Genitourinary fungal infections: a therapeutic conundrum

Fungi cause 8% of nosocomial infections. This is caused, in part, by the increasing pool of immunocompromised patients. Elderly, transplant and HIV patients, as well as premature infants, have become prime candidates for invasive fungal infections. The widespread use of broad spectrum antibiotics plays a role. Utilisation of appropriate antifungal treatment modalities requires an understanding of the pathogenesis of infection. This is a challenging problem as fungi can cause different clinical manifestations that depend on the type of fungal species and patient response to the infection. Although Candida spp. are the most frequent pathogen, other species such as Aspergillus and Cryptococcus have become major pathogens. Environmental fungi which include Blastomyces, Coccidioides and Histoplasma have become more aggressive in the vulnerable patient. The genitourinary system can be a source or target of disseminated fungal infection. Diagnosis depends on clinical awareness, utilisation of appropriate diagnostic modalities, imaging modalities and a thorough clinical assessment. The treatment of primary (Blastomyces, Coccidioides, Histoplasma) infection generally requires amphotericin B (AmpB). The opportunistic infections (Aspergillus, Cryptococcus and Candida) may respond to the triazoles although AmpB remains the 'gold standard'. Infections caused by Candida spp. represents the greatest challenge to the clinician. The presence of Candida spp. in the urine may indicate colonisation or infection. Untreated, Candida can remain as a 'saprophyte' or develop ascending infection, sepsis or death. The prophylactic use of fluconazole may in itself result in resistant infection, hence the 'conundrum'.