Molecular Diagnostics: Present and Future
Johan A. Maertens, Kieren A. Marr in Diagnosis of Fungal Infections, 2007
Also, different PCR assays for the detection of Histoplasma capsulatum were described. This slow-growing, dimorphic fungus causes disease ranging from focal and self-limited to disseminated and rapidly fatal. Immunocompromised patients, especially those with advanced AIDS, are at risk for disseminated histoplasmosis. Martagon-Villamil et al. designed and tested a real-time PCR assay by LightCycler, which was able to correctly identify 34 H. capsulatum isolates and additionally in clinical specimens from 3 patients (73). De Matos Guedes et al. also described a Histoplasma-specíñc PCR assay (74). Their PCR test correctly identified the 31 H. capsulatum var. capsulatum strains isolated from human, animal, and soil specimens and 1 H. capsulatum var. duboisii isolate. The specificity of the PCR using M-antigen-derived primers was confirmed by the absence of amplification products when genomic DNA from Paracoccidioides brasiliensis, Candida spp., Sporothrix schenckii, Cryptococcus neoformans, Blastomyces dermatitidis, Coccidioides immitis, A. niger, and A. fumigatus was analyzed.
Case 97: TB or not TB?
Layne Kerry, Janice Rymer in 100 Diagnostic Dilemmas in Clinical Medicine, 2017
Histoplasmosis is an infection of the fungal pathogen, Histoplasma capsulatum, which is endemic in North and Central America, and parts of Asia, Africa and South America. The organism is present in acidic soil, particularly in areas inhabited by bats or around chicken coops, or riverbanks and mining regions. Most infected people remain asymptomatic throughout their lives, although in those that become unwell, the disease may present with acute pneumonitis that progresses to severe disseminated disease, or chronic histoplasmosis with cavitating lung lesions. Adrenal involvement is common, and CT appearances show central hypodensity of the adrenal glands, in keeping with both tuberculosis and histoplasmosis. Treatment involves antifungal agents, corticosteroids and possibly mineralocorticoids, depending on the extent of adrenal disease.
THE EYE OF THE STORM
Rob Norman in The Woman Who Lost Her Skin, 2004
"What exactly is going on?" I asked. (Candice was not one to profess ill health unless she really had a problem.) "First I thought it was my glasses so I cleaned them. Then I took off my glasses and closed one eye at a time. I felt like I was looking through a window. It's like a suspension and it's all moving, and I can't get rid of it." I did a thorough history and asked about any previous family problems. "I had an aunt like that. She maybe had a cataract or something. My momma told me about it but I don't remember," Candice said. I looked her over and quickly got her in to see a colleague who was an ophthalmologist. The doctor called me back with a preliminary report. "Histo spots," she said. That description set my head into research and reflection mode. I had remembered other patients that had similar complaints to Candice. One I had seen in the emergency room many years before who said she had "Big spider webs all over my eyes that I can't shake." The description of visual occlusion was similar to Candice's. Both patients had similar backgrounds in one respect - they had spent extensive time in the Ohio and Mississippi River Valleys. And both turned out to have ocular histoplasmosis, a disease caused when airborne spores of the fungus Histoplasma capsulatum are inhaled into the lungs, the primary infection site. This microscopic fungus is found throughout the world in river valleys and soil where bird or bat droppings accumulate. It is released into the air when
Zoonotic fungal diseases and animal ownership in Nigeria
Published in Alexandria Journal of Medicine, 2018
Adebowale I. Adebiyi, Daniel O. Oluwayelu
Histoplasmosis is an infection caused by Histoplasma capsulatum, a dimorphic fungus with two known varieties: H. capsulatum var. capsulatum and H. capsulatum var. duboisii. The two varieties have been identified in Africa. African histoplasmosis caused by H. capsulatum var. duboisii is a deep mycosis endemic in the African continent, essentially between the Tropics of Cancer and Capricon47,48 as well as in the island of Madagascar.49 It has been detected in about 20 countries in tropical Africa located between 20° North and 20° South of the Equator and extending from Senegal in the West to Tanzania in the East.47,48,50,51 This region is characterized by high average rainfall, high humidity and little variation in diurnal temperature.48
Spontaneous pneumothorax secondary to chronic cavitary pulmonary histoplasmosis
Published in Journal of Community Hospital Internal Medicine Perspectives, 2020
Samuel Geurkink, Leslie Cler
Histoplasma capsulatum is a dimorphic fungus that is classically endemic to the Midwestern and Central USA [1]. This includes the Mississippi and Ohio River Valleys in which parts of North Texas are included [2]. It typically enters hosts through the respiratory tract and only causes symptoms in a small number of patients [3]. Infection with Histoplasma capsulatum, termed histoplasmosis, can present in a variety of ways, including both acute and chronic forms. Symptoms are somewhat non-specific, and include chest pain, productive cough, dyspnea, fever, and fatigue [3]. Chronic cavitary pulmonary histoplasmosis is one of the rarest presentations of histoplasmosis, and typically manifests as apical cavitary lesions in patients with pre-existing chronic obstructive pulmonary disease [3]. These apical cavitary lesions are frequently mistaken for malignancy or pulmonary tuberculosis. It is important to remember that chronic pulmonary infection with Histoplasma capsulatum can cause apical cavitary lung disease, it is often misdiagnosed, and lack of appropriate treatment portends a poor prognosis [4,5].
Disseminated histoplasmosis: case report and review of the literature
Published in Acta Clinica Belgica, 2018
Séverine Evrard, Philippe Caprasse, Pierre Gavage, Myriam Vasbien, Jean Radermacher, Marie-Pierre Hayette, Rosalie Sacheli, Marjan Van Esbroeck, Lieselotte Cnops, Eric Firre, Laurent Médart, Filip Moerman, Jean-Marc Minon
Antigen detection appears to be the most sensitive rapid assay, which detects Histoplasma capsulatum in the urine of 95% and the serum of 86% AIDS patients affected by disseminated histoplasmosis [18]. Several enzyme immunoassays (EIA) test for antigen detection exist. They can be performed on body fluids, especially urine and serum. They vary from each other by sensitivity, specificity, and possible cross-reactions with other fungal pathogens such as paracoccidiomycosis, coccidioidiomycosis, and blastomycosis. The third generation MVista® histoplasma QUANTITATIVE EIA antigen test (MiraVista diagnostics, USA) is currently a good validated method for the diagnosis of histoplasmosis in HIV-infected patients. Nevertheless, this test is not commercialized and it is hardly used apart from the USA [15]. To make such a test available to resource-challenged countries, a similar Histoplasma antigen capture ELISA was developed at the Centers for Disease Control and Prevention (CDC). This test showed a sensitivity of 81% and a specificity of 95% in a cohort of AIDS patients in Guatemala [19]. A trial in Colombia also found that the antigen test successfully monitors the response to therapy [20]. Such antigen tests are not yet available in Europe. In view of its low predictive value in non-endemic areas, pre-test probability should be carefully assessed by clinicians.
Related Knowledge Centers
- Aspergilloma
- Blastomyces Dermatitidis
- Dimorphic Fungus
- Histiocyte
- Histoplasmosis
- Yeast
- Paracoccidioides Brasiliensis
- Histoplasma Duboisii
- Endemic
- HIV/AIDS