Current Fungal Infection Reports最新文献

Purpose of review: Invasive fungal infections are a complication of COVID-19 disease. This article reviews literature characterizing invasive fungal infections associated with COVID-19.

Recent findings: Multiple invasive fungal infections including aspergillosis, candidiasis, pneumocystosis, other non-Aspergillus molds, and endemic fungi have been reported in patients with COVID-19. Risk factors for COVID-19-associated fungal disease include underlying lung disease, diabetes, steroid or immunomodulator use, leukopenia, and malignancy. COVID-19-associated pulmonary aspergillosis (CAPA) and COVID-19-associated mucormycosis (CAM) are the most common fungal infections described. However, there is variability in the reported incidences related to use of differing diagnostic algorithms.

Summary: Fungal pathogens are important cause of infection in patients with COVID-19, and the diagnostic strategies continue to evolve. Mortality in these patients is increased, and providers should operate with a high index of suspicion. Further studies will be required to elucidate the associations and pathogenesis of these diseases and best management and prevention strategies.

Purpose of review: There is global increase in the incidence of mucormycosis. However, a sudden increase in the COVID-associated mucormycosis (CAM) was noted, particularly in India, during the second wave of the COVID-19 pandemic. The interplay of factors involved in the pathogenesis is complex. In this review, the influence of pre-existing disease, exaggerated risk factors, altered milieu due to COVID-19 itself and the consequences of its treatment on the host pathogen interactions leading to the disease and morphology of the fungus will be highlighted.

Recent findings: Hyperglycemia, acidosis, available free iron, lowered host defenses, and the fungal virulence factors promote the growth of Mucorales. There is a high background prevalence of diabetes mellitus (DM) in India. Uncontrolled or undiagnosed DM, COVID-19 itself, and inappropriate administration of corticosteroids in high doses and for prolonged periods result in hyperglycemia. Diabetic ketoacidosis (DKA) and metabolic acidosis due to hypoxia or renal failure contribute to acidic pH and dissociate bound iron from serum proteins. The host defenses are lowered due to COVID-19-induced immune dysregulation, hyperglycemia itself, and administration of corticosteroids and immune suppressants for the treatment of COVID-19. The altered metabolic milieu in the local microenvironment of nose and paranasal sinuses (PNS) promotes specific interaction of glucose-regulated protein-78 (GRP-78) on host cells with spore coat protein homologue (CotH 3) on Mucorales resulting in rhino-orbito-cerebral mucormycosis (ROCM) as the predominant clinical form in CAM. The pathology is extensive soft tissue involvement with angioinvasion and perineural invasion. Melanized hyphae and sporangia were seen on histopathology, which is unique to CAM. While many factors favor the growth of Mucorales in CAM, hyperglycemia, hyperferritinemia, and administration of hyperbaric oxygen result in reactive oxygen species (ROS) and inadequate humidification results in dehydration. Melanization is possibly the adaptive and protective mechanism of Mucorales to escape the unfavorable conditions due to the treatment of COVID-19.

Summary: High background prevalence of DM, inappropriate administration of corticosteroids and immune dysregulation due to COVID-19 favor the growth of Mucorales in CAM. Melanization of Mucorales hyphae and sporangia on histopathology probably represent adaptive and protective mechanism due to the treatment with hyperbaric oxygen with inadequate humidification as well as the metabolic alterations.

Purpose of review: Pediatric sporotrichosis has not been sufficiently studied; this review aims to evaluate the risk and prognostic factors related to the development of sporotrichosis associated to this age group. Also, we want to evaluate the causes of the increased number of cases of sporotrichosis in the pediatric population such as environmental changes in endemic areas, the biodiversity, and virulence among the pathogenic clade causing sporotrichosis in different areas of the globe, and especially the progression of the zoonotic transmission of infections caused by Sporothrix brasiliensis infections, associated to zoonotic transmission in Brazil and other endemic sporotrichosis countries.

Recent findings: After evaluating a case series of 40 patients, we found that pediatric sporotrichosis in Mexico is mainly caused by Sporothrix schenckii which prevails in rural areas and is mainly sapronotically transmitted. In Brazil, the longest and largest pediatric sporotrichosis outbreak is caused by Sporothrix brasiliensis, etiologically related to sick cats, directly from lesions containing a high yeast cell burden. When affecting children S. schenckii and S. brasiliensis may cause distinct clinical manifestations especially in the onset of the disease and affected anatomical site. In Mexico, most of the patients are successfully treated with potassium iodide, whereas in Brazil, all patients respond to itraconazole.

Summary: Sporothrix schenckii is the major etiologic agent in Mexico, being sapronotically transmitted, while in Brazil, Sporothrix brasiliensis is only transmitted by cats. In Mexico, the disease prevails in male patients (60%) from rural areas; in Brazil, the disease is more frequent in females (60%) from an urban region. Due to the zoonotic sporotrichosis outbreak in Brazil, the time of evolution seems to be shorter in Brazilian patients than in Mexican patients. Most Brazilian patients presented with facial lesions, including ocular involvement, while in Mexico, most of the children presented upper limbs involvement. In Mexico, treatment with potassium iodide in children was observed to induce faster remission than itraconazole, but controlled studies are lacking to evaluate this versus itraconazole, due to the low number of cases. A comparative study should be designed to evaluate the best and safest antifungal therapy for pediatric sporotrichosis.

Supplementary information: The online version contains supplementary material available at 10.1007/s12281-022-00429-x.

Purpose of review: Histoplasmosis remains a challenging infection in solid organ transplantation. This review provides a topic update with emphasis on the changing Histoplasma epidemiology, along with new diagnostic and treatment innovations.

Recent findings: Recent years have observed expanding Histoplasma geographic distribution due to climate change, environmental disruption, and host factors. Early clinical experience also suggests a relationship between COVID-19 infection and histoplasmosis, particularly among immunocompromised individuals. Advances in diagnostic methods, such as newer enzyme immunoassays and molecular techniques, have broadened the capability for expedient and highly specific pathogen identification. Novel drug innovations, including the development of new formulations of existing antifungal agents, extended-spectrum azoles and new antifungal drug classes have expanded therapeutic options.

Summary: Advances in organ transplantation have largely outpaced those for histoplasmosis. However, these emerging insights enhance our understanding of this pathogen and management of clinical infection, particularly for transplant recipients with a higher incidence and severity of disease.