The epidemiology of blastomycosis in dogs: north central Wisconsin, USA

Geodemographic Features of Human Blastomycosis in Eastern Wisconsin

“…19 This is true involving Vilas County, 16,31 however, statistical association of forests with cases versus controls was not seen, perhaps because of the extensive forestation in the region. 13 In the present study, multivariable analysis revealed significantly increased odds of a blastomycosis home site being in close proximity to a park, forest or farm field. Perhaps these features, often considered to be more typical of rural areas but sometimes found in association with urban and suburban areas, provide important ecological habitat for Blastomyces to persist or temporarily thrive such that spores of the fungus blow into or propagate in the case property, 10,11,21 or the resident is exposed to the fungus during a short walk or soil-disturbing activity.…”

“…39 Recent studies have suggested differing clinical features of blastomycosis among different human genetic and ethnic groups. 8,40 In Vilas County, in rural northern Wisconsin, human and dog blastomycosis cases were associated with close proximity to waterways, 13,16 perhaps most especially lower elevation lakes. 12 In urban Milwaukee County, blastomycosis cases were most commonly associated with open inland water sites, followed by the Lake Michigan shoreline, compared to highly organized and controlled inland waterways.…”

“…3 While reports are emerging from lesser endemic portions of the state, 4,5 most epidemiologic investigations of sporadic and outbreak cases have focused on rural northern and central Wisconsin. [6][7][8][9][10][11][12][13][14][15][16][17] Despite generally lower incidence rates of blastomycosis in more urban eastern and southeastern Wisconsin counties, case numbers often meet or exceed those from their rural Wisconsin counterparts. For example, recent annual incidence rates for rural Vilas County, Wisconsin (27/100,000) 10 equate to 5.5 cases per year from this county.…”

“…12 In other studies the home sites were personally visited, however, observations of some portions of properties and the ability to very accurately measure distances to the nearest feature of interest were limited by observation from the nearest public access. 5,[13][14][15][16] Another recent study of blastomycosis endemic regions nationwide used only county level variables. 3 Thus, important geographic features or sources of chemical exposure on or in close proximity to the home sites of blastomycosis cases could have escaped observation.…”

“…3,5,[12][13][14][15][16] Linear distances were calculated via map view. Variables of interest were explored as defined and summarized in Table 1.…”