Disseminated Fusarium solani infection in patients undergoing hematopoietic stem cell transplantation

Abstract

A patient with a hematological malignancy is one example of a type of immunocompromised host, and critical opportunistic infections such as mycosis are not rare during medical treatment for such malignancy. Candidiasis and aspergillosis are typical mycoses and their importance has been recognized widely and great progress attained in their prevention and medical treatment. However, allogenic hematopoietic stem cell transplantation (allo-HSCT) to treat hematological malignancy has spread, and the increase in emerging mycoses such as Fusarium infection is reported. Fusarium spp. are common soil organisms and important plant pathogens, and have been conventionally known as a causative fungus of superficial mycosis in the dermatology and the ophthalmology domain. Reports of profound or disseminated Fusarium infection are found in immunocompromised hosts with such condition as a hematological malignancy or organ transplant, and have shown an upward tendency in recent years. The symptoms of disseminated Fusarium infection are shown in many cases with persistent fever refractory to antibiotics and pneumonia, and this is a highly fatal infection which merges fungemia with multiple organ injury such as that in the lung, liver, spleen, kidney, and the heart. Disseminated Fusarium infection has a high rate of isolation in blood cultures, and the rate of diagnosis while a patient is alive is high compared with aspergillosis, zygomycosis, etc. Despite the administration of anti-fungal drugs following allo-HSCT, two reported cases showing the symptoms of disseminated Fusarium infection finally died. Although definite diagnosis of these cases was made by blood cultures, no medical treatment effect with the anti-fungal drugs was determined. Since the existing antifungals are not expected to cure disseminated Fusarium infection certainly, an early diagnosis and the development of a new antifungal are desired to improve the medical treatment results.