Pharmacotherapy of disseminated histoplasmosis in patients with AIDS

Brain tumour? - Cerebellar histoplasmosis as a solitary mass lesion

A 50-year-old man who had been living in Thailand presented with a history of falls, deteriorating vision and weight loss over several months. He had been admitted to a hospital in Thailand where he was given a diagnosis of multiple sclerosis. Neurological examination revealed a mild ataxic gait and lateral nystagmus, but no other abnormalities. He tested positive for human immunodeficiency virus with a CD4 cell count of 16 cells/µL. Brain magnetic resonance imaging was suggestive of an intrinsic neoplasm and he underwent stereotactic brain biopsy which showed numerous yeast-like organisms. Panfungal polymerase chain reaction was positive for Histoplasma capsulatum. He received liposomal amphotericin B for six weeks, followed by itraconazole, and started antiretroviral therapy four weeks into treatment. He developed an immune reconstitution inflammatory syndrome which responded well to steroids. Six months after diagnosis, he has no neurological symptoms or signs and remains on itraconazole. Isolated bulky central nervous system histoplasmomas are exceedingly rare. A clinical suspicion of immunosuppression was key in making this diagnosis.

Opportunistic Invasive Mycoses in AIDS: Cryptococcosis, Histoplasmosis, Coccidiodomycosis, and Talaromycosis

PURPOSE OF REVIEW

The goal of this review is to provide an update on the epidemiology, diagnosis, and treatment of opportunistic fungal infections in patients with human immunodeficiency virus (HIV) infection including Cryptococcus spp., Histoplasma spp., Coccidioides spp., and Talaromyces marneffei, formerly Penicillium marneffei.

RECENT FINDINGS

In many settings, despite increasing roll out of antiretroviral therapy (ART), opportunistic invasive mycoses produce a substantial burden of disease. The prevalence of specific fungal pathogens depends on their endemicity. Viral suppression achieved by greater access to ART and increased the availability of point-of-care testing with rapid diagnostic tests (RDTs) aid to curtail the associated fungi morbidity. RDTs allow earlier screening to preemptively initiate treatment of opportunistic fungal pathogens. Identifying asymptomatic cryptococcal infection before starting ART is crucial in reducing the risk of the immune reconstitution inflammatory syndrome (IRIS). There is an urgent need to decrease the burden of opportunistic invasive fungal infections in individuals with HIV/AIDS through different interventions: (a) continue to expand the deployment of ART to the most affected populations to achieve viral suppression; (b) ensure early diagnosis of fungal pathogen with point-of-care testing;

Localized Histoplasma capsulatum osteomyelitis of the fibula in an immunocompetent teenage boy: a case report

Background

Infection of local bone with Histoplasma capsulatum is rare and difficult to diagnosis, and occurs particularly in immunocompetent subjects, who are more likely to be affected by a wide range of organisms.

Case presentation

An 11-year-old boy presented with localized histoplasmosis osteomyelitis in the left fibula without any evidence of abnormal immunological function or systemic disease. After surgical clearance of the lesion and homologous cancellous bone, the patient was treated orally with voriconazole for 6 months. The patient completely recovered with full function of his left leg during the 5-year follow-up.

Conclusions

Histoplasmosis osteomyelitis can occasionally occur in immunocompetent individuals and can be complete cured by surgical clearance of the lesion and antibiotic treatment.

Disseminated histoplasmosis: case report and brief review

Disseminated Histoplasmosis is a severe and often-fatal opportunistic infection when left untreated among patients with AIDS. Occurring in 3-5 percent of patients with AIDS living in the areas of endemicity, this infection should be suspected in patients with a CD4 cell count of <150 cells/microL presenting with non-specific clinical signs such as fever, weight loss, and lymphadenopathy. We report our experience to increase awareness of the clinical spectrum of disseminated histoplasmosis and its similarity to other infections and malignancies and update the reader on recommended therapeutic modalities.

Genitourinary fungal infections: a therapeutic conundrum

Fungi cause 8% of nosocomial infections. This is caused, in part, by the increasing pool of immunocompromised patients. Elderly, transplant and HIV patients, as well as premature infants, have become prime candidates for invasive fungal infections. The widespread use of broad spectrum antibiotics plays a role. Utilisation of appropriate antifungal treatment modalities requires an understanding of the pathogenesis of infection. This is a challenging problem as fungi can cause different clinical manifestations that depend on the type of fungal species and patient response to the infection. Although Candida spp. are the most frequent pathogen, other species such as Aspergillus and Cryptococcus have become major pathogens. Environmental fungi which include Blastomyces, Coccidioides and Histoplasma have become more aggressive in the vulnerable patient. The genitourinary system can be a source or target of disseminated fungal infection. Diagnosis depends on clinical awareness, utilisation of appropriate diagnostic modalities, imaging modalities and a thorough clinical assessment. The treatment of primary (Blastomyces, Coccidioides, Histoplasma) infection generally requires amphotericin B (AmpB). The opportunistic infections (Aspergillus, Cryptococcus and Candida) may respond to the triazoles although AmpB remains the 'gold standard'. Infections caused by Candida spp. represents the greatest challenge to the clinician. The presence of Candida spp. in the urine may indicate colonisation or infection. Untreated, Candida can remain as a 'saprophyte' or develop ascending infection, sepsis or death. The prophylactic use of fluconazole may in itself result in resistant infection, hence the 'conundrum'.

Fungal infections of the genitourinary system: manifestations, diagnosis, and treatment

There is an increasing pool of immunocompromised patients who are at an increased risk to fungi infections, which now cause 8% of nosocomial infections. Premature infants and elderly, transplant, and HIV patients are prime candidates for invasive fungal infections. The genitourinary system can be a source or target of disseminated fungal infection. Although candidal species are the most frequent pathogen, other species such as aspergila, cryptoccoccus have become major pathogens. "Environmental fungi," which include blastomyces, coccidioides and histoplasma, have become more aggressive in the vulnerable patient.

Case report. Successful therapy of disseminated histoplasmosis in AIDS with liposomal amphotericin B

A 36-year-old HIV-infected male patient presented with relapsing fever episodes to 39 degrees C, night sweats and weight loss. Computerized tomography of the abdomen showed enlarged multiple lymph nodes. After surgical resection of multiple lymph nodes, disseminated infection with Histoplasma capsulatum was diagnosed. Amphotericin B desoxycholate was initiated for 24 days. Fourteen days after therapy was discontinued, the patient suffered similar symptoms again. Subsequent treatment with liposomal amphotericin B led to rapid improvement within 3 days. Upon discharge, maintenance therapy with 600-mg itraconazole capsules was initiated and decreased to 400-mg 14-days later. Itraconazole therapy was continued until the patient died more than 2 years later because of complications of the underlying disease. At autopsy there were no signs of histoplasmosis.

Localised oral histoplasmosis lesions associated with HIV infection

Opportunistic fungal infections account for a significant amount of morbidity associated with HIV disease. We report here a case of localised oral histoplasmosis without evidence of disseminated disease in a patient who lacked stigmata of HIV disease at the time of initial presentation. The diagnosis is based on histology with special stains, complement fixing antibodies in serum, and culture of the organism from fresh tissues. Activation of subclinical disease following an infection in Uganda may explain the development of these exophytic oral lesions in this British resident.

Histoplasmosis: the otolaryngologist's perspective

Within the upper aerodigestive tract, histoplasmosis often mimics carcinoma, making prompt and accurate diagnosis imperative. More severe and potentially lethal infections with Histoplasma capsulatum are now being seen as the numbers of patients at the extremes of age, as well as those with compromised immune systems, increase. We reviewed the cases of 115 hospitalized patients with disseminated histoplasmosis. Of these, 9 patients were identified with otolaryngologic manifestations: 4 were infected with human immunodeficiency virus (HIV), 1 was diabetic, and 3 were renal transplant patients. Sites of involvement included the larynx (in 2 cases) and the oral cavity and oral pharynx (in 7 cases). Eight of the 9 patients had a positive biopsy result; the other, a positive culture. Treatment with amphotericin B was generally effective, while the use of newer azole anti-fungal agents were less effective. As the number of immunocompromised patients continues to increase in modern clinical practice, histoplasmosis will undoubtedly be encountered more frequently in the head and neck area.