Candidiasis

Candidaspecies were once largely regarded merely as causes of aggravating, but rarely life-threatening mucocutaneous infections such as thrush, vulvovaginitis, and intertrigo. Now, however,Candidaspecies have assumed the role of major nosocomial pathogens. This change has paralleled the advent of aggressive cancer chemotherapy, the widespread use of parenteral nutrition, and the practice of advanced surgical techniques including cardiovascular procedures.Candidais a heterogeneous genus presently grouped with the Fungi Imperfecti (Deuteromycetes). There are over 80 species ofCandida; only seven, however, have been recovered from humans:Candida albicans, Candida tropicalis, Candida pseudotropicalis, Candida guilliermondi, Candida krusei, Candida parapsilosis, andCandida stellatoidea. Approximately 90% the systemicCandidainfections are due toC. albicans; most of the remaining infections are due toC. tropicalis. Candidaspecies are normal commensals of humans. They are commonly found on the skin, in the gastrointestinal tract, sputum, the female genital tract, and urine from catheterized bladders.C. albicansis found only in human beings and in animal reservoirs. In other sites, such as hospital environments,Candidaprobably represents contamination by human excreta. OtherCandidaspecies may be cultured from soil and other environmental locations. UnlikeAspergillusspecies,Candidaspecies are uncommon laboratory contaminants.