Pathogenesis of Aleutian Mink Disease Virus Infection—Comparison of Natural Transmission with Experimental Aerosol and Intraperitoneal Inoculation

Though intraperitoneal (IP) inoculation is not the natural pathway of Aleutian Mink Disease Virus (AMDV) infection in mink, it is frequently used experimentally. To investigate AMDV pathogenesis, we compared the effects of IP, aerosol (AE), and natural infection in mink. Forty-six sapphire mink were divided into groups: negative controls, IP and AE AMDV-inoculated mink, and sentinels exposed to IP-inoculated mink for two-week periods. Mink in the control, IP, and AE groups were euthanized 2, 5, or 10 weeks post-inoculation. The mink were tested for AMDV antibodies and by PCR on serum samples throughout the study, and by PCR and histology in organs after euthanasia. The sentinel mink were introduced to determine when the risk of natural transmission was highest. AMDV was detected in the sentinels exposed during weeks 3–6, indicating that AMDV transmission risk is highest early in infection, before antibody-positive animals can be detected on the farm. Infection in the AE group progressed more gradually than in the IP group, which developed more pronounced lesions and higher viral loads in the liver. Compared to IP inoculation, the aerosol model provides a superior experimental approach for studying natural infection and transmission of AMDV.