Diagnosis and Management of Central Nervous System Histoplasmosis

Clinical Characteristics and Outcomes of Endemic Mycoses After Solid Organ Transplantation: A Comprehensive Review

Background

Geographically endemic fungi can cause significant disease among solid organ transplant (SOT) recipients. We provide an update on the epidemiology, clinical presentation, and outcomes of 5 endemic mycoses in SOT recipients.

Methods

Multiple databases were reviewed from inception through May 2023 using key words for endemic fungi (eg, coccidioidomycosis or Coccidioides, histoplasmosis or Histoplasma, etc). We included adult SOT recipients and publications in English or with English translation.

Results

Among 16 cohort studies that reported on blastomycosis (n = 3), coccidioidomycosis (n = 5), histoplasmosis (n = 4), and various endemic mycoses (n = 4), the incidence rates varied, as follows: coccidioidomycosis, 1.2%-5.8%; blastomycosis, 0.14%-0.99%; and histoplasmosis, 0.4%-1.1%. There were 204 reports describing 268 unique cases of endemic mycoses, including 172 histoplasmosis, 31 blastomycosis, 34 coccidioidomycosis, 6 paracoccidioidomycosis, and 25 talaromycosis cases. The majority of patients were male (176 of 261 [67.4%]). Transplanted allografts were mostly kidney (192 of 268 [71.6%]), followed by liver (n = 39 [14.6%]), heart (n = 18 [6.7%]), lung (n = 13 [4.9%]), and combined kidney-liver and kidney-pancreas (n = 6 [2.7%]). In all 5 endemic mycoses, most patients presented with fever (162 of 232 [69.8%]) and disseminated disease (179 of 268 [66.8%]). Cytopenias were frequently reported for histoplasmosis (71 of 91 [78.0%]), coccidioidomycosis (8 of 11 [72.7%]) and talaromycosis (7 of 8 [87.5%]). Graft loss was reported in 12 of 136 patients (8.8%). Death from all-causes was reported in 71 of 267 (26.6%); half of the deaths (n = 34 [50%]) were related to the underlying mycoses.

Conclusions

Endemic mycoses commonly present with fever, cytopenias and disseminated disease in SOT recipients. There is a relatively high all-cause mortality rate, including many deaths that were attributed to endemic mycoses.

Infectious Myelopathies

OBJECTIVE

Infectious myelopathy of any stage and etiology carries the potential for significant morbidity and mortality. This article details the clinical presentation, risk factors, and key diagnostic components of infectious myelopathies with the goal of improving the recognition of these disorders and guiding subsequent management.

LATEST DEVELOPMENTS

Despite our era of advanced multimodal imaging and laboratory diagnostic technology, a causative organism often remains unidentified in suspected infectious and parainfectious myelopathy cases. To improve diagnostic capability, newer technologies such as metagenomics are being harnessed to develop diagnostic assays with a greater breadth of data from each specimen and improvements in infection identification. Conventional assays have been optimized for improved sensitivity and specificity.

ESSENTIAL POINTS

Prompt recognition and treatment of infectious myelopathy decreases morbidity and mortality. The key diagnostic tools include serologies, CSF analysis, and imaging; however clinical presentation, epidemiologic risk factors, and history of recent illness are all vital to making the proper diagnosis because current laboratory and imaging modalities are often inconclusive. The cornerstone of recommended treatment is targeted antimicrobials with appropriate immune modulation, surgical intervention, supportive care, and interdisciplinary involvement, all of which further improve outcomes for patients with infectious myelopathy.

Intramedullary histoplasmosis of the thoracic cord as an isolated lesion: A rare case report and literature review

Background

Disseminated histoplasmosis involving the central nervous system occurs in 5-10% of cases. However, intramedullary spinal cord lesions are extremely rare. Here, 45-year-old female with a T8-9 intramedullary lesion did well following surgical extirpation.

Case Description

For 2 weeks, a 45-year-old female experienced progressive lower back pain, paresthesias, and paraparesis. The magnetic resonance imaging showed an intramedullary expansive lesion at the T8-T9 level that markedly enhanced with contrast. Surgery, consisting of T8-T10 laminectomies performed using neuronavigation, an operating microscope, and intraoperative monitoring, revealed a well-demarcated lesion that proved to be a focus of histoplasmosis; it was readily completely excised.

Conclusion

Surgery is the gold standard for treating spinal cord compression attributed to intramedullary histoplasmosis unresponsive to medical management.

Central Nervous System Histoplasmosis: An Updated Insight

Histoplasmosis is one of the systemic mycoses that can involve the Central Nervous System (CNS), and it is caused by the dimorphic ascomycete species of the Histoplasma capsulatum complex. Once in the CNS, this pathogen causes life-threatening injuries that are associated with clinical manifestations of meningitis, focal lesions (abscesses, histoplasmomas), and spinal cord injuries. The present review provides updated data and highlights a particular vision regarding this mycosis and its causative agent, as well as its epidemiology, clinical forms, pathogenesis, diagnosis, and therapy, focusing on the CNS.

Acrophialophora: A Comprehensive Review of Clinical Guidelines and Diagnosis

Acrophialophora is a saprotrophic genus of fungi found in both temperate and tropical regions. The genus is comprised of 16 species, with the subspecies A. fusispora and A. levis necessitating the most clinical concern. Acrophialophora is an opportunistic pathogen with a broad range of clinical manifestations; the fungus has been implicated in cases of fungal keratitis, lung infection, and brain abscess. Acrophialophora infection is particularly of concern for immunocompromised patients, who often present with a more severe disease course involving disseminated infection and may not exhibit typical symptoms. Early diagnosis and therapeutic intervention are critical to the successful clinical management of Acrophialophora infection. Guidelines for antifungal treatment have yet to be established, partially due to the lack of documented cases. Aggressive use of antifungal agents and long-term treatment is required, especially in immunocompromised patients and patients with systemic involvement, due to the potential for morbidity and mortality. In addition to outlining the rarity and epidemiology of the disease, this review provides an overview of the diagnosis and clinical management of Acrophialophora infection to facilitate an early diagnosis and appropriate interventions.

Intramedullary histoplasmosis lesion in children: A case report

Background:

Histoplasmosis is a fungal disease endemic in some regions of the United States of America, Canada, and Latin America. The geographic characteristics, humidity, soil, and climate are responsible for such distribution. In Brazil, there are case reports of histoplasmosis throughout its territory, being considered an endemic region. It is considered an opportunistic disease, affecting mostly immunocompromised patients. To the present date, scientific publications dealing with pediatric cases of histoplasmosis are restricted to case series. Spinal cord injuries caused by histoplasmosis are rare, even in the adult population, being described in few studies.

Case Description:

The present report deals with a 4-year-old patient, from the southeast region of Brazil, who started a condition of fever, weight loss, cervicobrachialgia, and symmetrical tetraparesis, with evolution over 2 months. In the diagnostic investigation, she was found to have primary immunodeficiency and neuroimaging examinations showed a cervical spinal cord lesion at the level of C4-C6. The anatomopathological diagnosis of histoplasmosis was possible after surgery for decompression and biopsy of the lesion.

Conclusion:

According to our research, there are no reports in the literature that address the situation of spinal cord compression syndrome due to histoplasmosis in the pediatric population.

Disseminated Histoplasmosis Presenting as Acute Respiratory Distress Syndrome and Disseminated Intravascular Coagulation in an HIV Positive Immigrant from Central America

Histoplasmosis rarely causes significant illness in immunocompetent patients. In endemic areas such as the Midwestern United States and Central America, most people are infected, but are rarely symptomatic, with variable presentation. The illness is usually self-limited in immunocompetent individuals. However, in immunocompromised patients, Histoplasma capsulatum can disseminate to various organs and should be suspected especially in the endemic areas or if there is a significant travel history involving these areas. We present a case of a 65-year-old male originally from Central America with no known past medical history presenting with Acute Respiratory Distress Syndrome complicated by disseminated intravascular coagulation due to acute histoplasmosis and incidentally found to have HIV/AIDS.

Ischemic brain infarcts and vasculitis in histoplasmosis of the central nervous system: A case report and review of the literature

Histoplasmosis is one of the most common endemic mycoses affecting immunocompromised individuals in the United States and Latin America. Involvement of the central nervous system carries higher mortality rates and worse prognosis, given its resemblance to stroke, vasculitis, and meningitis of other etiologies. The diagnosis is challenging, due to its subtle clinical presentation and the poor sensitivity of the cerebrospinal fluid culture. Herein the authors present a case of a middle-aged man with HIV, who presented with intermittent headaches exacerbated by an oculomotor nerve palsy, concerning for acute stroke. A diagnosis of central nervous system histoplasmosis was made, and his neurological deficits subsided after initiation of treatment. The stroke-like syndrome in this scenario may be secondary to granulomatous vasculitis of small caliber cerebral blood vessels. Histoplasmosis of the central nervous system remains a challenging diagnosis, which requires a high index of suspicion by the clinician for an early institution of therapy in order to improve outcomes.

Infectious Myelopathies

In the setting of both globalization and increasing use of immunosuppressive therapy, infectious myelopathies are an important cause of morbidity worldwide. Clinical spinal cord syndromes related to infection are varied, including transverse myelitis, acute flaccid paralysis related to anterior horn cell involvement, spinal cord compression, chronic spastic paraparesis, and myeloradiculitis. Causative pathogens include viruses, parasites, pyogenic and atypical bacteria, and fungi. The epidemiology, clinical characteristics, diagnosis, and treatment of selected organisms will be discussed in this article.

Central Nervous System Infections in the Immunocompromised Adult Presenting to the Emergency Department

Over the past 2 decades, the population of immunocompromised patients has increased dramatically in the United States. These patients are at elevated risk for both community-acquired and opportunistic central nervous system infections. We review the most common and serious central nervous system pathogens affecting these patients and outline a diagnostic and therapeutic approach to their management in the emergency department. We recommend a broad diagnostic evaluation, including neuroimaging and cerebrospinal fluid studies where appropriate, empiric antimicrobial therapy, and early involvement of subspecialists to provide comprehensive care for these complex patients.

Methods for rapid diagnosis of meningitis etiology in adults

Infectious meningitis can be caused by viral, bacterial or fungal pathogens. Despite widely available treatments, many types of infectious meningitis are still associated with significant morbidity and mortality. Delay in diagnosis contributes to poor outcomes. Cerebrospinal fluid cultures have been used traditionally but are time intensive and sensitivity is decreased by empiric treatment prior to culture. More rapid techniques such as the cryptococcal lateral flow assay (IMMY), GeneXpert MTB/Rif Ultra (Cepheid) and FilmArray multiplex-PCR (Biofire) are three examples that have drastically changed meningitis diagnostics. This review will discuss a holistic approach to diagnosing bacterial, mycobacterial, viral and fungal meningitis.

A Case of Histoplasmosis with Central Nervous System Relapse after Itraconazole Therapy Needs Further Research

Central nervous system (CNS) histoplasmosis occurs in 5-20% of all cases and is most commonly seen in immunosuppressed patients who have acquired immunodeficiency syndrome (AIDS) or have received organ transplant. The prevalence of histoplasmosis in patients greater than 65 years old between the years of 1999-2008 in the state of Texas was about 2-3 cases per 100,000 patients year. Since 1990 with the discovery of Triazoles, itraconazole (ICZ) has become the standard initial and suppressive therapy in patients with mild-moderate histoplasmosis without CNS involvement. However, poor penetration of ICZ into the brain, in vitro fluconazole resistance and lack of controlled-trials pose challenge in the treatment of cerebral histoplasmosis.

Primary Central Nervous System Infection by Histoplasma in an Immunocompetent Adult

Central nervous system (CNS) infection by Histoplasma capsulatum is a rare disease in immunocompromised individuals in endemic areas. About one quarter of cases result from hematogenous dissemination. A 23-year-old upholsterer with chronic occipital headache had developed intracranial hypertension and dizziness, incoordination with ataxic gait, and acute confusion 5 months prior to admission. Laboratory examinations and chest roentgenogram were normal. Postcontrast T1-weighted MRI of the brain revealed a multiple ring-enhancing cerebellar, brain stem and parietal lobe lesions, and meningeal contrast enhancement. Cerebrospinal fluid culture was positive for H. capsulatum species complex, which was confirmed by phylogenetic analysis. Thirteen years after the diagnosis and treatment, there was no H. capsulatum recurrence; sequels related to complications due to the ventriculoperitoneal shunt. This case shows a primary neurological presentation of cerebral histoplasmosis, without meningitis or disseminated disease in nonimmune-compromised patient. The authors propose a categorization of the diagnosis of CNS histoplasmosis. Routine diagnostics of sibling species within the H. capsulatum complex proved to be difficult.

Improvement in Diagnosis of Histoplasma Meningitis by Combined Testing for Histoplasma Antigen and Immunoglobulin G and Immunoglobulin M Anti-Histoplasma Antibody in Cerebrospinal Fluid

Background

Central nervous system (CNS) histoplasmosis is a life-threatening condition and represents a diagnostic and therapeutic challenge. Isolation of Histoplasma capsulatum from cerebrospinal fluid (CSF) or brain tissue is diagnostic; however, culture is insensitive and slow growth may result in significant treatment delay. We performed a retrospective multicenter study to evaluate the sensitivity and specificity of a new anti-Histoplasma antibody enzyme immunoassay (EIA) for the detection of IgG and IgM antibody in the CSF for diagnosis of CNS histoplasmosis, the primary objective of the study. The secondary objective was to determine the effect of improvements in the Histoplasma galactomannan antigen detection EIA on the diagnosis of Histoplasma meningitis.

Methods

Residual CSF specimens from patients with Histoplasma meningitis and controls were tested for Histoplasma antigen and anti-Histoplasma immunoglobulin G (IgG) and immunoglobulin M (IgM) antibody using assays developed at MiraVista Diagnostics.

Results

A total of 50 cases and 157 controls were evaluated. Fifty percent of patients with CNS histoplasmosis were immunocompromised, 14% had other medical conditions, and 36% were healthy. Histoplasma antigen was detected in CSF in 78% of cases and the specificity was 97%. Anti-Histoplasma IgG or IgM antibody was detected in 82% of cases and the specificity was 93%. The sensitivity of detection of antibody by currently available serologic testing including immunodiffusion and complement fixation was 51% and the specificity was 96%. Testing for both CSF antigen and antibody by EIA was the most sensitive approach, detecting 98% of cases.

Conclusions

Testing CSF for anti-Histoplasma IgG and IgM antibody complements antigen detection and improves the sensitivity for diagnosis of Histoplasma meningitis.

Infectious Myelopathies

PURPOSE OF REVIEW

This article reviews bacterial, viral, fungal, and parasitic pathogens associated with myelopathy. Infectious myelopathies may be due to direct infection or parainfectious autoimmune-mediated mechanisms; this article focuses primarily on the former.

RECENT FINDINGS

Some microorganisms exhibit neurotropism for the spinal cord (eg, enteroviruses such as poliovirus and flaviviruses such as West Nile virus), while others are more protean in neurologic manifestations (eg, herpesviruses such as varicella-zoster virus), and others are only rarely reported to cause myelopathy (eg, certain fungal and parasitic infections). Individuals who are immunocompromised are at increased risk of disseminated infection to the central nervous system. Within the last few years, an enterovirus D68 outbreak has been associated with cases of acute flaccid paralysis in children, and emerging Zika virus infection has been concurrent with cases of acute flaccid paralysis due to Guillain-Barré syndrome, although cases of myelitis have also been reported. Associated pathogens differ by geographic distribution, with myelopathies related to Borrelia burgdorferi (Lyme disease) and West Nile virus more commonly seen in the United States and parasitic infections encountered more often in Latin America, Southeast Asia, and Africa. Characteristic CSF and MRI patterns have been identified with many of these infections.

SUMMARY

A myriad of pathogens are associated with infectious myelopathies. Host factors, geographic distribution, clinical features, CSF profiles, and MRI findings can assist in formulating the differential diagnosis and ultimately guide management.

Diagnosis and treatment of histoplasmosis in solid organ transplant patients

PURPOSE OF REVIEW

Unlike immunocompetent hosts, solid organ transplant (SOT) recipients with posttransplant histoplasmosis (PTH) often present with disseminated disease and have an attributable mortality of approximately 10%. In this review, we discuss currently available diagnostic tests and treatment strategies in PTH.

RECENT FINDINGS

None of the available tests have a 100% diagnostic accuracy. Histoplasma antigen assays are the most sensitive commercially available tests. However, crossreactivity of histoplasma antigen with aspergillus galactomannan and false positive histoplasma antigen tests because of rabbit antithymocyte globulin may cause difficulty in interpreting positive test results in transplant recipients. Molecular assays such as amplification and sequencing of 'panfungal' portions of the 28S ribosomal RNA from clinical specimens appear to be promising.Lipid formulations of amphotericin B and itraconazole are the drugs of choice in the treatment of PTH. Other extended spectrum azoles also appear to be effective, but, like itraconazole, problems with drug interactions and prolongation of the QTc interval (except for isavuconazole, which shortens the QTc interval) remain. Mycophenolate therapy is associated with severe disease and should be stopped during active disease and, if feasible, calcineurin inhibitors and steroids should be reduced.

SUMMARY

A combination of various tests (culture, antigen tests, nucleic amplification tests, etc.) should be used to optimize diagnostic yield. The role of unbiased next generation sequencing for early diagnosis and newer azoles in the treatment needs to be further explored.

Disseminated Central Nervous System Histoplasmosis: A Case Report

Central nervous system (CNS) histoplasmosis is a rare manifestation of disease, often misdiagnosed due to the wide spectrum of neurological presentation. We present a rare case of CNS histoplasmosis in a 62-year-old male with untreated myeloproliferative disease who presented with altered mental status. This case emphasizes the clinical presentation and diagnostic difficulty in a patient with CNS histoplasmosis. We also highlight the importance of implementing a multidisciplinary approach in the medical management of disseminated histoplasmosis with CNS involvement.

Safety and efficacy of chronic suppressive azole therapy for endemic fungal infections in solid organ transplant recipients

BACKGROUND

Although the research is limited, treatment guidelines recommend lifelong suppressive azole therapy for disseminated endemic fungal infection (EFI) after solid organ transplantation (SOT). Suppressive azole therapy may prevent EFI recurrence at the risk of hepatotoxicity and drug interactions. We present real-world safety and effectiveness data of chronic suppressive azole therapy for EFI in SOT recipients over a 10-year period at a single comprehensive transplant center.

METHODS

A retrospective analysis was conducted of SOT recipients diagnosed with EFI from January 1, 2005, to May 1, 2015. Chronic suppressive azole therapy was defined as treatment for more than 12 months after diagnosis. Effectiveness of suppression was defined as preventing EFI reactivation. Safety endpoints included adverse reactions and drug interactions.

RESULTS

Over a 10-year period, 28 SOT recipients were diagnosed with EFI: 16 histoplasmosis, 9 blastomycosis, and 3 coccidioidomycosis. Eighteen (64%) patients were treated with chronic suppressive azole therapy for a median length of 36 months (range 15-90). One patient had an adverse drug interaction requiring azole discontinuation. There were no episodes of azole-related hepatotoxicity, toxicity from antirejection medication, or EFI reactivation.

CONCLUSIONS

Chronic suppressive azole therapy was safe and effective in preventing reactivation of EFI in SOT recipients.

Disseminated Histoplasmosis as AIDS-presentation. Case Report and Comprehensive Review of Current Literature

Progressive disseminated histoplasmosis (PDH) is an AIDS-defining illness with a high lethality rate if not promptly treated. The wide range of its possible clinical manifestations represents the main barrier to diagnosis in non-endemic countries. Here we present a case of PDH with haemophagocytic syndrome in a newly diagnosed HIV patient and a comprehensive review of disseminated histoplasmosis focused on epidemiology, clinical features, diagnostic tools and treatment options in HIV-infected patients.

Central nervous system histoplasmosis: Multicenter retrospective study on clinical features, diagnostic approach and outcome of treatment

Central nervous system (CNS) involvement occurs in 5 to 10% of individuals with disseminated histoplasmosis. Most experience has been derived from small single center case series, or case report literature reviews. Therefore, a larger study of central nervous system (CNS) histoplasmosis is needed in order to guide the approach to diagnosis, and treatment.A convenience sample of 77 patients with histoplasmosis infection of the CNS was evaluated. Data was collected that focused on recognition of infection, diagnostic techniques, and outcomes of treatment.Twenty nine percent of patients were not immunosuppressed. Histoplasma antigen, or anti-Histoplasma antibodies were detected in the cerebrospinal fluid (CSF) in 75% of patients. One year survival was 75% among patients treated initially with amphotericin B, and was highest with liposomal, or deoxycholate formulations. Mortality was higher in immunocompromised patients, and patients 54 years of age, or older. Six percent of patients relapsed, all of whom had the acquired immunodeficiency syndrome (AIDS), and were poorly adherent with treatment.While CNS histoplasmosis occurred most often in immunocompromised individuals, a significant proportion of patients were previously, healthy. The diagnosis can be established by antigen, and antibody testing of the CSF, and serum, and antigen testing of the urine in most patients. Treatment with liposomal amphotericin B (AMB-L) for at least 1 month; followed by itraconazole for at least 1 year, results in survival among the majority of individuals. Patients should be followed for relapse for at least 1 year, after stopping therapy.

Histoplasmosis in Africa: An emerging or a neglected disease?

Histoplasmosis in Africa has markedly increased since the advent of the HIV/AIDS epidemic but is under-recognised. Pulmonary histoplasmosis may be misdiagnosed as tuberculosis (TB). In the last six decades (1952-2017), 470 cases of histoplasmosis have been reported. HIV-infected patients accounted for 38% (178) of the cases. West Africa had the highest number of recorded cases with 179; the majority (162 cases) were caused by Histoplasma capsulatum var. dubuosii (Hcd). From the Southern African region, 150 cases have been reported, and the majority (119) were caused by H. capsulatum var. capsulatum (Hcc). There have been 12 histoplasmin skin test surveys with rates of 0% to 35% positivity. Most cases of Hcd presented as localised lesions in immunocompetent persons; however, it was disseminated in AIDS patients. Rapid diagnosis of histoplasmosis in Africa is only currently possible using microscopy; antigen testing and PCR are not available in most of Africa. Treatment requires amphotericin B and itraconazole, both of which are not licensed or available in several parts of Africa.

Histoplasmosis in transplant recipients

Histoplasma capsulatum is a dimorphic fungus that most often causes asymptomatic infection in the immunocompetent population. In immunocompromised patients, including solid organ transplant (SOT) and hematopoietic cell transplant (HCT) recipients, however, it is likely to cause severe life-threatening infection. Post-transplant histoplasmosis (PTH) in SOT is uncommon with an incidence of ≤1% and is even rarer in HCT patients. The majority of PTH in SOT is diagnosed in the first 2 years following transplantation. Histoplasmosis may result from endogenous reactivation of latent infection, de novo post-transplant acquisition, and donor-derived infection. Disseminated infection is common. Fever is the most common symptom and clinical features are often nonspecific, but patients with disseminated infection may present with a septic picture. Other features, including pancytopenia and hepatosplenomegaly, may not be prominent early in the course of illness. Contemporary histoplasma antigen assays are the most sensitive tests but cross-reactivity with antigens of other fungi, including with Aspergillus galactomannan, is not uncommon. Treatment should be continued for at least a year. Histoplasma antigen levels have prognostic value and can be used to monitor the response to therapy. The attributable mortality is approximately 10%. Routine screening of donors and recipients is not currently recommended.

Fungal infections in HIV/AIDS

Fungi are major contributors to the opportunistic infections that affect patients with HIV/AIDS. Systemic infections are mainly with Pneumocystis jirovecii (pneumocystosis), Cryptococcus neoformans (cryptococcosis), Histoplasma capsulatum (histoplasmosis), and Talaromyces (Penicillium) marneffei (talaromycosis). The incidence of systemic fungal infections has decreased in people with HIV in high-income countries because of the widespread availability of antiretroviral drugs and early testing for HIV. However, in many areas with high HIV prevalence, patients present to care with advanced HIV infection and with a low CD4 cell count or re-present with persistent low CD4 cell counts because of poor adherence, resistance to antiretroviral drugs, or both. Affordable, rapid point-of-care diagnostic tests (as have been developed for cryptococcosis) are urgently needed for pneumocystosis, talaromycosis, and histoplasmosis. Additionally, antifungal drugs, including amphotericin B, liposomal amphotericin B, and flucytosine, need to be much more widely available. Such measures, together with continued international efforts in education and training in the management of fungal disease, have the potential to improve patient outcomes substantially.

Central Nervous System Infections

This chapter provides an overview of infectious syndromes, pathogens, and diagnostic testing modalities for central nervous system infections in the immunocompromised host.

Clinical Perspectives in the Diagnosis and Management of Histoplasmosis

With increasing numbers of travelers and immunocompromised patients, histoplasmosis, caused by the dimorphic fungus Histoplasma capsulatum, has become a disease of national extent. The clinical spectrum of histoplasmosis is very wide, in terms of disease cadence, onset, distribution, and severity. A multipronged approach is recommended for diagnosis. Manifestations that are always treated include moderate to severe acute pulmonary histoplasmosis, disseminated disease, and histoplasmosis in immunocompromised individuals. Amphotericin B is the drug of choice for moderate to severe and disseminated presentations, whereas itraconazole is appropriate for mild disease and as step-down therapy.

The Simultaneous Occurrence of Histoplasmosis and Cryptococcal Fungemia: A Case Report and Review of the Literature

Simultaneous infections with Cryptococcus neoformans and Histoplasma capsulatum are rare and typically occur in immunocompromised individuals, particularly AIDS patients. Because both of those fungi can spur the development of latent infections, it is generally unknown which organism was first present. The diagnosis of one fungus can hide the diagnosis of the other, leading to underdiagnoses and poor prognosis. We report a case of C. neoformans and H. capsulatum co-infection. We also performed a systematic review of the literature. Our patient, a 69-year-old HIV-negative man, presented with a 9-month history of a productive cough, dyspnea and wheezing. His history showed chronic obstructive pulmonary disease and type II diabetes mellitus (DM). Pulmonary lesions of unidentified etiology were noted. Cryptococcal involvement of the central nervous system was confirmed, and C. neoformans and H. capsulatum were also isolated from blood cultures. In the literature, we found ten cases of simultaneous histoplasmosis and cryptococcosis. Including our patient, all of the cases were located in North America and Latin America, except for two, one Indian and one African diagnosed in France. AIDS was the main predisposing factor, followed by DM and age >60 years. Several diagnostic methods were employed. A blood culture and bronchoalveolar lavage (BAL) culture resulted in the growth of C. neoformans in most of the cases. H. capsulatum was more often detected in BAL and bone marrow cultures. Although co-infection by these pathogens is severe, it can be cured if it is diagnosed and treated early. We emphasized the importance of clinical suspicion and differential diagnosis of systemic mycoses.

From suspected Creutzfeldt-Jakob disease to confirmed histoplasma meningitis

A 77-year-old man with chronic obstructive lung disease who was on steroids, presented to the hospital after a fall with subacute headaches and ataxia. During the patient's hospital course, his clinical condition deteriorated with myoclonic jerks, fevers and severe encephalopathy. An extensive workup, including EEG, brain MRI and lumbar puncture, revealed possible Creutzfeldt-Jakob disease. Unfortunately, the patient failed to improve and died 12 days after admission. A brain-only autopsy revealed he had acute histoplasma meningitis with patchy superficial cerebritis.

Central Nervous System Histoplasmosis in Acquired Immunodeficiency Syndrome

BACKGROUND

Involvement of the central nervous system (CNS) by Histoplasma capsulatum in AIDS is uncommon and not easily recognized.

MATERIALS AND METHODS

CNS histoplasmosis cases from our institution were identified by a retrospective chart review from 2004-2014. A thorough literature search was performed for additional cases and their characteristics were compared. Clinical findings, treatment and outcomes are discussed.

RESULTS

A total of 5 cases from our institution were identified. They had a clinical presentation that included classic signs of meningitis, often with evidence of disseminated involvement, and was typically severe with important neurological impairment. These cases were treated with antifungal agents, including a lipid amphotericin B formulation and azole drugs, but eventually 3 experienced nonresolution of their disease likely because of lack of adherence to therapy and died from their infection. The clinical presentation, treatment and outcome of these cases did not significantly differ from cases found in the review of the literature.

CONCLUSIONS

Clinicians practicing in endemic areas should be aware of this rare but serious form of histoplasmosis. The recognition of 5 cases of CNS histoplasmosis in AIDS patients from a single institution suggests that histoplasmosis should be included in the differential diagnosis of the CNS complications of AIDS.

CNS infections in patients with hematological disorders (including allogeneic stem-cell transplantation)-Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Diagnosis of CNS infections remains a great challenge in patients with hematological disorders since symptoms might both be masked and be mimicked by other conditions such as metabolic disturbances or consequences from antineoplastic treatment. Thus, awareness of this complication is crucial and any suspicion of a CNS infection should lead to timely and adequate diagnostics and treatment to improve the outcome in this population.

Infections of the central nervous system (CNS) are infrequently diagnosed in immunocompetent patients, but they do occur in a significant proportion of patients with hematological disorders. In particular, patients undergoing allogeneic hematopoietic stem-cell transplantation carry a high risk for CNS infections of up to 15%. Fungi and Toxoplasma gondii are the predominant causative agents. The diagnosis of CNS infections is based on neuroimaging, cerebrospinal fluid examination and biopsy of suspicious lesions in selected patients. However, identification of CNS infections in immunocompromised patients could represent a major challenge since metabolic disturbances, side-effects of antineoplastic or immunosuppressive drugs and CNS involvement of the underlying hematological disorder may mimic symptoms of a CNS infection. The prognosis of CNS infections is generally poor in these patients, albeit the introduction of novel substances (e.g. voriconazole) has improved the outcome in distinct patient subgroups. This guideline has been developed by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) with the contribution of a panel of 14 experts certified in internal medicine, hematology/oncology, infectious diseases, intensive care, neurology and neuroradiology. Grades of recommendation and levels of evidence were categorized by using novel criteria, as recently published by the European Society of Clinical Microbiology and Infectious Diseases.

Histoplasmosis with Deep CNS Involvement: Case Presentation with Discussion and Literature Review

Central nervous system (CNS) histoplasmosis is rare and difficult to diagnose because it is often overlooked or mistaken for other pathologies due to its nonspecific symptoms. A 32-year-old Hispanic man with advanced acquired immunodeficiency virus presented with altered mental status and reported confusion for the past 3 months. He had a Glasgow Coma Scale of 12, repetitive nonfluent speech, and a disconjugate gaze with a right gaze preference. Lung computed tomography (CT) findings indicated a pulmonary histoplasmosis infection. Magnetic resonance imaging of the brain revealed a ring-enhancing lesion in the left caudate nucleus. A CT-guided left retroperitoneal node biopsy was performed and indicated a benign inflammatory process with organisms compatible with fungal yeast. Treatment with amphotericin B followed by itraconazole was initiated in spite of negative cerebrospinal fluid (CSF) cultures and proved effective in mitigating associated CNS lesions and resolving neurologic deficits. The patient was discharged 3 weeks later in stable condition. Six weeks later, his left basal ganglia mass decreased. Early recognition of symptoms and proper steps is key in improving outcomes of CNS histoplasmosis. Aggressive medical management is possible in the treatment of intracranial deep mass lesions, and disseminated histoplasmosis with CNS involvement can be appropriately diagnosed and treated, despite negative CSF and serology studies.

Compartmentalized Histoplasma capsulatum Infection of the Central Nervous System

Background. Histoplasmosis is a common fungal infection in the southeastern, mid-Atlantic, and central states; however, its presentation can be atypical. Case Presentation. We report a case of Histoplasma capsulatum infection presenting as slowly progressive weakness in the lower extremities, followed by the development of numbness below the midthoracic area, urinary incontinence, and slurred speech. Brain MRI showed leptomeningeal enhancement, predominantly linear, involving the basal cisterns, the brainstem, and spinal cord. Cerebrospinal fluid analysis showed lymphocytic pleocytosis. Discussion. CNS histoplasmosis is usually seen in patients with disseminated histoplasmosis. Isolated CNS histoplasmosis is rarely seen, especially in immunocompetent patients. Conclusions. Histoplasmosis should be considered in the differential diagnosis of patients experiencing slowly progressive neurological deficit.

British Society for Medical Mycology best practice recommendations for the diagnosis of serious fungal diseases

Invasive fungal diseases are an important cause of morbidity and mortality in a wide range of patients, and early diagnosis and management are a challenge. We therefore did a review of the scientific literature to generate a series of key recommendations for the appropriate use of microbiological, histological, and radiological diagnostic methods for diagnosis of invasive fungal diseases. The recommendations emphasise the role of microscopy in rapid diagnosis and identification of clinically significant isolates to species level, and the need for susceptibility testing of all Aspergillus spp, if treatment is to be given. In this Review, we provide information to improve understanding of the importance of antigen detection for cryptococcal disease and invasive aspergillosis, the use of molecular (PCR) diagnostics for aspergillosis, and the crucial role of antibody detection for chronic and allergic aspergillosis. Furthermore, we consider the importance of histopathology reporting with a panel of special stains, and emphasise the need for urgent (<48 hours) and optimised imaging for patients with suspected invasive fungal infection. All 43 recommendations are auditable and should be used to ensure best diagnostic practice and improved outcomes for patients.

Noncongenital central nervous system infections in children: radiology review

Infections of the central nervous system (CNS) are a very common worldwide health problem in childhood with significant morbidity and mortality. In children, viruses are the most common cause of CNS infections, followed by bacterial etiology, and less frequent due to mycosis and other causes. Noncomplicated meningitis is easier to recognize clinically; however, complications of meningitis such as abscesses, infarcts, venous thrombosis, or extra-axial empyemas are difficult to recognize clinically, and imaging plays a very important role on this setting. In addition, it is important to keep in mind that infectious process adjacent to the CNS such as mastoiditis can develop by contiguity in an infectious process within the CNS. We display the most common causes of meningitis and their complications.

Disseminated histoplasmosis in allogeneic bone marrow transplant: a diagnosis not to be missed

Immunosuppressed patients are at highest risk for disseminated histoplasmosis, but only a few cases have been reported in hematopoietic stem cell transplant recipients. We report a case of disseminated histoplasmosis in an allogeneic bone marrow transplant recipient residing in a non-endemic area. Diagnosis was first suspected based on a peripheral blood smear.

Disseminated histoplasmosis: a comparative study of the clinical features and outcome among immunocompromised and immunocompetent patients

BACKGROUND

Disseminated histoplasmosis is a chronic granulomatous disease caused by the dimorphic fungus, Histoplasma capsulatum. Clinical presentation can vary from the acute pulmonary to the chronic disseminated form. In India, disseminated histoplasmosis often presents with pyrexia of unknown origin with a presentation similar to 'disseminated tuberculosis' involving the adrenal glands and bone marrow. Due to rarity of the disease, data are lacking regarding its clinical presentation and outcome among immunocompromised and immunocompetent patients.

METHODS

During January 2000 to December 2010, we identified 37 patients of disseminated histoplasmosis and attempted to characterize the differences between immuno- compromised and immunocompetent patients. Demographic characteristics, clinical presentation, risk factors, laboratory findings, diagnostic yield, treatment received and prognosis were noted and compared between the two groups.

RESULTS

Eleven of 37 patients with disseminated histo- plasmosis were immunocompromised and 26 were immuno- competent. Comparison of their clinical features showed a higher frequency of skin lesions in the immunocompromised compared to the immunocompetent group (54.5% v. 11.5%). Pancytopenia and anaemia were more common among the immunocompromised (81.8%) compared to the immunocompetent (46.2%) group. In the immuno- compromised patients, the diagnosis was made most often by bone marrow aspirate and culture (72.7%) compared to the immunocompromised group where the diagnosis was most often obtained by adrenal gland biopsy and fungal cultures (57.7%). The cure rate was significantly higher in the immunocompetent group (73% v. 45%).

CONCLUSION

The clinical presentation and outcome of patients with disseminated histoplasmosis differs among immunocompromised and immunocompetent patients.