Lobomycosis: epidemiology, clinical presentation, and management options

Human Lobomycosis Caused by Paracoccidioides (Lacazia) loboi, Panama, 2022

We report a patient from Panama who had lobomycosis caused by Paracoccidioides (Lacazia) loboi. We used combined clinical-epidemiologic and phylogenetic data, including a new gene sequence dataset on this fungus in Panama, for analysis. Findings contribute useful insights to limited knowledge of this fungal infection in the Mesoamerican Biologic Corridor.

Fungal Density in Lobomycosis in French Guiana: A Proposal for a New Clinico-Histological and Therapeutic Classification

BACKGROUND

Lobomycosis is a rare cutaneous tropical neglected disease caused by the fungal agent Lacazia loboi, recently renamed Paracoccidioides lobogeorgii. Our objectives were to present all cases of lobomycosis diagnosed in French Guiana, to offer a precise description of their histopathological features and to propose a new clinico-histological prognostic classification.

METHODS

All cases of lobomycosis diagnosed in French Guiana between 1959 and 2022 were included. We looked for associations between the occurrence of relapses and the clinic-histological form.

RESULTS

31 patients diagnosed with lobomycosis were included. An epidemiological shift was observed in the 2000s as Brazilian patients became the most important ethnic group. Gold mining, forestry and fishing/sailing were reported as professional exposures. New histological features, such as inflammatory "rosettes" formations were described. We describe two clinic-histological patterns: a major form (high fungal density and/or multifocal lesions) and a minor form (low fungal density, unifocal lesions, association with fewer relapses).

CONCLUSIONS

The changing epidemiology of lobomycosis in French Guiana is characterized by a shift towards Brazilian patients, mostly gold miners. Minor forms should be treated with surgery, major forms with a combination of surgery followed by nultiple drug therapy (MDT) or posaconazole.

Lobomycosis in a Post-Covid 19 Patient: A Case Report and Review of Literature

AIM

To document a case of lobomycosis and to discuss its epidemiology & diagnosis.

CASE REPORT

A 53-year-old male presented with a history of nasal congestion, nasal discharge, and epistaxis following Covid 19 infection. On physical examination, there was necrotic slough in the nasal vestibule near the inferior turbinate. Scrapings and punch biopsy were taken from the lesion. Hematoxylin-eosin-stained sections showed necrotic and mucoid areas with mixed inflammatory cell infiltration and numerous budding yeasts 3- 7μm diameter in singles, and small clusters with single narrow based budding as well as multiple budding including sequential budding forming "chains of yeasts". A diagnosis of Lobomycosis was made. Yeasts of lobomycosis are often confused with other yeasts such as P. brasiliensis, Candida spp., B. dermatitidis, and Cryptococci, but characteristic 'sequential budding' with a 'chain of yeasts" aid in the final diagnosis. Demonstration of yeasts with characteristic chains either in tissue sections or in potassium hydroxide (KOH) preparation of scraped material, exudate, or exfoliative cytology is the mainstay in the diagnosis as the organisms are uncultivable in vitro in culture medium.

Lobomycosis Epidemiology and Management: The Quest for a Cure for the Most Neglected of Neglected Tropical Diseases

Lobomycosis is a chronic disease caused by Lacazia loboi, which is endemic to the Amazon rainforest, where it affects forest dwellers in Brazil. There is no disease control program and no official therapeutic protocol. This situation contributes to an unknown disease prevalence and unmet needs of people disabled by this disease who seek access to treatment. This review provides an update on the subject with an emphasis on therapeutic advances in humans. All relevant studies that addressed epidemiology, diagnosis, or therapeutics of lobomycosis were considered. Seventy-one articles published between 1931 and 2021 were included for a narrative literature review on the epidemiology and quest for a cure. An effective therapy for lobomycosis has been found following decades of research led by the State Dermatology Program of Acre in the Amazon rainforest, where the largest number of cases occur. This discovery opened new avenues for future studies. The main recommendations here, addressed to the Brazilian Ministry of Health, are for lobomycosis to become a reportable disease to ensure that disease prevalence is measured, and that it be prioritized such that affected individuals may access treatment free-of-charge.

Thinking Beyond Bacterial Infection: A Case of Cutaneous Blastomycosis

Blastomycosis is caused by Blastomyces dermatitidis, a dimorphic fungus that primarily causes pulmonary disease. Cutaneous blastomycosis is infrequent and tends to be misdiagnosed given its similar presentation to other cutaneous fungal infections and malignancies. A 51-year-old woman presented with a two-month history of disfiguring nasal lesions. The patient had a past medical history of cervical cancer which was currently in remission. Social history was significant for frequent travel throughout the United States as a truck driver, including the Midwest. The patient had a non-purulent verrucous plaque on her right nare, which was painless and mildly pruritic. Superficial cultures grew Enterococcus faecalis, prompting treatment with oral cephalexin and topical mupirocin. Given no relief, the patient was started on clindamycin followed by Augmentin. Both treatments were unsuccessful. 

The lesion was then biopsied and fungal cultures were sent. The biopsy showed broad-based budding yeast surrounded by pseudoepitheliomatous hyperplasia, and cultures grew Blastomyces dermatitidis. The patient was initiated on 200 mg itraconazole thrice daily for the first three days, followed by 200 mg itraconazole twice daily for the next 12 months. She showed notable improvement within a month.

This patient was initially misdiagnosed with bacterial infection due to superficial cultures, which were likely a contaminant. It was only after a biopsy that the patient was accurately diagnosed. Besides bacterial infection, cutaneous blastomycosis is often confused with coccidioidomycosis, mycobacterial infection, or squamous cell carcinoma. In patients such as ours who are presenting with persistent facial lesions in the setting of frequent travel history, fungal etiologies should be high on the differential. A biopsy and fungal cultures should be sent at the outset for accurate diagnosis and treatment.

Natural-Product-Based Solutions for Tropical Infectious Diseases

About half of the world's population and 80% of the world's biodiversity can be found in the tropics. Many diseases are specific to the tropics, with at least 41 diseases caused by endemic bacteria, viruses, parasites, and fungi. Such diseases are of increasing concern, as the geographic range of tropical diseases is expanding due to climate change, urbanization, change in agricultural practices, deforestation, and loss of biodiversity. While traditional medicines have been used for centuries in the treatment of tropical diseases, the active natural compounds within these medicines remain largely unknown. In this review, we describe infectious diseases specific to the tropics, including their causative pathogens, modes of transmission, recent major outbreaks, and geographic locations. We further review current treatments for these tropical diseases, carefully consider the biodiscovery potential of the tropical biome, and discuss a range of technologies being used for drug development from natural resources. We provide a list of natural products with antimicrobial activity, detailing the source organisms and their effectiveness as treatment. We discuss how technological advancements, such as next-generation sequencing, are driving high-throughput natural product screening pipelines to identify compounds with therapeutic properties. This review demonstrates the impact natural products from the vast tropical biome have in the treatment of tropical infectious diseases and how high-throughput technical capacity will accelerate this discovery process.

A global view on fungal infections in humans and animals: infections caused by dimorphic fungi and dermatophytoses

Fungal infections are still underappreciated and their prevalence is underestimated, which renders them a serious public health problem. Realistic discussions about their distribution, symptoms, and control can improve management and diagnosis and contribute to refinement of preventive actions using currently available tools. This article represents an overview of dermatophytes and endemic fungi that cause infections in humans and animals. In addition, the impact of climate change on the fungal spread is discussed. The endemic fungal infections characterized in this article include coccidioidomycosis, histoplasmosis, blastomycosis, lobomycosis, emergomycosis and sporotrichosis. Moreover the geographic distribution of these fungi, which are known to be climate sensitive and/or limited to endemic tropical and subtropical areas, is highlighted. In turn, dermatophytes cause superficial fungal infections of skin, hairs and nails, which are the most prevalent mycoses worldwide with a high economic burden. Therefore, the possibility of causing zoonoses and reverse zoonoses by dermatophytes is highly important. In conclusion, the article illustrates the current issues of the epidemiology and distribution of fungal diseases, emphasizing the lack of public programmes for prevention and control of these types of infection.

Subcutaneous Mycoses in Travelers

Purpose of Review

The increase in international travel in recent decades has contributed to the risk of acquiring diseases considered endemic to a region or country and the change in the epidemiology of these diseases. Endemic mycoses that may be acquired by travelers in the short or long term are endemic subcutaneous mycoses such as sporotrichosis and lobomycosis, while endemic systemic mycoses are a group of serious diseases including histoplasmosis and coccidioidomycosis. Herein, we review the current knowledge and highlight the most important aspects of these fungal infections in travelers.

Recent Findings

The most relevant advances in the study of these mycoses involve the epidemiological distribution; human mycoses can be fatal and there are few antifungal drugs available, increasing drug resistance, and a risk of emerging fungal diseases associated with climate change, as well as the increasing virulence, and the diagnostic strategies that may be limited in many countries.

Summary

Although endemic mycoses are relatively rare, they should be considered as potentially travel-related illnesses. A recent or late trip to an endemic country may guide the clinical suspicion, an early diagnosis, and the institution of effective therapy.

Multidrug Therapy for Leprosy Can Cure Patients with Lobomycosis in Acre State, Brazil: A Proof of Therapy Study

Lobomycosis, also referred to as lacaziosis, is an endemic cutaneous and subcutaneous fungal disease that mainly affects Amazonian forest dwellers in Brazil. There is no disease control program in place in Brazil, and antifungal therapy failures are common, and the therapy is inaccessible to most patients. We performed a randomized, unblinded clinical trial testing the cure rate of multiple drug therapy (MDT) for leprosy with surgical excision, with or without itraconazole. A control arm consisted of patients who did not adhere to either therapeutic regimens but continued to be followed up. Multiple drug therapy consisted of monthly supervised doses of 600 mg rifampicin, 300 mg clofazimine, and 100 mg dapsone, in addition to daily doses of 50 mg clofazimine and 100 mg dapsone. The patients in the MDT plus itraconazole arm also received itraconazole 100 mg twice daily. We followed up 54 patients from the MDT group and 26 patients from the MDT plus itraconazole group for an average of 4 years and 9 months. The 23 controls were followed up for 6 months on average. The following endpoints were observed: 1) unchanged (no apparent improvement), 2) improved (reduction in lesion size and/or pruritus), and 3) cured (complete remission of the lesions, no viable fungi, and no relapse for 2 years after the end of the drug treatment). The results indicated a significantly greater likelihood of cure associated with the use of multidrug therapy for leprosy with or without itraconazole when compared with the control group. The addition of itraconazole to MDT was not associated with improved outcomes, suggesting that MDT alone is effective.

Comparative effect of osmium tetroxide and ruthenium tetroxide on Lacazia loboi ultrastructure

Lobomycosis is a skin infection produced by the fungus Lacazia loboi, which mainly affects some indigenous and afro-descendant populations in Tropical America. We previously reported the comparative effect of osmium tetroxide (OsO₄ ) and ruthenium tetroxide (RuO₄ ) in the electron microscopy (EM) of other related microorganisms. The objective of this study is to compare the effect of postfixation with OsO₄ and RuO₄ in the ultrastructure of L. loboi yeasts. Skin biopsies on patients diagnosed with lobomycosis were fixed in glutaraldehyde at 3% and postfixed in the following solutions: (a) 1% OsO₄ , (b) 0.2% RuO₄ , and (c) OsO₄ at 1% followed by RuO₄ at 0.2%. They were then processed using the conventional method for EM. Unlike OsO_4, the treatment with RuO₄ revealed different shades of gray and electron dense bands in the cell wall and other cell components of L. loboi. The most notable finding was the presence of radial filamentous structures around the yeast, which made the image look like the sun. Postfixation with RuO₄ revealed ultrastructural details that had not been previously reported for L loboi. The combined use of OsO₄ and RuO₄ in EM of microorganisms with cell walls can be useful to evaluate the effect of microbicide substances.

Epidemiologic and Clinical Progression of Lobomycosis among Kaiabi Indians, Brazil, 1965-2019

Lobomycosis is a rare granulomatous skin disease with a high prevalence in the Amazon region. The Kaiabi Indians are an especially affected group. We studied the current epidemiologic and clinical progression of lobomycosis among the Kaiabi in Brazil, from initial case reports in 1965 through 2019. A total of 60 lobomycosis cases had been reported among the Kaiabi, and we identified 3 new cases in our review. Of 550 cases of lobomycosis ever reported worldwide, 11.5% were among the Kaiabi. We note a high incidence among female Kaiabi and a precocious onset of disease in this indigenous population. Male Kaiabi frequently are infected with the multicentric form and women more frequently exhibit the localized form. Ulcerated lesions are observed more often in the multicentric form. The prevalence among this indigenous group could be explained by genetic susceptibility and lifestyle, which exposes them to a particular agent in the habitats in which they live.

Lobomycosis in Soldiers, Colombia

Lobomycosis is a disease that is endemic to the Amazon rainforest and is caused by the still uncultured fungus Lacazia loboi. This disease occurs in loggers, farmers, miners, fishermen, and persons living near coastal rivers of this region. We report 6 soldiers in Colombia in whom lobomycosis developed after military service in the Amazon area. The patients had nodular and keloid-like lesions on the face, neck, trunk, and limbs. The duration of illness ranged from 2 years to 15 years. The initial diagnosis was leishmaniasis on the basis of clinical manifestations and direct smear results, but biopsies confirmed the final diagnosis of lobomycosis. Treatment with surgical excision, itraconazole and clofazimine was satisfactory. However, the follow-up time was short. Healthcare professionals responsible for the diagnosis and treatment of skin diseases need to be able to recognize the clinical signs of lobomycosis and differentiate them from those of cutaneous leishmaniasis.

Case Report: Molecular Confirmation of Lobomycosis in an Italian Traveler Acquired in the Amazon Region of Venezuela

Lobomycosis is a chronic skin mycosis endemic in Amazon regions characterized by chronic nodular or keloidal lesions caused by Lacazia loboi, an uncultivable fungus. Imported cases in nonendemic countries are rare and diagnosed after years. We describe a case of lobomycosis in a healthy 55-year-old Italian traveler who had acquired the infection during 5-day-honeymoon in the Amazon region of Venezuela in 1999. Several weeks after return, he recalled pruritus and papular skin lesions on the left lower limb, subsequently evolving to a plaque-like lesion. Blastomycosis and cryptococcosis were hypothesized based on microscopic morphology of yeast-like bodies found in three consecutive biopsies, although fungal cultures were always negative. In 2016, exfoliative cytology and a biopsy specimen examination showed round yeast-like organisms (6-12 μm), isolated or in a chain, connected by short tubular projections fulfilling the morphologic diagnostic criteria of Lacazia spp. The microscopic diagnosis was confirmed by molecular identification.

Subcutaneous mycoses in Peru: a systematic review and meta-analysis for the burden of disease

BACKGROUND

There is a worrying lack of epidemiological data on the geographical distribution and burden of subcutaneous mycoses in Peru, hindering the implementation of surveillance and control programs.

OBJECTIVES

This study aimed to estimate the disease burden of subcutaneous mycoses in Peru and identify which fungal species were commonly associated with these mycoses.

METHODS

We performed a meta-analysis after a systematic review of the published literature in PubMed, LILACS, and SciELO to estimate the burden of subcutaneous mycoses in 25 regions in Peru. The disease burden was determined in terms of prevalence (number of cases per 100,000 inhabitants) and the number of reported cases per year per region.

RESULTS

A total of 26 studies were eligible for inclusion. Results showed that sporotrichosis was the most common subcutaneous mycosis (99.7%), whereas lobomycosis, chromoblastomycosis, and subcutaneous phaeohyphomycosis were rare. Cases of eumycetoma and subcutaneous zygomycosis were not found. Of the 25 regions, the burden of sporotrichosis was estimated for four regions classified as endemic; in nine regions, only isolated cases were reported. The highest burden of sporotrichosis was in Apurimac (15 cases/100,000 inhabitants; 57 cases/year), followed by Cajamarca (3/100,000 inhabitants; 30/year), Cusco (0.5/100,000 inhabitants; 4/year), and La Libertad (0.2/100,000 inhabitants; 2/year). In two regions, the mycoses predominantly affected children.

CONCLUSIONS

Sporotrichosis is the most common subcutaneous mycosis in Peru, with a high disease burden in Apurimac. Chromoblastomycosis, lobomycosis, and subcutaneous phaeohyphomycosis are rare mycoses in Peru.

The cytotoxic T cells may contribute to the in situ immune response in Jorge Lobo's Disease human lesions

Jorge Lobo's Disease (JLD) is a cutaneous chronic granulomatous disease caused by the pathogenic fungus Lacazia loboi. It is characterized by a granulomatous reaction with multinucleated giant cells and high number of fungal cells. In order to contribute to the comprehension of immune mechanisms in JLD human lesions, we studied the cytotoxic immune response, focusing on TCD8+ and NK cells, and granzyme B. Forty skin biopsies of lower limbs were selected and an immunohistochemistry protocol was developed to detect CD8+ T cells, NK cells and Granzyme B. In order to compare the cellular populations, we also performed a protocol to visualize TCD4+ cells. Immunolabeled cells were quantified in nine randomized fields in the dermis. Lesions were characterized by inflammatory infiltrate of macrophages, lymphocytes, epithelioid and multinucleated giant cells with intense number of fungal forms. There was a prevalence of CD8 over CD4 cells, followed by NK cells. Our results suggest that in JLD the cytotoxic immune response could represent another important mechanism to control Lacazia loboi infection. We may suggest that, although CD4+ T cells are essential for host defense in JLD, CD8+ T cells could play a role in the elimination of the fungus.

Epidemiology of lobomycosis-like disease in bottlenose dolphins Tursiops spp. from South America and southern Africa

We report on the epidemiology of lobomycosis-like disease (LLD), a cutaneous disorder evoking lobomycosis, in 658 common bottlenose dolphins Tursiops truncatus from South America and 94 Indo-Pacific bottlenose dolphins T. aduncus from southern Africa. Photographs and stranding records of 387 inshore residents, 60 inshore non-residents and 305 specimens of undetermined origin (inshore and offshore) were examined for the presence of LLD lesions from 2004 to 2015. Seventeen residents, 3 non-residents and 1 inshore dolphin of unknown residence status were positive. LLD lesions appeared as single or multiple, light grey to whitish nodules and plaques that may ulcerate and increase in size over time. Among resident dolphins, prevalence varied significantly among 4 communities, being low in Posorja (2.35%, n = 85), Ecuador, and high in Salinas, Ecuador (16.7%, n = 18), and Laguna, Brazil (14.3%, n = 42). LLD prevalence increased in 36 T. truncatus from Laguna from 5.6% in 2007-2009 to 13.9% in 2013-2014, albeit not significantly. The disease has persisted for years in dolphins from Mayotte, Laguna, Salinas, the Sanquianga National Park and Bahía Málaga (Colombia) but vanished from the Tramandaí Estuary and the Mampituba River (Brazil). The geographical range of LLD has expanded in Brazil, South Africa and Ecuador, in areas that have been regularly surveyed for 10 to 35 yr. Two of the 21 LLD-affected dolphins were found dead with extensive lesions in southern Brazil, and 2 others disappeared, and presumably died, in Ecuador. These observations stress the need for targeted epidemiological, histological and molecular studies of LLD in dolphins, especially in the Southern Hemisphere.

Neglected fungal zoonoses: hidden threats to man and animals

Zoonotic fungi can be naturally transmitted between animals and humans, and in some cases cause significant public health problems. A number of mycoses associated with zoonotic transmission are among the group of the most common fungal diseases, worldwide. It is, however, notable that some fungal diseases with zoonotic potential have lacked adequate attention in international public health efforts, leading to insufficient attention on their preventive strategies. This review aims to highlight some mycoses whose zoonotic potential received less attention, including infections caused by Talaromyces (Penicillium) marneffei, Lacazia loboi, Emmonsia spp., Basidiobolus ranarum, Conidiobolus spp. and Paracoccidioides brasiliensis.