HISTOPLASMOSIS IN NONDOMESTIC FELIDS: A REVIEW OF SIX CASES.

One adult leopard (Panthera pardus) and five adult tigers (Panthera tigris) presented with a range of nonspecific clinical signs, including lethargy (6/6), mobility deficits (4/6), and hyporexia (3/6). Hematology and biochemistry revealed a hyperproteinemia characterized by hyperglobulinemia (4/6), hepatocellular enzyme activity increases (3/6), azotemia (3/6), leukocytosis (2/6), hyperbilirubinemia (2/6), or a combination of conditions. Further diagnostics and management varied with the presenting signs and clinicopathological findings, including supportive care, diagnostic imaging, and blastomyces urine antigen analyses. Two animals died, and four were euthanatized. Postmortem findings included granulomatous pneumonia (6/6), fibrinous pleural effusion (3/ 6), pericardial effusion (2/6), and diffuse icterus (1/6). Histopathology revealed round to oval structures with a thin clear wall and purple inclusions within cells of the mononuclear phagocyte system, consistent with Histoplasma capsulatum, in each animal. Disseminated histoplasmosis was found in five cases, with organisms present in the lung (5/5), liver (3/5), lymph nodes (3/5), spleen (2/5), bone marrow (2/5), thyroid (1/5), tongue (1/ 5), kidney (1/5), or a combination of organs. One tiger was found to have pulmonary histoplasmosis without evidence of disseminated infection. On the basis of clinical and pathological findings, histoplasmosis was diagnosed. This case series illustrates the difficulties in antemortem diagnosis of histoplasmosis on the basis of complete blood count, serum biochemistry profile, and antigen testing and underscores that histoplasmosis should be considered a differential diagnosis in any felid presenting with nonspecific clinical signs in endemic areas.

Gingival histoplasmosis: An atypical presentation of African histoplasmosis in three baboons (Papio spp).

Gingival lesions as the sole manifestation of African histoplasmosis (Histoplasma capsulatum var. duboisii) have never been reported in baboons. Grossly, lesions can be indistinguishable from bacterial ulcerative gingivitis or gingival hyperplasia. Clinical outcomes of primary gingival histoplasmosis in baboons are unknown and may complicate colony management decisions.

Histoplasmosis and multicentric lymphoma in a Nubian goat.

Following treatment for pneumonia, a 1-y-old female Nubian goat was presented because of a persistent fever for 3 mo and peripheral lymphadenopathy for 1 mo. Cytology and histology of the superficial cervical and prefemoral lymph nodes demonstrated a moderate-to-marked "left-shifted" lymphoid population, suggestive of lymphoma, and extremely rare extracellular, 2-4 µm, oval, basophilic yeast, consistent with Histoplasma capsulatum. On immunohistochemistry, >95% of the lymphocytes demonstrated positive cytoplasmic and membranous immunoreactivity for CD3. Histoplasma spp. urine antigen and serum antibody testing were positive and negative, respectively. Panfungal PCR and sequencing of DNA extracted from scrolls of formalin-fixed, paraffin-embedded tissue yielded matches to H. capsulatum with 99-100% identity. Given the poor prognosis and persistent pyrexia, the animal was euthanized. Postmortem examination confirmed concurrent multicentric, intermediate-size, T-cell, lymphoblastic lymphoma and histoplasmosis; lesions consistent with intestinal coccidiosis and suspected pulmonary Rhodococcus equi were also noted. Although dimorphic fungi have been described previously in goats, lesions of Histoplasma spp. had not been documented in this species, to our knowledge. Given the low disease burden, it is suspected that the lymphoma was primary, leading to an immunocompromised state and development of secondary, opportunistic infections.

INTESTINAL HISTOPLASMOSIS IN A CAPTIVE REINDEER (RANGIFER TARANDUS), MISSOURI, USA.

An infection with Histoplasma capsulatum was diagnosed in a farmed reindeer in Missouri, an endemic area for histoplasmosis, localized in the intestine. The intrahistiocytic organisms were identified in tissue sections using histologic methods and confirmed by immunohistochemistry. This is the first report of histoplasmosis in a reindeer or in any deer species.

Cutaneous histoplasmosis with prominent parasitization of epidermal keratinocytes: report of a case.

Disseminated histoplasmosis most commonly occurs in immunosuppressed individuals and involves the skin in approximately 6% of patients. Cutaneous histoplasmosis with an intraepithelial-predominant distribution has not been described. A 47-year-old man was admitted to our institution with fever and vancomycin-resistant enterococcal bacteremia. He had been diagnosed with T-cell prolymphocytic leukemia 4 years earlier and had undergone matched-unrelated-donor stem cell transplant 2 years earlier; on admission, he had relapsed disease. His medical history was significant for disseminated histoplasmosis 6 months before admission, controlled with multiple antifungal regimens. During this final hospitalization, the patient developed multiple 2-5 mm erythematous papules, a hemorrhagic crust across the chest, shoulders, forearms, dorsal aspect of the fingers, abdomen and thighs. Skin biopsy revealed clusters of oval yeast forms mostly confined to the cytoplasm of keratinocytes and within the stratum corneum; scattered organisms were present in the underlying superficial dermis without any significant associated inflammatory infiltrate. Special stains and immunohistochemical studies confirmed these to be Histoplasma organisms. We highlight this previously unrecognized pattern of cutaneous histoplasmosis to ensure its prompt recognition and appropriate antifungal therapy.

Detection and phylogenetic characterization of a case of Histoplasma capsulatum infection in mainland China.

Histoplasmosis usually occurs in specific endemic areas. Sporadic cases have also been reported in mainland China. Here, we described an indigenous case of disseminated histoplasmosis. Phylogenetic analysis revealed that the Histoplasma capsulatum isolated in our case belongs to the Australian clade. Combined with previous studies, it revealed high genetic diversity among Chinese H. capsulatum isolates.

Lung parasites of shrews from Pennsylvania.

We examined lung parasites of three species of soricids, Sorex cinereus (n = 58), Sorex fumeus (n = 23) and Blarina brevicauda (n = 45) collected from Pennsylvania (USA), from 1990 to 1995. Yeast-like cells of Hisfoplasma capsulatum var. capsulatum were found in lung sections stained with Grocott's modification of Gomori's methenamine silver, periodic acid-Schiff, Giemsa, and hematoxylin-eosin in two (3%) S. cinereus, eight (35%) S. fumeus and two (4%) B. brevicauda. The number of spores of H. capsulatum in the lungs was low and no inflammatory reaction was evident. The infection was not disseminated to other organs. This is the first report of H. capsulatum infection in any species of shrews of the genus Sorex and the prevalence in S. fumeus was remarkably high compared to those reported for other wild mammals. A nematode, possibly Angiostrongylus michiganensis, was found in the lungs of one S. fumeus on necropsy and in a stained lung section of one S. cinereus. In both cases the host was also infected with the fungus. Pneumocystis carinii, which is the most common lung parasite in Sorex araneus (the numerically dominant Eurasian species of shrew), was not found in any of the North American species of shrew examined in this study.

New records of histoplasma capsulatum from wild animals in the Brazilian amazon

Vinte e oito amostras de Histoplasma capsulatum foram obtidas de oito especies de mamiferos silvestres nos Estados do Amazonas, Para e Rondonia. Os isolamentos foram feitos mediante inoculacao de amostras trituradas de figado e baco em hamsters por via intradermica e intraperitoneal. O diagnostico micologico nos hamsters que apresentaram lesoes foi confirmado por histopatologia e cultivo em meio dextrose-agar de Sabourad. Os hamsters infectados desenvolveram sinais de doenca apos dois a nove meses; todos apresentaram lesoes disseminadas nas visceras e a maioria apresentou tambem lesoes cutaneas nos locais da inoculacao. Nenhum dos hamsters inoculados com material de pele dos hospedeiros originais desenvolveu histoplasmose, e H. capsulatum nao foi detectado nos exames histopatologicos dos animais silvestres. A prevalencia de infeccao foi consideravelmente mais alta entre femeas tanto para Didelphis marsupialis como para o total de animais silvestres examinados (479)...

Histoplasma variation and adaptive strategies for parasitism: new perspectives on histoplasmosis.

This review summarizes the biology of Histoplasma capsulatum in relation to a wide variety of corresponding pathologies in histoplasmosis. Features of these disease syndromes can be explained in part by natural variations within the fungal population and adaptations made by individual organisms to specific environments. H. capsulatum grows as mycelia and conidia in the soil; once inhaled, the organism undergoes a dramatic morphological and physiological conversion to a yeast form. The yeasts proliferate within the phagolysosomes of macrophages, using a variety of specific strategies for intracellular survival. Even avirulent strains or variants are able to avoid being killed by macrophages and instead establish inapparent or persistent infections. The ingested avirulent organisms assume enlarged shapes similar in appearance to those seen in histological sections of tissues from patients with histoplasmosis. Respiratory tract epithelial cells also appear to play a role in persistence: within them yeasts undergo phenotypic switching akin to the phase variation observed in other pathogens. This particular change involves the loss or modification of cell wall alpha-(1,3)-glucan, which is also correlated with the spontaneous appearance of avirulent variants. The repertoire of adaptive responses and natural variations within this species probably evolved from the need to adjust to a wide range of dynamic environments. In combination with the immune status of the host, these characteristics of H. capsulatum appear to influence the epidemiology, extent, and persistence of histoplasmosis.

Distribution of Histoplasma capsulatum in Amazonian wildlife.

In a survey of 296 sylvatic animals captured from virgin forests in the north-eastern and south-western Amazon of Brazil, Histoplasma capsulatum was isolated, via the indirect hamster inoculation method, from the liver and spleen of four common opossums Didelphis marsupialis and two pacas Agouti paca. The infected animals did not show any clinical symptoms or histopathology. The known Amazonian mammalian species with natural histoplasmosis now total five, the previously reported species being the spiny rat Proechimys guyannensis, the two-toed sloth Choloepus didactylus and the nine-banded armadillo Dasypus novemcinctus.

[Histoplasma capsulatum: isolation from bats in Cuba]. / Histoplasma capsulatum: aislamiento de murciélagos en Cuba.

A mycologic-serologic study of 169 bats of species Artibeus jamaicensis parvipos, Brachyphyllanana, Eptesicus fuscus dutertreus, Tadarida brasiliensis muscula and Mormoops blainvillei which were catched in a cave of Havana province is presented. Histoplasma capsulatum were isolated from the lungs, liver and spleen, in four out of the five species studied. All species were serologically negative.