Blastoschizomyces capitatus pulmonary infections in immunocompetent patients: case report, case series and literature review.

Blastoschizomyces capitatus is an uncommon opportunistic yeast associated with infections in neutropaenic patients secondary to haematological malignancies, with a special predilection for the lungs. Globalisation and population migration impact on the epidemiology of infection with this organism but its effect on the immunocompetent population has rarely been described. We present here a case report, an overview of 11 other cases published between 2000 and 2016, and a comprehensive literature review of Blastoschizomyces pneumonia in the non-immunocompromised. The median age at diagnosis was 68 years (range 40-86 years) and more than half the cases reported a positive history of either current or past tobacco smoking. Six cases had either clinical or radiological evidence of chronic obstructive pulmonary disease and three had a history of prior treated tuberculosis. Fluconazole and itraconazole, alone or in combination, was the most utilised treatment. We conclude that unlike most other invasive yeast species, B. capitatus poses an infectious risk for immunocompetent patients, usually of middle to older age with risk factors for distorted lung architecture. Further research is warranted into the pathophysiology of Blastoschizomyces infections in the immunocompetent, including standardised treatment options.