Epidemiology of Zygomycosis: Analysis of National Data from Pathological Autopsy Cases in Japan

Infectious factors in myocarditis: a comprehensive review of common and rare pathogens

BACKGROUND

Myocarditis is a significant health threat today, with infectious agents being the most common cause. Accurate diagnosis of the etiology of infectious myocarditis is crucial for effective treatment.

MAIN BODY

Infectious myocarditis can be caused by viruses, prokaryotes, parasites, and fungi. Viral infections are typically the primary cause. However, some rare opportunistic pathogens can also damage heart muscle cells in patients with immunodeficiencies, neoplasms and those who have undergone heart surgery.

CONCLUSIONS

This article reviews research on common and rare pathogens of infectious myocarditis, emphasizing the complexity of its etiology, with the aim of helping clinicians make an accurate diagnosis of infectious myocarditis.

Early diagnosis and aggressive surgical resection matters to cure rhinocerebral mucormycosis: Six case reports

Rhino-cerebral mucormycosis (RM) is a rare and opportunistic fungal infection observed in immune-compromised patients and metabolic imbalances such as Diabetes Mellitus. RM rapidly infiltrates blood vessels, leading to vascular thrombosis, subsequent tissue necrosis, and high mortality rates (23.6-60%). Due to its fast advancement, RM is a life-threatening condition requiring accurate clinical decisions by the medical and surgical teams. Based on the report of six cases, we emphasize the need for an early diagnosis and starting antifungal pharmacological therapy at the slightest suspicion of RM. Moreover, the restitution of metabolic balance and aggressive surgical debridement are vital steps to control RM, reducing the possibility of fatal outcomes.

Comparison Approach for Identifying Missed Invasive Fungal Infections in Formalin-Fixed, Paraffin-Embedded Autopsy Specimens

Invasive fungal infection (IFI) has a high mortality rate in patients who undergo hematopoietic stem cell transplantation, and it is often confirmed by postmortem dissection. When IFI is initially confirmed after an autopsy, the tissue culture and frozen section are challenging to secure, and in many cases, formalin-fixed, paraffin-embedded (FFPE) samples represent the only modality for identifying fungi. Histopathological diagnosis is a useful method in combination with molecular biological methods that can achieve more precise identification with reproducibility. Meanwhile, polymerase chain reaction (PCR) using fungal-specific primers helps identify fungi from FFPE tissues. Autopsy FFPE specimens have a disadvantage regarding the quality of DNA extracted compared with that of specimens obtained via biopsy or surgery. In the case of mucormycosis diagnosed postmortem histologically, we examined currently available molecular biological methods such as PCR, immunohistochemistry (IHC), and in situ hybridization (ISH) to identify fungi. It is reasonable that PCR with some modification is valuable for identifying fungi in autopsy FFPE specimens. However, PCR does not always correctly identify fungi in autopsy FFPE tissues, and other approaches such as ISH or IHC are worth considering for clarifying the broad classification (such as the genus- or species-level classification).

Invasive mold infection of the gastrointestinal tract - A case series of 22 immunocompromised patients from a single academic center

Invasive mold infection (IMI) of the gastrointestinal (GI) tract is a rare complication in immunocompromised patients that carries a high mortality rate. It is most often described in the setting of disseminated disease. Early diagnosis and treatment are critical in its management, but this is rarely obtained, leading to delayed therapy. To describe the clinical characteristics, treatment and outcomes of this infection, we reviewed all the cases of adult patients with histopathological findings from autopsy or surgical specimens that demonstrated fungal invasion into the GI tract at Stanford Hospital & Clinics from January 1997 to August 2020. Twenty-two patients that met criteria were identified and they were all immunocompromised, either due to their underlying medical conditions or the treatments that they received. The most common underlying disease was hematological malignancies (63.6%) and the most common symptoms were abdominal pain, GI bleeding and diarrhea. A majority of patients (72.7%) had disseminated invasive mold infection, while the rest had isolated GI tract involvement. In 2/3 of our cases, the fungal genus or species was confirmed based on culture or PCR results. Given the very high mortality associated with GI mold infection, this diagnosis should be considered when evaluating immunocompromised patients with concerning GI signs and symptoms. A timely recognition of the infection, prompt initiation of appropriate antifungal therapy as well as surgical intervention if feasible, are key to improve survival from this devastating infection.

Epidemiology of visceral mycoses in patients with acute leukemia and myelodysplastic syndrome: Analyzing the national autopsy database in Japan

Visceral mycoses (VM) are a deadly common infection in patients with acute leukemia and myelodysplastic syndrome (MDS). We retrospectively analyzed the data from the centralized "Annual Report of Autopsy Cases in Japan" that archives the national autopsy cases since 1989. Among the total of 175,615 archived autopsy cases, 7183 cases (4.1%) were acute leukemia and MDS patients. While VM was only found in 7756 cases (4.4% in total cases), we found VM had a disproportionally high prevalence among acute leukemia and MDS patients: 1562 VM cases (21.7%) and nearly sixfold higher in prevalence. Aspergillus spp. was the most predominant causative agent (45.0%), and Candida spp. was the second (22.7%) among confirmed single pathogen involved cases. The prevalence of Candida spp. infection decreased about 50% due to the widely use of fluconazole prophylaxis, which may skew toward doubling of the Mucormycetes incidence compared to 30 years ago. Complicated fungal infection (> one pathogen) was 11.0% in acute leukemia and MDS in 2015. It was 14.7 times higher than in other populations. Among 937 patients who received allogeneic hematopoietic cell transplantation (HCT), the prevalence of VM was 28.3% and 23.3% with GVHD. Aspergillus spp. was less prevalent, but Candida spp. was more associated with GVHD. Its prevalence remains stable. Although Aspergillus spp. was the primary causative agent, non-albicans Candida spp. was increasing as a breakthrough infection especially in GVHD cases. Complicated pathogen cases were more common in acute leukemia and MDS.

The disease burden of mucormycosis in Japan: results from a systematic literature review and retrospective database study

OBJECTIVE

To evaluate outcomes, healthcare resource utilization, and costs associated with mucormycosis in inpatient settings in Japan.

METHODS

We performed a systematic literature review, followed by a retrospective database study using hospital health claims for patients in Japan hospitalized with a diagnosis of mucormycosis between January 2010 and January 2019. Outcomes assessed included duration of index hospitalization; index stay mortality; hospital readmission within 30, 60, and 90 days after index hospitalization discharge; drug/treatment utilization and patterns; number of patients examined for mucormycosis during the index hospitalization; and index stay inpatient costs.

RESULTS

From our systematic literature review of articles describing 133 patients with mucormycosis, mortality in the index hospitalization was 55.6%. From our database study of 126 patients hospitalized for mucormycosis, mortality during the index hospitalization was 35.7% and mean index stay duration was 94 days. Hematologic malignancies were the most common risk factor in the literature review and the most common comorbidity in the database study. During the index stay, 39 patients (31.0%) received liposomal amphotericin B (L-AMB) treatment and 74 patients (58.7%) received other antifungal treatments. Median total inpatient costs for the index hospitalization were equivalent to approximately US$60,945, including US$29,283 in drug costs.

CONCLUSIONS

This study investigated the healthcare resource utilization and cost of medical resources caused by mucormycosis in Japan. The drug costs for antifungal treatments comprised about half of total inpatient costs. Mucormycosis leads to high mortality, high healthcare resource utilization, and high costs.

Has the mortality from pulmonary mucormycosis changed over time? A systematic review and meta-analysis

OBJECTIVES

Pulmonary mucormycosis (PM) is increasingly being reported in immunocompromised patients and has a high mortality. Our aim was to assess the mortality of PM and its trend over time. We also evaluated the role of combined medical-surgical therapy in PM.

METHODS

We performed a systematic review of Pubmed, Embase, and Cochrane central databases. Studies were eligible if they described at least five confirmed cases of PM and reported mortality. We also assessed the effect of combined medical-surgical therapy versus medical treatment alone on PM mortality. We used a random-effects model to estimate the pooled mortality of PM and compared it across three time periods. The factors influencing mortality were assessed using meta-regression. We evaluated the risk difference (RD) of death in the following: subjects undergoing combined medical-surgical therapy versus medical therapy alone, subjects with isolated PM versus disseminated disease, and PM in diabetes mellitus (DM) versus non-DM as a risk factor.

RESULTS

We included 79 studies (1544 subjects). The pooled mortality of PM was 57.1% (95% confidence interval [CI] 51.7-62.6%). Mortality improved significantly over time (72.1% versus 58.3% versus 49.8% for studies before 2000, 2000-2009, and 2010-2020, respectively, p 0.00001). This improved survival was confirmed in meta-regression after adjusting for the study design, the country's income level, and the sample size. Combined medical-surgical therapy was associated with a significantly lower RD (95%CI) of death: -0.32 (-0.49 to -0.16). The disseminated disease had a higher risk of death than isolated PM, but DM was not associated with a higher risk of death than other risk factors.

CONCLUSIONS

While PM is still associated with high mortality, we noted improved survival over time. Combined medical-surgical therapy improved survival compared to medical treatment alone.

The Postmortem Features of Mucormycosis

Mucormycosis is a rare and severe invasive fungal infection caused by ubiquitous fungi of the order Mucorales. Infection often occurs in immunocompromised hosts and includes cutaneous, pulmonary, gastrointestinal, rhinocerebral, and disseminated forms of disease. Although the clinical characteristics of mucormycosis are well established, infection can be difficult to diagnose antemortem, resulting in frequent postmortem diagnoses. Despite this, the gross appearance of mucormycosis at autopsy has not been well described. In the present report we illustrate the gross and histologic findings in four autopsy cases of mucormycosis, including one case of pulmonary disease and three cases of disseminated mucormycosis with cerebral, pulmonary, hepatic, renal, and gastrointestinal involvement. In all cases autopsy examination demonstrated characteristic hemorrhagic infarcts with a targetoid appearance in the affected organs. These findings are secondary to fungal angioinvasion with subsequent thrombosis and tissue necrosis. Mucormycosis should be suspected at autopsy when these characteristic infarcts are identified within the proper clinical context, and a high suspicion for atypical infections should be maintained postmortem in immunosuppressed patients.

Fulminant myocarditis and pulmonary cavity lesion induced by disseminated mucormycosis in a chronic hemodialysis patient: Report of an autopsied case

Mucormycosis is a rare fungal infection occurring in the immunocompromised host. It is difficult to diagnose, and its cardiac involvement is extremely rare. Here, we report a 64-year-old Japanese man with a 5-year history of hemodialysis with disseminated mucormycosis causing fulminant myocarditis and pulmonary necrosis under glucocorticoid use. Two months before, he had received an implantable cardioverter defibrillator and started to take amiodarone for recurrent ventricular arrhythmias due to hypertensive cardiomyopathy. He developed amiodarone-induced interstitial pneumonia and then received glucocorticoid therapy. Although the interstitial pneumonia partially improved, a lung cavitary lesion developed in the upper right lobe. Antibiotics had no effect, and serologic tests, blood and sputum cultures and bronchoalveolar lavage fluid were all negative for infectious pathogens. Eventually, he died of fulminant myocarditis. Autopsy revealed disseminated mucormycosis with vascular invasion and fungal thrombi, hemorrhage and infarction in lung (cavity lesion), heart (severe myocarditis), brain, thyroid and subcutaneous tissue around the implantable cardioverter defibrillator. The lung cavitary lesion was the only clinical finding suggestive of mucormycosis before autopsy. When an immunocompromised patient shows a progressive lung cavity lesion, the possibility of mucormycosis should be considered so that a broad-spectrum antifungal agent can be empirically administered in a timely fashion.

Comparison in Quantities from Including Angles Comprising Lines of Hypha Themselves in Histological Images between Mucorales and Aspergillus

BACKGROUND

The rate of aspergillosis has decreased due to improvements in therapy. The rate of mucormycosis, however, has gradually increased in recent years. Both aspergillosis and mucormycosis produce histologically similar hyphae, pointing to the need for an objective tool to distinguish between them.

METHODS

Three aspergillosis cases and three mucormycosis cases were selected from autopsy cases in our hospital. Representative histological images were captured and hyphal angles in extravascular and intravascular lesions were calculated.

RESULTS

For both extravascular and intravascular lesions, the average hyphal angle of aspergillosis was acute, and the standard deviation was less than that of mucormycosis. In aspergillosis, the average hyphal angle for extravascular lesions was acute, and the standard deviation was less than that for intravascular lesions. However, for mucormycosis, there was no significant difference in both the average and standard deviation of the hyphal angles.

CONCLUSION

Surgical pathologists should carefully examine the histological characteristics of the fungus to correctly identify specimens and be able to administer proper therapies.

Invasive hepatic mucormycosis: A case report and review of the literature

Mucormycosis generally develops under immunocompromised conditions, including hematological malignancies and solid organ or hematopoietic stem cell transplantation. Although mucormycosis usually affects the lungs and paranasal sinuses, sporadic cases of invasive mucormycosis of the liver have been reported. We hereby report a patient with myelofibrosis who developed hepatic mucormycosis diagnosed by post-mortem examination. An extensive literature review identified 13 reported cases of hepatic mucormycosis, including ours, without lung involvement. Most of the underlying diseases or conditions were hematological malignancies and solid organ transplantation. Three cases had splenic lesions and four had gastrointestinal lesions, suggesting the possibility of translocation to the liver and/or spleen from the gastrointestinal tracts. Hepatic mucormycosis should be recognized as one of the presentations of invasive mucormycosis, especially when hepatic nodules are found in immunocompromised patients such as those with hematological malignancy or recipients of solid organ transplantation.

Rhinocerebral mucormycosis, risk factors and the type of oral manifestations in patients referred to a University Hospital in Tabriz, Iran 2007-2017

Inadequate data are available on the global epidemiology of mucormycosis, mainly derived from the evaluation of specific population groups. Rhinocerebral mucormycosis is an invading and fatal mycosis, particularly among diabetic patients. In the present study, patients hospitalised in Imam Reza Hospital in Tabriz, from 2007 to 2017, were evaluated. The hospital information system (HIS) was used to collect the records of the patients. A total of 42 patients with a diagnosis of mucormycosis were included in the study, 40 cases (95%) of which had a diagnosis of the rhinocerebral form. Of these 40 patients, 21 (52.5%) and 19 (47.5%) were male and female, respectively. Seven cases (17.5%) of rhinocerebral mucormycosis were due to dental procedures. The most predisposing factor in the patients was diabetes with 36 (90%) cases. In our study, the role of tooth extraction in patients with uncontrolled diabetes was identified as an important factor. It may show the important role of dentists in preventing of the disease in diabetic patients.