Clinical Manifestations and Outcomes in Immunocompetent and Immunocompromised Patients With Blastomycosis

Abstract

Background Blastomyces is a dimorphic fungus that infects persons with or without underlying immunocompromise. To date, no study has compared the clinical features and outcomes of blastomycosis between immunocompromised and immunocompetent persons. Methods A retrospective study of adult patients with proven blastomycosis from 2004–2016 was conducted at the University of Wisconsin. Epidemiology, clinical features, and outcomes were analyzed among solid-organ transplantation (SOT) recipients, persons with non-SOT immunocompromise (non-SOT IC), and persons with no immunocompromise (NIC). Results A total of 106 cases met the inclusion criteria including 74 NIC, 19 SOT, and 13 non-SOT IC (malignancy, HIV/AIDS, idiopathic CD4+ lymphopenia). The majority of patients (61.3%) had at least 1 epidemiologic risk factor for acquisition of Blastomyces. Pneumonia was the most common manifestation in all groups; however, immunocompromised patients had higher rates of acute pulmonary disease (P = .03), more severe infection (P = .007), respiratory failure (P = .010), and increased mortality (P = .02). Receipt of SOT primarily accounted for increased severity, respiratory failure, and mortality in immunosuppressed patients. SOT recipients had an 18-fold higher annual incidence of blastomycosis than the general population. The rate of disseminated blastomycosis was similar among NIC, SOT, and non-SOT IC. Relapse rates were low (5.3–7.7%). Conclusions Immunosuppression had implications regarding the acuity, severity, and respiratory failure. The rate of dissemination was similar across the immunologic spectrum, which is in sharp contrast to other endemic fungi. This suggests that pathogen-related factors have a greater influence on dissemination for blastomycosis than immune defense.

Fungal Infections in Liver Transplant Recipients

“…Time from transplantation to infection is bimodal; in the TRANSNET study, 40% of 64 cases were diagnosed within the first 6 months, and 34% ranging from 2 to 11 years [ 73 ]. This pattern was seen in other cohorts [ 78 , 79 ].…”

“…Outside these regions, cases may represent remote travel, reactivation, or donor-derived infection particularly within the first month after transplantation [ 75 , 77 ]. Donor-derived blastomycosis has not been reported [ 78 ]. Routine screening and prophylaxis are only recommended for coccidioidomycosis in its endemic region [ 75 ].…”

“…The incidence of histoplasmosis in a TRANSNET study was 0.102%. In a single center in Wisconsin, the incidence of blastomycosis was 0.27%, 18 times higher than in the general population [ 73 , 78 ]. Therefore, most guidance on endemic mycoses in liver transplant recipients is extrapolated from cohorts evaluating all SOTRs.…”

“…Presentation ranges from indolent pulmonary infection to acute respiratory distress syndrome (ARDS) and extrapulmonary dissemination to the skin, osteoarticular system, CNS, and genitourinary system [ 75 ]. SOTRs are at increased risk of severe disease, dissemination, and death [ 75 , 76 , 78 , 79 ]. The rates of dissemination in SOTRs were 81% for histoplasmosis [ 79 ], 75% for coccidioidomycosis [ 77 ], and 37.5% for blastomycosis in [ 78 ].…”

Blastomycosis Surveillance in 5 States, United States, 1987–2018

“…Blastomycosis often results in severe illness, even in previously healthy persons ( 9 ), but this observation might be influenced by underdetection of asymptomatic or milder, self-resolving disease. The high hospitalization rate of 57% noted in this analysis demonstrates that blastomycosis surveillance detects severe cases, which is typical for passive disease surveillance.…”