martes, 21 de octubre de 2014

Blastomycosis Mortality Rates, United States, 1990–2010 - Volume 20, Number 11—November 2014 - Emerging Infectious Disease journal - CDC


Blastomycosis Mortality Rates, United States, 1990–2010 - Volume 20, Number 11—November 2014 - Emerging Infectious Disease journal - CDC

Volume 20, Number 11—November 2014


Blastomycosis Mortality Rates, United States, 1990–2010

Diana KhuuComments to Author , Shira Shafir, Benjamin Bristow, and Frank Sorvillo
Author affiliations: University of California, Los Angeles, California, USA (D. Khuu, S. Shafir, F. Sorvillo)Icahn School of Medicine at Mount Sinai, New York, New York, USA (B. Bristow)


Blastomycosis is a potentially fatal fungal infection endemic to parts of North America. We used national multiple-cause-of-death data and census population estimates for 1990–2010 to calculate age-adjusted mortality rates and rate ratios (RRs). We modeled trends over time using Poisson regression. Death occurred more often among older persons (RR 2.11, 95% confidence limit [CL] 1.76, 2.53 for those 75–84 years of age vs. 55–64 years), men (RR 2.43, 95% CL 2.19, 2.70), Native Americans (RR 4.13, 95% CL 3.86, 4.42 vs. whites), and blacks (RR 1.86, 95% CL 1.73, 2.01 vs. whites), in notably younger persons of Asian origin (mean = 41.6 years vs. 64.2 years for whites); and in the South (RR 18.15, 95% CL 11.63, 28.34 vs. West) and Midwest (RR 23.10, 95% CL14.78, 36.12 vs. West). In regions where blastomycosis is endemic, we recommend that the diagnosis be considered in patients with pulmonary disease and that it be a reportable disease.
Blastomycosis is a systemic infection caused by the thermally dimorphic fungus Blastomyces dermatitidis that can result in severe disease and death among humans and animals. B. dermatitidis is endemic to the states bordering the Mississippi and Ohio Rivers, the Great Lakes, and southern Canada; it is found in moist, acidic, enriched soil near wooded areas and in decaying vegetation or other organic material (1). Conidia, the spores, become airborne after disruption of areas contaminated with B. dermatitidis. Infection occurs primarily through inhalation of the B. dermatitidis spores into the lungs, where they undergo transition to the invasive yeast phase. The infection can progress in the lung, where the infection may be limited, or it can disseminate and result in extrapulmonary disease, affecting other organ systems (2).
The incubation period for blastomycosis is 3–15 weeks. About 30%–50% of infections are asymptomatic. Pulmonary symptoms are the most common clinical manifestations; however, extrapulmonary disease can frequently manifest as cutaneous and skeletal disease and, less frequently, as genitourinary or central nervous system disease. Liver, spleen, pericardium, thyroid, gastrointestinal tract, or adrenal glands may also be involved (3). Misdiagnoses and delayed diagnoses are common because the signs and symptoms resemble those of other diseases, such as bacterial pneumonia, influenza, tuberculosis, other fungal infections, and some malignancies (4). Accurate diagnosis relies on a high index of suspicion with confirmation by using histologic examination, culture, antigen detection assays, or PCR tests (5).
Antifungal agents, such as itraconazole for mild or moderate disease and amphotericin B for severe disease, can provide effective therapy, especially when administered early (1,2). With appropriate treatment, blastomycosis can be successfully treated without relapse; however, case-fatality rates of 4%–22% have been observed (4,69). Although spontaneous recovery can occur (10,11), case-patients often require monitoring of clinical progress and administration of drugs on an inpatient basis. Previous studies estimated average hospitalization costs for adults to be $20,000; that is likely less than the current true cost (12). Some reviews of outbreaks indicate a higher distribution of infection among persons of older age, male sex (2,13), black, Asian, and Native American racial/ethnic groups (3,13), and those who have outdoor occupations (13,14). Both immunocompetent and immunocompromised hosts may experience disease and death (2,6,1519), although B. dermatitidis disproportionately affects immunocompromised patients, who tend to have more rapid and extensive pulmonary involvement, extrapulmonary infection, complications, and higher mortality rates (25%–54%) (2,6,1619).
Past studies have expanded the knowledge about blastomycosis through focusing on cases documented in specific immunocompromised persons and statewide occurrences or in areas in which the disease is endemic (4,69,1618); however, such studies may be limited for making definitive conclusions by their scope and small sample size. Much remains unknown about the public health burden of blastomycosis-related deaths in the United States. Reports suggest an increase in the number of blastomycosis cases in recent years (13,20). Clearer identification of risk factors from national data may raise awareness of blastomycosis in the United States and support adding it to the list of reportable diseases in regions where the pathogen is endemic to improve surveillance and control. In this study, we assessed the public health burden of blastomycosis-related deaths by examining US mortality-associated data and evaluating demographic, temporal, and geographic associations as potential risk factors.


We thank Matthew Redelings for his contributions to the analysis of data in this study.
Ms Khuu is a doctoral student in epidemiology at the University of California, Los Angeles, School of Public Health. Her research interests include the epidemiology and control of infectious diseases.


  1. Chapman SWSullivan DC. Blastomycosis. In: Infectious disease: diagnosis and treatment of human mycoses. Totowa (NJ): Humana Press. 2008. p. 279–293.
  2. Saccente MWoods GLClinical and laboratory update on blastomycosis. Clin Microbiol Rev2010;23:36781 . DOIPubMed
  3. Lemos LBGuo MBaliga MBlastomycosis: organ involvement and etiologic diagnosis. A review of 123 patients from Mississippi. Ann Diagn Pathol.2000;4:391406DOIPubMed
  4. Chapman SWLin ACHendricks KANolan RLCurrier MMMorris KREndemic blastomycosis in Mississippi: epidemiological and clinical studies.Semin Respir Infect1997;12:21928 .PubMed
  5. Hage CAKnox KSWheat LJEndemic mycoses: overlooked causes of community acquired pneumonia. Respir Med2012;106:76976.DOIPubMed
  6. Pappas PGThrelkeld MGBedsole GDCleveland KOGelfand MSDismukes WEBlastomycosis in immunocompromised patients. Medicine.1993;72:31125 . DOIPubMed
  7. Centers for Disease Control and PreventionBlastomycosis—Wisconsin, 1986–1995. MMWR Morb Mortal Wkly Rep1996;45:6013 .PubMed
  8. Pappas PGPottage JCPowderly WGFraser VJStratton CWMcKenzie SBlastomycosis in patients with the acquired immunodeficiency syndrome. Ann Intern Med1992;116:84753 and. DOIPubMed
  9. Crampton TLLight RBBerg GMMeyers MPSchroeder GCHershfield ESEpidemiology and clinical spectrum of blastomycosis diagnosed at Manitoba hospitals. Clin Infect Dis2002;34:13106DOIPubMed
  10. Klein BSVergeront JMDavis JPEpidemiologic aspects of blastomycosis, the enigmatic systemic mycosis. Semin Respir Infect1986;1:2939.PubMed
  11. Bradsher RWBlastomycosis. Clin Infect Dis1992;14:S8290DOIPubMed
  12. Chu JHFeudtner CHeydon KWalsh TJZaoutis TEHospitalizations for endemic mycoses: a population-based national study. Clin Infect Dis.2006;42:8225DOIPubMed
  13. Benedict KRoy MChiller TDavis JP. Epidemiologic and ecologic features of blastomycosis: a review. Current Fungal Infection Reports.2012;6:327–35.
  14. Choptiany MWiebe LLimerick BSarsfield PCheang MLight BRisk factors for acquisition of endemic blastomycosis. Can J Infect Dis Med Microbiol2009;20:11721 .PubMed
  15. Recht LDDavies SFEckman MRSarosi GABlastomycosis in immunosuppressed patients. Am Rev Respir Dis1982;125:35962 .PubMed
  16. Lemos LBBaliga MGuo MBlastomycosis: The great pretender can also be an opportunist. Initial clinical diagnosis and underlying diseases in 123 patients. Ann Diagn Pathol2002;6:194203DOIPubMed
  17. Grim SAProia LMiller RAlhyraba MCostas-Chavarri AOberholzer JA multicenter study of histoplasmosis and blastomycosis after solid organ transplantation. Transpl Infect Dis2012;14:1723DOIPubMed
  18. Witzig RSHoadley DJGreer DLAbriola KPHernandez RLBlastomycosis and human immunodeficiency virus: three new cases and review. South Med J1994;87:7159DOIPubMed
  19. Vasquez JEMehta JBAgrawal RSarubbi FABlastomycosis in northeast Tennessee. Chest1998;114:43643DOIPubMed
  20. Carlos WGRose ASWheat LJNorris SSarosi GAKnox KSBlastomycosis in Indiana: digging up more cases. Chest2010;138:137782.DOIPubMed
  21. Rothman KJLash TLGreenland S. Modern epidemiology. 3rd ed. Philadelphia: Wolters Kluwer Health; 2012.
  22. Gardner JWSanborn JSYears of potential life lost (YPLL)—what does it measure? Epidemiology1990;1:3229DOIPubMed
  23. Centers for Disease Control and Prevention. Health, United States, 2012: with special feature on emergency care. 2013 May [cited 2013 Jul 30].
  24. Dworkin MSDuckro ANProia LSemel JDHuhn GThe epidemiology of blastomycosis in Illinois and factors associated with death. Clin Infect Dis.2005;41:e10711DOIPubMed
  25. Klein BSMolecular basis of pathogenicity in Blastomyces dermatitidis: the importance of adhesion. Curr Opin Microbiol2000;3:33943.DOIPubMed
  26. Roy MBenedict KDeak EKirby MAMcNiel JTSickler CJA large community outbreak of blastomycosis in Wisconsin with geographic and ethnic clustering. Clin Infect Dis2013;57:65562DOIPubMed



Suggested citation for this article: Khuu D, Shafir S, Bristow B, Sorvillo F. Blastomycosis mortality rates, United States, 1990–2010. Emerg Infect Dis. 2014 Nov [date cited].
DOI: 10.3201/eid2011.131175

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