Fungal & Infectious Diseases

During the past 2 decades, mucormycosis has emerged as an important fungal infection with high associated mortality rates. It is a life-threatening, invasive infection caused by fungi of the sub phylum Mucoromycotina, order Mucorales. The term mucormycosis was used for years and then was supplanted by zygomycosis for several decades. Based on molecular studies, mucormycosis is currently again the appropriate term. It has emerged as the third most common invasive mycosis in order of importance after candidiasis and aspergillosis in patients with hematological and allogeneic stem cell transplantation. Traditional risk factors for the development of invasive mucormycosis include uncontrolled diabetes, defects in host phagocytes, corticosteroid use, organ or stem cell transplantation and increased levels of available serum iron as a result of acidosis or administration of deferoxamine. In recent years, the disease has been increasingly seen in patients without traditional risk factors. With the advent of effective antifungal agents against Candida and Aspergillus spp., a growing population of immune-compromised hosts, improved diagnostic tools and possible selection pressure from widespread use of broad-spectrum antifungal agents, mucormycosis has emerged as an important infection. Breakthrough mucor in immune-suppressed patients empirically treated with voriconazole or caspofungin, which have no activity against Mucor, is being seen vey commonly. The relatively low frequency of mucormycosis in HIV infected patients reflects the uncommon occurrence of mucormycosis in this group compared with other immune-compromised population. Devastating rhino-orbital-cerebral and pulmonary infections are the most common syndromes caused by these fungi. Other organ involvement such as renal and gastrointestinal, are probably underdiagnosed. The need to make a rapid diagnosis is underscored by several hallmark features of mucormycosis including angioinvasion, thrombosis and tissue necrosis. These features result in poor penetration of anti-fungal agents to the site of infection, making radical de-bulking surgery essential in order to affect cure.