Candidiasis and opportunistic mycosis in human

Abstract

Pathogenic fungi cause serious diseases in humans, plants and animals. These include mainly, Candida spp., Aspergillus spp., Cryptococcus spp., Fusarium spp., and Pneumocytis spp. Candida species cause infections in individuals with deficient immune systems, and Th1-type cell-mediated immunity (CMI) is required for clearance of this fungal infection. Candida albicans is an opportunistic pathogen of humans and has a parasexual cycle that appears to be stimulated by environmental stresses. Aspergilli represent the most common pathogenic species especially for Aspergillus flavus and A. fumigatus. A. flavus produces aflatoxins which act both as toxins and carcinogens, and can potentially contaminate foods. A. clavatus causes allergic disease of human; its symptoms include; fever, cough chest pain or breathlessness. Cryptococcus neoformans is one of the most effective human pathogens; it causes severe form of meningitis and meningo-encephalitis in patients with HIV infection and AIDS. C. gattii was endemic to tropical parts of Africa and Australia; cause disease in immunocompromised people. Fusarium spp. are important pathogenic mold fungi; second only to Aspergillus spp. Fusaria also produce toxins that could cause poisoning through consumption of toxin-contaminated foods. The aims of this review were to highlight the etiology, risk factors, pathogenesis, human defence and preventive measures of some of the most common fungal human pathogens, to avoid infections and their subsequent cause of fatal diseases.