
This is believed to be the first spa type I S. aureus from a marine mammal and among the first nonhuman infections in the Pacific Northwest. As both the parapoxvirus and S. aureus are zoonotic, veterinarians and facility managers should continue to instruct animal handlers of potential risks of infections.2 Appropriate measures to control MRSA include identification and separation of colonized and infected animals, restricting antibiotic use except with veterinary review and strict infection control measures including potentially restricting infected workers from contact with animals.
References
1. Dvorak G, Rovid-Spickler A, Roth J. eds. Handbook for zoonotic diseases of companion animals. The Center for Food Security and Public Health. Iowa State University, College of Veterinary Medicine, Ames, Iowa. 2008; pp. 177–184.
2. National Association of Public Health Veterinarians. Compendium of veterinary standard precautions for zoonotic disease prevention in veterinary personnel. J Am Vet Med Assoc 2008; 233: 415–430.