Expanding the horizons of histoplasmosis: disseminated histoplasmosis in a renal transplant patient after a trip to Bangladesh

Clinical Characteristics and Outcomes of Endemic Mycoses After Solid Organ Transplantation: A Comprehensive Review

Background

Geographically endemic fungi can cause significant disease among solid organ transplant (SOT) recipients. We provide an update on the epidemiology, clinical presentation, and outcomes of 5 endemic mycoses in SOT recipients.

Methods

Multiple databases were reviewed from inception through May 2023 using key words for endemic fungi (eg, coccidioidomycosis or Coccidioides, histoplasmosis or Histoplasma, etc). We included adult SOT recipients and publications in English or with English translation.

Results

Among 16 cohort studies that reported on blastomycosis (n = 3), coccidioidomycosis (n = 5), histoplasmosis (n = 4), and various endemic mycoses (n = 4), the incidence rates varied, as follows: coccidioidomycosis, 1.2%-5.8%; blastomycosis, 0.14%-0.99%; and histoplasmosis, 0.4%-1.1%. There were 204 reports describing 268 unique cases of endemic mycoses, including 172 histoplasmosis, 31 blastomycosis, 34 coccidioidomycosis, 6 paracoccidioidomycosis, and 25 talaromycosis cases. The majority of patients were male (176 of 261 [67.4%]). Transplanted allografts were mostly kidney (192 of 268 [71.6%]), followed by liver (n = 39 [14.6%]), heart (n = 18 [6.7%]), lung (n = 13 [4.9%]), and combined kidney-liver and kidney-pancreas (n = 6 [2.7%]). In all 5 endemic mycoses, most patients presented with fever (162 of 232 [69.8%]) and disseminated disease (179 of 268 [66.8%]). Cytopenias were frequently reported for histoplasmosis (71 of 91 [78.0%]), coccidioidomycosis (8 of 11 [72.7%]) and talaromycosis (7 of 8 [87.5%]). Graft loss was reported in 12 of 136 patients (8.8%). Death from all-causes was reported in 71 of 267 (26.6%); half of the deaths (n = 34 [50%]) were related to the underlying mycoses.

Conclusions

Endemic mycoses commonly present with fever, cytopenias and disseminated disease in SOT recipients. There is a relatively high all-cause mortality rate, including many deaths that were attributed to endemic mycoses.

Cutaneous manifestations leading to a diagnosis of a case of severe disseminated histoplasmosis in a human immunodeficiency virus-positive child

This 9-year-old boy who was human immunodeficiency virus positive since birth presented with raised skin lesions, breathlessness, and cough and was treated as a case of disseminated tuberculosis. When no improvement was seen, he was referred to the dermatologist whose examination revealed papulonodular lesions with crusting over the face and extremities. Based on clinical suspicion of histoplasmosis, investigations done revealed a CD4 count of 3 cells/μL and histopathological features of histoplasmosis along with the disseminated disease. Cutaneous manifestations thus led to an early diagnosis of the case and a good prognostic outcome.

Fungal pneumonia in kidney transplant recipients

Fungal pneumonia is a dreaded complication encountered after kidney transplantation, complicated by increased mortality and often associated with graft failure. Diagnosis can be challenging because the clinical presentation is non-specific and diagnostic tools have limited sensitivity and specificity in kidney transplant recipients and must be interpreted in the context of the clinical setting. Management is difficult due to the increased risk of dissemination and severity, multiple comorbidities, drug interactions and reduced immunosuppression which should be applied as an important adjunct to therapy. This review will focus on the main causes of fungal pneumonia in kidney transplant recipients including Pneumocystis, Aspergillus, Cryptococcus, mucormycetes and Histoplasma. Epidemiology, clinical presentation, laboratory and radiographic features, specific characteristics will be discussed with an update on diagnostic procedures and treatment.

A Case of Histoplasmosis Mimicking Primary Lung Cancer With Liver Metastasis

Histoplasmosis is usually self-limiting in healthy individuals but often fatal in immunocompromised patients. It can mimic primary lung malignancy and liver metastasis, causing a delay in appropriate therapy. We report a case of a 58-year-old male, with a 20 pack-year smoking habit, who presented with a three-week history of persistent fevers and productive cough with night sweats. Computed tomography (CT) scan of chest, abdomen and pelvis showed findings suggestive for primary lung malignancy associated with liver metastasis. Liver biopsy showed budding yeast. Bronchoalveolar lavage (BAL) fluid grew fungal organisms. Urine and serology were positive for histoplasmosis. Patient was pancytopenic, hence, we decided to evaluate further with a bone marrow biopsy which revealed underlying hairy cell leukemia. In the case of disseminated histoplasmosis, a high degree of suspicion towards any immunosuppressive condition should be entertained and any signs should be promptly investigated.

Metagenomic next-generation sequencing identified Histoplasma capsulatum in the lung and epiglottis of a Chinese patient: A case report

Histoplasmosis is an endemic disease mainly occurring in North America and is rare in China. Confirmation of histoplasmosis should be based on a compatible clinical scenario and a positive culture or histopathology. However, there are still many cases that are misdiagnosed or missed, especially in individuals from non-endemic areas. In recent years, metagenomic next-generation sequencing (mNGS) has led to the accurate and timely diagnosis of some rare and complicated infectious diseases. We describe the case of a 27-year-old Chinese man who had chronic progressive pulmonary lesions without any symptoms for more than 1year, until the lesions reached the epiglottis and led to progressive pharyngeal pain. There were no positive results from bronchoalveolar lavage fluid (BALF) and epiglottis tissue cultures, or from epiglottis and lung pathological examinations, but mNGS was able to identify Histoplasma capsulatum in the epiglottis tissues and BALF as the cause of the lesions. The patient was treated successfully with itraconazole.

Histoplasmosis: An Emerging or Neglected Disease in Bangladesh? A Systematic Review

Histoplasmosis is uncommon in many parts of the world, including Bangladesh, where, in recent years, cases are increasingly reported. We sought to describe the sociodemographic characteristics, clinical presentation, investigations, treatment, and outcome of histoplasmosis in Bangladesh. We conducted a retrospective data review of published literature from 1962 to 2017, containing information on histoplasmosis in and/or from Bangladesh. Unpublished, well-documented histoplasmosis cases were also included. A total of 26 male patients aged 8–75 years, with a diagnosis of histoplasmosis were included; nine were farmers, seven had diabetes, one was a renal transplant recipient, and four had HIV/AIDS. Fever (n = 20), weight loss (n = 17), anemia (n = 15), lymphadenopathy (n = 9), and hepatosplenomegaly (n = 7) were common. Eleven patients had bilateral adrenal enlargement. Diagnosis was confirmed by histo/cytopathology from skin (n = 1), oropharyngeal ulcers (n = 8), lymph nodes (n = 3), adrenal glands (n = 11), paravertebral soft tissue (n = 2), and bone marrow (n = 4). Cultures of representative samples and antibodies were detected in three and two cases, respectively. Twenty-two patients had disseminated histoplasmosis and four patients had localized oropharyngeal disease. Nine patients were prescribed anti-tuberculosis drugs empirically before establishing the diagnosis of histoplasmosis. Treatment consisted of amphotericin B and itraconazole. Six patients died in hospital, 14 patients recovered with relapse in two cases, and the outcome of the other patients could not be ascertained. Histoplasmosis is thought to be endemic in Bangladesh, but few cases are reported to date, which may be due to many asymptomatic, undiagnosed, misdiagnosed, or under-reported cases. Histoplasmosis should be considered as a differential in appropriate clinical scenarios.

Endemic fungal infections in solid organ transplant recipients-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention and management of blastomycosis, histoplasmosis, and coccidioidomycosis in the pre- and post-transplant period. Though each of these endemic fungal infections has unique epidemiology and clinical manifestations, they all share a predilection for primary pulmonary infection and may cause disseminated infection, particularly in immunocompromised hosts. Culture remains the gold standard for definitive diagnosis, but more rapid diagnosis may be achieved with direct visualization of organisms from clinical specimens and antigen-based enzyme immunoassay assays. Serology is of limited utility in transplant recipients. The mainstay of treatment for severe infections remains liposomal amphotericin followed by a step-down azole therapy. Cases of mild to moderate severity with no CNS involvement may be treated with azole therapy alone. The newer generation azoles provide additional treatment options, but supported currently with limited clinical efficacy data. Azole therapy in transplant recipients presents a unique challenge owing to the drug-drug interactions with immunosuppressant agents. Therapeutic drug monitoring of azole levels is an essential component of effective and safe therapy. Infection prevention centers around minimizing epidemiological exposures, early clinical recognition, and azole prophylaxis in selected individuals.

Travel medicine, transplant tourism, and the solid organ transplant recipient-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review recommendations for prevention and management of travel-related infection in solid organ transplant (SOT) recipients as well as risks associated with transplant tourism. Counseling regarding travel post-transplant should be included during the pre-transplant evaluation, and all SOT recipients should be seen by a travel medicine specialist prior to traveling to destinations with higher rates of infection. Patients should be advised on vaccine-preventable illnesses as well as any need for prophylaxis (ie, malaria) based on their individual travel itineraries. Information with regards to specific recommendations for vaccines and prophylactic medications, along with drug-drug interactions, is summarized. Counseling should be provided for modifiable risks and exposures (ie, food and water safety, and insect bite prevention) as well as non-infectious travel topics. These guidelines also briefly address risks associated with transplant tourism and specific infections to consider if patients seek care for transplants done in foreign countries.

Histoplasmosis in transplant recipients

Histoplasma capsulatum is a dimorphic fungus that most often causes asymptomatic infection in the immunocompetent population. In immunocompromised patients, including solid organ transplant (SOT) and hematopoietic cell transplant (HCT) recipients, however, it is likely to cause severe life-threatening infection. Post-transplant histoplasmosis (PTH) in SOT is uncommon with an incidence of ≤1% and is even rarer in HCT patients. The majority of PTH in SOT is diagnosed in the first 2 years following transplantation. Histoplasmosis may result from endogenous reactivation of latent infection, de novo post-transplant acquisition, and donor-derived infection. Disseminated infection is common. Fever is the most common symptom and clinical features are often nonspecific, but patients with disseminated infection may present with a septic picture. Other features, including pancytopenia and hepatosplenomegaly, may not be prominent early in the course of illness. Contemporary histoplasma antigen assays are the most sensitive tests but cross-reactivity with antigens of other fungi, including with Aspergillus galactomannan, is not uncommon. Treatment should be continued for at least a year. Histoplasma antigen levels have prognostic value and can be used to monitor the response to therapy. The attributable mortality is approximately 10%. Routine screening of donors and recipients is not currently recommended.

Infectious Complications of Transplantation

Post-transplant infection is a common cause of graft deterioration, morbidity and mortality. It is also responsible for delayed discharge, multiple, often prolonged admissions and thus a significant clinical challenge. Infections can be donor derived, pre-existing in the recipient, nosocomial and opportunistic. For each of these categories, it is often possible to significantly reduce hazard and thus the adverse consequences by first identifying patients at high risk. As always, clinical vigilance is vital, but equally important is the establishment of robust clinical systems for prevention, screening and rapid treatment.

Disseminated histoplasmosis with oral and cutaneous manifestations

Histoplasmosis is a systemic mycotic infection caused by the dimorphic fungus, Histoplasma capsulatum. Systemic histoplasmosis has emerged as an important opportunistic infection in human immunodeficiency virus (HIV) patients and those in endemic areas. Reported cases of histoplasmosis have been low in India with less than 50 cases being reported. We are reporting a case of disseminated histoplasmosis with oral and cutaneous involvement in an HIV seronegative patient.

Travel and transplantation: travel-related diseases in transplant recipients

PURPOSE OF REVIEW

Travel-related diseases may be seen in transplant recipients after travel, after transplant tourism, and via transmission from blood and organ donors, augmented by recent increases in travel, migration, and globalization. Such infections include tuberculosis, Plasmodium (malaria), Babesia, Trypanosoma cruzi (Chagas disease), Strongyloides, Coccidioides, Histoplasma, Leishmania, Brucella, HTLV, dengue, among numerous others.

RECENT FINDINGS

Review of cohorts of transplant recipients show that they tend to have minimal or suboptimal preparation prior to travel, with limited pretravel vaccination, medications, and education, which poses a greatly increased risk of travel-related infections and complications. The epidemiology of such travel-related infections in transplant recipients, along with methods for prevention, including vaccines, chemoprophylaxis, and education may help SOT recipients avoid travel-related infections, and are discussed in this review.

SUMMARY

Optimizing the understanding of the risk of tropical, geographically restricted, and other unusual or unexpected, travel-related infections will enhance the safety of vulnerable transplant recipients from potentially life-threatening infections.