Histoplasmosis Diagnosed in Europe and Israel: A Case Report and Systematic Review of the Literature from 2005 to 2020

Molecular Detection of Histoplasma in Bat-Inhabited Tunnels of Camino de Hierro Tourist Route, Spain

We detected Histoplasma capsulatum in 2 bat-inhabited tunnels of a tourist route in northern Spain. This finding confirms that the geographic distribution of this fungal pathogen is wider than previously thought. Our results highlight the need for surveillance and assessment of the potential infection risk for workers and visitors.

Elevating fungal care: bridging Brazil's healthcare practices to global standards

Brazil faces unique challenges in managing invasive fungal infections (IFIs) due to diverse ecosystems, a rural workforce, and prevalent health conditions. In Europe, IFIs are primarily associated with transplantation, intensive care, and chronic diseases. Inspired by initiatives in the Caribbean and Latin America in 2019, efforts to map global diagnostic and treatment resources expanded to Africa, Europe, and Asia/Pacific. This study conducts a comparative analysis, mainly drawing data from Brazil and Europe, to investigate IFI epidemiology and management. Data were collected through online surveys distributed to Brazilian and European institutions, with collaborations from scientific organizations. Surveys covered institutional profiles, IFI diagnoses, accessibility to diagnostic techniques, and antifungal drugs. A comparative survey involving 96 Brazilian and 388 European institutions revealed variations in the perception and practices related to fungal pathogens. Differences in ranking and prevalence were observed, along with variations in diagnostic procedures, fluorescence dye usage, culture practices, antifungal medication availability, and technological approaches. Europe exhibited higher utilization rates for molecular diagnostic approaches, including PCR tests, and therapeutic drug monitoring (TDM) was more widespread in Europe compared with Brazil, indicating substantial differences in understanding and managing fungal infections. Customized IFI management is crucial, considering regional differences and addressing technological gaps like underutilized PCR. The study advocates for increased international collaboration, targeted training, and enhanced resources to foster a unified global approach in preventing, diagnosing, and treating IFI.

IMPORTANCE

This work is significant as it highlights the unique challenges Brazil faces in managing invasive fungal infections (IFIs) due to its diverse ecosystems and public health landscape. By comparing Brazil's situation with Europe-where IFIs are mainly linked to transplantation and intensive care-this study identifies key disparities in diagnostic and treatment practices. The findings reveal substantial differences in the availability and use of molecular diagnostics, antifungal drugs, and therapeutic drug monitoring, with Europe demonstrating more advanced practices. By mapping these variations, the study underscores the importance of tailored approaches to IFI management that consider regional differences and technological gaps. Ultimately, it calls for enhanced international collaboration, targeted training, and resource allocation to improve IFI outcomes globally, particularly in regions with limited access to advanced diagnostic tools and treatments.

Disseminated histoplasmosis in a Congolese migrant under long-term steroid hormone replacement therapy

We report a disseminated histoplasmosis in a Congolese migrant under long-term steroid hormone replacement therapy. Organs involved were the skin, oral and nose mucosae, brain, lungs and colon. Histoplasma capsulatum var capsulatum was detected by histopathology and identified by fungal culture. The outcome was favourable following liposomal amphotericin B then itraconazole.

Disseminated Histoplasmosis as a Presentation of Advanced HIV-1 Infection in a Non-endemic Country

Disseminated histoplasmosis is an opportunistic fungal infection considered an AIDS-defining illness, sometimes with a fatal outcome. We report a case of disseminated histoplasmosis as the initial presentation of advanced HIV-1 infection in a migrant living in a non-endemic area. Histoplasmosis was suspected based on the clinical presentation, epidemiological factors, and observation in the peripheral blood smear of neutrophils and monocytes with yeast-like forms. The diagnosis was confirmed through a positive peripheral blood smear and subsequent culture of Histoplasma capsulatum from a bronchoalveolar lavage sample. The patient was treated with 14 days of liposomal amphotericin B plus oral itraconazole for two years, with a good response. Direct examination of peripheral blood has been considered a valuable diagnostic method, specifically in severely immunocompromised patients, as our case report. The presented case highlights the importance of considering disseminated histoplasmosis in the differential diagnosis of HIV-infected patients, even in non-endemic regions. Hence, the need for a high index of suspicion to ensure early diagnosis and treatment is crucial as the influx of migrants increases globally.

Histoplasma capsulatum in Bat Species in Portugal

Histoplasmosis, caused by the fungus Histoplasma capsulatum, poses health risks to various mammals, including humans. Bats are primary wild carriers of Histoplasma capsulatum, playing a crucial role in its epidemiology. However, fecal shedding in Europe remains poorly studied, with no data available for Portugal. This study analyzed 285 guano samples from 22 bat species, collected across Portuguese regions between 2014 and 2018, using a nested PCR assay. Despite using a sensitive method, no positive samples were detected. These results align with other European studies, suggesting that Histoplasma capsulatum circulates at low levels in European bat populations. However, they contrast with findings from regions like Brazil and Mexico, where the fungus is more prevalent due to differing geographic, climatic, and ecological factors. The absence of Histoplasma capsulatum in Portuguese bat guano highlights the importance of local environmental conditions and raises questions about its distribution in Europe. Although bats can harbor zoonotic pathogens, our findings suggest they do not shed Histoplasma capsulatum in Portugal. Continuous monitoring and research are essential in understanding infectious disease dynamics. Targeted surveillance in caves could improve early detection and management strategies for potential histoplasmosis outbreaks, contributing to public health efforts in these ecosystems.

Imported Systemic Endemic Mycoses in Spain 1997-2021: An Analysis of a National Hospital Database

BACKGROUND

Systemic endemic mycoses are systemic fungal infections typically found in tropical and subtropical regions. Their global incidence is rising, including in nonendemic countries, mainly due to migration and international travel. They are a major cause of morbidity and mortality worldwide, especially in immunocompromised patients. This study aimed to analyse incidence trends of endemic mycoses and their presentation in hospitalised patients in Spain from 1997 to 2021.

METHODS

This retrospective, observational study drew data from the Spanish National Hospital Discharge Database. We used the diagnostic codes of the 9th and 10th International Classification of Diseases for histoplasmosis, coccidioidomycosis, paracoccidioidomycosis and talaromycosis, retrieving systemic endemic mycoses cases from the national public registry.

RESULTS

Over the study period, 646 cases of histoplasmosis, 138 of coccidioidomycosis, 47 of paracoccidioidomycosis and 24 talaromycosis were reported, with a rising number of cases annually, driven mainly by an increase in histoplasmosis. A segmented linear regression predictive model with a 10-year forecast showed a steady increase, reaching 128 hospitalisations (95% confidence interval [CI] 87-168) in Spain in 2031. Overall, in-hospital mortality was 10.9%, higher in histoplasmosis (11.3%) and coccidioidomycosis (10.9%) and independently associated with immunosuppression for both histoplasmosis (adjusted odds ratio [aOR] 3.28, 95% CI 1.72-6.24; p < 0.001) and coccidioidomycosis (aOR 4.05, 95% CI 1.22-13.44; p = 0.022).

CONCLUSIONS

Hospitalisations for systemic endemic mycoses, especially histoplasmosis, are on the rise in Spain. Mortality is significant and primarily associated with immunosuppression. This trend is expected to continue in the coming years, underscoring the importance of maintaining hospital-based surveillance of endemic mycoses in nonendemic regions.

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.

Histoplasmosis in patients living with HIV in Europe: review of literature

Histoplasma capsulatum (var. capsulatum Hcc and duboisii Hcd), is a dimorphic fungus that causes histoplasmosis. It usually affects people coming from endemic areas, causing a variety of clinical manifestations up to progressive disseminated histoplasmosis (PDH), especially among people living with HIV (PLWH). We conducted a systematic review to assess histoplasmosis burden of PLWH in Europe. The review follows PRISMA guidelines, with protocol registered in PROSPERO (CRD42023429779). Seventy-eight articles were selected, including 109 patients (32 women). On overall, median age was 37 years. Forty-six patients were Americans, 39 Africans, 17 Europeans, 5 Asians, in 2 cases nationality was not specified. Cases were mainly diagnosed in Italy (28.4%), France (17.3%) and Spain (17.4%), with a north-south gradient. Six cases lacked epidemiologic links with endemic areas. Concerning CDC HIV staging at diagnosis, the information was available for 60 PLWH (55%) and all subjects were at stage C3 except for two subjects at stage B3. PDH was the AIDS-presenting illness in 39 patients. Most patients had a PDH (80.7%); other common extrapulmonary forms were isolated cutaneous histoplasmosis (7.3%), or lymphatic localization (2.7%). In 30 cases, the diagnosis was made by analyzing only one sample. For the remaining 79 cases, multiple samples were collected from each patient. Regarding the biological sample more frequently used for the diagnosis of histoplasmosis, bronchoalveolar lavage sample was taken from 39 patients, and tested positive in 51.3% of cases; 36 patients underwent a skin biopsy which was positive in 86.1% of cases and 28 patients performed bone-marrow biopsy, which led to the diagnosis of histoplasmosis in 92.9% of cases. The identification of Histoplasma capsulatum was available in 97 PLWH through examination of different samples: Hcc and Hcd were identified in 89 and 8 PLWH, respectively. Concerning therapies, 67.9% were treated with liposomal amphotericin B, 18.3% with itraconazole, 10 died pre-treatment. The overall mortality rate was 23.6%. Non-survivors exhibited more frequently gastrointestinal symptoms (p = 0.017), while cutaneous signs correlated with better survival (p = 0.05). Untreated patients faced higher mortality (p < 0.001). Histoplasmosis should be considered amongst opportunistic infection in PLWH, even in Europe, especially if patients originate from or have travelled to endemic areas. Systematic review registration: The registration number is CRD42023429779.

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.

Histoplasma capsulatum as a cause for prolonged pulmonary illness in an immunocompetent returning traveller from Bangladesh

Fungal infections can be challenging to diagnose in returning travellers due to their non-specific clinical manifestations and changing epidemiology. We present a case of progressive disseminated histoplasmosis in a returning traveller from Bangladesh. The patient had a progressive and prolonged respiratory illness necessitating mechanical ventilatory support. The clue to potential fungal aetiology was provided by serum fungal markers - 1-3-β-D-glucan and Aspergillus galactomannan. Diagnosis was eventually made using panfungal PCR on bronchioalveolar lavage fluid.

Progressive disseminated histoplasmosis: The experience in one non-endemic medical center

Histoplasmosis, the most common endemic mycosis in North America, presents in a myriad of ways, spanning the spectrum from self-limiting pneumonia to progressive disseminated histoplasmosis (PDH). Toward better describing contemporary histoplasmosis syndromes, risks, and outcomes, this single-center retrospective cohort study was performed (2009-2019). The population who developed PDH was similar to that with other forms of histoplasmosis (OFH) except for higher rates of preexisting immunocompromising conditions (91.3% vs. 40%, P < .001) and a trend toward receiving more chronic immunosuppression (65.2% vs. 33.3%, P = .054) compared to those with OFH. Diagnosis was most frequently achieved by urinary or serum antigen positivity. People with PDH more frequently tested positive compared to those with OFH, but negative tests did not rule out histoplasmosis. Median time to diagnosis was prolonged among people with both PDH and OFH (32 vs. 31 days, respectively). Following diagnosis, people with PDH received more liposomal amphotericin (78.3% vs. 20%, P < .001). Subsequent survival at 90 and 365 days and treatment response were similar in both groups. Patients with PDH were more often hospitalized (95.7% vs. 60%, P = .006); however, once admitted, there were no differences in hospital length of stay or intensive care unit admission rate. The challenges of diagnosing histoplasmosis based on clinical presentation alone highlight the need for heightened awareness of these entities especially given the recent reports on expanded endemicity and delays in diagnosis.

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.

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.

The current state of laboratory mycology and access to antifungal treatment in Europe: a European Confederation of Medical Mycology survey

Access to the appropriate tools is crucial for early diagnosis and clinical management of invasive fungal infections. This Review aims to describe the invasive fungal infection diagnostic capacity of Europe to better understand the status and the most pressing aspects that need improvement. To our knowledge, this is the first time that the mycological diagnostic capability and access to antifungal treatments of institutions has been evaluated at a pan-European level. Between Nov 1, 2021, and Jan 31, 2022, 388 institutions in Europe self-assessed their invasive fungal infection management capability. Of the 388 participating institutions from 45 countries, 383 (99%) had access to cultures, 375 (97%) to microscopy, 363 (94%) to antigen-detection assays, 329 (85%) to molecular tests (mostly PCR), and 324 (84%) to antibody tests for diagnosis and management. With the exception of microscopy, there were considerable differences in access to techniques among countries according to their gross domestic product. At least one triazole was available in 363 (94%) of the institutions, one echinocandin in 346 (89%), and liposomal amphotericin B in 301 (78%), with country gross domestic product-based differences. Differences were also observed in the access to therapeutic drug monitoring. Although Europe is well prepared to manage invasive fungal infections, some institutions do not have access to certain diagnostic tools and antifungal drugs, despite most being considered essential by WHO. These limitations need to be overcome to ensure that all patients receive the best diagnostic and therapeutic management.

Disseminated Mucocutaneous Histoplasmosis Diagnosed in the United Kingdom, Presumably as a Result of Recrudescence Decades After Primary Infection Following Immunosuppressive Treatment of Its Mimic, Sarcoidosis: A Multidisciplinary Cautionary Tale

ABSTRACT

Histoplasmosis is a dimorphic fungal infection, which is rare outside endemic pockets in North, Central, and South America, Asia, and Africa. Herein, we describe a woman in her 80s living in the Scottish Borders region of the United Kingdom with a recent diagnosis of granulomatous rosacea, who on receiving escalating immunosuppression for suspected sarcoidosis, and long-standing rheumatoid arthritis developed a striking eruption involving her eyelids along with painful ulceration of the oral and nasal mucosa. Histopathologic examination of the skin and mucosal lesions demonstrated granulomatous inflammation with numerous yeast forms of fungal organisms with morphological characteristics of Histoplasma species. This was confirmed to be H. capsulatum on fungal culture and direct panfungal polymerase chain reaction assay. Although the patient had not left the United Kingdom for more than 20 years, she gave a travel history involving multiple trips to countries where histoplasmosis is known to occur, before that. This case exemplifies the challenges involved in making a diagnosis of histoplasmosis in nonendemic regions for both clinicians and pathologists alike. In this particular patient, the diagnostic difficulties were compounded by the clinicopathological overlap with other cutaneous and systemic granulomatous disorders like granulomatous rosacea and suspected sarcoidosis and also the exceptionally long latency period between the purported historical primary infection and recent recrudescence. We highlight this unusual case to increase an awareness of histoplasmosis, which is very rare in nonendemic regions like the United Kingdom and involves cases acquired during residence in or travel to endemic areas, to ensure its prompt recognition and treatment.

Pathogenicity & Virulence of Histoplasma capsulatum - a multifaceted organism adapted to intracellular environments

Histoplasmosis is a systemic mycosis caused by the thermally dimorphic fungus Histoplasma capsulatum. Although healthy individuals can develop histoplasmosis, the disease is particularly life-threatening in immunocompromised patients, with a wide range of clinical manifestations depending on the inoculum and virulence of the infecting strain. In this review, we discuss the established virulence factors and pathogenesis traits that make H. capsulatum highly adapted to a wide variety of hosts, including mammals. Understanding and integrating these mechanisms is a key step towards devising new preventative and therapeutic interventions.

Animal Histoplasmosis in Europe: Review of the Literature and Molecular Typing of the Etiological Agents

Histoplasmosis has been previously diagnosed in animals from Europe. The aim of this study is to review the literature on these reports, to analyze cases diagnosed at our laboratory (2000–2022) and to improve molecular typing of Histoplasma capsulatum directly from tissue to study the molecular epidemiology of Histoplasma capsulatum causing animal infections in Europe. Including 15 cases studied in our laboratory, we identified 39 cases of animal histoplasmosis between 1968 and 2022. They were diagnosed mostly in superficial tissue biopsies from cats and badgers from Central Europe. Using phylogenetic analyses of six partial genes, we were able to classify eight of the etiological agents as belonging to a highly supported lineage within the Eurasian clade. This study confirms the occurrence of autochthonous histoplasmosis in animals in Central Europe and proposes the addition of new loci to the MLST scheme to study the molecular epidemiology of histoplasmosis using either formalin-fixed paraffin-embedded tissue and fresh or cadaveric biopsies.

Let's talk about Sex Characteristics - as a Risk Factor for Invasive Fungal Diseases

Biological sex, which comprises differences in host sex hormone homeostasis and immune responses, can have a substantial impact on the epidemiology of infectious diseases. Comprehensive data on sex distributions in invasive fungal diseases (IFDs) is lacking. In this review we performed a literature search of in vitro/animal studies, clinical studies, systematic reviews, and meta-analyses of invasive fungal infections. Females represented 51.2% of invasive candidiasis cases, mostly matching the proportions of females among the general population in the United States and Europe (>51%). In contrast, other IFDs were overrepresented in males, including invasive aspergillosis (51% males), mucormycosis (60%), cryptococcosis (74%), coccidioidomycosis (70%), histoplasmosis (61%), and blastomycosis (66%). Behavioral variations, as well as differences related to biological sex, may only in part explain these findings. Further investigations concerning the association between biological sex/gender and the pathogenesis of IFDs is warranted.