How common is blastomycosis?
Overall, blastomycosis is uncommon. Most cases occur in the United States and Canada. In states where blastomycosis is reportable, yearly incidence rates are approximately 1 to 2 cases per 100,000 population.1–3 Wisconsin may have the highest incidence of blastomycosis of any state, with yearly rates ranging from 10 to 40 cases per 100,000 persons in some northern counties.4
Public health surveillance for blastomycosis
Blastomycosis is reportable in certain states. Check with your local, state, or territorial public health department for more information about disease reporting requirements and procedures in your area.
Although most cases of blastomycosis are not associated with outbreaks, blastomycosis outbreaks linked to a common source do occasionally occur. Common-source blastomycosis outbreaks often involve activities that disrupt soil such as construction5,6 or excavation,7,8 or recreational activities near lakes or rivers such as hunting,9 fishing,10 or camping.11
Deaths due to blastomycosis
An analysis of blastomycosis deaths in the United States found that 1,216 blastomycosis-related deaths occurred during 1990–2010, and the overall age-adjusted mortality rate was 0.21 per 1 million person-years.12
- CDC. Blastomycosis in Wisconsin, 1985–1994. Wis Epidemiol Bull. 1995;16(2):1–5.
- Herrmann JA, Kostiuk SL, Dworkin MS, Johnson YJ. Temporal and spatial distribution of blastomycosis cases among humans and dogs in Illinois (2001–2007)external icon. J Am Vet Med Assoc. 2011;239 (3):335–43.
- Carlos WG, Rose AS, Wheat LJ, Norris S, Sarosi GA, Knox KS, et al. Blastomycosis in Indiana: digging up more casesexternal icon. Chest. 2010;138(6):1377–82.
- Benedict K, Roy M, Chiller T, Davis JP. Epidemiologic and ecologic features of blastomycosis: a reviewexternal icon. Current Fungal Infection Reports. 2012.
- Tosh FE, Hammerman KJ, Weeks RJ, Sarosi GA. A common source epidemic of North American blastomycosisexternal icon. Am Rev Respir Dis. 1974;109(5):525–9.
- Kitchen MS, Reiber CD, Eastin GB. An urban epidemic of North American blastomycosisexternal icon. Am Rev Respir Dis. 1977;115 (6):1063–6.
- Baumgardner DJ, Burdick JS. An outbreak of human and canine blastomycosisexternal icon. Rev Infect Dis. 1991;13(5):898–905.
- MacDonald PD, Langley RL, Gerkin SR, Torok MR, MacCormack JN. Human and canine pulmonary blastomycosis, North Carolina, 2001-2002external icon. Emerg Infect Dis. 2006;12(8):1242–4.
- Armstrong CW, Jenkins SR, Kaufman L, Kerkering TM, Rouse BS, Miller Jr. GB. Common-source outbreak of blastomycosis in hunters and their dogsexternal icon. J Infect Dis. 1987;155(3):568–70.
- Klein BS, Vergeront JM, DiSalvo AF, Kaufman L, Davis JP. Two outbreaks of blastomycosis along rivers in Wisconsin. Isolation of Blastomyces dermatitidis from riverbank soil and evidence of its transmission along waterwaysexternal icon. Am Rev Respir Dis. 1987;136 (6):1333–8.
- Cockerill 3rd FR, Roberts GD, Rosenblatt JE, Utz JP, Utz DC. Epidemic of pulmonary blastomycosis (Namekagon fever) in Wisconsin canoeistsexternal icon. Chest. 1984;86(5):688–92.
- Khuu D, Shafir S, Bristow B, Sorvillo F. Blastomycosis mortality rates, United States, 1990-2010external icon. Emerg Infect Dis. 2014 Nov;20(11):1789-94.