Evaluation of an epidemic of sporotrichosis in cats: 347 cases (1998-2001)

Sporothrix schenckii complex and sporotrichosis, an emerging health problem

Sporothrix schenckii, now named the S. schenckii species complex, has largely been known as the etiological agent of sporotrichosis, which is an acute or chronic subcutaneous mycosis of humans and other mammals. Gene sequencing has revealed the following species in the S. schenckii complex: Sporothrix albicans, Sporothrix brasiliensis, Sporothrix globosa, Sporothrix luriei, Sporothrix mexicana and S. schenckii. The increasing number of reports of Sporothrix infection in immunocompromised patients, mainly the HIV-infected population, suggests sporotrichosis as an emerging global health problem concomitant with the AIDS pandemic. Molecular studies have demonstrated a high level of intraspecific variability. Components of the S. schenckii cell wall that act as adhesins and immunogenic inducers, such as a 70-kDa glycoprotein, are apparently specific to this fungus. The main glycan peptidorhamnomannan cell wall component is the only O-linked glycan structure known in S. schenckii. It contains an α-mannobiose core followed by one α-glucuronic acid unit, which may be mono- or di-rhamnosylated. The oligomeric structure of glucosamine-6-P synthase has led to a significant advance in the development of antifungals targeted to the enzyme’s catalytic domain in S. schenckii.

Response to azolic antifungal agents for treating feline sporotrichosis

The effectiveness and safety of treatment with ketoconazole and itraconazole were compared in 773 sporotrichosis-infected cats over a four-year period (2002 to 2005). Five hundred and ninety-eight cats received oral ketoconazole and 175 received oral itraconazole. Treatment was successful in 238 (30.8 per cent) cats, of which 171 (28.6 per cent) of 598 received 13.5 to 27.0 mg/kg/day ketoconazole and 67 (38.3 per cent) of 175 received 8.3 to 27.7 mg/kg/day itraconazole. Adverse effects were reported in 306 (39.6 per cent) of the cats, 105 (13.6 per cent) died and 430 (55.6 per cent) dropped out of treatment or were still under treatment at the time of data analysis.

Molecular characterisation of Sporothrix schenckii isolates from humans and cats involved in the sporotrichosis epidemic in Rio de Janeiro, Brazil

An epidemic of sporotrichosis, a subcutaneous mycosis caused by the fungus Sporothrix schenckii, is ongoing in Rio de Janeiro, Brazil, in which cases of human infection are related to exposure to cats. In an attempt to demonstrate the zoonotic character of this epidemic using molecular methodology, we characterised by DNA-based typing methods 19 human and 25 animal S. schenckii isolates from the epidemic, as well as two control strains. To analyse the isolates, the random amplified polymorphic DNA (RAPD) technique was performed using three different primers, together with DNA fingerprinting using the minisatellite derived from the wild-type phage M13 core-sequence. The analyses generated amplicons with considerable polymorphism. Although isolates exhibited high levels of genetic relatedness, they could be clustered into 5-10 genotypes. The RAPD profiles of epidemic S. schenckii isolates could be distinguished from that of the United States isolate, displaying 20% similarity to each primer and 60% when amplified with the M13 primer. DNA fingerprinting of S. schenckii isolated from the nails (42.8%) and the oral cavities (66%) of cats were identical to related human samples, suggesting that there is a common infection source for animals and humans in this epidemic. It is clear that cats act as a vehicle for dissemination of S. schenckii.

Intralesional amphotericin B in a cat with refractory localised sporotrichosis

The present report concerns a case of sporotrichosis in a 3-year-old male crossbred cat. After 9 months of oral itraconazole (20mg/kg) therapy, all skin lesions had resolved with the exception of a single nodular lesion located on the bridge of the nose. Therefore, a combined therapy that included intralesional (IL) amphotericin B (1mg/kg) was started. The lesion resolved completely after three weekly administrations of IL amphotericin B, given in concert with oral itraconazole. The cat remains well 1 year after discontinuing therapy, with no signs of recurrence.

Feline sporotrichosis in the southern region of rio grande do sul, Brazil: clinical, zoonotic and therapeutic aspects

Clinical cases of feline sporotrichosis, originating in the Pelotas region and diagnosed at the Laboratory of Infectious Diseases (UFPel), were studied in the period from 2002 to 2006. The animals were evaluated according to the clinical forms of the mycosis, time of lesion appearance, severity of the clinical diagnosis and evolution of cutaneous lesions throughout the treatment period. Mycological analyses, carried out through direct examination, cultivation of tissue samples and exudates of feline lesions all confirmed the diagnosis of sporotrichosis in the 15 animals under study. The cutaneous dissemination form was observed in 10 animals, of which three showed prostration, anorexia and dehydration. The zoonosis occurred in 20% of case studies, and the pet owners and one attendant at a veterinary clinic were infected, developing the fixed and disseminated cutaneous forms. The treatment of mycosis was carried out with itraconazole, 10 mg kg(-1), once a day, on 12 animals. The cure of the clinical symptoms was observed on 50% of the felines. This study demonstrates a good clinical response of felines with sporotrichosis, when they were treated itraconazole and calls the attention for the incidence of human sporotrichosis on people related to the veterinary activity as well as for pet owners.

Molecular epidemiology and antifungal susceptibility patterns of Sporothrix schenckii isolates from a cat-transmitted epidemic of sporotrichosis in Rio de Janeiro, Brazil

Since 1998 a cat-transmitted epidemic of sporotrichosis has been observed in Rio de Janeiro (RJ), Brazil. Besides the lymphocutaneous and fixed forms, other presentations, such as disseminated cutaneous and mucosal involvement, as well as for the first time, erythema nodosum and erythema multiforme have been reported associated with sporotrichosis. This study investigates the phenotypes and genotypes of Sporothrix schenckii isolates recovered from different clinical forms of the disease noted as part of this epidemic. A total of 88 isolates recovered from 59 cases associated with the epidemic and 29 controls (from cases in other Brazilian regions and Spain) were included in this study. In vitro susceptibility testing was conducted as part of the phenotypic analysis, while the genotypic analysis involved a DNA fingerprinting method with primer M13 and ribosomal DNA sequencing of the internal transcribed spacer (ITS). MIC values of amphotericin B, itraconazole, posaconazole, ravuconazole, and terbinafine were found to be significantly lower (P<0.01) for isolates associated with the epidemic than for control strains. No differences in MIC values were observed related to clinical forms of the infection. Fingerprinting analysis showed that RJ epidemic strains were genetically related. Although nine subtypes were found, they were not associated with specific clinical forms. Similar results were obtained with the ITS sequence analysis. These data suggest that the strains isolated from the epidemic cases of sporotrichosis in RJ all originated from a common source.

Evaluation of cats as the source of endemic sporotrichosis in Peru

Although contact with domestic cats has been shown to be a risk factor for sporotrichosis in endemic areas, systematic evaluation of apparently unaffected cats as possible reservoirs for infection has not been explored. The goals of this study were to identify the following aspects of sporotrichosis in the endemic area of Abancay, Peru: (i) the overall prevalence of sporotrichosis in the cat population, (ii) the most common site where the fungus can be isolated from these cats, and (iii) whether cats without identifiable skin lesions may be carriers of the fungus in the oral mucosa, nasal mucosa, or nails. One household cat in each of 85 neighborhoods within the endemic area of Abancay, Peru was randomly selected. Oral and nasal swabs, as well as nail clippings were taken from 84 of the cats. In addition, samples from skin lesions that were suspected to be due to sporotrichosis were collected from cats or members of families that owned the pets. Cultures inoculated with two nasal swabs and one set of nail clippings from two different cats yielded Sporothrix schenckii, the identity of which were confirmed by rDNA sequencing. The overall prevalence of Sporothrix schenckii colonization was 2.38% (95% CI 0.41-9.14) in this cat population. None of the skin lesion samples from the cats and only one such sample from a family member were positive for Sporothrix schenckii in culture. These results suggest a role for domestic cats as a possible reservoir for sporotrichosis infection in Abancay.

Comparison of virulence of different Sporothrix schenckii clinical isolates using experimental murine model

The virulence of two strains of Sporothrix schenckii isolated from patients with lymphocutaneous or disseminated sporotrichosis were examined in BALB/c mice (Group 1 and 2, respectively). The mice were inoculated subcutaneously into the left hind footpad with 4 x 10(6) S. schenckii yeast cells in order to evaluate (i) the development of cutaneous lesions, (ii) signs of inactivity, (iii) weight loss, (iv) survival rates, (v) number of viable yeast cells in the lungs and spleen, (vi) splenic index, (vii) extent of organ lesions, and (viii) immunological responses. Comparison of the two groups showed more severe disease in Group 2 mice that developed significant weight and hair loss associated with inactivity and left hind footpad lesions that extended close to the testicular area. The histopathology and large number of viable microorganisms isolated from the spleen confirmed the higher invasive ability of this strain. Moreover, a decrease of an in vitro specific lymphoproliferative response and IFN-gamma production were observed over time in Group 2 mice. As a result, at the end of the experiment, the S. schenckii-antigen (Ss-Ag) response was considered negative with a stimulation index (SI) = 2. In contrast, Group 1 mice presented a positive response to Ss-Ag (SI = 14.1). These results confirm the existence of different virulence profiles in S. schenckii strains. In addition, the use of subcutaneous inoculation as a suitable route for verification of the pathogenicity of this fungus in the murine model was confirmed.

Endemic of zoonotic sporotrichosis: profile of cases in children

BACKGROUND

Sporotrichosis in childhood is rare in most countries. Isolated cases and small outbreaks related to recreational activities or without identification of the transmission mechanism have been reported.

METHODS

Series of case reports. The isolation of Sporothrix schenckii from exudates or fragments of lesions obtained from the patients was used as the criterion of inclusion in the study.

RESULTS

A total of 81 cases of sporotrichosis in children younger than 15 years of age were diagnosed at the Evandro Chagas Research Institute, Fiocruz, Brazil, between 1998 and 2004. These cases are part of the endemic disease occurring in Rio de Janeiro related to contact with domestic cats. There was a predominance of girls in the 10-14 year age group. The most frequent clinical form was the cutaneouslymphatic form located on the upper limbs. Itraconazole was used as the first-choice treatment. Sixty-six patients were cured, 9 were lost to follow-up, and 6 had spontaneous regression of the lesions.

CONCLUSIONS

This is the largest series of childhood sporotrichosis with zoonotic transmission. The clinical presentation of sporotrichosis in children followed the same pattern of the disease in adults in this ongoing endemic.

An epidemic of sporotrichosis in Rio de Janeiro, Brazil: epidemiological aspects of a series of cases

The first epidemic of sporotrichosis in humans as a result of zoonotic transmission was identified in Rio de Janeiro, Brazil, in 1998. A cross-sectional study was conducted applying questionnaires to patients seen in 2002 at Evandro Chagas Clinical Research Institute, Fiocruz, with a confirmed diagnosis of sporotrichosis. A total of 73 dwellings were studied, where 255 individuals, including 94 patients and 161 healthy household contacts, lived with 133 cats with sporotrichosis. Most dwellings were houses with 83% having complete basic sanitation. Among patients, there was a predominance of women with a median age of 41 years who were engaged in domestic activities. These women contracted the disease twice more often than men. The prevalence of sporotrichosis was four times higher among patients caring for animals, irrespective of gender. In the current epidemic of sporotrichosis, taking care of sick cats was the main factor associated with transmission of the disease to humans.

[In vitro susceptibility of isolates of Sporothrix schenckii to terbinafine and itraconazole]

The study objective was to determine the in vitro activity of terbinafine and itraconazole through the microdilution technique in broth (NCCLSM27-A2), adapted for dimorphic fungus, in relation to 12 isolates of Sporothrix schenckii. Six were from feline sporotrichosis, three from human sporotrichosis, one from a dog and two from human isolates originating from Instituto Oswaldo Cruz. The inoculum and antifungal concentrates were distributed on microplates that were incubated at 35 degrees C for five days. Minimum inhibitory concentration readings were made at the end of this period. The MIC for terbinafine ranged from 0.055 microg/ml to 0.109 microg/ml, and the MIC for itraconazole ranged from 0.219 microg/ml to 1.75 microg/ml. For both drugs, the MIC from the isolates from IOC was 0.875 microg/ml. The present study demonstrates the high susceptibility of Sporothrix schenckii to terbinafine. Further studies to correlate the in vitro susceptibility tests with the clinical response of patients with sporotrichosis are needed.

Mycological evaluation of bronchoalveolar lavage in cats with respiratory signs from Rio de Janeiro, Brazil

Twenty-three cats with respiratory signs who had domiciliary contact with cats with sporotrichosis were studied. Sneezing was the predominant extracutaneous sign. Twelve cats had no skin lesions and 11 had ulcerated skin lesions. Mycological culture of material obtained from the nasal cavity, oral cavity, bronchoalveolar lavage (BAL) and skin lesions, when present, was performed for all cats. In the case of autopsy, lung fragments were cultured. Sporothrix schenckii was isolated from four of the 12 cats without skin lesions: BAL (one cat) and oral and/or nasal cavity (three cats). The latter three animals developed nasal and distant skin lesions within the following 2-4 weeks. The cat with S. schenckii isolated from BAL did not develop skin lesions or lower respiratory tract symptoms during the 6 months of follow-up. S. schenckii was isolated from one or more biological samples of all 11 cats with skin lesions: oral cavity (five), nasal cavity (eight), BAL fluid (four), skin lesions (eight), and blood culture (one). No yeast-like structures were observed upon BAL cytology in any of the 23 cats. The results suggest that S. schenckii can cause infection of skin contiguous to the natural facial orifices through colonisation of the mucosal surfaces of the upper airways.

Esporotricosis en Irán

This report describes a 23 year-old male florist gardener diagnosed with subcutaneous sporotrichosis caused by the dimorphic pathogenic soil fungus Sporothrix schenckii. The patient had several small skin lesions over the left upper arm with ascendant chains of enlarged lymph nodes.Sporothrix schenckii was detected from clinical samples by direct microscopy and culture and its ability to switch from mould to yeast form at 37 degrees C. The patient was successfully treated with long-term potassium iodide and advised to wear gloves and long sleeves when handling any kind of plant material.

Lymphocutaneous and nasal sporotrichosis in a dog from southern Italy: case report

Sporotrichosis is a chronic, granulomatous and usually lymphocutaneous infection of humans and animals caused by the dimorphic fungus, Sporothrix schenckii. This study reports a case of lymphocutaneous and nasal sporotrichosis in a hunting dog with a three month history of non-healing skin lesions. Cytological examination of nasal discharge and of the material collected from ulcerated skin surfaces showed a few cigar-shaped organisms within macrophages. Fungal cultures of nasal and ulcerated skin swabs yielded colonies of S. schenckii. The dog received oral itraconazole but died of unrelated causes. Necropsic examination was not performed.

Sporotrichosis: the main differential diagnosis with tegumentary leishmaniosis in dogs from Rio de Janeiro, Brazil

Seventy-four dogs from the State of Rio de Janeiro with ulcerated cutaneous lesions were submitted to clinical, dermatological, parasitological, mycological, histopathological and cytopathological exams, a leishmanin skin test, an indirect immunofluorescence (IIF) test for leishmaniosis, and nonspecific laboratory tests such as blood count and serum biochemistry. Sporothrix schenckii was isolated from 41 dogs and Leishmania (Viannia) braziliensis was isolated from 33 animals. Most dogs with sporotrichosis were from the municipality of Rio de Janeiro (53.7%) and presented ulcerated cutaneous lesions on the head (68.3%). Laboratory alterations in these animals included anemia (58.5%), hypoalbuminemia (83%) and hyperglobulinemia (75.6%). Histopathology revealed the predominance of a chronic granulomatous inflammatory infiltrate (70.7%), and yeast-like structures were detected in 17% of the histopathological exams and in 32% of the cytological exams. Three of 41 dogs with sporotrichosis were seropositive by IIF for leishmaniosis and 2 of 20 animals tested within this group had a positive leishmanin skin test. Similarly, most of the 33 dogs with leishmaniosis were from the municipality of Rio de Janeiro (69.7%) and had ulcerated cutaneous lesions on the head (84.8%). Laboratory alterations in these animals included anemia (66.7%), hypoalbuminemia (100%) and hyperglobulinemia (91%). Histopathology showed the predominance of a chronic granulomatous inflammatory infiltrate (63.6%) and amastigote forms were detected in 30.3% of the histopathological exams and in 31.8% of the 22 cytological exams performed. About 72.7% of the dogs were seropositive by IIF and five of seven animals had a positive skin test. Due to the clinical similarities, histopathological and nonspecific laboratory results similarities, the serological and skin tests for leishmaniosis positive in dogs with sporotrichosis, and the overlapping endemic areas in Rio de Janeiro, the differential diagnosis between the two diseases requires the demonstration of their respective etiological agents.

Canine sporotrichosis in Rio de Janeiro, Brazil: clinical presentation, laboratory diagnosis and therapeutic response in 44 cases (1998-2003)

A sporotichosis epidemic involving forty-four dogs in the Metropolitan area of Rio de Janeiro is described. Solitary skin lesions were noted in 18 dogs (40.9%), 2-4 such lesions were observed in 17 animals (38.6%), and nine (20.5%) animals had five or more lesions. Twenty-five (56.8%) animals had single ulcerated skin lesions on the nose and nine (20.5%) showed nasal mucosal involvement (three of which also has a skin lesion). Respiratory symptoms were observed in 17 (38.6%) dogs and were found to be the most common extracutaneous signs of infection. Anemia, leukocytosis with neutrophilia, hypoalbuminemia and hyperglobulinemia were the most frequent hematological abnormalities. Histopathological analysis of skin biopsies in most cases revealed granulomatous reactions characterized by histiocytic hyperplasia and neutrophil infiltration. Yeast-like cells were observed in seven (16.7%) of 42 dogs examined histologically. During the study, eight (18.2%) animals were lost to follow-up and three (6.8%) were submitted to euthanasia. Of the remaining 33 dogs, five (15.2%) presented spontaneous regression of the lesions, 26 (78.8%) were cured after treatment, and two (6%) continue to be treated. The present cases indicate that many dogs with sporotrichosis respond well to treatment and in a few dogs, the disease may be self-limiting.

Sporothrix schenckii and sporotrichosis

For a long time sporotrichosis has been regarded to have a low incidence in Brazil; however, recent studies demonstrate that not only the number of reported cases but also the incidence of more severe or atypical clinical forms of the disease are increasing. Recent data indicate that these more severe forms occur in about 10% of patients with confirmed diagnosis. The less frequent forms, mainly osteoarticular sporotrichosis, might be associated both with patient immunodepression and zoonotic transmission of the disease. The extracutaneous form and the atypical forms are a challenge to a newly developed serological test, introduced as an auxiliary tool for the diagnosis of unusual clinical forms of sporotrichosis.

Cat-transmitted sporotrichosis, Rio de Janeiro, Brazil

Sporotrichosis is an emerging zoonosis in Rio de Janeiro, Brazil. From 1998 to 2003, 497 humans and 1,056 cats with culture-proven sporotrichosis were studied. A total of 421 patients, 67.4% with a history of a scratch or bite, reported contact with cats that had sporotrichosis.

Primary Conjunctival Sporotrichosis

PURPOSE

To describe Sporothrix schenckii conjunctivitis in 2 owners of cats with sporotrichosis.

METHODS

Small case series and literature review.

RESULTS

Two women had been caring for their pet cats with sporotrichosis for 2 months but did not recall any traumatic injury such as scratches or bites. Each presented a conjunctival granulomatous lesion measuring 4 to 5 mm accompanied by local hyperemia, secretion, and edema, in addition to painful facial subcutaneous nodes and regional lymph node enlargement. Pyogenic material was collected from the conjunctival sac and from cutaneous lesions on the cats. In both the patients and their respective cats, fungal colonies were isolated and identified as S. schenckii. Treatment with oral itraconazole 100 mg/d for 3 months resulted in complete healing of lesions in both patients. Patients remained clinically cured 15 months after end of treatment.

CONCLUSION

Sporotrichosis is presently occurring as an emerging zoonosis in Rio de Janeiro, and some unusual clinical forms have been diagnosed in humans. The cases reported here suggest atraumatic exposure to cats infected by S. schenckii.

Positive Montenegro skin test among patients with sporotrichosis in Rio De Janeiro

We studied 52 patients with sporotrichosis confirmed by isolation of Sporothrix schenckii and reactivity to the Montenegro skin test (MST) during an ongoing outbreak of this mycosis in Rio de Janeiro. The objective was to emphasize the importance of parasitological confirmation and the possibility of incorrect diagnosis based on the lesion's appearance, epidemiological information, and immunological tests. The antigen used for the MST was conserved in either thimerosal 1:10,000 (group 1) or 0.4% phenol (group 2). Nineteen patients (39%) in group 1 and seven (12%) in group 2 presented an induration>or=10 mm (p<0.001). Sera from three patients (6.7%) reacted to indirect immunofluorescence (IIF) for leishmaniasis, while sera from 10 patients (22.2%) reacted to enzyme-linked immunosorbent assay (ELISA). Fifteen patients (28.8%) presented up to two lesions, with a predominance of ulcers. Forty-four patients (84.6%) were treated with itraconazole. In the differential diagnosis between sporotrichosis and cutaneous leishmaniasis, the possibility of co-infection, allergy to the reagent diluent, and cross-reactions should be further investigated, especially in regions with limited laboratory facilities.