Risk factors of severe blastomycosis and comparison of diagnosis and outcomes between immunocompetent and immunocompromised patients

Abstract

Background Blastomycosis is an endemic fungal infection that causes pulmonary and systemic disease. It can occur irrespective of the patient's immune status. The risk factors associated with the severity of the disease are not well studied. Methods This is a retrospective study of patients admitted with blastomycosis at the University of Kentucky Hospital from 2004 to 2019. Logistic regression was used to identify variables associated with severe blastomycosis. Results A total of 76 patients were identified; 22 (28.9%) had at least one immunosuppressive condition. Pulmonary blastomycosis was reported in 49/76 (65%) of the patients and disseminated infection in 27/76 (35.5%). All diagnostic tests were not significantly different in diagnostic results in immunocompromised vs immunocompetent patients. Cultures and histopathology were positive in 56/61 (91.8%) and 54/63 (85.7%) respectively. Blastomyces or Histoplasma antigen test was positive in 13/17 (76.4%) in immunocompromised patients compared to 26/42 (61.9%) in immunocompetent patients. Immunocompromised patients were more likely to be admitted to the hospital and ICU compared to immunocompetent patients. In the multivariate analysis, pulmonary multilobar disease (RR 5.68; 95% CI 2.13–15.15), obesity (RR 2.39; 95% CI 1.26‐4.51), diabetes mellitus (RR 3.50; 95% CI 1.38‐8.90) and immunosuppression (RR 2.28; 95% CI 1.14‐4.56) were significant independent risk factors for severe blastomycosis. Inpatient mortality proportion was higher in immunocompromised patients but not statistically significant. Conclusion Pulmonary multilobar disease, obesity, diabetes mellitus and immunosuppression were risk factors associated with severe blastomycosis. Immunocompromised patients required more frequent hospitalisations compared to immunocompetent patients.

Beware of the Acute Respiratory Distress Syndrome in a Pulmonary Blastomycosis!

“…Immunocompromised patients required more frequent hospitalizations compared with immunocompetent patients. 2 Infection can be seen more commonly in young adults; more in men than in women. It can be seen in all races but seen more in African Americans.…”

Clinical Manifestations of Human Exposure to Fungi

“…No person-to-person transmission has been reported [ 219 ]. The risk factors associated with blastomycosis include age (adult), gender (male), and underlying medical conditions (e.g., pulmonary multilobar disease, obesity, diabetes mellitus, and immunosuppression) [ 220 , 224 ].…”

“…Diagnosis requires a detailed medical and travel history, symptoms record, physical examinations, lab tests (histopathology, culture, antibody testing, B. dermatitidis antigen detection, and molecular identification from tracheal aspirates, sputum, bronchoalveolar lavage, bone, blood, cerebrospinal fluid (CSF), prostatic tissue, urine), and imagological tests (X-ray) [ 224 , 225 ].…”