Cases Of Blastomycosis Research Articles

Blastomycosis in Africa: Clinical Features, Diagnosis, and Treatment

Four cases of blastomycosis seen in two acute care hospitals in Harare, Zimbabwe, are described. All patients had symptoms of at least 2 months' duration before presentation, and all had radiographic evidence of pulmonary consolidation. Three patients had confirmed bone involvement, and two had chronic discharging sinuses. The features of blastomycosis in Africa are reviewed, and problems of diagnosis and treatment are discussed. It is concluded that blastomycosis in Africa may often be misdiagnosed as tuberculosis or pyogenic infection in the absence of adequate facilities for mycologic investigation.

Two Cases of Blastomycosis from a Common Source: Use of DNA Restriction Analysis to Identify Strains

Two friends, one with AIDS, developed severe pulmonary blastomycosis but differed markedly in clinical course. The human immunodeficiency virus-negative patient responded completely to ketoconazole; the patient with AIDS died of progressive disseminated infection despite treatment with fluconazole and amphotericin B. Epidemiologic investigation suggested a common source of infection, but serologic evaluation and environmental cultures were unrevealing. EcoRI digestion of the Blastomyces dermatitidis isolates showed identical restriction fragment patterns that differed from patterns obtained from other clinical isolates. Analysis using a Histoplasma capsulatum ribosomal DNA probe that cross-hybridizes with B. dermatitidis showed that the isolates from the two patients were identical and different from others. Thus, the patients were probably infected with the same strain, possibly from a common source. These data indicate the critical role of cellular immunity in patients with blastomycosis, show that there are multiple genotypes of B. dermatitidis, and suggest that DNA restriction analysis is a useful epidemiologic tool.

Hyperendemic urban blastomycosis.

Within the United States, blastomycosis is primarily endemic in the Mississippi and Ohio River valleys, but reliable figures as to its prevalence and incidence are scarce. A review of pathology department files and medical records from three hospitals in Rockford, Illinois, revealed 32 documented cases of blastomycosis in an eight and one-half year period beginning in March 1981. Twenty-three of these cases were urban since they occurred within the Rockford census tract boundaries--an incidence more than 3.5 times greater than expected in an endemic area. Addresses of patients in 18 of the 23 cases were concentrated at the northeast and southwest ends of the city. Implications are discussed.

Roentgenologic Features of Pulmonary Blastomycosis

In 35 cases of pulmonary blastomycosis, the roentgenologic features were as follows: consolidation 26%, mass 31%, intermediate-sized nodules 6%, miliary pattern 11%, solitary cavity 9%, fibrotic and cavitary changes 6%, interstitial pattern 6%, diffuse alveolar involvement 3%, and mixed alveolar and interstitial infiltrate 3%. All symptomatic cases of consolidation were acute (symptoms for less than 1 month), and most were in young patients (mean age, 34 years). Consolidation constituted 58% of the acute cases in this series. Two of the nine cases of consolidation were asymptomatic epidemic cases detected by screening. A pulmonary mass was the most common initial manifestation in this series; it tended to occur in patients with chronic symptoms (more than 1 month). The mass was considered suggestive enough of bronchogenic carcinoma to necessitate resection in 55% of cases. The military form of pulmonary blastomycosis occurred in older patients with disseminated disease. Fibrotic and cavitary disease was chronic in nature. The presence of intermediate-sized nodules elsewhere in the lung proved to be a helpful diagnostic finding in several patients with consolidation, mass, or cavitary disease. Hilar adenopathy, postinfectious calcification, chest wall invasion, and pleural effusion occurred infrequently or not at all in this series.

South American Blastomycosis: Ophthalmic and Oculomotor Nerve Lesions

A case of South American blastomycosis began with an oropharyngeal lesion which was followed by a granulomatous uveitis. The patient was treated with Amphotericin B and showed a clinical regression. Four months later, he developed a right 3rd cranial nerve palsy, aggravating the clinical aspect with a severe generalized involvement of the central nervous system and death. Necropsy showed blastomycotic meningoencephalitis.

Giant Forms of Blastomyces dermatitidis in the Pulmonary Lesions of Blastomycosis: Potential Confusion with Coccidioides immitis

Typical yeast-phase cells of Blastomyces dermatitidis have a characteristic appearance in tissue sections. Fungal morphologic variation occurs infrequently in the lesions of blastomycosis, yet it can complicate the differential diagnosis, particularly if fresh tissue is not available for microbiologic culture. The authors report a case of pulmonary blastomycosis, confirmed by culture and direct immunofluorescence, in which some of the yeast-like cells were abnormally large. These giant yeast-like cells exceeded the size range accepted for the tissue forms of B. dermatitidis; therefore, coccidioidomycosis was considered initially in the differential diagnosis. Otherwise characteristic morphologic features of these cells, in particular multinucleation and the production of broad-based blastoconidia, helped resolve the differential diagnosis. The diagnosis can be confirmed by direct immunofluorescence or microbiologic culture.

South american blastomycosis of the maxilla: Report of a case

An unusual case of localized South American blastomycosis of the maxilla, occurring in the United States, is reported. Clinical presentation, diagnosis, treatment, and reconstruction are reviewed.

A New Enzyme Immunoassay Specific for Blastomycosis

A highly specific enzyme immunoassay (EIA) was developed for the serodiagnosis of blastomycosis. Among the earliest sera available from eight active cases of blastomycosis, seven were reactive by EIA, three by immunodiffusion, and three by complement fixation. The one seronegative case was associated with acquired immunodeficiency syndrome (AIDS). No cross-reaction was observed with sera from 12 patients with active histoplasmosis or from five patients with active coccidioidomycosis or from 23 healthy persons. In contrast, all patients' sera cross-reacted in conventional EIAs based on commercial immunodiffusion antigens. The blastomycosis-specific EIA seems to offer sensitivity without compromising specificity. Rheumatoid factors, which could cause false-positive reactions, were controlled for.

Blastomycosis in Africa

The known African cases of blastomycosis to 1987 are presented, including thirteen previously undescribed cases. This brings to 81 the total number of cases known to have occurred in Africa. The question of whether the disease in Africa is the same in all respects as that in North America is addressed; the age and sex distributions of patients are similar. Minor differences in the clinical features relate particularly to the type of skin lesion, the more frequent bone involvement and the less frequent central nervous system involvement in the African patient. Little is known about the epidemiology of blastomycosis in Africa; one noteworthy feature is the apparent absence of the disease in dogs. Isolates of Blastomyces dermatitidis from the two continents, although closely related, differ in some respects.

Treatment of Histoplasmosis and Blastomycosis

Prior to the development of ketoconazole, the treatment of systemic histoplasmosis and blastomycosis was limited to AMB. The convenience of oral dosing, combined with avoidance of the significant toxicities associated with AMB, make ketoconazole an attractive alternative for the treatment of selected forms of histoplasmosis and blastomycosis. Although high-dose (800 mg/day) ketoconazole is generally more effective than low-dose (400 mg/day), therapy should be initiated at the lower dose due to significantly more adverse effects at higher doses; the daily dose should be increased in patients with progressive disease. Caution should be exercised when ketoconazole is used to treat patients with GU tract disease and in patients with naturally occurring or pharmacologically induced achlorhydria. Thus, AMB remains the drug of choice for difficult to treat cases of histoplasmosis and blastomycosis; however, recent studies have established ketoconazole as the drug of choice in immunocompetent patients with non-life-threatening, non-meningeal H capsulatum and B dermatitidis disease.

Epidemiologic and immunologic evaluation of an outbreak of canine blastomycosis.

Five confirmed cases of canine blastomycosis occurred over the 10-month period of December 1983 to September 1984 in a south-eastern Wisconsin colony of 30 dogs maintained for sled competition. Contrary to other published reports of canine blastomycosis, the sex-specific attack rates were higher among females than males. Four of the five confirmed cases and all four deaths occurred among young female dogs. Differences in the age distribution and/or the micro-environment of the females may have contributed at least in part to the difference in sex-specific attack rates. The serologic response and leukocyte function of the clinically affected and apparently healthy dogs from this colony were assessed during the outbreak. A survey of the adult dogs in the colony suggested that the mitogen-induced lymphocyte blastogenesis of dogs with clinical signs of blastomycosis was suppressed compared with that of dogs that remained free of clinical signs. In contrast to previous reports that autologous sera from dogs and humans with clinical blastomycosis inhibited mitogen-induced lymphocyte blastogenesis, lymphocyte responsiveness was similar to, or greater in the presence of autologous canine serum than it was in the presence of fetal bovine serum.

Blastomycosis of the paranasal sinuses

Fungal infections of the paranasal sinuses are not very frequently seen. the authors describe an unusual case of blastomycosis with none of its usual modes of presentation.

Common-source outbreak of blastomycosis in hunters and their dogs.

Most cases of blastomycosis are sporadic, and few outbreaks have been reported. We report here an outbreak associated with raccoon hunting in Southampton County, Virginia. Four patients, ranging in age from 15 to 21 years, had onsets of illness during March 1984. All were white men, and each presented with fever, cough, and an infiltrate on chest radiograph. Diagnosis was established by culturing Blastomyces dermatitidis, by using standard techniques [1], from sputum or lung tissue from three of the four patients. The fourth patient had budding yeast cells consistent with B. dermatitidis visualized on microscopy of his sputum. Subsequently, serum specimens collected within one month of illness onset demonstrated CF antibodies to the A antigen of B. dermatitidis at a titer of ^ 1132 for two of four patients, A precipitin bands on blastomycin immunodiffusion (ID) testing for three of the four, and antibody titers of ^1:32 (range, 1:32-1:256) by the blastomycosis enzyme immunoassay (EIA) for all four specimens. All patients were successfully treated either with amphotericin B or ketoconazole or both, and none developed skin lesions. Each patient was acquainted with the others, all were avid raccoon hunters, and all went hunting together on a weekly basis during the raccoon hunting season that extends from October through February. Hunting was done locally, at night, in wooded, frequently swampy areas. The patients were usually accompanied by several trained hunting dogs (one Doberman pinscher and six Bluetick hounds) supplied by one patient's grandfather. Three of the dogs had onset of illness at approximately the same time as the hunters, and a fourth dog developed chronic disseminated blastomycosis approximately one month later. By using standard techniques [1], we cultured B. dermatitidis from pus or tissue from three of the dogs. Diagnosis for one of the four ill hunting dogs was based on clinical presentation alone (fever, shortness of breath, and weight loss). All four dogs died. There was no history of any hunter having been bitten by one of these dogs. To confirm the hypothesis that the hunters and their dogs acquired blastomycosis while hunting raccoons, we conducted a case-control study that included serological testing and obtaining information on hobbies and selected activities from the four patients and matched controls. We also conducted serological testing of all the dogs owned

Blastomycotic meningitis

A difficult and tragic case of central nervous system blastomycosis is presented as the basis for a review of the diagnostic criteria required to establish this diagnosis and to present a scheme for the diagnosis and therapy of chronic meningitis. The diagnosis in our case was complicated by preexisting inadequately treated tuberculosis; a prepontine mass; and a cervical intradural, extramedullary, circumferential mass. This exceptional case of chronic basilar meningitis with cervical myelopathy was caused by Blastomyces dermatitidis.

Isolation of Blastomyces dermatitidis in soil associated with a large outbreak of blastomycosis in Wisconsin.

In investigating six cases of blastomycosis in two school groups that had separately visited an environmental camp in northern Wisconsin in June 1984, we identified a large outbreak of the disease and isolated Blastomyces dermatitidis from soil at a beaver pond near the camp. Of 89 elementary-school children and 10 adults from the two groups, 48 (51 percent) of the 95 evaluated in September had blastomycosis. Of the cases, 26 (54 percent) were symptomatic (the median incubation period was 45 days; range, 21 to 106 days). No cases were identified in 10 groups that visited the camp two weeks before or after these two groups. A review of camp itineraries, a questionnaire survey, and environmental investigation showed that blastomycosis occurred in two of four groups that visited a beaver pond and in none of eight groups that did not. Walking on the beaver lodge (P = 0.008) and picking up items from its soil (P = 0.05) were associated with illness. Cultures of soil from the beaver lodge and decomposed wood near the beaver dam yielded B. dermatitidis. We conclude that B. dermatitidis in the soil can be a reservoir for human infection.

Diagnostic assessment of an enzyme-linked immunosorbent assay for human and canine blastomycosis

An enzyme-linked immunosorbent assay (ELISA) for blastomycosis was evaluated with 65 human sera from culturally or histologically proven cases of blastomycosis, 53 sera from humans with heterologous infections, and 115 sera from apparently normal people. The diagnostic value of the ELISA was compared with that of the widely used complement fixation (CF) and immunodiffusion (ID) tests. The assay gave a sensitivity of 80% and a specificity of 98% with a minimal positive titer of 1:16. In contrast, the CF and ID tests demonstrated sensitivities of only 40 and 65%, respectively, and both were 100% specific. It was concluded that ELISA titers of 1:32 or greater are indicative of active blastomycosis, whereas lower titers, which might represent cross-reactions, were considered suggestive of the disease. The specificity of low titers should be confirmed by immunodiffusion tests or from the study of serial serum specimens. Preliminary studies with sera from 6 dogs with active blastomycosis and 31 asymptomatic dogs revealed an ELISA sensitivity of 100% and a specificity of 97% when a 1:8 cutoff titer was used. Although a wide range of titers was obtained in both human and canine specimens, no single titer could be relied on to reflect the clinical form of disease. However, a four-fold-or-greater reduction in titer for serial specimens appeared indicative of a favorable prognosis.

Blastomycosis of the Esophagus Presenting With Gastrointestinal Bleeding

A patient with abdominal discomfort and hematemesis was found to have lower esophageal inflammation on endoscopy. A biopsy specimen from this area showed yeast forms of Blastomyces dermatitidis with a polymorphonuclear infiltrate and granuloma formation. Extensive evaluation showed no other bleeding site. Sputum samples obtained earlier also showed B. dermatitidis. Treatment with amphotericin B led to resolution of bleeding and eradication of the fungus on repeat biopsy and sputum samples. An esophageal stricture subsequently developed and required dilation. Seven previously reported cases of esophageal blastomycosis are reviewed.

The diagnostic value of fungal autofluorescence

Many pathogenic and saprophytic fungi fluoresce under ultraviolet light. Autofluorescence usually persists even if the specimen has undergone fixation, paraffin embedding, and staining with hematoxylin and eosin. Thus, fluorescence microscopy can help to identify organisms in histopathologic sections of ocular and periocular tissue. It may reveal microorganisms that do not stain with hematoxylin and eosin, and it does not alter or adversely affect microscopic sections. We describe a case of periocular cutaneous blastomycosis which was misdiagnosed clinically and histologically as squamous cell carcinoma. Fluorescence microscopy of the initial hematoxylin and eosin stained section revealed microorganisms that were not appreciated on the first skin biopsy.

A case of blastomycosis from Zaria, Nigeria

A case of blastomycosis from Zaria, Nigeria is reported. The clinical features were indistinguishable from those of tuberculosis which is very common in this environment. Lack of response to anti-tuberculosis therapy within eight weeks prompted the search for other organisms which resulted in the isolation of Blastomyces dermatitidis. Compatible histological evidence was obtained. Subsequent favourable response to amphotericin B was evident. Infection with this organism should be included in the differential diagnosis of pulmonary and pleural lesions simulating tuberculosis in West Africa.

Localized oral blastomycosis mimicking actinomycosis

A case of blastomycosis limited to the oral cavity is presented. The disease apparently originated in the mandible and eroded into the oral cavity. Secondary bacterial infection of the sinus tracts resulted in a clinical picture that mimicked cervicofacial actinomycosis. Appropriate microbiologic studies, including culture confirmation of the causative organism, were necessary to establish a definitive diagnosis.