Tracing histoplasmosis genomic epidemiology and species occurrence across the USA

ABSTRACTHistoplasmosis is an endemic mycosis in North America frequently reported along the Ohio and Mississippi River Valleys, although autochthonous cases occur in non-endemic areas. In the United States, the disease is provoked by two genetically distinct clades of Histoplasma capsulatum sensu lato, Histoplasma mississippiense (Nam1) and H. ohiense (Nam2). To bridge the molecular epidemiological gap, we genotyped 93 Histoplasma isolates (62 novel genomes) including clinical, environmental, and veterinarian samples from a broader geographical range by whole-genome sequencing, followed by evolutionary and species niche modelling analyses. We show that histoplasmosis is caused by two major lineages, H. ohiense and H. mississippiense; with sporadic cases caused by H. suramericanum in California and Texas. While H. ohiense is prevalent in eastern states, H. mississipiense was found to be prevalent in the central and western portions of the United States, but also geographically overlapping in some areas suggesting that these species might co-occur. Species Niche Modelling revealed that H. ohiense thrives in places with warmer and drier conditions, while H. mississippiense is endemic to areas with cooler temperatures and more precipitation. In addition, we predicted multiple areas of secondary contact zones where the two species co-occur, potentially facilitating gene exchange and hybridization. This study provides the most comprehensive understanding of the genomic epidemiology of histoplasmosis in the USA and lays a blueprint for the study of invasive fungal diseases.

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.

Gastrointestinal histoplasmosis with small intestinal perforation: 20-year experience

Postmortem studies show gastrointestinal tract involvement in as many as 70% of patients affected by disseminated histoplasmosis. Although gastrointestinal involvement is common in disseminated disease, the presentation of small intestinal perforation is exceedingly rare with few reported cases in the literature. Herein we present our institutional case series. The aim of the study is to describe small intestinal perforation in gastrointestinal histoplasmosis with attention to management and outcomes. This is a retrospective single-institution review of patients ≥ 18 years of age treated for small intestinal perforation due to gastrointestinal histoplasmosis. A prospectively maintained institutional database was searched from 2002 to 2022. Data obtained included demographics, comorbidities, treatment course, and outcomes. Five patients with a mean age of 54 years (range 25-72) were identified. Pertinent underlying comorbid conditions included Crohn's disease, psoriatic arthritis, rheumatoid arthritis, and solid organ transplantation. All patients were on chronic immunosuppressive medication(s) with the most common being tumor necrosis factors alpha inhibitors and corticosteroids. Four had a clinical diagnosis of perforation based on physical examination and imaging. All patients underwent segmental resection(s) of the small intestine and received medical treatment with intravenous amphotericin B and eventual transition to an oral antifungal. No patients experienced complications related to surgery. The limitations of the study include nonrandomized retrospective review, single-institution experience, and small patient sample size. Although rare, histoplasmosis should be considered in the differential of patients on chronic immunosuppressive therapy who present with gastrointestinal symptoms concerning perforation, especially from endemic areas. Small intestinal perforation due to gastrointestinal histoplasmosis can be successfully treated with resection and antifungal therapy.

Estimated burden of fungal infections in Panama

Data published on Panamanian fungal disease are scarce, mostly case reports. To date, there is no paper that compiles the burden of fungal disease Here we estimate for the first time the incidence and prevalence of fungal diseases in Panama. Data on fungal disease were obtained from different search engines: PubMed, Google Scholar, Scielo and Lilacs. For population and at risk diseases, we used statistics from worldometer, UNAIDS, and WHO. Incidence, prevalence, and absolute numbers were calculated based on the population at risk. Panamanian population in 2022 was 4,429,739. We estimated that 85,530 (1.93 %) people suffer from fungal diseases. The most frequent fungal infection was recurrent Candida vaginitis (3285/100,000). There are 31,000 HIV-infected people in Panama and based on the number of cases not receiving anti-retroviral therapy (14,570), and previous reports of prevalence of opportunistic infections, we estimated annual incidences of 4.0/100,000 for cryptococcal meningitis, 29.5/100,000 for oral candidiasis, 23.1/100,000 for esophageal candidiasis, 29.5/100,000 for Pneumocystis pneumonia, 15.1/100,000, and for histoplasmosis. For chronic pulmonary aspergillosis (CPA) and fungal asthma we used data from Guatemala and Colombia to estimate COPD and asthma prevalence and WHO report for tuberculosis. We estimated annual incidences of 6.1/100,000 for invasive aspergillosis and prevalence of 31.5/100,000 for CPA, 60.2/100,000 for allergic bronchopulmonary aspergillosis, and 79.5/100,000 for severe asthma with fungal sensitisation. Other incidence estimates were 5.0/100,000 for candidaemia, 0.20/100,000 for mucormycosis, and 4.97/100,000 for fungal keratitis. Even though this report on burden of fungal disease is a forward step, more epidemiological studies to validate these estimates are needed.

Diagnostic insights into disseminated histoplasmosis: a case report highlighting bone marrow analysis

We present a case of a 43-year-old immunocompromised female patient diagnosed with disseminated histoplasmosis on bone marrow examination, at clinical laboratory of Kasturba Hospital, Manipal, Karnataka, India. The patient, presenting with symptoms like weight loss, appetite loss, and pancytopenia, underwent bone marrow aspiration and biopsy. The bone marrow studies revealed HIV-associated changes and the yeast form of Histoplasma capsulatum, confirming disseminated histoplasmosis. Bone marrow examination is highlighted as a diagnostic tool with significant sensitivity in such cases. The report stresses on the importance of awareness and early diagnosis of histoplasmosis in immunocompromised patients, given its potential lethality and the need for timely therapeutic intervention for better prognosis.

Pericardial effusion in an immunocompetent host- a unique presentation of histoplasmosis

Histoplasma capsulatum infection is infrequently considered in the differential diagnoses for acute pericarditis in immunocompetent hosts when presenting with tamponade physiology, given its gradual infective nature. We describe a case of a young male presenting solely with acute pericarditis with pericardial effusion and early cardiac tamponade physiology secondary to a pulmonary histoplasmosis infection. Our patient had no pulmonary symptoms; the only pulmonary manifestation of histoplasmosis included incidental findings of subcarinal lymphadenopathy and a left lingular nodule abutting the pericardium. Given failure of symptom improvement with pericardiocentesis and first-line therapy for idiopathic/viral pericarditis, further workup of the pulmonary nodule was pursued. Histopathologic analysis of tissue showed caseating granulomas and fungal Grocott-Gömöri's methenamine silver stain revealed yeast consistent with Histoplasma species. The patient improved with itraconazole therapy.

Learning objective

Pulmonary histoplasmosis has potential to present as a pericardial effusion in the immunocompetent individual. In addition to pericardiocentesis, antifungal therapy can be curative.

Lung infection or inflammation-a puzzling case of MDA-5 associated juvenile dermatomyositis

BACKGROUND

Juvenile dermatomyositis (JDM) is an uncommon inflammatory myopathy predominantly affecting children under 18 years of age. Diagnosis relies on identifying specific clinical features, such as muscle weakness, skin rash, elevated muscle enzymes, and MRI and muscle biopsy findings. Autoantibodies associated with inflammatory myopathy offer valuable prognostic insights and can indicate the risk of internal organ involvement, though they are relatively rare in childhood myopathies. JDM can progress to interstitial lung disease (ILD) if associated with MDA5 antibodies, and immunosuppressive therapy constitutes the primary treatment approach.

CASE PRESENTATION

We present a unique case of JDM complicated by disseminated histoplasmosis in a 12-year-old African American male cross-country runner with no prior medical history. He presented with unintentional weight loss and a rash on his hands, genitals, and fingertips, which persisted despite previous treatments. Diagnosis of JDM was confirmed through clinical and laboratory evaluations. Over time, the patient developed recurrent fevers, thrombocytopenia, and signs of ILD, leading to the identification of disseminated histoplasmosis as a complicating factor. Appropriate antifungal treatment resolved the infectious condition, while continued immunosuppression aided in managing JDM and ILD.

CONCLUSIONS

Juvenile dermatomyositis (JDM) remains a rare and intricate autoimmune disorder affecting young individuals. The presence of MDA5 antibodies in JDM patients can lead to severe complications like ILD, necessitating vigilant monitoring. Management includes immunosuppressive therapy, with glucocorticoids and mycophenolate mofetil proving effective, particularly in Clinically Amyopathic Dermatomyositis (CADM) cases. In cases of refractory disease, intravenous immunoglobulin (IVIG) plays a crucial role, offering a safe and beneficial adjunct to treatment. We emphasize the importance of recognizing atypical presentations of JDM, as it can lead to delays in diagnosis and treatment. Our case highlights the complexities of managing dual lung pathology, where a secondary infection exacerbated lung nodules and thrombocytopenia, while ILD was a consequence of atypical myopathy. Combining antifungal treatment with immunosuppression effectively managed both conditions and follow-up evaluations demonstrated improvement in ILD. Awareness of potential fungal infections in immunosuppressed JDM patients is crucial for successful treatment and patient outcomes.

Increased IgG4+ plasma cells are common in excised lymph nodes from children and adolescents without IgG4-related disease

Lymphadenopathy is a common finding in patients with IgG4-related disease (IgG4-RD) and often associated with increased IgG4+ plasma cells in this setting. The histologic features of so-called IgG4-related lymphadenopathy (IgG4-LAD) have seldom been investigated in children and adolescents, and step-wise progression to extranodal IgG4-RD has not been described. This study was performed to further evaluate the frequency, pathologic features, and clinical significance of IgG4-LAD-like histologic changes in the pediatric setting. We analyzed 37 benign lymph nodes collected semi-consecutively from children aged 0-18 years at our institution for both absolute and relative IgG4+ plasma cell abundance and recurrent histomorphologic patterns associated with IgG4-LAD. The combination of IgG4+/IgG+ plasma cell ratio >40% and IgG4+ plasma cell count ≥50 were considered as IgG4-LAD-like per expert consensus guidelines. Seven cases (19%) met both diagnostic criteria. The dominant histomorphologic patterns were follicular hyperplasia (n = 6), interfollicular expansion (n = 3), and progressive transformation of germinal centers (n = 3). Extranodal manifestations of IgG4-RD were not identified in this cohort (38 months average follow-up). Instead, clinical and laboratory findings indicated that lymph node enlargement in most patients could likely be attributed to alternative processes including antecedent dentistry, concurrent infection, and incipient Crohn's disease. Our findings suggest that the histologic features of IgG4-LAD are likely much more common in children and adolescents than previously recognized, often existing in complex with common reactive lymphadenopathies. The diagnostic value of routine immunohistochemical assessment for IgG4+ plasma cells in benign lymph nodes from pediatric patients without established extranodal IgG4-RD and/or other supportive clinical and laboratory data is therefore uncertain.

Histoplasmosis Masquerading as Second Primary in Head and Neck Tumours - A Case Report

Histoplasmosis is a chronic granulomatous disease seen in immunocompromised individuals, rarely immunocompetent patients. We report disseminated histoplasmosis involving adrenal glands and oral cavity with synchronous squamous cell carcinoma of right pyriform fossa. With early diagnosis and treatment he recovered well.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03962-4.

Multimodal imaging of an acute presentation of ocular histoplasmosis syndrome in an immunocompetent patient

Purpose

Presumed ocular histoplasmosis syndrome (POHS) is a posterior segment disorder that is usually subclinical unless choroidal neovascular membrane (CNVM) develops. It is thought to be the sequela of a prior systemic infection with Histoplasma capsulatum, and evidence supporting this association is based on epidemiologic, animal, and few enucleation studies. Acute presentation of chorioretinal involvement during an initial histoplasmosis systemic infection in immunocompetent patients is rarely reported, presumably due to the usual lack of or minimal symptoms of both the systemic and ocular disease. We report on an immunocompetent male with choroidal lesions detected during disseminated histoplasmosis infection and characterize the lesions using multimodal imaging.

Observations

A 17-year-old male presented when routine optometry screening detected two deep, yellowish-white lesions in the left fundus. Optical coherence tomography (OCT) imaging confirmed a choroidal mass with extension through Bruch's membrane into the subretinal space and a small amount of subretinal fluid. Fluorescein angiography was suggestive of CNVM. There were no clinical findings of intraocular inflammation, and the patient was initially lost to follow-up. Eight weeks after last follow-up, the patient presented to the emergency department with fatigue, mild respiratory symptoms, and abdominal pain for the last month. Imaging revealed a mediastinal mass with hilar extension and innumerable nodules throughout the lung and spleen. Serum Histoplasma IgM/IgG were positive, and biopsy of the mediastinal mass revealed Histoplasma organisms. The patient was treated with antifungals and discharged. The patient underwent an extensive immunologic evaluation while admitted, which did not reveal an underlying immunodeficiency. On last follow-up, the choroidal lesions were smaller and more consolidated, and the subretinal fluid had resolved.

Conclusions and Importance

We present a patient with choroidal lesions in the setting of disseminated systemic histoplasmosis infection and characterize a lesion using multimodal imaging. The presentation of acute chorioretinal lesions in the setting of biopsy proven systemic Histoplasma infection supports H. capsulatum as the etiology of POHS.

Adjunctive phototherapies for oral manifestation of HIV-related histoplasmosis and leishmaniasis: An unusual case report

BACKGROUND

Secondary infections of leishmaniasis and histoplasmosis in patients with advanced HIV are still a concern in low- and middle-income countries. The most common drugs for the treatment of both infections may be problematic mainly due to their toxicity.

AIM AND CASE REPORT

The present study aimed to report a case in which a concurrent oral manifestation of leishmaniasis and histoplasmosis in a hospitalized patient with HIV was managed with a combination of photobiomodulation therapy (PBMT) and antimicrobial photodynamic therapy (aPDT) as an adjuvant treatment. In addition to the use of conventional systemic oral drugs, a single aPDT session followed by two PBMT sessions was proposed, which resulted in complete wound healing within four days.

CONCLUSION

Given the complexity of the current case, PBMT in combination with aPDT may be considered as an effective adjuvant option for managing oral infectious lesions of histoplasmosis and leishmaniasis in immunocompromised patients.

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.

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.

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.

Evidence of anti-Hcp100 antibodies in COVID-19 critically ill patients with detectable anti-histoplasmin antibodies in a highly endemic area for histoplasmosis

Patients with severe COVID-19 are at increased risk for invasive fungal infections, which are underestimated. Histoplasmosis reactivation in endemic areas should not be overlooked in this population. In a previous study, seroconversion to anti-histoplasmin antibodies by ELISA was detected in 6/39 (15.4%) patients with severe COVID-19. In this work, samples were further investigated to detect seroconversion to antibodies against the Histoplasma capsulatum 100-kDa antigen (Hcp100) by ELISA. Seroconversion to anti-Hcp100 antibodies was detected in 7/39 patients, of whom 6 seroconverted also anti-histoplasmin antibodies. These results reinforce previous findings that show histoplasmosis as an underdiagnosed fungal entity complicating COVID-19.

Bilateral adrenal histoplasmosis presenting as adrenal mass mimicking malignancy in an immunocompetent patient

We report a case of a 78-year-old immunocompetent man who presented with worsening fatigue and lethargy for one month. He had also been complaining of cough and SOB for two months which had been attributed to his underlying COPD and possible pneumonia. CT showed bilateral pleural effusions, ground-glass opacities, cirrhosis, splenomegaly and bilateral adrenal masses which was highly suspicious for malignancy. After pheochromocytoma was ruled out, EUS-FNA guided biopsy was performed on the left adrenal gland. Histology was positive for yeast cells, with fungal staining (PAS) revealing narrow-based budding compatible with Histoplasma. The patient was treated with amphotericin and itraconazole. Our case is unique as he presented with hepatosplenomegaly, which is reported in less than a quarter of cases. Although typically a diagnosis in immunocompromised patients, a high index of clinical suspicion is required to diagnose disseminated histoplasmosis in an immunocompetent patient. The gold standard for diagnosis is fungal tissue culture. However results may take up to weeks. EUS-FNA guided biopsy of adrenal glands can aid in early definitive diagnosis and management.

Endemic mycoses in children in North America: a review of radiologic findings

Clinically significant endemic mycoses (fungal infections) in the United States (U.S.) include Blastomyces dermatitidis, Histoplasma capsulatum, and Coccidioides immitis/posadasii. While the majority of infections go clinically unnoticed, symptomatic disease can occur in immunocompromised or hospitalized patients, and occasionally in immune-competent individuals. Clinical manifestations vary widely and their diagnosis may require fungal culture, making the rapid diagnosis a challenge. Imaging can be helpful in making a clinical diagnosis prior to laboratory confirmation, as well as assist in characterizing disease extent and severity. In this review, we discuss the three major endemic fungal infections that occur in the U.S., including mycology, epidemiology, clinical presentations, and typical imaging features with an emphasis on the pediatric population.

Computed tomography findings of pulmonary histoplasmosis: pictorial essay

Endemic systemic mycoses are prevalent in specific geographic areas of the world and are responsible for high rates of morbidity and mortality in the populations of such areas, as well as in immigrants and travelers returning from endemic regions. Pulmonary histoplasmosis is an infection caused by Histoplasma capsulatum, a dimorphic fungus. This infection has a worldwide distribution, being endemic in Brazil. Histoplasmosis can affect the lungs, and its diagnosis and management remain challenging, especially in non-endemic areas. Therefore, recognition of the various radiological manifestations of pulmonary histoplasmosis, together with the clinical and epidemiological history of the patient, is essential to narrowing the differential diagnosis. This essay discusses the main computed tomography findings of pulmonary histoplasmosis.

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.

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.

Development of a case-fatality prognostic score for HIV-associated histoplasmosis

OBJECTIVES

The burden of histoplasmosis is as great as that of tuberculosis in Latin America and the attributable mortality is even higher. A better assessment of severity could help reduce mortality.

METHODS

From the French Guiana HIV-Histoplasmosis database, we attempted to identify factors associated with 30-day death after antifungal drug initiation and constructed a prognostic score. We evaluated its discrimination performance, using several resampling methods.

RESULTS

Of the 415 patients included, 56 (13.5%) died within 30 days of treatment. Fatality-associated factors were performance status ≥3, altered mental status, dyspnea, CRP ≥75 mg/L, hemoglobin <9 g/dL and/or a platelet <100000 /mL, and an interstitial lung pattern on chest X-ray. We constructed a 12-point prognostic score. A threshold ≥5 classified patients as alive or dead at 30 days with a sensitivity of 84%, a specificity of 81%, a PPV of 40%, and a NPV of 97%. The AUC of the ROC curves from the different resamples were stable between 0.88 and 0.93.

CONCLUSIONS

The Histoplasmosis case-Fatality Score, which is easy and inexpensive to perform, is a good tool for assessing severity and helping in the choice of induction therapy. An external validation remains necessary to generalize these results.

Synovitis due to Histoplasma capsulatum: a case series and literature review

Musculoskeletal manifestations of Histoplasma capsulatum infection are uncommon but can mimic inflammatory arthritis. Early diagnosis of this complication is of critical importance in the era of potent immunosuppression for rheumatologic diseases. We conducted a retrospective chart review for patients with histoplasmosis and tenosynovitis, synovitis, or arthritis, diagnosed and treated at our institution between January 1, 2000, and December 31, 2019. We also reviewed the relevant literature. Four patients with biopsy-proven, culture-proven histoplasma tenosynovitis were identified at our institution. All four patients had wrist or hand involvement in an asymmetric pattern, and one patient had lower extremity involvement as well. Two patients were not immunocompromised at baseline. One patient underwent a lengthy evaluation and received immunosuppression for 4 years without improvement prior to the diagnosis of histoplasmosis. Histoplasma serologic tests varied among patients with localized infection. Pathologic findings revealed non-caseating granulomatous inflammation. Three patients recovered after 6-12 months of antifungal treatment. One patient still had recurrent infection despite 20 months of treatment. Histoplasma tenosynovitis and synovitis are rare causes of inflammatory arthritis. Infectious causes should be considered and carefully evaluated when patients present with asymmetric oligoarthritis. Early recognition is crucial for successful treatment, especially in patients with concomitant rheumatologic diseases receiving immunosuppressive treatment.

A novel biosensor for ultrasensitive detection of fungal genes

Fungal infections are a rapidly increasing public health problem due to their high morbidity and mortality rates, especially in populations with compromised immune systems. Rapid and accurate diagnosis of these diseases is, therefore, necessary to improve the prognosis of afflicted patients. Unfortunately, current clinical chemistry practice relies on lengthy culturing methods that are insufficient to meet the fast turnaround requirements. Here we present a cost-effective and robust nucleic acid sensor that can identify the presence of histoplasmosis causing fungal genes, in whole blood or bronchoalveolar lavage (BAL) samples, far earlier than current methods. Our novel assay involves the hybridization of target gene sequences with immobilized nucleic acid probes, allowing direct, label-free detection of Hcp100, CBP1, and M antigen genes through electrochemical analysis. The resultant current is attributed to the presence of fungal targets in the sample solution. The assay provides ultra-sensitive detection of DNA molecules with a limit of detection (LOD) values down to 100 aM, sufficient to meet the clinical diagnostic need. In addition, the turnaround time for the sample to result is less than 90 min compared to the current clinical procedure's turnaround time of 3-4 weeks.

Fungal Lesions of the Oral Mucosa Diagnosis and Management

Oral fungal infections are opportunistic and due to impaired host resistance. The increasing number of immunosuppressed individuals contributes to rising numbers of mycoses worldwide, and the ease of global migration has allowed the geographic range of endemic mycoses to expand. Deep fungal infections can clinically mimic other pathologic conditions including malignancy. This review highlights the pathogenesis, clinical features, diagnosis, and treatment recommendations of eight fungal infections that can be encountered in the dental setting.

In silico-chemogenomic repurposing of new chemical scaffolds for histoplasmosis treatment

BACKGROUND

Histoplasmosis is a systemic form of endemic mycosis to the American continent and may be lethal to people living with HIV/AIDS. The drugs available for treating histoplasmosis are limited, costly, and highly toxic. New drug development is time-consuming and costly; hence, drug repositioning is an advantageous strategy for discovering new therapeutic options.

OBJECTIVE

This study was conducted to identify drugs that can be repositioned for treating histoplasmosis in immunocompromised patients.

METHODS

Homologous proteins among Histoplasma capsulatum strains were selected and used to search for homologous targets in the DrugBank and Therapeutic Target Database. Essential genes were selected using Saccharomyces cerevisiae as a model, and functional regions of the therapeutic targets were analyzed. The antifungal activity of the selected drugs was verified, and homology modeling and molecular docking were performed to verify the interactions between the drugs with low inhibitory concentration values and their corresponding targets.

RESULTS

We selected 149 approved drugs with potential activity against histoplasmosis, among which eight were selected for evaluating their in vitro activity. For drugs with low minimum inhibitory concentration values, such as mebendazole, everolimus, butenafine, and bifonazole, molecular docking studies were performed. A chemogenomic framework revealed lanosterol 14-α-demethylase, squalene monooxygenase, serine/threonine-protein kinase mTOR, and the β-4B tubulin chain of H. capsulatum, respectively, as the protein targets of the drugs.

CONCLUSIONS

Our strategy can be used to identify promising antifungal targets, and drugs with repositioning potential for treating H. capsulatum.

When dyspnea is a Hickam's Dictum

Synchronous opportunistic infections are luckily rare in people living with HIV (PLWH) in the era of highly effective antiretroviral medications. We describe the case of a middle-aged man who presented with diarrhea and shortness of breath and was found to have pneumocystis pneumonia, disseminated histoplasmosis and disseminated mycobacterium avium complex infection along with a new diagnosis of human immunodeficiency virus (HIV) infection. This case highlights that individuals who remain undiagnosed with HIV infection for a long time can still present with concurrent infections and clinicians should remain aware of this.

A Case of Histoplasmosis Detected Through Bone Marrow Analysis

Histoplasmosis is an endemic infection caused by Histoplasma capsulatum, leading to a broad spectrum of disease from asymptomatic to severe disseminated disease. To diagnose Histoplasmosis, culture remains the gold standard for the laboratory diagnosis; however, this fungus grows slowly, taking a long time 2 to 3 weeks or may take up to 8 weeks. Therefore, some other methods such as bone marrow examination play an essential role in rapid identification and early diagnosis, especially in cases of severe disseminated disease. In this case, we report a 55-year-old man with a 1-year history of gout, self-medicating (including Medrol) who was admitted to the hospital because of persistent fever and swelling of his left arm. About laboratory investigation, there was a bicytopenia (RBC and PLT), blood and pus cultures many times were negative. On the slide of the bone marrow specimen, images of yeast suspected of Histoplasma capsulatum were observed. Therefore, the patient was treated with antifungal medication, and the culture was repeated with prolonged follow-up time and positive results with H. capsulatum after 16 days. In conclusion, bone marrow test plays a significant role in the diagnosis of some fungal infections, which can contribute to an early diagnosis, especially in cases of culture and serological tests are not available or cannot be performed. Patients who present with fever and bicytopenia or pancytopenia should be performed early bone marrow test, which can support the earlier diagnosis to have appropriate treatment.

Histoplasma tympanomastoiditis: Case report and literature review

Histoplasma is a dimorphic fungus capable of producing a diverse array of clinical pathology in humans dependent upon the host immune status. Acute symptomatic infection typically presents as an isolated pulmonary or nodal disease in immunocompetent patients with extra-thoracic manifestations rarely seen in this population. In this report, we describe a novel case of Histoplasma capsulatum tympanomastoiditis in an immunocompetent patient who presented with progressively worsening purulent otorrhea, vertigo, and facial nerve palsy. He was successfully managed with surgical debridement and a prolonged antifungal course.

Vertebromedular histoplasmosis: About a case of transverse myelitis in a young and immunocompetent adult

Systemic mycosis raging endemic, histoplasmosis has an increasing incidence with the advent of HIV-AIDS. The authors report a case of vertebra-medullar histoplasmosis mimicking tuberculous spondylodiscitis in a patient without proven immunosuppression. This was a patient who spent 3 years in a highly endemic area. He presented with signs of transverse myelitis. MRI of the lumbar spine showed a para-vertebral tumor lesion that partially infiltrated the spinal cord. The positive diagnosis of histoplasmosis was made by histomorphology, and symptoms were reduced with administration of itraconazole. These findings show the need for a proper coding of the management of patients living or having stayed in histoplasmosis endemic areas, whether they are immunocompromised or not.

Disseminated histoplasmosis in a patient with chronic lymphoedema

A 54 year-old man with lymphopenia secondary to lymphatic filariasis was admitted with dry cough, fever and wasting syndrome. He was diagnosed with sarcoidosis and therapy with corticosteroid was initiated. The patient evolved with worsening of the symptoms. Histoplasma species was recovered in lung biopsy tissue, lung tissue culture, and bone marrow aspirate. The authors describe the first case of disseminated histoplasmosis secondary to lymphatic filariasis, followed by a literature review. 2012 Elsevier Ltd. All rights reserved.

Histoplasmosis of Larynx and Itraconazole as the Treatment of Choice

Histoplasmosis of Larynx is a very rare anomaly and is usually not seen in an immunocompetent indivual. We present to you a case of 50 year old male, who came to our OPD with complaint of hoarseness of voice. Due to its high probability of mimicking the symptoms of laryngeal carcinoma, differential diagnosis of fungal laryngitis should always be kept in mind. Timely intervention with right diagnosis has very good prognosis in patients with histoplamosis.

Hepatic Histoplasmosis: An Update

Histoplasma capsulatum is the most common cause of endemic mycosis in developing countries. It is a self-limited and asymptomatic disease in immunocompetent individuals but remains a frequent cause of opportunistic infection in patients with compromised immune status. Liver involvement as a part of disseminated histoplasmosis is well known. However, liver infection as a primary manifestation of histoplasmosis without evidence of primary lung involvement is rare. In conclusion, clinicians should be aware of isolated histoplasmosis affecting the hepatobiliary system, and careful evaluation is warranted to confirm the diagnosis. Given the appropriate clinical context, histoplasmosis should be considered in both immunocompetent and immunocompromised patients, regardless of pulmonary symptoms, in non endemic as well as endemic areas.

HTLV-1 and HTLV-2 infections in patients with endemic mycoses in São Paulo, Brazil: A cross-sectional, observational study

Background

Brazil is a country endemic for human T-lymphotropic virus 1 and 2 (HTLV-1 and HTLV-2), systemic mycoses such as paracoccidioidomycosis (PCM) and histoplasmosis (HP), and aspergillosis (AP). The prevalence of HTLV-1/-2 infections in individuals with endemic mycoses in Latin America is unknown; however, an association between HTLV-1 and severe PCM and HP has been observed in Peru. Addressing this knowledge gap, we searched for HTLV-1/-2 antibodies in serum samples sent to the Instituto Adolfo Lutz, São Paulo, Brazil, for systemic mycosis diagnosis.

Methods

We used 387 sera from a biorepository that had seropositive results for Paracoccidioides spp. (G1, n=212), Histoplasma capsulatum (G2, n=95), Aspergillus spp. (G3, n=61), and at least two of these fungi (G4, n=19). We searched for the presence of HTLV-1/-2 antibodies using commercial immunoassays: enzyme immunoassay (HTLV-I+II Murex, Diasorin), western blotting (HTLV Blot 2.4, MP Biomedicals), and line immunoassay (INNO-LIA HTLV I/II, Fujirebio). Demographic characteristics were evaluated in each group.

Findings

Different regions in São Paulo were sampled. Most samples were from males (76.2%; p=0.001), except for G3, in which no sex bias was detected. Mean age differences were observed between groups: patients with PCM and HP had a similar mean age (42.8 and 42.0 years, respectively), while those with AP and co-fungal infection were older (55.1 and 52.8 years, respectively, (p<0.001). Noteworthy, males were older than females in G1 (p=0.005). Screening detected HTLV-1/2 antibodies in five samples (1.30%; 95% CI: 0.8-1.8%), with two borderline results. HTLV-1/2 was confirmed in two samples: 2/387 (0.52%; 0.063-1.85%): one HTLV-2, male, 42 years, from G1: 1/212 (0.47%; 0.012-2.60%), and one HTLV-1, male, 51 years, from G3: 1/61 (1.64%; 0.042-8.80%).

Interpretation

In the state of São Paulo, HTLV-1 and HTLV-2 seem to circulate in male patients with systemic mycoses, and since HTLV-1 could impact fungal disease severity, the identification of co-infection is important regardless of prevalence.

Funding

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP), and Instituto Adolfo Lutz.

CNS Histoplasmosis as a Gliosarcoma mimicker: The diagnostic dilemma of solitary brain lesions

Histoplasmosis is usually a benign, self-limited disease with lungs predilection. However, it might manifest as a disseminated disease in immunocompromised individuals. The involvement of the central nervous system (CNS) accounts for about 5–10% of cases with disseminated disease. Isolated histoplasmosis of the CNS is rare, and the literature shows only a few reported cases. By imaging studies, it usually presents as an isolated ring-enhancing lesion. Its spectrum of symptoms ranges from acute severe infection to progressive chronic meningitis, which delays the initial diagnosis, correct work-up and initiation of appropriate therapy. We present a case of a 57-year-old man from the Midwest of the United States who misdiagnosed with Gliosarcoma in 2019, for which he underwent appropriate management for Gliosarcoma. Presented for follow-up after new neurological symptoms; worsening in ring-enhancing brain lesions was found on magnetic resonance image MRI. After a re-examination of surgical pathological cases, histoplasmosis of the CNS was diagnosed. Failure of diagnosis CNS histoplasmosis early can lead to poor outcome and decrease chances of recovery.

Presentations of chronic cavitary pulmonary histoplasmosis mimic infected cystic bronchiectasis in an immunocompetent host: A case report

Background

Chronic cavitary pulmonary disease and laryngeal involvement are unusual manifestations of Histoplasmosis capsulatum infection, particularly in patients who are not immunocompromised. The presence of fibro-cavitary lesions has been reported as a radiologic presentation of chronic histoplasmosis in patients with pre-existing lung disease. However, there have been few reports of extensive basal predominant cavitary lesions that mimic cystic-bronchiectasis.

Case presentation

A 65-year-old previously healthy Thai male presented with productive cough, hoarseness, low-grade fever, and weight loss for 6 months. There was no history of significant exposure to Histoplasmosis capsulatum. Tests for HIV and anti–IFN–γ antibody were negative. Chest CT revealed multifocal thick wall cavities, which were distributed in a peri-bronchial pattern, and some areas of consolidation in both basal lungs. Laryngoscopy revealed an ulcerative lesion of the false vocal cords. Histopathological study of false vocal cords and lung tissue showed granulomatous inflammation with mixed inflammatory cell infiltration and aggregation of histiocytes containing round intracytoplasmic organisms. GMS-staining was positive, but negative mucicarmine-staining was negative. A real-time PCR assay of the lung tissue was positive for Histoplasmosis capsulatum. The final diagnosis was chronic cavitary pulmonary histoplasmosis with laryngeal involvement.

Conclusion

Chronic cavitary pulmonary histoplasmosis is rare, as is laryngeal involvement. However, there have been such cases in endemic areas, even in immunocompetent patients. Chronic histoplasmosis should be considered in patients who present with the extensive basal predominant cavitary-pulmonary lesions that mimic cystic bronchiectasis.

Evaluation of OIDx Histoplasma Urinary Antigen EIA

A sandwich enzyme immunoassay (EIA) for the detection of Histoplasma antigens (Ag) in urine, developed by Optimum Imaging Diagnostics (OIDx) was evaluated. A verification using a standardized reference panel of urine samples found sensitivity of 92%, specificity of 32% and accuracy of 51%. In this study, the OIDx Histoplasma urinary Ag EIA displayed high sensitivity, however, in non-histoplasmosis cases this EIA displayed false-positive results in 68% of specimens tested.

Indolent nonendemic central nervous system histoplasmosis presenting as an isolated intramedullary enhancing spinal cord lesion

Background

Histoplasma capsulatum infection is largely seen in endemic regions; it results in symptomatic disease in <5% of those infected and is most often a self-limiting respiratory disease. Disseminated histoplasmosis is considered rare in the immunocompetent host. Central nervous system (CNS) dissemination can result in meningitis, encephalitis, and focal lesions in the brain and spinal cord, stroke, and hydrocephalus. An intramedullary spinal cord lesion as the only manifestation of CNS histoplasmosis has been rarely described.

Case Description

We present an atypical case of a 44-year-old man from a nonendemic region, on adalimumab therapy for ulcerative colitis who developed an isolated intramedullary spinal cord lesion in the setting of disseminated histoplasmosis. His course was initially indolent with vague systemic symptoms that led to consideration of several other diagnoses including sarcoidosis and lymphoma. Biopsies of several positron emission tomography positive lymph nodes revealed granulomatous inflammation, but no firm diagnosis was achieved. He was ultimately diagnosed with histoplasmosis after an acute respiratory infection in the setting of anti-tumor necrosis factor therapy. With appropriate antifungal therapy, the spinal cord lesion regressed. The previous systemic biopsies were re-reviewed, and rare fungal elements consistent with H. capsulatum were identified. A presumptive diagnosis of CNS histoplasmosis was made in the absence of direct laboratory confirmation in the setting of rapid and complete resolution on antifungal therapy.

Conclusion

Disseminated histoplasmosis should be considered in granulomatous disease, even if the patient resides in a nonendemic region. Furthermore, clinicians should be mindful that CNS histoplasmosis may present in an atypical fashion.

Disseminated histoplasmosis in a renal transplantation recipient: Peripheral blood smear was the key

Disseminated histoplasmosis is common in immunocompromised patients such as patients with AIDS, hematologic malignancies, transplant recipients, and those on prolonged corticosteroid use. We report the case of a 53-year-old man with a history of end-stage renal disease due to uncontrolled hypertension who underwent renal transplantation in 2013. He presented to the hospital with a 5-day history of dyspnea, and blood tests showed pancytopenia. The diagnosis of disseminated histoplasmosis was made rapidly by peripheral blood smear. We encourage clinicians to check peripheral blood smear if disseminated histoplasmosis is suspected.

Closing gaps in histoplasmosis: clinical characteristics and factors associated with probable/histoplasmosis in HIV/AIDS hospitalized patients, a retrospective cross-sectional study in two tertiary centers in Pereira, Colombia

BACKGROUND

The HIV pandemic continues to cause a high burden of morbidity and mortality due to delayed diagnosis. Histoplasmosis is prevalent in Latin America and Colombia, is difficult to diagnose and has a high mortality. Here we determined the clinical characteristics and risk factors of histoplasmosis in people living with HIV (PLWH) in Pereira, Colombia.

MATERIALS AND METHODS

This was a retrospective cross-sectional study (2014-2019) involving two tertiary medical centers in Pereira, Colombia. People hospitalized with HIV were included. Histoplasma antigen detection was performed in urine samples. Probable histoplasmosis was defined according to European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group/National Institute of Allergy and Infectious Diseases Mycoses Study Group criteria.

RESULTS

172 HIV-infected patients were analyzed. Histoplasmosis was confirmed in 29% (n = 50/172) of patients. The logistic regression analysis showed that the risk factors for histoplasmosis were pancytopenia (OR 4.1, 95% CI 1.6-10.3, P = 0.002), < 50 CD4 + cells/μL (OR 3.1, 95% CI 1.3-7.3, P = 0.006) and Aspartate transaminase (AST) levels > 46 IU/L (OR 3.2, 95% CI 1.3-8, P = 0.010).

CONCLUSIONS

Histoplasmosis is highly prevalent in hospitalized patients with HIV in Pereira, Colombia. The clinical findings are nonspecific, but there are some clinical abnormalities that can lead to suspicion of the disease, early diagnosis and prompt treatment. Urine antigen detection is useful for diagnosis, but is not widely available. An algorithmic approach is proposed for low-resource clinical settings.

Histoplasmosis tenosynovitis of the forearm and wrist: imaging, surgical and pathologic findings

Histoplasmosis is a disease endemic to several parts of the world, including South America. It progresses in a mostly asymptomatic and self-limiting manner but has the potential to cause disseminated pulmonary infection, especially in immunocompromised patients. Rare reports from the literature describe musculoskeletal manifestations related to the two varieties of the pathogen that cause histoplasmosis, namely, the capsulatum or duboissi variety. In this report, we describe the case of a previously healthy, middle-aged man, with slowly progressing pain in the right forearm, wrist, and fingers, diagnosed with a case of pathologically confirmed histoplasmosis tenosynovitis. We also describe the imaging, surgical, and histological findings and discuss the differential diagnoses for tenosynovitis, in case of atypical infections.

[Puzzling B symptoms in a 61-year-old patient under treatment for rheumatoid arthritis]

Ein Patient mit rheumatoider Arthritis sowie B‑Symptomatik, Polyneuropathie und einschmelzenden Lungenveränderungen unter Immunsuppression entwickelte nach zunächst subakutem Verlauf rasch progrediente zentrale neurologische Symptome und ein letales Multiorganversagen. Als ursächlich erwies sich eine disseminierte Infektion mit Histoplasma capsulatum unter Beteiligung des zentralen Nervensystems. Die Erstinfektion hatte sich fünf Jahre zuvor bei einem Karibikurlaub ereignet. Die Kombination aus Reiseaktivität und Immunsuppression erfordert die Berücksichtigung sonst in Deutschland sehr seltener infektiologischer Diagnosen.

Occupational Histoplasmosis: Epidemiology and Prevention Measures

In areas where Histoplasma is endemic in the environment, occupations involving activities exposing workers to soil that contains bird or bat droppings may pose a risk for histoplasmosis. Occupational exposures are frequently implicated in histoplasmosis outbreaks. In this paper, we review the literature on occupationally acquired histoplasmosis. We describe the epidemiology, occupational risk factors, and prevention measures according to the hierarchy of controls.

Hemophagocytic lymphohistiocytosis secondary to progressive disseminated histoplasmosis presenting as cellulitis

Histoplasmosis-associated hemophagocytic lymphohistiocytosis is a rate but lethal disease in immunocompromised hosts. Unusual clinical presentations make diagnosing invasive fungal infection even more challenging. Here we present a case of hemophagocytic lymphohistiocytosis secondary to progressive disseminated histoplasmosis presenting as cellulitis in a patient with systemic lupus erythematous. A high index of suspicion combined with histopathology and molecular diagnostic techniques are important to establish an accurate and timely diagnosis of opportunistic infections in immunocompromised patients.