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BMC Veterinary Research May 2021Histoplasma (H.) capsulatum is a dimorphic fungus, and infection is typically via inhalation of microconidia. After conversion to the yeast phase within the lung, the...
BACKGROUND
Histoplasma (H.) capsulatum is a dimorphic fungus, and infection is typically via inhalation of microconidia. After conversion to the yeast phase within the lung, the organism is subsequently disseminated to other tissues by macrophages. Nasal histoplasmosis appears to be a rare condition in dogs.
CASE PRESENTATION
We report the clinical case of a 4.5-year-old male neutered Cocker spaniel/Poodle mix, 7.7 kg, body condition score 6/9, that presented with a 3-month history of sneezing and left-sided mucoid nasal discharge. The history also included a mild swelling (transient) of the right carpus with a lameness (grade II-III/IV), coinciding with the onset of sneezing and nasal discharge. The dog lived primarily indoors in the Texas Gulf Coast area. On physical examination, the dog was febrile, and the left nostril was swollen, ulcerative, deformed, and hypopigmented. Mandibular lymph nodes were firm and mildly enlarged bilaterally. Mild lymphopenia, thrombocytopenia, and hyperglobulinemia were noted. Thoracic radiographs were unremarkable. Computed tomography and rhinoscopy revealed swelling of the rostral portion of the left and right nasal passages. Cytology and histology of biopsies of the affected nasal tissue showed pyogranulomatous inflammation and yeast organisms consistent with H. capsulatum. Weak antigenuria was detected on the MVista H. capsulatum antigen test. Treatment with oral itraconazole led to a resolution of the nasal signs and normalization of the appearance of the nostril over 13 weeks, and neither antigenuria nor antigenemia was detected on several recheck examinations. The dog remained in good general and physical condition and showed no signs of disease recurrence more than 6 years after the last examination.
CONCLUSION
We report a rare case of nasal mucocutaneous histoplasmosis in an immunocompetent dog, with an excellent clinical response to oral itraconazole. This case documents that histoplasmosis in dogs can affect primarily the nasal cavity, which responds rapidly to triazole antifungal therapy and has a good prognosis. A similar case has only been reported in human medicine in a young adult.
Topics: Animals; Antifungal Agents; Dog Diseases; Dogs; Histoplasma; Histoplasmosis; Itraconazole; Male; Nasal Cavity; Texas
PubMed: 33985507
DOI: 10.1186/s12917-021-02896-9 -
Microbiology and Molecular Biology... Jun 2024Histoplasmosis is arguably the most common fungal respiratory infection worldwide, with hundreds of thousands of new infections occurring annually in the United States... (Review)
Review
Histoplasmosis is arguably the most common fungal respiratory infection worldwide, with hundreds of thousands of new infections occurring annually in the United States alone. The infection can progress in the lung or disseminate to visceral organs and can be difficult to treat with antifungal drugs. , the causative agent of the disease, is a pathogenic fungus that causes life-threatening lung infections and is globally distributed. The fungus has the ability to germinate from conidia into either hyphal (mold) or yeast form, depending on the environmental temperature. This transition also regulates virulence. and histoplasmosis have been classified as being of emergent importance, and in 2022, the World Health Organization included as 1 of the 19 most concerning human fungal pathogens. In this review, we synthesize the current understanding of the ecological niche, evolutionary history, and virulence strategies of . We also describe general patterns of the symptomatology and epidemiology of histoplasmosis. We underscore areas where research is sorely needed and highlight research avenues that have been productive.
Topics: Histoplasma; Histoplasmosis; Humans; Virulence; Genetic Variation; Animals; Genotype
PubMed: 38819148
DOI: 10.1128/mmbr.00076-23 -
Arab Journal of Gastroenterology : the... Feb 2024Fungi have a well-established role in medicine. Herein, we describe the fungal profile and abundance in the gut of healthy Saudi children.
BACKGROUND AND STUDY AIM
Fungi have a well-established role in medicine. Herein, we describe the fungal profile and abundance in the gut of healthy Saudi children.
PATIENTS AND METHODS
Fecal samples from a random sample of 20 school-age Saudi children were collected, stored at -80 °C, and dispatched to the laboratory in the USA where fungal DNAs were isolated and shotgun metagenomic sequencing was performed. Abundance was presented as average percentage of fungal taxa.
RESULTS
The median age of the participants was 12.5 years (range: 7-16 years), and 35 % were male. Ascomycota were the most abundant phyla and Eurotiomycetes, Saccharomycetes, were the most abundant class. The average abundance of fungal genera were Histoplasma (36 %) and Saccharomyces (31 %). The most abundant species were Histoplasma capsulatum (36 %) and Saccharomyces pastorianus (23 %). Other less abundant but may be functionally important genera and species included Candida (2.6 %) and Saccharomycescerevisiae (8 %).
CONCLUSION
The profile and abundance of the gut fungi in healthy Saudi children reveals important differences compared to Western literature. Accordingly, this report represents a more appropriate reference than Western data to use as controls for regional studies aiming to identify fungi associated with disease.
Topics: Child; Humans; Male; Adolescent; Female; Fungi; Saudi Arabia; Mycobiome; Candida; Research Design
PubMed: 37993375
DOI: 10.1016/j.ajg.2023.11.001 -
Journal of Clinical Microbiology Nov 2021
PubMed: 34792389
DOI: 10.1128/JCM.02899-20 -
Journal of Immunology (Baltimore, Md. :... Feb 2021Although fibrotic disorders are frequently assumed to be linked to T cells, quantitative tissue interrogation studies have rarely been performed to establish this link...
Although fibrotic disorders are frequently assumed to be linked to T cells, quantitative tissue interrogation studies have rarely been performed to establish this link and certainly many fibrotic diseases do not fall within the type 2/allergic disease spectrum. We have previously linked two human autoimmune fibrotic diseases, IgG4-related disease and systemic sclerosis, to the clonal expansion and lesional accumulation of CD4CTLs. In both these diseases T cell accumulation was found to be sparse. Fibrosing mediastinitis linked to infection histologically resembles IgG4-related disease in terms of the inflammatory infiltrate and fibrosis, and it provides an example of a fibrotic disease of infectious origin in which the potentially profibrotic T cells may be induced and reactivated by fungal Ags. We show in this study that, in this human disease, CD4CTLs accumulate in the blood, are clonally expanded, infiltrate into disease lesions, and can be reactivated in vitro by Ags. T cells are relatively sparse at lesional sites. These studies support a general role for CD4CTLs in inflammatory fibrosis and suggest that fibrosing mediastinitis is an Ag-driven disease that may provide important mechanistic insights into the pathogenesis of idiopathic fibrotic diseases.
Topics: Adult; CD4 Antigens; Cells, Cultured; Cohort Studies; Female; Histoplasma; Histoplasmosis; Humans; Immunoglobulin G4-Related Disease; Lymphocyte Activation; Male; Mediastinitis; Middle Aged; Sclerosis; T-Lymphocytes, Cytotoxic; Th2 Cells
PubMed: 33328214
DOI: 10.4049/jimmunol.2000433 -
Mycopathologia Feb 2022A sandwich enzyme immunoassay (EIA) for the detection of Histoplasma antigens (Ag) in urine, developed by Optimum Imaging Diagnostics (OIDx) was evaluated. A...
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.
Topics: Antigens, Fungal; Histoplasma; Histoplasmosis; Humans; Immunoenzyme Techniques; Sensitivity and Specificity
PubMed: 34802111
DOI: 10.1007/s11046-021-00602-9 -
British Medical Bulletin Sep 2023Fungal disease has historically presented a diagnostic challenge due to its often non-specific clinical presentations, relative infrequency and reliance on insensitive...
INTRODUCTION
Fungal disease has historically presented a diagnostic challenge due to its often non-specific clinical presentations, relative infrequency and reliance on insensitive and time-intensive fungal culture.
SOURCES OF DATA
We present the recent developments in fungal diagnostics in the fields of serological and molecular diagnosis for the most clinically relevant pathogens; developments that have the potential to revolutionize fungal diagnosis through improvements in speed, simplicity and sensitivity. We have drawn on a body of evidence including recent studies and reviews demonstrating the effectiveness of antigen and antibody detection and polymerase chain reaction (PCR) in patients with and without concurrent human immunodeficiency virus infection.
AREAS OF AGREEMENT
This includes recently developed fungal lateral flow assays, which have a low cost and operator skill requirement that give them great applicability to low-resource settings. Antigen detection for Cryptococcus, Histoplasma and Aspergillus spp. are much more sensitive than culture. PCR for Candida spp., Aspergillus spp., Mucorales and Pneumocystis jirovecii is more sensitive than culture and usually faster.
AREAS OF CONTROVERSY
Effort must be made to utilize recent developments in fungal diagnostics in clinical settings outside of specialist centres and integrate their use into standard medical practice. Given the clinical similarities of the conditions and frequent co-infection, further study is required into the use of serological and molecular fungal tests, particularly in patients being treated for tuberculosis.
GROWING POINTS
Further study is needed to clarify the utility of these tests in low-resource settings confounded by a high prevalence of tuberculosis.
AREAS TIMELY FOR DEVELOPING RESEARCH
The diagnostic utility of these tests may require revision of laboratory work flows, care pathways and clinical and lab coordination, especially for any facility caring for the immunosuppressed, critically ill or those with chronic chest conditions, in whom fungal disease is common and underappreciated.
Topics: Humans; Mycoses; Candida; Polymerase Chain Reaction
PubMed: 37328942
DOI: 10.1093/bmb/ldad011 -
Open Forum Infectious Diseases Jul 2022Cryptococcal meningitis (CM) and disseminated histoplasmosis (DH) are common in people with human immunodeficiency virus (PWH) and diagnosed by detecting cryptococcal...
Cryptococcal and Antigen Screening Among People With Human Immunodeficiency Virus in Ghana and Comparative Analysis of OIDx Lateral Flow Assay and IMMY Enzyme Immunoassay.
BACKGROUND
Cryptococcal meningitis (CM) and disseminated histoplasmosis (DH) are common in people with human immunodeficiency virus (PWH) and diagnosed by detecting cryptococcal antigen (CrAg) and antigen (HistoAg), respectively. In Ghana, CM and DH are rarely suspected by clinicians due to limited epidemiological data.
METHODS
This study was conducted among PWH in Ghana who are unwell. Sociodemographic and clinical data were collected by questionnaire. Serum and/or urine were screened for CrAg and HistoAg, using IMMY CrAg lateral flow assay (LFA) and IMMY enzyme immunoassay (EIA) kits, respectively, regardless of symptoms. Samples run with IMMY EIA were simultaneously run with Optimum Imaging Diagnostics (OIDx) LFA. Laboratory investigations were conducted by the research team, and diagnosis incorporating clinical assessment, screening, and confirmatory testing results and treatment decisions were made by the clinical team. Treatment and outcome information on CM and DH patients were evaluated.
RESULTS
Overall, 150 participants were recruited. There were 73% ( = 109) females, and the age range was 18-62 years. The prevalence rates of CrAg and HistoAg were 2.7% (4 of 150) and 4.7% (5 of 107), respectively. The OIDx LFA showed a high concordance (98.4%) with the IMMY EIA. All antigen-positive cases by standard tests were diagnosed with CM and DH. Antifungal treatment was given in 5 patients and follow-up revealed 2 deaths and 3 recoveries.
CONCLUSIONS
Histoplasmosis among PWH may be more common than previously anticipated and may be more frequent than cryptococcosis in Ghana. The performance of the OIDx LFA should be further explored.
PubMed: 35854987
DOI: 10.1093/ofid/ofac277 -
Virulence Dec 2022Histoplasmosis is a systemic mycosis caused by the thermally dimorphic fungus . Although healthy individuals can develop histoplasmosis, the disease is particularly... (Review)
Review
Histoplasmosis is a systemic mycosis caused by the thermally dimorphic fungus . 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 highly adapted to a wide variety of hosts, including mammals. Understanding and integrating these mechanisms is a key step toward devising new preventative and therapeutic interventions.
Topics: Animals; Humans; Histoplasma; Histoplasmosis; Virulence; Adaptation, Physiological; Virulence Factors; Mammals
PubMed: 36266777
DOI: 10.1080/21505594.2022.2137987 -
American Journal of Otolaryngology 2019Head and neck involvement with histoplasmosis usually occurs as a part of the disseminated illness. There are no pathognomic features of the upper aerodigestive tract... (Review)
Review
INTRODUCTION
Head and neck involvement with histoplasmosis usually occurs as a part of the disseminated illness. There are no pathognomic features of the upper aerodigestive tract involvement and the lesion may mimic a host of other conditions. The current report presents our experience with head and neck histoplasmosis in a non-endemic tertiary care center.
MATERIALS AND METHODS
We present a case of disseminated histoplasmosis with oral symptoms and lesions as the chief complaints. A 10 years' retrospective institutional database search was undertaken to identify the patients with histoplasmosis affecting head and neck region treated at our institution. The demographic and treatment details of the patients were reviewed.
RESULTS
In addition to the index patient, four more patients (two with gingivobuccal and one each with nasal and laryngeal histoplasmosis) were found. Out of the five patients, only one patient was found to have underlying immunosuppression. All of the patients were diagnosed with biopsy showing typical appearance of the intracellular organism. All the patients were satisfactorily treated with systemic antifungal treatment.
CONCLUSION
Upper aerodigestive tract involvement with histoplasmosis can present as an intriguing clinical puzzle. A high index of suspicion is needed and biopsy is the gold standard for the diagnosis. Intravenous Liposomal Amphotericin B and oral Itraconazole are standard treatment agents of choice and are highly efficacious in achieving cure.
Topics: Aged; Amphotericin B; Antifungal Agents; Biopsy, Needle; Drug Therapy, Combination; Female; Follow-Up Studies; Histoplasma; Histoplasmosis; Humans; Immunohistochemistry; Itraconazole; Magnetic Resonance Imaging; Risk Assessment; Tongue; Treatment Outcome
PubMed: 31178282
DOI: 10.1016/j.amjoto.2019.06.002