Blastomycosis Statistics and Maps
Blastomycosis is a fungal infection usually acquired by breathing in the spores of the fungus (Blastomycosis dermatitidis) that grows in moist soils, particularly in wooded areas and along waterways. Blastomycosis occurs most often in people living in the central and southeastern United States, particularly in the Mississippi and Ohio River valleys and the Great Lakes states. In Minnesota, blastomycosis is most common in St. Louis, Itasca, Cass, Beltrami, Washington, and Chisago counties.
In addition to surveillance of cases in humans, the Minnesota Department of Health and the Board of Animal Health are also studying blastomycosis in animals to better define areas in the state where the disease is found. Veterinary cases (mostly dogs) are more numerous than human cases and the location where the pet was exposed can often be more easily identified.
From 1999 -- 2017, 613 laboratory-confirmed cases of human blastomycosis were reported to MDH. A confirmed case of blastomycosis is defined as a Minnesota resident with (1) a positive Blastomyces culture; (2) Blastomyces organisms visualized in tissue or bodily fluid; or (3) a positive Blastomyces antigen test with compatible clinical symptoms.
- Blastomycosis occurs most commonly in dogs; however cats and horses have also been known to become infected.
- From 1999-2014, 1,149 laboratory-confirmed cases of veterinary blastomycosis were reported to MDH. A confirmed case is defined as a Minnesota resident animal with: a positive urine or serum antigen test and compatible clinical symptoms (or) B. dermatitidis organisms cultured or visualized from tissue or body fluid.
- Veterinary Blastomycosis, MN 1999-2016, Month of Diagnosis (PDF)
Graph of veterinary blastomycosis cases by month of diagnosis.
Veterinary Blastomycosis Cases in Minnesota by Year, 1999-2016 (PDF)
Graph of veterinary blastomycosis cases by year.
- Veterinary Blastomycosis Cases by County of Residence, 1997-2016 (PDF)
Map of canine blastomycosis cases by county of residence.
- Veterinary Blastomycosis Cases in Minnesota by Probable County of Exposure, 1999-2016 (PDF)
Graph of canine blastomycosis cases by probable county of exposure.
Minnesota Department of Health, Disease Control Newsletter; June 2003: Volume 31, Number 4.