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

TL;DR

This study examines the spread of Cryptococcus gattii infections in animals in Oregon, identifying patterns in species, locations, and seasons.

Contribution

The first comprehensive analysis of C. gattii infections in domestic and wild animals in Oregon.

Findings

VGII genotypes caused 98% of C. gattii infections in animals, with VGIIa being the most common.

Dogs and cats were most affected, with different infection sites observed across species.

Infections were most common in Marion and Lane Counties, primarily during Fall and Winter.

Abstract

An outbreak of infection caused by Cryptococcus gattii occurred in the Pacific Northwest region of the North America from 2008 to 2019. The pathogen is found in the environment and can infect humans and animals. This study is the first comprehensive study about the infection in domestic and wild animals. The study contains the incidence of infection by counties and months of the year, the genotypes of the pathogen causing those infections, the affected animal species, and the sites of infections in individual animals. The study looks at environmental factors that could have been associated with the infections. The study offers important information about the regions in the state, the clinical presentations, and the broad number of species of animals affected.

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.