Histoplasmosis

Acute Myelopathy as Initial Presentation of Disseminated Histoplasmosis: A Case Report

Histoplasmosis is a fungal infection caused by the fungus Histoplasma capsulatum that can rarely present with central nervous system (CNS) manifestations that include meningitis, encephalitis, focal brain or spinal cord lesions, and stroke syndromes. Because of this variation from patient to patient, CNS histoplasmosis is a difficult clinical diagnosis to make, which can be further hindered by no highly sensitive diagnostic testing available. Here, we present a unique case of a 46-year-old male immunocompromised due to type 1 diabetes mellitus with disseminated histoplasmosis as an acute presentation of myelopathy. Patient had left leg weakness for a few days prior to presentation and a neurological exam remarkable for signs of acute thoracic myelopathy, specifically concerning for Brown-Séquard syndrome. MRI imaging demonstrated an enhancing thoracic spinal cord lesion along with multiple cerebral enhancing lesions, bilateral adrenal masses, and innumerable pulmonary nodules. Biopsy results demonstrated yeast forms consistent with Histoplasma species.

Lung Nodules and Masses in Patients Who Are Not HIV Immunocompromised: A Clinical Imaging Algorithmic Approach

TOPIC IMPORTANCE

The incidence of pulmonary nodules and masses in immunocompromised patients without HIV has significantly increased due to advancements in hematopoietic stem cell transplantation and solid organ transplantation and the widespread use of chemotherapy and immunosuppressive therapies. Differentiating between infectious and noninfectious causes is critical for appropriate diagnosis and management, especially because radiologic and clinical presentations can be nonspecific.

REVIEW FINDINGS

This review provides a practical framework for evaluating pulmonary nodules and masses in immunocompromised patients without HIV, incorporating clinical, immunologic, and radiologic features. It emphasizes the importance of differentiating between infectious and noninfectious etiologies based on imaging and clinical context. The review highlights the importance of correlating imaging features with the patient's immune status and underlying clinical conditions to narrow down the differential diagnosis.

SUMMARY

Pulmonary nodules and masses in immunocompromised patients represent a diagnostic challenge due to overlapping radiologic and clinical presentations. By integrating clinical context, immune status, and imaging findings, clinicians can more accurately diagnose and manage these lesions, improving patient outcomes. This review presents an algorithmic approach for differentiating between various causes of pulmonary nodules and masses in immunocompromised individuals without HIV, providing a valuable tool for clinical practice.

CD86 immunohistochemical staining for the detection of Talaromyces marneffei in lesions

Talaromycosis is an invasive fungal disease caused by the pathogenic thermodimorphic fungus Talaromyces marneffei (TM), which is often overlooked in tropical and subtropical regions of Asia. In view of the diversity of clinical manifestations in patients with TM infection, early diagnosis remains challenging. We assessed the sensitivity and specificity of a novel immunohistochemical staining by performing CD86 immunohistochemical staining on 56 tissue sections from patients with talaromycosis who had fungal culture or metagenomic next-generation sequencing confirmed to exist in clinical specimens, as well as 26 patients with other fungi that had been culture-proven. Hematoxylin and eosin and periodic acid Schiff (PAS) stains were also applied to each specimen. We found that anti-CD86 antibody can label TM pathogens in 38 HIV-negative specimens (38/42) and 14 HIV-positive specimens (14/14); conversely, PAS staining yielded positive results in seven cases of HIV-negative specimens (7/42) and 13 cases of HIV-positive specimens (13/14). Additionally, CD86 immunohistochemical staining was negative in other fungi. Importantly, CD86 immunohistochemical staining significantly outperformed PAS staining in terms of localizing and highlighting TM yeasts, as well as demonstrating the specificity of 100% and a significantly higher sensitivity compared to PAS staining at 92.9% versus 35.7% (P < 0.05, McNemar test). Our findings suggest that CD86 immunohistochemical staining has the potential for the rapid diagnosis of talaromycosis.IMPORTANCETalaromycosis is an opportunistic endemic disease without typical clinical manifestations that has emerged as a fungal disease impacting the survival and mortality of immunocompromised individuals and HIV-positive individuals in endemic regions. Nonetheless, talaromycosis is completely curable if it is accurately diagnosed and treated effectively at an early stage. Rapid pathological diagnosis relies on the unique morphological features of Talaromyces marneffei observed under the microscope. This study introduces a novel pathological diagnostic approach, CD86 immunohistochemical staining, to enhance the early detection of TM-infected lesions.

Retrospective Investigation of Pediatric Histoplasmosis Diagnosed at a Tertiary Children's Hospital in an Endemic Area Over 11 Years

BACKGROUND

Most histoplasmosis data are from adults. We describe pediatric histoplasmosis diagnosed at a tertiary pediatric care center in an endemic area.

METHODS

We performed a retrospective chart review of patients birth-18 years seen in our institution (January 1, 2010 to August 15, 2022) with histoplasmosis identified by International Classification of Disease codes. We performed descriptive and univariate analyses of demographic, historical, clinical, laboratory, and treatment data.

RESULTS

Of 122 patients, 26 had disseminated histoplasmosis (DH), 71 pulmonary/thoracic (P/T) disease, 21 had histoplasmosis as an incidental finding, and 4 were classified as other. Median age was 14 years (range 0.3-18.7 years); most were non-Hispanic White (70.5%) and city dwellers (77.1%). We noted neither seasonality nor disease category differences for age, race and ethnicity, residence, or environmental factors. Compared to P/T, DH more frequently had complex chronic conditions (73.1% vs 12.7%, P < .001), fever (88.5% vs 52.1%, P < .001), fatigue (76.9% vs 46.5%, P = .01), vomiting (53.8% vs 25.3%, P = .01), anemia (hemoglobin median 10.05 vs 12.5 g/dL, P < .001), elevated sedimentation rate values (median 31 vs 29 mm/h, P = .02), blood and urine Histoplasma antigen detection (63.6/84.6% vs 20.0/14.8%, P < .001), and antifungal treatment (100% vs 70.4%, P < .001). Patients with DH had longer antifungal treatment courses (399 vs 84 days, P < .001). Exposures were rarely recorded, but the most common was chickens. Chest radiographs were less likely to show adenopathy in DH compared to P/T (8.7% vs 55%, P < .001).

CONCLUSIONS

Presentations, risk factors, diagnostics use/results, and therapy for pediatric histoplasmosis most often parallel those in adults.

The Contribution of Human Antimicrobial Peptides to Fungi

Various species of fungi can be detected in the environment and within the human body, many of which may become pathogenic under specific conditions, leading to various forms of fungal infections. Antimicrobial peptides (AMPs) are evolutionarily ancient components of the immune response that are quickly induced in response to infections with many pathogens in almost all tissues. There is a wide range of AMP classes in humans, many of which exhibit broad-spectrum antimicrobial function. This review provides a comprehensive overview of the mechanisms of action of AMPs, their distribution in the human body, and their antifungal activity against a range of both common and rare clinical fungal pathogens. It also discusses the current research status of promising novel antifungal strategies, highlighting the challenges that must be overcome in the development of these therapies. The hope is that antimicrobial peptides, as a class of antimicrobial agents, will soon progress through large-scale clinical trials and be implemented in clinical practice, offering new treatment options for patients suffering from infections.

Disseminated liver histoplasmosis in an immunocompetent individual cured by liver transplantation and voriconazole from China: A case report

BACKGROUND

Histoplasmosis is a rare infectious condition with mainly pulmonary involvement which is generally self-limiting in immunocompetent individuals. Its manifestation varies and lacks specificity. This study reports a case of primary disseminated liver histoplasmosis in a normal host presenting as liver failure cured by liver transplantation and voriconazole.

CASE SUMMARY

A 43-year-old Chinese man with intermittent fever, malaise, jaundice and extreme hepatomegaly for more than 40 days was admitted to the Second Xiang-ya Hospital. The patient was immunocompetent and lacked a definitive history of exposure. His condition deteriorated to liver failure, and he promptly underwent liver transplantation to ensure survival. One year later, the patient presented with severe gastrointestinal symptoms, including fever, abdominal pain, and diarrhea. Subsequently, tissue samples acquired via gastrointestinal endoscopy were subjected to pathological examination and next-generation sequencing analysis. Through a comprehensive amalgamation of clinical presentation, biopsy pathology, and next-generation sequencing analysis, the patient was ultimately diagnosed with disseminated hepatic histoplasmosis. The patient achieved complete recovery after 6 months of voriconazole treatment.

CONCLUSION

In patients with chronic-hepatitis-B having atypical symptoms, histoplasmosis can be a differential diagnosis. Voriconazole is effective in treating histoplasmosis.

Efficacy of nitrofuran derivatives against biofilms of Histoplasma capsulatum strains and their in vivo toxicity

AIM

To evaluate the efficacy of two nitrofuran derivatives against biofilms formed by two strains of Histoplasma capsulatum and to study the toxicity of these compounds in alternative models: Caenorhabditis elegans, Galleria mellonella, and zebrafish.

METHODS

The metabolic activity of biofilms was measured after treatment using the XTT reduction assay. Scanning electron microscopy (SEM) and confocal microscopy were used to observe damage to mature biofilms. Survival curves were generated for G. mellonella, while percentage survival was determined for C. elegans and zebrafish.

RESULTS

The compounds showed efficacy against early and mature biofilms at concentrations equal to or up to two times higher than those required to eliminate planktonic fungal cells (3.90 to 31.25 μg/mL). Micrographs showed a reduction in metabolic activity, biofilm thickness, and extracellular matrix. In addition, the compounds showed little or no toxicity in alternative models, even at the highest concentrations tested.

CONCLUSION

These results are promising for the development of new therapeutic alternatives, especially for species, such as H. capsulatum, which are recognized as high-priority pathogens. Few studies have investigated resistance and antifungal treatment targeting biofilms of this species, making this work a relevant contribution to future approaches.

Histoplasmosis

This review provides an update of histoplasmosis, covering the changing epidemiology, pathogenesis, disease manifestations, diagnostic strategies, and management considerations for immunocompetent and immunocompromised populations.

Disseminated histoplasmosis presenting as adrenal insufficiency: A case report

This report aims to highlight rarity of disseminated histoplasmosis (DH) presenting as adrenal insufficiency and the need for considering it in the differential diagnosis, even in non-endemic areas. A case is presented of a 69-year-old male patient with a background of hypertension and diabetes mellitus, with a persistent fever, significant loss of weight, and general weakness. Imaging studies showed adrenal masses in both adrenal glands, and laboratory tests showed hyperkalemia and hyponatremia. Hormonal tests confirmed the diagnosis of adrenal insufficiency. CT-guided adrenal biopsy confirmed the diagnosis of histoplasmosis. The patient received a 14-day course of Amphotericin B, followed by oral Itraconazole and glucocorticoid substitution therapy, with improvement in adrenal function over a period of time.

Primary cutaneous cryptococcosis - History, concepts, clinical and therapeutic update

Cryptococcosis is a disease caused by fungi of the genus Cryptococcus, with the species Cryptococcus neoformans and Cryptococcus gattii being recognized as pathogenic. Cutaneous cryptococcosis can be classified as "secondary", developing from a previous systemic disease, or, on the contrary, "primary", resulting from transcutaneous inoculation of the agent. It can also be classified as "disseminated cutaneous cryptococcosis", when there is an associated systemic disease, or "localized", when it is restricted to the skin. This article uses the term "primary cutaneous cryptococcosis" because it is the most widely used and already established in the literature. Historically, the first report of a possible case of primary cutaneous cryptococcosis (PCC) occurred in 1950 by Gancy WM and was published in the Archives of Dermatology and Syphilology. Subsequently, the rare and sporadic reports in the following decades were reviewed and reported in the 1985 publication by Baes & van Cutsen. However, the unequivocal acceptance of the existence of PCC as a distinct disease only occurred in 2003 with the publication by Neville S et al. of the French Cryptococcosis Study Group. The fundamental criterion established to consider it as PCC was the proven absence of systemic disease, whether pulmonary, in the CNS or other location at the time of diagnosis of the cutaneous condition, characterized by a single lesion and, mostly, in an exposed area. These and other clinical criteria, diagnostic confirmation, and therapeutic choice are discussed in detail in the full text.

Disseminated histoplasmosis and presumptive CNS toxoplasmosis-associated immune reconstitution inflammatory syndrome in a patient with HIV/AIDS: a case report

BACKGROUND

Co-infections associated with Immune Reconstitution Inflammatory Syndrome (IRIS) have been described in literature, however they constitute an uncommon finding in the medical community.

CASE PRESENTATION

Here we report a rare case of a 55-year-old woman from Cuba with prior medical history of HIV/AIDS adherent to her antiretroviral therapy (ART) regimen, who was hospitalized in Miami, Florida because of fluid dysphagia, odynophagia and right-sided cervical lymphadenopathy. A prior biopsy of the right cervical lymph node performed in an outside hospital found evidence of non-caseating granulomas with budding yeast, which was later confirmed to be disseminated histoplasmosis by a positive (1-3) -β-glucan assay and histoplasmosis urine antigen in this admission. Furthermore, after multiple imaging testing due to her clinical condition, a brain MRI demonstrated findings concerning for cerebral toxoplasmosis, which was supported by serology findings. Treatment with liposomal amphotericin B and TMP-SMX led to clinical and radiological improvement of this patient's conditions, and she was discharged with an appointment for follow-up in the clinic.

CONCLUSION

This case highlights the complexities and challenges in managing opportunistic infections (OIs) during immune recovery in HIV/AIDS patients on ART, and emphasizes the necessity of continuous, vigilant monitoring and having a broad differential diagnosis in this group of patients.

Disseminated Histoplasmosis With Lung and Liver Involvement in an Immunocompetent Patient

Histoplasmosis, caused by the fungus Histoplasma capsulatum, is a significant public health concern in endemic regions like Mexico. Immunocompromised individuals, especially those with HIV infection and those exposed to nitrogen-rich environments, such as bird excrement or bat guano, are particularly vulnerable. This case report describes a middle-aged patient with jaundice in the skin and mucous membranes. Suspecting cholecystitis, abdominal imaging was performed, revealing hepatomegaly and bilateral pulmonary infiltrates with consolidations and nodular lesions on computed tomography. After being transferred to the internal medicine unit, a comprehensive diagnostic evaluation was carried out. Despite negative results from HIV serology and acid-fast bacillus testing, the patient tested positive for urine Histoplasma antigen, confirming the diagnosis of disseminated histoplasmosis. This case underscores the importance of considering histoplasmosis in the differential diagnosis of patients with relevant risk factors presenting with systemic symptoms.

Disseminated histoplasmosis from western Mexico-rethinking our geographic distribution of endemic fungal species: a case report and review of literature

BACKGROUND

Histoplasma is a fungal pathogen found in many parts of the world. In North America, its distribution is traditionally thought to be endemic to the Ohio and Mississippi River valleys. Development of histoplasmosis after Histoplasma exposure is related to degree of inoculum exposure and susceptibility, for example, immunocompromised status. Most exposed, healthy individuals are asymptomatic and few develop pulmonary symptoms. A limited number of infectious etiologies (that is, Histoplasma, Coccidioides, and Mycobacterium tuberculosis) can cause miliary pattern on chest imaging, and thus, histoplasmosis should be considered whenever a patient presents with pulmonary symptoms and these unique radiographic findings.

CASE PRESENTATION

A previously healthy 13-year-old Hispanic male presented as a transfer from an outside hospital with fever and hypoxia in the setting of a progressive, subacute gastrointestinal illness. Given hypoxia, the concern for sepsis, and unclear etiology of his illness, broad-spectrum antimicrobial therapy and noninvasive ventilation were started. Initial evaluation demonstrated miliary pulmonary infiltrates, and travel history raised suspicion for coccidioidomycosis or tuberculosis. After a complete evaluation, lab studies confirmed a diagnosis of histoplasmosis, and the patient made a full recovery after the initiation and completion of antifungal therapy.

CONCLUSION

Herein, we present a patient who acquired histoplasmosis from an area of Mexico not currently acknowledged as endemic and review recently published data emphasizing new areas of Histoplasma endemicity in North America, particularly the southwest USA and most states of Mexico. Though limited surveillance data exist, mounting case reports/series and local epidemiologic studies illustrate the expanding worldwide endemicity of Histoplasma and underscore histoplasmosis as a growing global health concern.

The Incidence, Aetiology and Clinical Course of Serious Infections Complicating Biological and Targeted Synthetic Disease-Modifying Antirheumatic Drug Therapy in Patients with Rheumatoid Arthritis in Tropical Australia

Introduction: Patients receiving biological and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) for rheumatological conditions are at an increased risk of serious, potentially life-threatening, infection. However, the incidence, aetiology, and clinical course of serious infection in patients receiving b/tsDMARDs in tropical settings are incompletely defined. Methods: We retrospectively reviewed all patients with rheumatoid arthritis receiving b/tsDMARDs between October 2012 and October 2021, at Cairns Hospital in tropical Australia. The incidence, aetiology, and clinical course of serious infections (those requiring admission to hospital or parenteral antibiotics) were determined. Results: 310 patients had 1468 patient years of b/tsDMARD therapy during the study period; 74/310 (24%) had 147 serious infections translating to an overall risk of 10.0 episodes of serious infection per 100 patient years. The respiratory tract (50/147, 34%) and skin (37/147, 25%) were the most frequently affected sites. A pathogen was identified in 59/147 (40%) episodes and was most commonly Staphylococcus aureus (24/147, 16%). Only 2/147 (1%) were confirmed "tropical infections": 1 case of Burkholderia pseudomallei and 1 case of mixed B. pseudomallei and community-acquired Acinetobacter baumannii infection. Overall, 13/147 (9%) episodes of serious infection required Intensive Care Unit admission (0.9 per 100-patient years of b/tsDMARD therapy) and 4/147 (3%) died from their infection (0.3 per 100-patient years of b/tsDMARD therapy). The burden of comorbidity and co-administration of prednisone were the strongest predictors of death or a requirement for ICU admission. Conclusions: The risk of serious infection in patients taking b/tsDMARDs in tropical Australia is higher than in temperate settings, but this is not explained by an increased incidence of traditional tropical pathogens.

Disseminated Histoplasmosis Diagnosed in an Immunocompetent Patient from a Non-Endemic Area: Neglected or Emerging Disease?

Histoplasma capsulatum (H. capsulatum) is considered to be one of the most extensively spread dysmorphic fungi worldwide. Histoplasmosis primarily impacts patients with weakened immune systems and can result in a diverse range of clinical manifestations. In immunocompetent patients, the disease may manifest as a self-limiting or asymptomatic infection; however, in immunocompromised individuals, it can occur as a debilitating, disseminated disease. Diagnosing histoplasmosis may be challenging. A medical professional that specializes in treating endemic fungal illnesses is better able to assist with an accurate and timely diagnosis since they have a deeper grasp of these illnesses. Consequently, the process of diagnosing histoplasmosis might be difficult for less experienced physicians. The case presented is an example of the myriad faces that histoplasmosis can take on, mimicking other common infectious or malignant conditions, leading to extensive work-up and invasive procedures in establishing the diagnosis of this otherwise benign condition. We hereby report the case of disseminated histoplasmosis in a young immunocompetent female patient.

Paving the way for affordable and equitable liposomal amphotericin B access worldwide

Amphotericin B has long been crucial for treating many serious infectious diseases, such as invasive fungal infections and visceral leishmaniasis, particularly for patients who are immunocompromised, including those with advanced HIV infection. The conventional amphotericin B deoxycholate formulation has largely been replaced in high-income countries with liposomal amphotericin B (LAmB), which has many advantages, including lower rates of adverse events, such as nephrotoxicity and anaemia. Despite an evident need for LAmB in low-income and middle-income countries, where mortality from invasive fungal infections is still substantial, many low-income and middle-income countries still often use the amphotericin B deoxycholate formulation because of a small number of generic formulations and the high price of the originator LAmB. The pricing of LAmB is also highly variable between countries. Overcoming supply barriers through the availability of additional quality-assured, generic formulations of LAmB at accessible prices would substantially facilitate equitable access and have a substantial effect on mortality attributable to deadly fungal infections.

Fatal misdiagnosis of progressive disseminated histoplasmosis

Disseminated histoplasmosis is the form of a mycosis caused by the fungus Histoplasma capsulatum that mainly occurs in immunosuppressed hosts, usually with non-specific symptoms. In non-endemic areas, where the disease is rarely involved in the differential diagnosis, a delay in treatment may lead to severe medical complications. Due to the rising prevalence of disseminated histoplasmosis in these areas, a thorough medical history is regarded as the decisive factor in prompt diagnosis of the disease. We, herein, report the case of an immunocompetent Greek farmer with disseminated histoplasmosis whose condition was initially misdiagnosed, and the consequential inadequate treatment led to his death.

Acute Histoplasmosis With Pericarditis in Children: A Single-Center Experience

Pericarditis is a potential manifestation of acute histoplasmosis. Noninvasive diagnostics and imaging can be useful in defining a diagnosis. Therapy with itraconazole and corticosteroids was utilized frequently in a cohort with significant effusions at presentation.

Histoplasmosis: A systematic review to inform the World Health Organization of a fungal priority pathogens list

Histoplasmosis, a significant mycosis primarily prevalent in Africa, North and South America, with emerging reports globally, poses notable health challenges, particularly in immunocompromised individuals such as people living with HIV/AIDS and organ transplant recipients. This systematic review, aimed at informing the World Health Organization's Fungal Priority Pathogens List, critically examines literature from 2011 to 2021 using PubMed and Web of Science, focusing on the incidence, mortality, morbidity, antifungal resistance, preventability, and distribution of Histoplasma. We also found a high prevalence (22%-44%) in people living with HIV, with mortality rates ranging from 21% to 53%. Despite limited data, the prevalence of histoplasmosis seems stable, with lower estimates in Europe. Complications such as central nervous system disease, pulmonary issues, and lymphoedema due to granuloma or sclerosis are noted, though their burden remains uncertain. Antifungal susceptibility varies, particularly against fluconazole (MIC: ≥32 mg/l) and caspofungin (MICs: 4-32 mg/l), while resistance to amphotericin B (MIC: 0.125-0.16 mg/l), itraconazole (MICs: 0.004-0.125 mg/l), and voriconazole (MICs: 0.004-0.125 mg/l) remains low. This review identifies critical knowledge gaps, underlining the need for robust, globally representative surveillance systems to better understand and combat this fungal threat.

Histoplasmosis in Taiwan: Case Summary and Literature Review

Histoplasmosis is a global infection caused by the thermally dimorphic fungus, Histoplasma capsulatum complex. It is endemic in the United States, as well as in Central and South America. In Taiwan, histoplasmosis is rare, with the first reported case not occurring until 1977. We summarized a total of 17 cases reported in Taiwan over the past 40 years and provided detailed descriptions for four probable indigenous cases. Due to the lack of rapid diagnostic tools and clinical suspicion, histoplasmosis may be underdiagnosed in Taiwan. We recognize that a limitation of our review is the lack of data on the environmental surveillance for H. capsulatum complex in Taiwan. Conducting a further phylogenetic analysis on both environmental and clinical isolates would provide valuable evidence for the region.

Granulomatous Lung Diseases: A Practical Approach and Review of Common Entities

Granulomas are frequently encountered by pathologists in all types of lung specimens and arise from diverse etiologies. They should always be reported as necrotizing or non-necrotizing, with microorganism stains performed to evaluate for infection. With attention to distribution, quality (poorly vs well-formed), associated features, and correlation with clinical, radiologic, and laboratory data, the differential diagnosis for granulomatous lung disease can usually be narrowed to a clinically helpful "short list." This review describes a practical approach to pulmonary granulomas and reviews the clinicopathological aspects of common entities, including infectious (mycobacteria, fungi) and noninfectious (hypersensitivity pneumonitis, sarcoid, and vasculitis) causes.

Itraconazole in human medicine and veterinary practice

Diagnosis and management of fungal infections are challenging in both animals and humans, especially in immunologically weakened hosts. Due to its broad spectrum and safety profile when compared to other antifungals, itraconazole (ITZ) has been widely used in the treatment and prophylaxis of fungal infections, both in human and veterinary medicine. The dose and duration of management depend on factors such as the type of fungal pathogen, the site of infection, sensitivity to ITZ, chronic stages of the disease, the health status of the hosts, pharmacological interactions with other medications and the therapeutic protocol used. In veterinary practice, ITZ doses generally vary between 3 mg/kg and 50 mg/kg, once or twice a day. In humans, doses usually vary between 100 and 400 mg/day. As human and veterinary fungal infections are increasingly associated, and ITZ is one of the main medications used, this review addresses relevant aspects related to the use of this drug in both clinics, including case reports and different clinical aspects available in the literature.

Persistent fever after coronavirus disease 2019 in liver/kidney transplant recipient

In this case, a 64-year-old male with a history of simultaneous orthotopic liver transplant and cadaveric renal transplant presented five years prior presented with persistent fevers two days after a positive SARS-CoV-2 nasal PCR. A CT scan of the chest on hospital day nine revealed innumerable 1-2 mm nodules in a miliary pattern throughout the lung. (1,3)-β-D-glucan on hospital day 11 was 133 pg/mL. In this article, the approach, diagnostic and management strategies for patients with persistent fevers after diagnosis of COVID-19 in a transplant recipient are discussed.

Improving disseminated histoplasmosis diagnosis in HIV/AIDS patients in Suriname: The role of a urine lateral flow assay

Histoplasmosis is a frequent cause of infections in people living with HIV/AIDS (PLWHA). This study introduces the application of a Histoplasma capsulatum urine antigen lateral flow assay (LFA) for diagnosing disseminated histoplasmosis in PLWHA in Suriname. The LFA's diagnostic accuracy was compared with the current diagnostic approach, aiming to assess whether this test resulted in improved early detection and management. Additionally, the prevalence of histoplasmosis among advanced stage HIV patients without clinical suspicion of infection was evaluated using the same LFA. In total, 98 patients were included in the study, of which 58 were classified as "possible disseminated histoplasmosis (DH)" based on clinical criteria and 40 as "controls". Of these possible DH cases, only 19 (32.7%) had a positive LFA. During the study, decisions for treatment were made without the treating physician being aware of the LFA result. Only 55% of the patients who started treatment for histoplasmosis based on clinical criteria had a positive LFA, and 21% of untreated patients had a positive LFA. This study shows that combining clinical signs with LFA results enhances diagnostic accuracy and is cost effective, resulting in better treatment decisions.

Navigating the Complexities of Disseminated Histoplasmosis Diagnosis and Management in the Migrant Population: A Case Report

Histoplasma capsulatum is a dimorphic fungus that grows in nature as a mold or in culture but converts to a small yeast during cellular invasion. While most histoplasmosis infections are primarily asymptomatic or mildly symptomatic, disseminated histoplasmosis is a relentlessly progressive granulomatous disease that can mimic other granulomatous diseases, such as tuberculosis, sarcoidosis or coccidioidomycosis, more so in the proper context of immunosuppression. The current global migrant crisis, particularly the United States migrant crisis conversation is mostly socio-political; however, it also has a public health implication as exemplified by the case of a 35-year-old male who migrated from Haiti via Chile and Mexico to the United States. He presented with a four-day history of fever, generalized body aches, and cough. This case underscores the importance of entertaining a myriad of differentials and avoiding the tendency for anchoring, especially when initial therapy yields little clinical response.

Potential Fungal Zoonotic Pathogens in Cetaceans: An Emerging Concern

Over 60% of emerging infectious diseases in humans are zoonotic, often originating from wild animals. This long-standing ecological phenomenon has accelerated due to human-induced environmental changes. Recent data show a significant increase in fungal infections, with 6.5 million cases annually leading to 3.7 million deaths, indicating their growing impact on global health. Despite the vast diversity of fungal species, only a few are known to infect humans and marine mammals. Fungal zoonoses, especially those involving marine mammals like cetaceans, are of global public health concern. Increased human-cetacean interactions, in both professional and recreational settings, pose risks for zoonotic disease transmission. This review focuses on the epidemiology, clinical manifestations, and zoonotic potential of major fungal pathogens shared in humans and cetaceans, highlighting their interspecies transmission capability and the challenges posed by antifungal resistance and environmental changes. It underscores the need for enhanced awareness and preventative measures in high-risk settings to protect public health and marine ecosystems.

Disseminated Histoplasmosis Infection Diagnosed by Metagenomic Next-Generation Sequencing: A Case Report

Histoplasmosis is an endemic disease caused by Histoplasma capsulatum. This systemic disease can affect various organs beyond the lungs, such as the liver, spleen, adrenal gland, and lymph nodes. The clinical symptoms can range from asymptomatic to severe, life-threatening conditions, depending on the state of the patient's immune system. This report describes a 40-year-old male who presented with reports of weight loss, low back pain, and progressively worsening movement disorder of the bilateral lower extremities for months. Computed tomography (CT) examination showed multiple lytic lesions of vertebral bodies, bilateral ribs, and pelvic bone, histopathological examination and tumor-related serum markers exclude tumors. mNGS was employed to identify H. capsulatum var. capsulatum as the etiological agent of the lesions in the bone biopsy. Through phylogenetic tree analysis, Histoplasma capsulatum var. Capsulatum (Hcc) was the main responsible pathogen, rarely reported in bone lesions. The patient underwent spinal surgery and was successfully treated with liposomal amphotericin B and itraconazole. Based on the diagnosis and treatment of this case, we discuss the epidemiologic status, clinical presentations, diagnostic criteria, and treatment guidelines of histoplasmosis to provide additional information about this disease. mNGS is utilized in this case, and it appears to be a reliable method for early and accurate diagnosis of this disease.

HIV and skin infections

HIV infection alters the skin microbiome and predisposes to a wide range of cutaneous infections, from atypical presentations of common skin infections to severe disseminated infections involving the skin that are AIDS-defining illnesses. Bacterial infection of the skin, most commonly caused by Staphylococcus aureus, occurs frequently and can result in bacteremia. Nontuberculous mycobacterial infections that are usually localized to the skin may disseminate, and guidance on the treatment of these infections is limited. Herpes simplex can be severe, and less common presentations such as herpetic sycosis and herpes vegetans have been reported. Severe herpes zoster, including disseminated infection, requires intravenous antiviral treatment. Viral warts can be particularly difficult to treat, and in atypical or treatment-resistant cases a biopsy should be considered. Superficial candidosis occurs very commonly in people living with HIV, and antifungal resistance is an increasing problem in non-albicans Candida species. Systemic infections carry a poor prognosis. In tropical settings the endemic mycoses including histoplasmosis are a problem for people living with HIV, and opportunistic infections can affect those with advanced HIV in all parts of the world. Most cutaneous infections can develop or worsen as a result of immune reconstitution in the weeks to months after starting antiretroviral therapy. Direct microscopic examination of clinical material can facilitate rapid diagnosis and treatment initiation, although culture is important to provide microbiological confirmation and guide treatment.

Histoplasmosis peritonitis in an immunocompetent patient: case report

Histoplasmosis is a fungal infection most frequently seen in immunocompromised patients. It is endemic in Central and South America and in Africa. The infection is usually asymptomatic in a healthy individual. Extrapulmonary dissemination can be seen in immunocompromised hosts. Gastrointestinal manifestations frequently involve the terminal ileum and cecum, mimicking Crohn's disease or malignancy. We describe the case of a 36-year-old healthy man from Cameroon, living in Switzerland for 13 years and without any medical nor surgical history, who presented peritonitis not responding to antibiotics. CT-scan showed bowel obstruction and signs of peritonitis. We opted for an explorative laparoscopy, which was converted to laparotomy with extensive adhesiolysis. Diagnostic of histoplasmosis was confirmed by histology and PCR analysis on biopsy. To our knowledge, this is the first described case of peritonitis as main outcome of a disseminated histoplasmosis involving the peritoneum in an immunocompetent patient.

An Incarcerated Individual With Weight Loss and Interstitial Pulmonary Infiltrates

A man with HIV had syncopal episodes and hypoxemia after recent exposure to SARS-CoV-2; computed tomography revealed diffuse bilateral pulmonary micronodular opacities, a 2.2-cm nodule in the lingula, and mediastinal and hilar lymphadenopathy. What is the diagnosis and what would you do next?

Colonic histoplasmosis

An Ivorian woman presented to us with a 2-month history of fever, abdominal pain and nausea. Human immunodeficiency virus serology was positive. Abdominal ultrasound showed enlarged abdominal lymph nodes and wall thickening of the right colon. Colonic biopsy was suggestive of fungal infection and polymerase chain reaction for Histoplasma capsulatum on biopsy was positive.

Single High Dose of Liposomal Amphotericin B in Human Immunodeficiency Virus/AIDS-Related Disseminated Histoplasmosis: A Randomized Trial

BACKGROUND

Histoplasmosis is a major AIDS-defining illness in Latin America. Liposomal amphotericin B (L-AmB) is the drug of choice for treatment, but access is restricted due to the high drug and hospitalization costs of the conventional long regimens.

METHODS

Prospective randomized multicenter open-label trial of 1- or 2-dose induction therapy with L-AmB versus control for disseminated histoplasmosis in AIDS, followed by oral itraconazole therapy. We randomized subjects to: (i) single dose 10 mg/kg of L-AmB; (ii) 10 mg/kg of L-AmB on D1, and 5 mg/kg of L-AmB on D3; (iii) 3 mg/kg of L-AmB daily for 2 weeks (control). The primary outcome was clinical response (resolution of fever and signs/symptoms attributable to histoplasmosis) at day 14.

RESULTS

A total of 118 subjects were randomized, and median CD4+ counts, and clinical presentations were similar between arms. Infusion-related toxicity, kidney toxicity at multiple time-points, and frequency of anemia, hypokalemia, hypomagnesemia, and liver toxicity were similar. Day 14 clinical response was 84% for single-dose L-AmB, 69% 2-dose L-AmB, and 74% for control arm (P = .69). Overall survival on D14 was 89.0% (34/38) for single-dose L-AmB, 78.0% (29/37) for 2-dose L-AmB, and 92.1% (35/38) for control arm (P = .82).

CONCLUSIONS

One day induction therapy with 10 mg/kg of L-AmB in AIDS-related histoplasmosis was safe. Although clinical response may be non-inferior to standard L-AmB therapy, a confirmatory phase III clinical trial is needed. A single induction dose would markedly reduce drug-acquisition costs (>4-fold) and markedly shorten and simplify treatment, which are key points in terms of increased access.

Histoplasmosis: An epidemiological and clinical update in China, review and a case report

Histoplasmosis is a systemic mycosis caused by the dimorphic fungus in the genus Histoplasma. Histoplasmosis is overlooked in China. This study aims to provide an epidemiological and clinical update on histoplasmosis in China by literature review. We reviewed cases of histoplasmosis reported in recent 11 years  and described a case of histoplasmosis-triggered hemophagocytic lymphohistiocytosis (HLH) in an immunocompetent patient. A total of 225 cases of histoplasmosis diagnosed in China between 2012 and 2022 were involved in this study, compared with 300 cases reviewed from 1990 to 2011, an increasing number of cases of histoplasmosis have been diagnosed in the last 11 years. The majority of cases of histoplasmosis were autochthonous cases, mainly from provinces Sichuan (56/225, 24.9%), Hunan (50/225, 22.2%), Guangdong (31/225, 13.8%), and Yunnan (24/225, 10.7%). Higher incidence (52.5%, 53/99) of histoplasmosis occurred in immunocompetent patients which is similar to those from the previous 21 years, and the prevalence of the disease did not vary highly over time. Of note, the number of histoplasmosis cases is increasing, and the geographic distribution is shifting southwards over time. Improved awareness is critically important for informing clinical practice in China.

A Fatal Case of Disseminated Histoplasmosis by Histoplasma capsulatum var. capsulatum Misdiagnosed as Visceral Leishmaniasis-Molecular Diagnosis and Identification

Histoplasmosis is an endemic mycosis in the Americas. However, its diagnosis is challenging due to the complexity and limited availability of conventional laboratory techniques-antigen tests, culture, and staining. Microscopic preparations often confuse with other pathogens, such as Leishmania spp. The genus Histoplasma capsulatum comprises three varieties: var. capsulatum, var. duboissi, and var. farciminosum, which cannot be distinguished using conventional techniques. An infant from a tropical region of Ecuador was hospitalized for fever, bloody diarrhea, and anemia persisting for two months. Upon admission, he received antibiotics and immunosuppressants. Histopathological examination of the lymph nodes, intestines, and bone marrow aspirate reported the presence of Leishmania-like amastigotes, and treatment was initiated with meglumine antimoniate and conventional amphotericin B. However, subsequent analysis of samples using PCR and DNA sequencing identified H. capsulatum var. capsulatum but not Leishmania. Despite fluconazole and amphotericin B, the infant succumbed to the disease. The delay in clinical and laboratory diagnosis of histoplasmosis and the use of nonspecific and ineffective drugs such as fluconazole led to disease dissemination and, ultimately, death. Implementing molecular diagnosis and antigen tests in laboratories located in endemic regions and reference hospitals is crucial.

Hemophagocytic lymphohistiocytosis secondary to histoplasmosis: A case report in a patient with AIDS and recent SARS-CoV-2 infection and minireview

Here, we describe the case of a naïve HIV late presenter female African patient with progressive disseminated histoplasmosis and a severe life-threatening clinical picture in a non-endemic area. She had not visited Africa in the past decade. She developed a reactive hemophagocytic lymphohistiocytosis and an acute psychiatric disorder. Histoplasmosis was diagnosed after two bone marrow biopsies. Therapy with liposomal amphotericin B resulted in rapid and progressive improvements in blood examinations and clinical conditions, including the disappearance of psychiatric disorders. The characteristics of our case were compared with those of all other cases of hemophagocytic syndrome secondary to histoplasmosis in HIV-positive patients reported in PubMed. In conclusion, clinicians outside endemic areas should evaluate histoplasmosis as a cause of severe clinical picture, especially in a patient with a travel history to an endemic area, even after many years, considering the possible reactivation of latent infection.

Endemic Systemic Mycoses in Italy: A Systematic Review of Literature and a Practical Update

Endemic systemic mycoses such as blastomycosis, coccidioidomycosis, histoplasmosis, talaromycosis, paracoccidioidomycosis are emerging as an important cause of morbidity and mortality worldwide. We conducted a systematic review on endemic systemic mycoses reported in Italy from 1914 to nowadays. We found out: 105 cases of histoplasmosis, 15 of paracoccidioidomycosis, 10 of coccidioidomycosis, 10 of blastomycosis and 3 of talaromycosis. Most cases have been reported in returning travelers and expatriates or immigrants. Thirtytwo patients did not have a story of traveling to an endemic area. Fortysix subjects had HIV/AIDS. Immunosuppression was the major risk factor for getting these infections and for severe outcomes. We provided an overview on microbiological characteristics and clinical management principles of systemic endemic mycoses with a focus on the cases reported in Italy.

Anticytokine Autoantibodies and Fungal Infections

Anticytokine autoantibodies (ACAAs) can cause adult onset immunodeficiencies which mimic primary immunodeficiencies and can present as refractory and severe fungal infections. This paper provides an overview of the role of innate immunity, including key cytokines, in fungal infections and then describes four clinical scenarios where ACAAs are associated with severe presentations of a fungal infection: (1) Talaromyces marneffei infection and anti-interferon-γ, (2) histoplasmosis and anti-interferon-γ, (3) Cryptococcus gattii infection and anti-GM-CSF, and (4) mucocutaneous candidiasis and anti-IL-17A/F (IL-22). Testing for ACAAs and potential therapeutic options are discussed.

Adrenal Abscesses: A Systematic Review of the Literature

Objective: To summarize the existing knowledge about adrenal gland abscesses, including etiology, clinical presentation, common laboratory and imaging findings, management and overall morbidity and mortality. Design: Systematic literature review. Methods: We performed a search in the PubMed database using search terms: 'abscess and adrenal glands', 'adrenalitis', 'infection and adrenal gland', 'adrenal abscess', 'adrenal infection' and 'infectious adrenalitis'. Articles from 2017 to 2022 were included. We found total of 116 articles, and after applying exclusion criteria, data from 73 articles was included in the final statistical analysis. Results: Of 84 patients included in this review, 68 were male (81%), with a mean age of 55 years (range: 29 to 85 years). Weight loss was the most frequent symptom reported in 58.3% patients, followed by fever in 49%. Mean duration of symptoms was 4.5 months. The most common laboratory findings were low cortisol (51.9%), elevated ACTH (43.2%), hyponatremia (88.2%) and anemia (83.3%). Adrenal cultures were positive in 86.4% cases, with Histoplasma capsulatum (37.3%) being the leading causative agent. Blood cultures were positive in 30% of patients. The majority of the adrenal infections occurred through secondary dissemination from other infectious foci and abscesses were more commonly bilateral (70%). A total of 46.4% of patients developed long-term adrenal insufficiency requiring treatment. Abscess drainage was performed in 7 patients (8.3%) and adrenalectomy was performed in 18 (21.4%) patients. The survival rate was 92.9%. Multivariate analysis showed that the only independent risk factor for mortality was thrombocytopenia (p = 0.048). Conclusion: Our review shows that adrenal abscesses are usually caused by fungal pathogens, and among these, Histoplasma capsulatum is the most common. The adrenal glands are usually involved in a bilateral fashion and become infected through dissemination from other primary sources of infection. Long-term adrenal insufficiency develops in 46% of patients, which is more common than what is observed in non-infectious etiology of adrenal gland disorders. Mortality is about 7%, and the presence of thrombocytopenia is associated with worse prognosis. Further prospective studies are needed to better characterize optimal testing and treatment duration in patients with this relatively rare but challenging disorder.

Disseminated Histoplasmosis in an Indigenous Child With Malnutrition: A Case Report

Histoplasmosis is a mycosis caused by Histoplasma capsulatum, a dimorphic fungus endemic to areas with nitrogen-rich soil, like the one contaminated with bird and bat excrement. Patients with a deficient immune response are especially at risk for developing invasive infections, such as disseminated histoplasmosis, and secondary immunodeficiency can be a consequence of malnutrition. This case report presents a 15-month-old male infant with malnutrition who presented with signs and symptoms of disseminated histoplasmosis, including fever, malaise, weight loss, cough, and diarrhea. The infant came from a geographic area where histoplasmosis is endemic, and he was a member of a cultural group with a higher prevalence of histoplasmosis than the general population. On physical examination, hepatosplenomegaly, lymphadenopathy, and lung crackles were found, which are common in most patients with histoplasmosis. The keystone of diagnosis of H. capsulatum infection is antigen detection, but the criterion standard is isolation of the organism from body specimens through laboratory culture. Histological diagnosis is especially useful for rapid diagnosis. Treatment of disseminated histoplasmosis in the pediatric population consists of deoxycholate amphotericin B for four to six weeks followed by itraconazole to complete a total of three months of treatment. Despite the involvement of multiple organ systems, the patient recovered satisfactorily after the completion of amphotericin B treatment for one month and the resolution of his malnourishment.

Hepatic Manifestations of Systemic Diseases

In addition to being the primary target of infections such as viral hepatitis, the liver may also be affected by systemic disease. These include bacterial, mycotic, and viral infections, as well as autoimmune and infiltrative diseases. These conditions generally manifest as abnormal liver biochemistries, often with a cholestatic profile, and may present with additional signs/symptoms such as jaundice and fever. A high index of suspicion and familiarity with potential causal entities is necessary to guide appropriate testing, diagnosis, and treatment.

Chemical stimuli override a temperature-dependent morphological program by reprogramming the transcriptome of a fungal pathogen

The human fungal pathogen Histoplasma changes its morphology in response to temperature. At 37°C it grows as a budding yeast whereas at room temperature it transitions to hyphal growth. Prior work has demonstrated that 15-20% of transcripts are temperature-regulated, and that transcription factors Ryp1-4 are necessary to establish yeast growth. However, little is known about transcriptional regulators of the hyphal program. To identify TFs that regulate filamentation, we utilize chemical inducers of hyphal growth. We show that addition of cAMP analogs or an inhibitor of cAMP breakdown overrides yeast morphology, yielding inappropriate hyphal growth at 37°C. Additionally, butyrate supplementation triggers hyphal growth at 37°C. Transcriptional profiling of cultures filamenting in response to cAMP or butyrate reveals that a limited set of genes respond to cAMP while butyrate dysregulates a larger set. Comparison of these profiles to previous temperature- or morphology-regulated gene sets identifies a small set of morphology-specific transcripts. This set contains 9 TFs of which we characterized three, STU1 , FBC1 , and PAC2 , whose orthologs regulate development in other fungi. We found that each of these TFs is individually dispensable for room-temperature (RT) induced filamentation but each is required for other aspects of RT development. FBC1 and PAC2 , but not STU1 , are necessary for filamentation in response to cAMP at 37°C. Ectopic expression of each of these TFs is sufficient to induce filamentation at 37°C. Finally, PAC2 induction of filamentation at 37°C is dependent on STU1 , suggesting these TFs form a regulatory circuit that, when activated at RT, promotes the hyphal program.

Importance

Fungal illnesses pose a significant disease burden. However, the regulatory circuits that govern the development and virulence of fungi remain largely unknown. This study utilizes chemicals that can override the normal growth morphology of the human pathogen Histoplasma . Using transcriptomic approaches, we identify novel regulators of hyphal morphology and refine our understanding of the transcriptional circuits governing morphology in Histoplasma .

Factors related to mortality in critically ill histoplasmosis: a multicenter retrospective study in Guadeloupe and French Guyana

PURPOSE

To describe clinical and biological features and the outcomes of patients admitted for histoplasmosis in two intensive care units (ICU) in French Guyana and in the French West Indies (Guadeloupe).

METHODS

All patients admitted to these two ICUs for culture-proven histoplasmosis between January 2014 to August 2022 were included in the study. Using univariate and multivariate analysis, we assessed risk factors at ICU admission that were associated with death.

RESULTS

Forty patients were included (65% men). Median age was 56 years and simplified acute physiologic score (SAPS) II was 65. HIV was found in 58%, another immunodeficiency was identified in 28%, and no underlying immunodeficiency could be identified in 14% of patients. Within the first 24 h of ICU admission, 85% of patients had acute respiratory failure, 78% had shock, 30% had coma, and 48% had hemophagocytic lymphohistiocytosis. Mechanical ventilation was instituted in 78% of patients and renal replacement therapy in 55%. The 30-day mortality was 53%. By multivariate analysis, factors independently associated with 30-day mortality were SOFA score (odds ratio [OR] 1.5, 95% confidence interval [CI] [1.1-2.1]), time between symptom onset and treatment per day (OR 1.1, 95% CI 1.0-1.1), and hemophagocytic lymphohistiocytosis (OR 6.4, 95% CI 1.1-47.5).

CONCLUSION

Histoplasmosis requiring ICU admission is a protean disease with multiple and severe organ involvement. Immunodeficiency is found in most patients. The prognosis remains severe despite appropriate treatment and is worsened by late treatment initiation.