Epidemiological Study of Cryptococcus gattii Complex Infection in Domestic and Wild Animals in Oregon

The members of the Cryptococcus gattii species complex are the etiologic agents of potentially fatal human infection. C. gattii causes disease in both immunocompetent and immunocompromised hosts. In the early 2000s, infection caused by C. gattii emerged in the Pacific Northwest of the US. While many studies have been published about the human infection, the epidemiological characteristics of the infection in animals, with a possible role in human infection, have not been in investigated. Cases of C. gattii diagnosed in animals in Oregon from 2008 to 2019 were cataloged by county, species of animal, site of the infection, season of the year, and C. gattii genotype. One hundred and nine cases were diagnosed, and among the genotypes of C. gattii, VGII (Cryptococcus deuterogatti) with the genotypes VGIIa, VGIIb, and VGIIc was responsible for 98% of the cases. VGIIa was identified in more than 50% of the animals, and Cryptococcus bacilliporus (VGIII) was only isolated from cat patients. The majority of the infections were diagnosed in dogs and cats, although caprines, equines, camelids, ovines, and elk were also seen with the disease. The most common site of infection in dogs was the brain; that in cats was the nasal cavity and the skin, while the lung was the most affected site in caprines, equines, camelids and elk. Marion and Lane Counties account for the majority of the infections, followed by Clackamas, Benton, and Multnomah Counties. The infection was predominantly identified during the Fall and Winter months, except for Benton County, where it was seen more commonly during the Summer months. This study reviews all the cases identified by the Department of Public Health and by the veterinarians in Oregon in the years between 2008 and 2019.