Imported mycoses: an update.

Abstract

Most of the fungal infections seen in Japan are caused by fungi existing in this country. Some fungal infections are seen in only limited areas of the world, and in these cases the causative fungi live in these limited areas. Fungal infections caused by these fungi in nonnative locations are called imported mycoses. This term is particularly applicable when the causative fungi are highly virulent and capable of causing biohazards. In Japan, the presently known imported mycoses include coccidioidomycosis (caused by Coccidioides immitis), histoplasmosis (caused by Histoplasma capsulatum), paracoccidioidomycosis (caused by Paracoccidioides brasiliensis), and penicilliosis marneffei (caused by Penicillium marneffei). Although no case has ever been reported in Japan, blastomycosis (caused by Blastomyces dermatitidis) is often included in this entity, because the fungus is highly contagious and its move from endemic areas is very frequent (Table 1). Pathogenic fungi indigenous to Japan generally affect immunocompromised patients, causing opportunistic infections. In contrast, the causative fungi of the imported mycoses have higher virulence than native fungi and possess the capacity to infect immunocompetent hosts, causing deep-seated and sometimes systemic infection. Great caution should be exercised when practioners are seeing these patients and, in particular, great care should be taken in the handling of the clinical specimens. Although few cases of patient-to-patient infection are known, biohazardous accidents during the isolation and identification of the causative fungi in clinical microbiology laboratories are fairly common.