Renal transplant patient survives a donor-derived abdominal invasive mucormycosis (Lichtheimia ramos a)

Epidemiology, Clinical Manifestations, and Outcome of Mucormycosis in Solid Organ Transplant Recipients: A Systematic Review of Reported Cases

Mucormycosis is an emerging disease primarily affecting the immunocompromised host, but scarce evidence is available for solid organ transplant recipients (SOTRs). We systematically reviewed 183 cases occurring in SOTRs, exploring epidemiology, clinical characteristics, causative pathogens, therapeutic approaches, and outcomes. Kidney transplants accounted for half of the cases, followed by heart (18.6%), liver (16.9%), and lung (10.4%). Diagnosis showed a dichotomous distribution, with 63.7% of cases reported within 100 days of transplantation and 20.6% occurring at least 1 year after transplant. The 90-day and 1-year mortality rates were 36.3% and 63.4%, respectively. Disseminated disease had the highest mortality at both time points (75% and 93%). Treatment with >3 immunosuppressive drugs showed a significant impact on 90-day mortality (odds ratio [OR], 2.33; 95% CI, 1.02-5.66; P = .0493), as did a disseminated disease manifestation (OR, 8.23; 95% CI, 2.20-36.71; P = .0027) and the presence of diabetes (OR, 2.35; 95% CI, 1.01-5.65; P = .0497). Notably, prophylaxis was administered to 12 cases with amphotericin B. Further investigations are needed to validate these findings and to evaluate the potential implementation of prophylactic regimens in SOTRs at high risk.

Case report: The clinical utility of metagenomic next-generation sequencing in mucormycosis diagnosis caused by fatal Lichtheimia ramosa infection in pediatric neuroblastoma

Lichtheimia ramosa (L. ramosa) is an opportunistic fungal pathogen of the order Mucorales that may result in a rare but serious mucormycosis infection. Mucormycosis could be angioinvasive, causing thrombosis and necrosis in the nose, brain, digestive tract, and respiratory tract. The infection is highly lethal, especially in immunocompromised hosts, and the incidence has been on the rise. However, due to its relatively low incidence in pediatric population and the challenges with diagnosis, the awareness and management experience for pediatric mucormycosis are extremely limited, which might lead to poor outcomes. In this study, we comprehensively reviewed the course of a fatal rhinocerebral mucormycosis case in a pediatric neuroblastoma patient receiving chemotherapy. Due to a lack of awareness of the infection, the standard care of amphotericin B treatment was delayed and not administered until the identification of L. ramosa by metagenomic next-generation sequencing (mNGS)-based pan-pathogen detection of the patient's peripheral blood sample. We also reviewed the literature on L. ramosa infection cases reported worldwide between 2010 and 2022, with an analysis of clinical manifestation, prognosis, and epidemiological data. Our study not only highlighted the clinical value of comprehensive mNGS in rapid pathogen detection but also raised awareness of recognizing lethal fungal infection early in immunocompromised hosts including pediatric cancer patients.

Mucor indicus caused disseminated infection diagnosed by metagenomic next-generation sequencing in an acute myeloid leukemia patient: A case report

Background

Mucormycosis commonly occurs in immunosuppressed patients with hematological diseases, which can be life-threatening. However, many cases are often misdiagnosed due to lack of specific clinical manifestations. Additionally, the traditional blood culture or serological testing, with a high false-negative rate, is time-consuming. Thus, precise and timely diagnosis of infections is essential for the clinical care of infected patients.

Case presentation

We report a 29-year-old Chinese man with acute myeloid leukemia (AML) who developed febrile neutropenia after the first course of induction chemotherapy. He received empirical antibiotics, which did not relieve his symptoms. No pathogen was detected by traditional microbiologic assays, while Mucor indicus was identified by metagenomic next-generation sequencing (mNGS) in the blood specimen. Liposomal amphotericin B (LAmB) was used, resulting in the patient's temperature returning to normal. A few days later, abdominal computed tomography (CT) scan showed multiple liver abscesses; fluorescence staining, histopathology, and mNGS identified the causative agent-M. indicus. Posaconazole was combined with LAmB as long-term antifungal treatment. Finally, the patient received allogeneic hematopoietic stem cell transplantation successfully after controlled infection. During follow-up 1 year after transplantation, the number of liver abscesses was reduced to one and remained stable.

Conclusion

This report described the first case of an AML patient diagnosed with culture-negative disseminated infections caused by M. indicus leading to rare hepatic manifestations using mNGS of peripheral blood and liver biopsy. LAmB combined with posaconazole was given in time, resulting in a favorable outcome. mNGS is a new method that assists in detecting the probable pathogen and increases the accuracy of identifying an etiology.

Clinical presentations, diagnosis, management, and outcomes of renal mucormycosis: An overview of case reports

Background

Renal mucormycosis (RM) is a rare presentation of invasive mucormycosis with a high mortality rate. There is no single systematic review of the literature that indicates the different clinical aspects of RM.

Methods

A systematic search of PubMed/Medline was performed to collect individual case reports of RM in patients of all ages published between 2010 and April 2022.

Results

Seventy-one individual cases were detected through PubMed bibliographic database searches, with a final assessment performed on 60 patients with RM. India and Asia had the largest number of reported cases, with 30 (50%) and 42 (70%) reports, respectively. Also, 74 and 26% of the patients with a mean age of 33 years were male and female, respectively. RM showed 44% mortality rate in the analyzed cases. Immunosuppressive agent therapy followed by tissue transplantation (kidney and liver) and diabetes were the most remarkable risk factors in patients. Nevertheless, 22% of the patients were immunocompetent with no apparent underlying condition. COVID-19 positivity was detected in eight adult patients with an 87% mortality rate. The most common signs of infection were fever, flank pain, and oliguria; additionally, isolated RM was reported in 57% of the cases. In 55% of the patients, histopathologic examination alone was sufficient to diagnose RM, whereas molecular methods and culture were used in only 18 and 35% of patients, respectively. Surgery alone, surgery plus anti-infection therapy, and anti-infection therapy alone were used in 12, 60, and 13% of patients, respectively. Furthermore, 15% of the patients died before any treatment.

Conclusion

The early diagnosis of RM is necessary. In this regard, the use of molecular-based diagnostic assays can help identify the fungus at the genus and species levels and use an appropriate treatment in the shortest possible amount of time. Because of the increase in antibiotic resistance in recent years, determining microbial susceptibility tests can lead to the better infection management. Additionally, withdrawal of immunosuppressant, appropriate surgical intervention, and antifungal therapy are the main factors associated with a successful outcome in RM.