Diagnosis Of Pulmonary Histoplasmosis Research Articles

Endemic Fungi Presenting as Community-Acquired Pneumonia: A Review.

In endemic areas, dimorphic fungal infections due to Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides posadasii/immitis account for up to 30% of cases of community-acquired pneumonia. Because respiratory manifestations are often indistinguishable from common bacterial causes of pneumonia, the diagnosis of pulmonary histoplasmosis, blastomycosis, and coccidioidomycosis is often delayed and associated with antibiotics overuse. In addition to being highly endemic to certain regions of North America, dimorphic fungi have global significance due to established areas of endemicity in all six inhabited continents, an increasingly interconnected world of travelers and transported goods, and a changing epidemiology as a result of global heating and anthropomorphic land utilization. In this review, we discuss the epidemiology, pathogenesis, clinical presentation, diagnostic modalities, and treatment strategies for histoplasmosis, blastomycosis, and coccidioidomycosis.

Histoplasmose pulmonar grave em um gato doméstico: tratamento com Anfotericina B e Itraconazol

Background: Histoplasmosis is a systemic mycosis whose etiologic agent is the fungus Histoplasma capsulatum. This fungal infection, which is the second most frequent systemic mycotic fungal disease in felines in the United States, has rarely been found in cats in Brazil. This paper reports on a case of acute pulmonary histoplasmosis in a domestic cat treated with oral itraconazole associated with amphotericin B administered subcutaneously. This treatment resulted in clinical remission of the patient’s symptoms, as evidenced by radiographic follow-ups.Case: A domestic cat suffering from acute dyspnea was taken to a veterinary clinic. The animal was subjected to emergency oxygen therapy, and kept at rest through sedation with midazolam. A physical examination revealed normally colored mucosa, 8% dehydration, bristly fur, body condition score 2/9, tachypnea with respiratory rate of 100 breaths per minute and expiratory dyspnea. The radiographic examination showed marked opacification of all the pulmonary fields, with a mixed pattern (interstitial and alveolar) of heterogeneous appearance and diffuse distribution, which are changes consistent with an inflammatory infectious process (pneumonia). A cytological analysis of the pleural fluid revealed round to oval-shaped intracytoplasmic structures, varying in size from 2 to 4 μm, inside foamy macrophages, consistent with Histoplasma capsulatum. Based on the diagnosis of pulmonary histoplasmosis, and in view of the patient’s acute respiratory distress, it was decided to treat the cat using itraconazole associated with amphotericin B. Itraconazole was administered orally at a dose of 100 mg/cat every 24 h, while amphotericin B was administered subcutaneously at a dose of 0.5 mg/kg, combined with 100 mL of sodium chloride 0.9% and 100 mL of 5% glycated serum, with monitoring of serum concentrations of symmetric dimethylarginine (SDMA). Amphotericin B was administered every 48 h up to the 7th dose, followed by three times a week up to the 11th dose, and then twice a week up to the 16th dose. The animal was released from the veterinary hospital 10 days after its admission, showing a considerably improved respiratory condition and a respiratory rate of 40 breaths per minute. Continuation of the antifungal treatment with itraconazole was prescribed, maintaining the same dose and frequency of administration until a new recommendation would be made, as well as frequent return visits for the administration of amphotericin B and reassessment of the animal. The administration of amphotericin B was discontinued when the animal’s respiratory condition stabilized; hence, the feline received a total of 16 doses of the drug. The animal showed remission of clinical respiratory symptoms, confirmed by follow-up chest X-rays, which revealed significantly less radiodense pulmonary parenchyma in response to treatment with itraconazole and amphotericin B. Five months after beginning its treatment, the cat is being treated orally with itraconazole (100 mg/cat, every 24 h), without recrudescence of the clinical symptoms.Discussion: To date, six cases of feline histoplasmosis have been reported in Brazil, only one of which had pulmonary involvement and was treated successfully. The use of oral itraconazole associated with subcutaneous amphotericin B has proved to be effective for the treatment of acute pulmonary histoplasmosis in domestic cats. Note that a rapid diagnosis of pulmonary disease is essential in order to immediately implement a combined drug therapy linked with monitoring to ensure the protocol is safe for the patient

Pulmonary histoplasmosis as an example of imported mycoses in Japan

As travel increases, histoplasmosis as an imported mycosis that has the potential to increase abruptly in Japan. A 56-year-old Japanese man who had been in Bolivia for 2 years complained of a dry cough. Chest computed tomography revealed multiple lesions in the right and left lower lobes of his lung that were difficult to diagnose and differentiate from advanced lung cancer. We performed surgical resection for biopsy by video-assisted thoracoscopic surgery. An intraoperative histopathological examination suggested a diagnosis of tuberculoma, but Mycobacterium tuberculosis DNA was not detected in the tumor tissue. Further histopathological examination, however, strongly suggested a diagnosis of histoplasmosis because multiple small, round yeast foci were observed after Grocott staining. The serological test was positive for anti-Histoplasma capsulatum and confirmed the diagnosis of pulmonary histoplasmosis. The postoperative course was uneventful, and fluconazole was administrated for 90 days after the operation. Concerning imported mycoses, physicians should be keep abreast of updated and detailed information.

Pitfalls in diagnosis of pulmonary histoplasmosis

Summary Many diagnoses are missed or delayed because pulmonary histoplasmosis is not considered. Therefore, recognition of its different clinical manifestations and differential diagnoses, accompanied by knowledge of the accuracy and limitations of tests for this condition, is essential. Three cases are reported and diagnostic pitfalls are discussed.

Diagnosis of pulmonary histoplasmosis and blastomycosis by detection of antigen in bronchoalveolar lavage fluid using an improved second-generation enzyme-linked immunoassay

Antigen detection is a useful adjunct for the diagnosis of histoplasmosis. The purpose of this study was to evaluate antigen detection in bronchoalveolar lavage (BAL) fluid using an improved second-generation Histoplasma antigen assay. Antigen was detected in 16 of 19 (84%) cases of histoplasmosis and 5 of 6 (83.3%) blastomycosis cases using the second-generation assay vs. 13 of 19 (68%) and 4 of 6 (66.7%), respectively, in the original assay. Ten-fold concentration permitted detection of antigen in an additional case of histoplasmosis and another with blastomycosis, for an overall sensitivity of 23 of 25 (92.0%). Specificity was 98.2% in both assays in controls with other pulmonary infections. These findings support the diagnostic utility of the second-generation assay in patients with pulmonary histoplasmosis and blastomycosis.

Bronchoscopy in the Diagnosis of Pulmonary Histoplasmosis

Although histoplasmosis is the most common fungal infection of the lungs in the United States, there are no reports evaluating the efficacy of fiberoptic bronchoscopy in the diagnosis of this disease. We reviewed all cases of histoplasmosis diagnosed at our institution from 1972 to 1987. Of 469 patients, 71 underwent fiberoptic bronchoscopy and had culture/histologic proof of histoplasmosis established by fiberoptic bronchoscopy or other means. A diagnosis of pulmonary histoplasmosis could be made without thoracotomy in only 27. Among those not requiring thoracotomy, diagnosis of pulmonary histoplasmosis was confirmed by fiberoptic bronchoscopy and cultures of sputum, gastric washings, blood, bone marrow, and urine. In this subgroup, fiberoptic bronchoscopy was the only positive diagnostic method in eight of 27 patients. We conclude that fiberoptic bronchoscopy is a useful adjunct to other noninvasive measures yielding diagnostic material in most cases, except for solitary pulmonary nodule where it is rarely helpful.

Propylene Glycol Aerosolization and the Diagnosis of Pulmonary Histoplasmosis

It has been established that propylene glycol aerosolization to induce sputum from patients with unproductive cough has diagnostic value in cytologic examinations and for culture of acid-fast bacilli. In contrast, propylene glycol in concentrations found in sputum induced by aerosolization appears to interfere with yeast-to-mycelial phase dimorphism of Histoplasma capsulatum. Usual diagnostic cultural procedures rely upon conversion of the tissue phase (yeast phase) to the saprophytic phase (mycelial phase). It would appear, therefore, that induction of sputum for cultural procedures in the diagnosis of pulmonary histoplasmosis by the use of propylene glycol aerosol may significantly handicap laboratory confirmation.

A CASE OF CAVITARY DISEASE, LUNG, ETIOLOGY UNDETERMINED, COMPLICATED BY ASPERGILLUS

Chronic pulmonary histoplasmosis and aspergillosis, chronic granulomatous type are symptomatically similar.Definitive diagnosis of pulmonary histoplasmosis should be made by the demonstration of the etiologic agent but in regard to aspergillosis, even if there is the presence of the Aspergillus in the sputum, definitive diagnosis is not easily made because the organisms are frequent laboratory contaminants.X-rays, serologic tests and skin tests are also important to aid the diagnosis of such diseases.The treatment of both diseases appears to be ameable to definitive surgical therapy.