Antifungal drug resistance in developing countries

Opportunistic fungal infections are a major cause of morbidity and mortality in immunosuppressed patients; and in HIV-positive individuals, infections due to Candida, Cryptococcus, and Pneumocystis are AIDS-defining illnesses. The widespread use of antifungal drugs, particularly triazole drugs, has led to the emergence of primary resistance, which largely reflects infection with inherently less susceptible strains. Secondary resistance in normally susceptible strains also occurs and involves a variety of mechanisms including target site modification and drug efflux transporters. Resistance is a clinical management issue, but it has remained relatively constant in most developed countries. In developing countries, resistance is minimal due to limited antifungal therapy. However, as access to these drugs increases, it is particularly important to evaluate trends that reflect evolving resistance issues observed elsewhere, especially among individuals with HIV/AIDS.