Fungal infections in immunocompromised hosts are common and are associated with significant mortality and morbidity. These are either endemic fungi caused by ubiquitous fungi such as: Histoplasma capsulatum and Mucor spp, or opportunistic fungi such as: Candida species, Aspergillus species, pneumocystic jirovecii and Cyptococcus neoformans. Opportunistic fungal infections are the most common fungal infections seen in the immunocompromised and are attributed to decreased CD4+ T cell counts, neutrophil counts, and general immunity. They are seen in HIV-positive patients, those who have undergone major surgery, patients with hematologic disorders, and those receiving corticosteroids, cytotoxic or suppressive chemotherapy. As a result, infections such as: candidiasis, cryptococcosis, pneumocystis pneumonia and aspergillosis are disseminated in these hosts. Candidiasis is usually caused by Candida albicans, a normal oral flora in the genitourinary tract, gastrointestinal tract and on the skin. It forms biofilms on any surface and causes mucosal and systemic infections in immunocompromised hosts, disseminated as oral thrush, vulvovaginitis and endocarditis, among others. Although Candida albicans remains the major cause of nosocomial infections, other non-albicans Candida species such as: Candida glabrata, Candida tropicalis and Candida parapsilosis are becoming increasingly common. According to Pfaller et al., 2007, Candida glabrata was the second leading cause of invasive infections in the United States, while the ARTEMIS global antifungal surveillance program found that Candida albicans caused the greatest number of fungal infections in the world, followed by Candida glabrata, Candida tropicalis and Candida parapsilosis respectively. The main predisposing factor...... middle of article ....... However, infections related to aspergillosis, namely: endophthalmitis, endocarditis and abscesses of the myocardium, kidneys , liver, spleen, soft tissues and bones may occur. (Reference). These infections could progress rapidly in severely immunocompromised hosts such as: patients with leukemia, those receiving corticosteroids or cytotoxic therapy and those who have recently undergone bone marrow transplantation or patients with advanced AIDS or chronic granulomatous disease. As a result, fever, blood vessel invasion leading to multifocal infiltrates and spread to the central nervous system, may occur [76]. The fungus evades the host's immune system to cause diseases through the expression of several genetic products such as: cell wall assembly, conidia germination, hyphae elongation and growth, resistance to oxidative stress and nutrient acquisition, among others..