Beyond Rabies: Are Free-Ranging Skunks (Mephitis mephitis) in British Columbia Reservoirs of Emerging Infection?

Wild animal reservoirs are an important source of emerging and zoonotic infection. Skunks (Mephitis mephitis) are a reservoir of skunk strain rabies virus in Canada, with the exception of some areas including the province of British Columbia (BC). Beyond rabies, the reservoir status of skunks for emerging and zoonotic pathogens in BC is unknown. From March 2011 to February 2015, 50 free-ranging skunks were necropsied and tested for 4 pathogens: influenza A, Aleutian disease virus (ADV), Leptospira spp. and Salmonella spp. Two skunks (4%) with respiratory disease caused by influenza A (H1N1) pdm09 were detected during the human flu season suggesting that skunks may represent a target population for reverse zoonosis of this strain of influenza A virus. High prevalence of ADV infection was detected (43/50, 86%). Two of the infected skunks exhibited Aleutian disease (AD) suggesting that skunks act as both a reservoir and a target population for the virus. Most studies of ADV have focused on the potential for infection of free-ranging species living near mink farms. Our study suggests that urban skunks may be a primary host for the virus independent of domestic mink. Whether skunks act as a reservoir of ADV infection for other peridomestic species will depend on host specificity of the viral strains. Leptospira interrogans was detected in 18% (9/49) of the skunks. Identification of the serovar(s) detected is needed to determine any public health risk of leptospirosis following exposure to infected skunks. Salmonella spp. was isolated from three of 43 skunks (7%), specifically S. Typhimurium, S. Muenchen and S. Enteritidis. These serotypes cause disease in humans, but the low prevalence of infection suggests there is a low risk for zoonotic transmission.