Introduction to Candida

Candidiasis is the prototypic opportunistic fungal disease. Candida spp. reside most commonly in the gastrointestinal tract1,2 and vagina, where they are normally held in check by as-yet incompletely defined local factors that include competition with the resident bacterial flora and innate effectors of nonspecific mucosal resistance.3,4 Infrequently, but under a wide variety of clinical circumstances, these normally inconspicuous commensals can multiply on or invade through the mucosal surface to initiate local or systemic disease. Various immunologic and nonimmunologic conditions can predispose to such opportunistic infections.5 Among the former are certain malignancies6–8 and the use of cytotoxic or immunosuppressive therapy.9,10 Nonimmunologic predisposing factors include diabetes,11 trauma,12 pregnancy,13 antibiotic therapy,7 and hyperalimentation.14 Not infrequently, such predisposing factors occur in combination.