Sporotrichosis: hyperendemic by zoonotic transmission, with atypical presentations, hypersensitivity reactions and greater severity

Zoonotic Sporotrichosis outbreak: Emerging public health threat in the Amazon State, Brazil

BACKGROUND

Sporotrichosis is the most common subcutaneous mycosis caused by Sporothrix spp. Traditionally, it is transmitted through injuries involving plant debris. However, over the past few decades, there has been an epidemic increase in human cases resulting from contact with infected animals, particularly cats, in various regions of Brazil. In this report, we report a notable increase in both human and animal cases within the Brazilian Amazon state.

METHODOLOGY/PRINCIPAL FINDINGS

An ecological study was conducted by analyzing official records of human and animal sporotrichosis diagnosed in the state of Amazon from 2020 to 2023. Data including patient demographics, clinical manifestations, mycological examination results, and species identification through PCR confirmation were evaluated. During this period, a total of 950 human cases and 2,823 animal cases of sporotrichosis were reported at an exponential rate, since no human cases were registered in 2020. The spatial and temporal dispersion of human sporotrichosis followed that of animal cases, moving from downtown areas to the periphery. Contact with infected animals was reported in 77.7% of cases, with cats being the most commonly implicated (73.5%). Only 66.7% of individuals underwent mycological examination. Among the positive cultures for Sporothrix spp., 65.4% were identified as S. brasiliensis. All patients were treated with systemic antifungals.

CONCLUSIONS/SIGNIFICANCE

This study highlights a rising incidence of sporotrichosis among animals and humans in the Brazilian Amazon region over the past four years, with S. brasiliensis being the predominant agent. Collaborative efforts involving healthcare professionals, veterinarians, and public health authorities are crucial to implement effective control measures, educate populations at risk, and promote responsible guidance for pet guardians. These measures are essential to mitigate the burden of epidemic sporotrichosis in Brazil.

Sporothrix brasiliensis Causing Atypical Sporotrichosis in Brazil: A Systematic Review

Zoonotic sporotrichosis, a subcutaneous mycosis caused by Sporothrix brasiliensis, has become hyperendemic and a serious public health issue in Brazil and an emerging disease throughout the world. Typical sporotrichosis is defined as fixed or lymphocutaneous lesion development, however, reports of atypical presentations have been described in hyperendemic areas, which may result in a worse prognosis. Thus, considering an increase in atypical cases and in more severe extracutaneous cases and hospitalizations reported in Brazil, we aimed to perform a systematic review to search for hypersensitivity reactions (HRs) and extracutaneous presentations associated with zoonotic sporotrichosis. A systematic review was performed, following the PRISMA guidelines to search for atypical/extracutaneous cases (mucosal, osteoarthritis, HRs, pulmonary, meningeal) of zoonotic sporotrichosis. A total of 791 published cases over 26 years (1998-2023) in eleven Brazilian states were reviewed. Most cases corresponded to a HR (47%; n = 370), followed by mucosal (32%; n = 256), multifocal (8%; n = 60), osteoarthritis (7%; n = 59), meningeal (4%; n = 32), and pulmonary (2%; n = 14) infections. When available (n = 607), the outcome was death in 7% (n = 43) of cases. Here, we show a frequent and worrisome scenario of zoonotic sporotrichosis in Brazil, with a high and dispersed incidence of atypical/extracutaneous cases throughout the Brazilian territory. Therefore, educational measures are necessary to make health professionals and the overall population aware of this fungal pathogen in Brazil as well as in other countries in the Americas.

Overview of invasive fungal infections in children in South America - the threat of resistant Candida species and the role of climate change in the new geographic distribution of endemic systemic mycosis

PURPOSE OF REVIEW

Invasive fungal infection (IFI) in children is a growing problem with crescent morbidity and mortality, well recognized in developed countries, affecting mainly immunocompromised children, including neonates and children in intensive care units. The burden of IFI in South American children is less well comprehended. In addition, the current epidemiology of endemic systemic mycoses in children may have changed over time.

RECENT FINDINGS

Candida spp. infections are very prevalent in South America hospitalized children, especially in neonates, in a rate far superior compared to developed countries. C. auris, has already been responsible for outbreaks in neonates and children in Venezuela and Colombia. Sporotrichosis is well established as an urban zoonosis in impoverish families. Paracoccidioidomycosis and histoplasmosis are affecting new areas of Brazil, probably due to climate change, deforestation, and human migration.

SUMMARY

This review aims to unveil the real dimension of these infections in South American children. Hopefully, the awareness brought by this review will help healthcare professionals to recognize IFI more easily and it will provide support for getting more resources for IFI treatment and prevention.

Infections in the era of immunobiologicals

Immunobiologicals represent an innovative therapeutic option in dermatology. They are indicated in severe and refractory cases of different diseases when there is contraindication, intolerance, or failure of conventional systemic therapy and in cases with significant impairment of patient quality of life. The main immunobiologicals used in dermatology basically include inhibitors of tumor necrosis factor-alpha (anti-TNF), inhibitors of interleukin-12 and -23 (anti-IL12/23), inhibitors of interleukin-17 and its receptor (anti-IL17), inhibitors of interleukin-23 (anti-IL23), rituximab (anti-CD20 antibody), dupilumab (anti-IL4/IL13) and intravenous immunoglobulin. Their immunomodulatory action may be associated with an increase in the risk of infections in the short and long term, and each case must be assessed individually, according to the risk inherent to the drug, the patient general condition, and the need for precautions. This article will discuss the main risks of infection associated with the use of immunobiologicals, addressing the risk in immunocompetent and immunosuppressed patients, vaccination, fungal infections, tuberculosis, leprosy, and viral hepatitis, and how to manage the patient in the most diverse scenarios.

The present and future research agenda of sporotrichosis on the silver anniversary of zoonotic sporotrichosis in Rio de Janeiro, Brazil

Twenty-five years have passed since the initial observation of endemic zoonotic sporotrichosis in Rio de Janeiro, Brazil. Since then, this disease has spread throughout South America. Accompanying the emergence of this mycosis, some progress has been made, including the expansion of a research network in this field and higher visibility of sporotrichosis within government authorities and funding agencies. However, there are still some challenges to curbing the expansion of this disease in the coming years. These include the development of rapid and accurate diagnostic tests, new antifungal drugs, particularly for the treatment of extracutaneous manifestations of sporotrichosis, and more comprehensive care for cats with sporotrichosis. Including these actions in the sporotrichosis research agenda is required so as to change the development of this disease in the years to come.

Clinical characteristics, diagnosis, and treatment of central nervous system sporotrichosis: Systematic review and meta-analysis

BACKGROUND

The clinical features of central nervous system (CNS) sporotrichosis are derived from case reports and a limited series of cases. Our objective was to carry out a systematic review and meta-analysis of CNS sporotrichosis.

METHODS

We searched PubMed/MEDLINE, Embase, Scopus, and LILACS on 9 September 2023. Our inclusion criteria were documentation of Sporothrix and demonstrated CNS involvement. A metaproportion or metamean analysis was performed to estimate a summary proportion with 95% confidence intervals.

RESULTS

We included 52 cases of CNS sporotrichosis published from 1966 to 2023. Forty-six patients were male (88%, 95% CI: 77-95), and the mean age was 39 years (95% CI: 36-43). Close contact with cats was reported in 55% of cases (95% CI: 37-72). Thirty-two (61.5%) patients were from Brazil, 18 patients from the United State of America (34.6%). Only two Sporothrix species were reported: S. schenckii (26/41, 63%), and S. brasiliensis (15/41, 37%). The most common neurological symptom was headache. Meningitis was chronic in approximately 80% of cases. A significant majority of the patients were immunocompromised. HIV infection was the primary cause of immunosuppression (85%, 95% CI: 61-95). Overall mortality was 56% (22/39). The comparison of Kaplan-Meier survival curve showed a higher mortality with a statistically significant difference in immunosuppressed patients (p = .019).

CONCLUSION

CNS sporotrichosis represents a notable cause of chronic meningitis, especially in individuals living in the Americas with HIV infection and concurrent skin lesions.

A Randomized Clinical Trial Comparing Itraconazole and a Combination Therapy with Itraconazole and Potassium Iodide for the Treatment of Feline Sporotrichosis

Feline sporotrichosis is an endemic disease with high occurrence in Brazil. Itraconazole (ITZ) remains the drug of choice for treating this disease in cats, despite the increasing reports of therapeutic failure. A controlled, randomized clinical trial was performed on 166 naive cats with sporotrichosis to assess the effectiveness and safety of the combination therapy with ITZ and potassium iodide (KI) compared with ITZ monotherapy. Cats were randomly allocated into two treatment groups: G1-ITZ 100 mg/cat/day-and G2-ITZ 100 mg/cat/day + KI 2.5-20 mg/kg/day. Cats treated in G2 presented 77% more risk of reaching a clinical cure (a positive effect) than those treated in G1, even when controlled by negative predictors. The survival curves of the two treatment protocols indicate that a clinical cure was achieved faster in G2. An increase in the KI dose was necessary in 28 cats due to the persistence of clinical signs. Adverse reactions were equally frequent in both groups and manageable with a temporary drug suspension and/or a hepatoprotective therapy. The combination therapy was associated with a higher cure rate and a shorter treatment time, suggesting that ITZ+KI arises as a better option for treating feline sporotrichosis and should be considered the first-line treatment, especially in the presence of negative predictors.

Clinical factors associated with systemic sporotrichosis in Brazil

BACKGROUND

Systemic sporotrichosis occurs when organs, other than subcutaneous tissues and lymph nodes, are infected. Interestingly, systemic sporotrichosis in apparently immunocompetent individuals is increasing in Brazil, but data on clinical manifestations and risk factors are scarce. Most of the existing data on such condition relate to people living with HIV. We aimed to study the risk factors associated with systemic sporotrichosis among HIV-negative and HIV-positive patients.

METHODS

We performed a retrospective cross-sectional study with 80 patients from Brazil, diagnosed between 2014 and 2021. The association between disease classification, clinical presentation and risk factors were analysed by logistic regression.

RESULTS

Of the 80 patients, 29 (36.3%) presented with systemic sporotrichosis. All HIV-positive patients developed the systemic form, with increased mortality (p = .002). Alcohol ingestion (p = .009) and diabetes (p = .010) were associated with systemic disease. Alcohol ingestion seemed to favour pulmonary infection (p = .013) and, diabetes favoured osteoarticular (p = .009) and ocular involvement (p = .033). The occurrence of fever (p = .001) and weight loss (p = .006) were significantly associated with systemic sporotrichosis, while meningeal involvement (p = .001) increased mortality risk. Nine (11.3%) patients died from sporotrichosis. The presence of fungal structures in the mycological examination of the patients' lesions were associated with the systemic form (p = .017) and death (p = .002).

CONCLUSION

Our study points to the factors that drive systemic sporotrichosis other than HIV, such as alcohol ingestion and diabetes. Considering the high number of patients presenting severe sporotrichosis, the recognising these factors may contribute to timely diagnosis and proper treatment.

Sporothrix brasiliensis Infection Modulates Antimicrobial Peptides and Stress Management Gene Expression in the Invertebrate Biomodel Galleria mellonella

Sporothrix brasiliensis is the most pathogenic species, responsible for the Brazilian cat-transmitted sporotrichosis hyperendemic. In this scenario, an investigation of the pathogen-host interaction can provide relevant information for future treatment strategies. To this end, the invertebrate Galleria mellonella has proven to be a suitable alternative for evaluating the virulence of pathogenic fungi, since the insect immune system is similar to the mammalian innate immune response. The aim of this work was to investigate phenotypic and molecular aspects of the immune response of G. mellonella throughout the S. brasiliensis infection. Hemocyte density and the evolution of the fungal load were evaluated. In parallel, RT-qPCR expression analysis of genes encoding antimicrobial peptides (Gallerimycin and Galiomycin) and stress management genes (C7 Contig 15362 and C8 Contig 19101) was conducted. The fungal load and hemocyte densities increased simultaneously and proportionally to the deleterious morphological events and larvae mortality. Gallerimycin, C7 Contig 15362 and C8 Contig 19101 genes were positively regulated (p < 0.05) at distinct moments of S. brasiliensis infection, characterizing a time-dependent and alternately modulated profile. Galiomycin gene expression remained unchanged. Our results contribute to the future proposal of potential alternative pathways for treating and consequently controlling S. brasiliensis zoonosis, a major public health issue in Latin America.

Sporotrichosis co-infection with human immunodeficiency virus/acquired immunodeficiency syndrome

Sporotrichosis is a subcutaneous mycosis caused by a dimorphic fungus belonging to the genus Sporothrix. This fungal infection can affect both humans and domestic animals, and in recent years, an increase in the geographic spread and prevalence of sporotrichosis has been observed globally. This systematic review aimed to examine the clinical-epidemiological and therapeutic aspects related to sporotrichosis co-infection with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). An extensive electronic search was conducted on databases including PubMed, Web of Science, Lilacs, Medline, Embase, Scopus and SciELO was performed to identify clinical cases of people living with HIV (PLWH) with sporotrichosis published until May 2023. As a result, we found that most co-infected patients were male, representing 71.76% (94/131) of cases. The most prevalent age group was 41-50 years, with a mean age of 36.98 years. The countries with the highest number of cases were Brazil (75.57%, 99/131) and the United States (16.03%, 21/131). The most frequent clinical presentation was systemic dissemination, accounting for 69.47% (91/131) of the cases, followed by cutaneous dissemination with 13% (17/131). The mean CD4+ cell count was 154.07 cells/μL, and most patients used amphotericin B with at least one azole, which represented 47.33% (62/131) of cases, followed by azole monotherapy in 17.56% (23/131) of cases. As for the outcome, 51.15% (67/131) of the patients remained alive, and 37.4% (49/131) died. Therefore, it was concluded that sporotrichosis in PLWH is a disease with a high prevalence in Brazil and may be associated with systemic clinical manifestations requiring longer periods of systemic antifungal therapy.

First Cases of Feline Sporotrichosis Caused by Sporothrix brasiliensis in Paraguay

Sporothrix brasiliensis is an emerging fungal pathogen causing cat-transmitted sporotrichosis, an epi-zoonosis affecting humans, cats and dogs in Brazil and now spreading to neighboring South American countries. Here, we report the first two autochthonous cases of cat-transmitted sporotrichosis in Paraguay. The first case was a four-year-old male cat showing several ulcerative lesions, nasal deformity and respiratory symptoms. The second case was a one-year-old male cat showing a single ulcerated lesion, respiratory symptoms and nasal deformity. Both cases were admitted to a veterinary clinic in Ciudad del Este, Paraguay. Isolates were recovered from swabs of the two cases. Using molecular methods, the isolates were identified as S. brasiliensis.

Rising Incidence of Sporothrix brasiliensis Infections, Curitiba, Brazil, 2011-2022

Zoonotic outbreaks of sporotrichosis are increasing in Brazil. We examined and described the emergence of cat-transmitted sporotrichosis (CTS) caused by the fungal pathogen Sporothrix brasiliensis. We calculated incidence and mapped geographic distribution of cases in Curitiba, Brazil, by reviewing medical records from 216 sporotrichosis cases diagnosed during 2011-May 2022. Proven sporotrichosis was established in 84 (39%) patients and probable sporotrichosis in 132 (61%). Incidence increased from 0.3 cases/100,000 outpatient visit-years in 2011 to 21.4 cases/100,000 outpatient visit-years in 2021; of the 216 cases, 58% (n = 126) were diagnosed during 2019-2021. The main clinical form of sporotrichosis was lymphocutaneous (63%), followed by localized cutaneous (24%), ocular (10%), multisite infections (3%), and cutaneous disseminated (<0.5%). Since the first report of CTS in Curitiba in 2011, sporotrichosis has increased substantially, indicating continuous disease transmission. Clinician and public awareness of CTS and efforts to prevent transmission are needed.

Differential Recognition of Clinically Relevant Sporothrix Species by Human Mononuclear Cells

Sporotrichosis is a human and animal fungal infection distributed worldwide that is caused by the thermodimorphic species of the Sporothrix pathogenic clade, which includes Sporothrix brasiliensis, Sporothrix schenckii, and Sporothrix globosa. The cell wall composition and the immune response against the Sporothrix species have been studied mainly in S. brasiliensis and S. schenckii, whilst little is known about the S. globosa cell wall and the immune response that its components trigger. Therefore, in this study, we aimed to analyze the cell wall composition of S. globosa in three morphologies (germlings, conidia, and yeast-like cells) and the differences in cytokine production when human peripheral blood mononuclear cells (PBMCs) interact with these morphotypes, using S. schenckii and S. brasiliensis as a comparison. We found that S. globosa conidia and yeast-like cells have a higher cell wall chitin content, while all three morphologies have a higher β-1,3-glucan content, which was found most exposed at the cell surface when compared to S. schenckii and S. brasiliensis. In addition, S. globosa has lower levels of mannose- and rhamnose-based glycoconjugates, as well as of N- and O-linked glycans, indicating that this fungal cell wall has species-specific proportions and organization of its components. When interacting with PBMCs, S. brasiliensis and S. globosa showed a similar cytokine stimulation profile, but with a higher stimulation of IL-10 by S. globosa. Additionally, when the inner cell wall components of S. globosa were exposed at the surface or N- and O-glycans were removed, the cytokine production profile of this species in its three morphotypes did not significantly change, contrasting with the S. schenckii and S. brasiliensis species that showed different cytokine profiles depending on the treatment applied to the walls. In addition, it was found that the anti-inflammatory response stimulated by S. globosa was dependent on the activation of dectin-1, mannose receptor, and TLR2, but not TLR4. All of these results indicate that the cell wall composition and structure of the three Sporothrix species in the three morphologies are different, affecting their interaction with human PBMCs and generating species-specific cytokine profiles.

Late Diagnosis of Disseminated Sporothrix brasiliensis Infection with Bone Marrow Involvement in an HIV-Negative Patient

Sporotrichosis is a fungal disease that causes symptoms similar to those of other infectious and non-infectious diseases, making diagnosis difficult and challenging. Here, we report a case of an HIV-negative patient presenting disseminated sporotrichosis with widespread cutaneous lesions mimicking pyoderma gangrenosum, with bone marrow infection, pancytopenia, and hemophagocytic syndrome. However, all the clinical manifestations and a bacterial coinfection delayed the request for a fungal diagnosis. Therefore, sporotrichosis should always be investigated in patients from endemic areas presenting with widespread cutaneous lesions associated with pancytopenia.

A Lateral Flow Assay for the Immunodiagnosis of Human Cat-Transmitted Sporotrichosis

BACKGROUND

Cat-transmitted sporotrichosis (CTS) caused by Sporothrix brasiliensis has emerged as an important zoonosis in Brazil and neighboring countries.

OBJECTIVES

Evaluate the performance of a lateral flow assay (LFA) for the detection of anti-Sporothrix antibodies in human sera.

METHODS

A LFA for the detection of anti-Sporothrix antibodies (Anti-Sporo LFA) in human sera, developed by IMMY, was evaluated using 300 human sera collected prospectively at the Hospital de Clínicas, Federal University of Paraná (HC-UFPR), in Curitiba, Brazil. These specimens included 100 sera from patients with CTS. CTS cases were classified as: 59 lymphocutaneous, 27 fixed cutaneous,13 ocular, and one mixed form. One-hundred specimens from patients with other mycoses, including cryptococcosis (n=32), candidemia (n=27), paracoccidioidomycosis (n=14), aspergillosis (n=10), histoplasmosis (n=9), fusariosis (n=4), lobomycosis (n=1), chromoblastomycosis (n=1), mucormycosis (n=1), and trichosporonosis (n=1). And 100 specimens from apparently healthy volunteers (AHV).

RESULTS

The Anti-Sporo LFA showed a global sensitivity of 83% (95% confidence interval [CI] = 74%-90%), a global specificity of 82% (95% CI = 76%-87%), and accuracy of 82% (95% CI = 77%-86%). By clinical form sensitivity was as follows: Mixed form 100%, ocular 92%, lymphocutaneous 83%, and fixed cutaneous 78%. False-positive results were observed in 11 specimens from people with other mycoses and 26 specimens from AHV.

CONCLUSION-DISCUSSION

This study presents the results of the evaluation of the first lateral flow assay for the detection of anti-Sporothrix antibodies in human sera. The findings here show evidence that IMMY´s Anti-Sporo LFA is a promising tool for the rapid diagnosis of CTS.

Human sporotrichosis: recommendations from the Brazilian Society of Dermatology for the clinical, diagnostic and therapeutic management

BACKGROUND

The increase in the zoonotic epidemic of sporotrichosis caused by Sporothrix brasiliensis, which started in the late 1990s in Rio de Janeiro and is now found in almost all Brazilian states, has been equally advancing in neighboring countries of Brazil. Changes in the clinical-epidemiological profile, advances in the laboratory diagnosis of the disease, and therapeutic difficulties have been observed throughout these almost 25 years of the epidemic, although there is no national consensus. The last international guideline dates from 2007.

OBJECTIVES

Update the clinical classification, diagnostic methods and recommendations on the therapeutic management of patients with sporotrichosis.

METHODS

Twelve experts in human sporotrichosis were selected from different Brazilian regions, and divided into three work groups: clinical, diagnosis and treatment. The bibliographic research was carried out on the EBSCOHost platform. Meetings took place via electronic mail and remote/face-to-face and hybrid settings, resulting in a questionnaire which pointed out 13 divergences, resolved based on the opinion of the majority of the participants.

RESULTS

The clinical classification and laboratory diagnosis were updated. Therapeutic recommendations were made for the different clinical forms.

CONCLUSION

Publication of the first national recommendation, carried out by the Brazilian Society of Dermatology, aimed at the Brazilian scientific community, especially dermatologists, infectologists, pediatricians, family medicine personnel, and laboratory professionals who work in the management of human sporotrichosis.