Association of itraconazole and potassium iodide in the treatment of feline sporotrichosis: a prospective study.

Feline sporotrichosis is an endemic disease in Rio de Janeiro, Brazil, where zoonotic transmission of Sporothrix spp. has been reported since 1998. Itraconazole (ITZ) remains the first choice for treating this disease in cats. However, there have been reports of therapeutic failure and a long-term endeavor. Potassium iodide (KI), considered in the past as a drug with variable effectiveness in cats with sporotrichosis, arises as an important option in the treatment of cats from the endemic area of Rio de Janeiro. In order to evaluate the effectiveness of the association of ITZ and KI in naive cats with sporotrichosis, a prospective cohort study was conducted on 30 cats receiving ITZ 100 mg/day and KI 2.5 mg-20 mg/kg/day. Clinical and laboratory adverse effects were assessed once a month according to the standard care protocol. The cure rate was 96.15% within a median of 14 weeks of treatment. Adverse effects were observed in 50% of cats and were managed with a temporary drug suspension and/or a hepatoprotective therapy. The association of ITZ and KI emerges as an effective option for the treatment of feline sporotrichosis.

Severe feline sporotrichosis associated with an increased population of CD8low cells and a decrease in CD4⁺ cells.

Sporotrichosis is a subcutaneous mycosis with worldwide distribution, especially in tropical and subtropical areas. Zoonotic transmission is described with cats being the main animal species involved. The occurrence of severe feline sporotrichosis with high fungal levels demonstrates the susceptibility of cats to this disease and the importance of studying its pathogenesis. This study describes the leukocytes profile in blood of cats with sporotrichosis by flow cytometry and its correlation with histopathology and fungal load. The cats with sporotrichosis were separated into groups L1, L2, and L3 (lesions at one, two, and three or more noncontiguous skin locations, respectively) and were classified as good, fair, or poor general conditions. The highest percentage of CD4+ cells was associated to L1 (P = .04) and to good general condition (P = .03). The percentage of CD8+ cells was greater in L2 and L3 (P = .01). CD8(low) expression occurred in 20 animals with sporotrichosis, mainly in L3 (P = .01) and was not observed in healthy controls. This expression was related to macrophage granulomas (P = .01) and predominated in cases with high fungal load. Altogether, the results indicated that control over feline sporotrichosis, with maintenance of a good general condition, fixed lesions, well-organized response and lower fungal load, is associated with increased CD4+ cells percentages. In contrast, a poor general condition, disseminated lesions and high fungal load were related to increased CD8+ cell percentages and increased expression of CD8(low). As conclusion these results point to an important role of the CD4:CD8 balance in determining the clinical outcome in feline sporotrichosis.

Feline sporotrichosis: epidemiological and clinical aspects.

Feline sporotrichosis, which is caused by species of the Sporothrix schenckii complex, is endemic to Rio de Janeiro, Brazil. More than 4000 cases of the disease were diagnosed at Fundação Oswaldo Cruz, Brazil, between 1998 and 2012. Sporotrichosis in cats has been reported in several countries, but nowhere has an outbreak of animal sporotrichosis been as large as that seen in Brazil. The clinical manifestations of the disease range from an isolated skin lesion that can progress to multiple skin lesions and even fatal systemic involvement. Nodules and ulcers are the most common types of lesions, and respiratory signs and mucosa involvement are frequent. The definitive diagnosis depends on isolation of the etiologic agent in culture. Cytology, histopathology, and serology are useful tools for preliminary diagnosis. Severe pyogranulomatous inflammatory infiltrate, high fungal load, and extension of lesions to mucosa, cartilage, and bone in the nose of cats are indicative of an agent of high virulence in this endemic region. Itraconazole is the drug of choice, while, in refractory cases, amphotericin B or potassium iodide might be alternative treatments; however, recurrence after discharge may occur. Sporotrichosis persists as a neglected disease in Rio de Janeiro, and the treatment of cats remains a challenging and long-term endeavor.

Feline sporotrichosis: histopathological profile of cutaneous lesions and their correlation with clinical presentation.

Cutaneous lesions of feline sporotrichosis show high fungal load and are associated with severe disease and elevated zoonotic potential. The present study describes the histopathology and fungal load of the lesions in different clinical presentations of feline sporotrichosis. Cats with sporotrichosis were separated into groups L1, L2 and L3 (lesions in one, two and three or more locations, respectively) and subjected to skin biopsies for histopathology. Eighty-six cats were included in the study. Lesions were suppurative granulomatous in 84 cases and poorly formed granulomas were predominant. The well-formed granulomas were associated with group L1. The high fungal load was predominant in group L3 and in poorly formed granuloma cases and did not occur in well-formed granulomas cases. The good general condition was associated with low fungal load. These findings suggest that the fungal load control in animals with more localized lesions and well-organized response is linked with the improvement in the outcome of infected cats.

Disseminated intravascular coagulation in a dog naturally infected by Leishmania (Leishmania) chagasi from Rio de Janeiro - Brazil.

BACKGROUND: Disseminated intravascular coagulation (DIC) is an acquired disorder characterized by the activation of intravascular coagulation and excessive fibrin formation. It always occurs in association with other clinical conditions, including parasitic diseases. DIC has been described as a unusual complication in human and canine visceral leishmaniasis. CASE PRESENTATION: DIC was found in a seven-year-old male mongrel dog naturally infected by Leishmania (Leishmania) chagasi. Haemostasis parameters demonstrated changes in primary and secondary haemostasis and fibrinolysis. CONCLUSION: DIC is a unusual condition described in canine visceral leishmaniasis and it seems to be associated with several immunological and pathological mechanisms involved in the disease.

Sensitivity and specificity of in situ hybridization for diagnosis of cutaneous infection by Leishmania infantum in dogs.

An accurate diagnosis of infection by Leishmania infantum in dogs is fundamental for the control of zoonotic visceral leishmaniasis (VL). Histopathology (HP) and immunohistochemistry (IHC) are frequently used for the histological diagnosis of L. infantum in dogs but have shown limited accuracy. To improve the sensitivity and specificity of the histological diagnosis of VL, we evaluated automated in situ hybridization (ISH) using a generic probe for Leishmania and a specific probe for L. infantum in surgical skin biopsy specimens of dogs. The ISH results were compared with those of HP and IHC, using parasitological culture as the reference standard. Skin samples from 51 dogs with cutaneous L. infantum infection and 51 noninfected dogs were randomly selected from samples of dogs from various cities in Brazil where canine VL is endemic. These samples were processed for parasitological culture, HP, IHC, and ISH using both probes. The sensitivities of ISH using the specific probe, ISH using the generic probe, IHC, and HP were, respectively, 74.5%, 70.6%, 69.5%, and 57.6%. The specificity of both ISH probes tested was 100%, and there was no cross-hybridization of the generic and specific probes with selected pathogenic fungi and protozoa. The specific probe discriminated L. infantum from the other species of Leishmania that infect dogs in the New World. ISH is highly sensitive and specific for the diagnosis of L. infantum in histologic samples of skin from infected dogs and can be used on routine biopsy material to make a diagnosis of leishmaniasis.

Potassium iodide capsule treatment of feline sporotrichosis.

Sporotrichosis is a mycosis caused by Sporothrix schenckii. The most affected animal is the cat; it has played an important role in the zoonotic transmission of this disease, especially in Rio de Janeiro, Brazil, since 1998. In order to evaluate the treatment of feline sporotrichosis with potassium iodide, an observational cohort was conducted in 48 cats with sporotrichosis at Instituto de Pesquisa Clínica Evandro Chagas, Fiocruz. All cats received potassium iodide capsules, 2.5 mg/kg to 20 mg/kg q24h. The cure rate was 47.9%, treatment failure was 37.5%, treatment abandonment was 10.4% and death was 4.2%. Clinical adverse effects were observed in 52.1% of the cases. Thirteen cats had a mild increase in hepatic transaminase levels during the treatment, six of them presented clinical signs suggestive of hepatotoxicity. Compared to previous studies with itraconazole and iodide in saturated solution, potassium iodide capsules are an alternative for feline sporotrichosis treatment.

Evaluation of immunohistochemistry for the diagnosis of sporotrichosis in dogs.

The aim of this study was to apply immunohistochemistry (IHC) for the diagnosis of canine sporotrichosis and to compare this method with the Grocott's silver stain (GSS) and periodic acid Schiff (PAS) techniques. Eighty-seven dogs with sporotrichosis (group 1) and 35 with American tegumentary leishmaniosis (ATL) (group 2) were studied. The fungus was detected in group 1 by GSS, PAS and IHC. IHC was also applied to group 2 to evaluate the occurrence of cross-reactions. PAS, GSS and IHC detected yeast cells in 19.5%, 43.7% and 65.5% of the group 1 cases, respectively. The detection of intracellular antigens of Sporothrix schenckii by IHC increased the sensitivity of the histological diagnosis to 80.5%. No positive reaction was observed in ATL lesions. The results suggest that IHC may be indicated for the diagnosis of sporotrichosis because of its higher diagnostic sensitivity.

Sensitivity of cytopathological examination in the diagnosis of feline sporotrichosis.

Sporotrichosis is caused by Sporothrix schenckii. The cat is the animal species most affected by this mycosis and plays an important role in the zoonotic transmission of this disease. The definitive diagnosis is made by isolation of the fungus in culture; however, cytopathological examination is frequently used in cats. Medical records from cats treated at Instituto de Pesquisa Clínica Evandro Chagas/Fiocruz, Rio de Janeiro, Brazil, between 2004 and 2006 were reviewed. Criteria for inclusion were a diagnosis by isolation of S schenckii in culture and cytopathological examination of the same lesion as that used for collection of the culture material. Eight hundred and six cats were included in the study. Yeast-like structures suggestive of S schenckii were observed in 636 cases. The sensitivity of the method was 78.9%. Its practicality, low cost and sensitivity validate cytopathology as a safe technique for the presumptive diagnosis of sporotrichosis in cats.

First encounter of subclinical human Leishmania (Viannia) infection in State of Rio Grande do Sul, Brazil

The objective of the present study was to evaluate the specificity of the Montenegro skin test (MST) in an area in Brazil, state of Grande do Sul State (RS), which was considered to be non-endemic for leishmaniasis. Sixty subjects presented a positive MST and were reevaluated by clinical examination, serology and polymerase chain reaction (PCR) of peripheral blood for the detection of subclinical Leishmania infection. None of the subjects presented clinical signs or symptoms of current leishmaniasis or a history of the disease.Leishmania (Viannia) DNA was detected in blood by PCR and hybridization in one subject. The PCR skin test-positive individual remained asymptomatic throughout the study. Clinical examination showed no scars suggestive of past cutaneous leishmaniasis. Human subclinical infection with Leishmania (Viannia) in RS was confirmed by PCR. This is the first report of subclinical infection with this parasite in the human population of this area.

Use of ELISA employing Leishmania (Viannia) braziliensis and Leishmania (Leishmania) chagasi antigens for the detection of IgG and IgG1 and IgG2 subclasses in the diagnosis of American tegumentary leishmaniasis in dogs.

American tegumentary leishmaniasis (ATL) shows a reduced humoral response in dogs and levels of specific antibodies may therefore not be detected by indirect immunofluorescence. Although the sensitivity of enzyme-linked immunosorbent assay (ELISA) is higher than that of indirect immunofluorescence, the best antigen for the diagnosis of ATL in dogs has not been defined. The detection of IgG subclasses represents an alternative to increase the efficiency of the serological diagnosis. In Rio de Janeiro, sporotrichosis is the main differential diagnosis of ATL in dogs, and a sensitive, specific and little invasive method that permits the discrimination of the two diseases is desired. In the present study, 69 serum samples, 34 obtained from dogs with ATL and 35 from dogs with sporotrichosis, all of them with a confirmed etiological diagnosis, were tested. The samples were analyzed by ELISA using Leishmania (Viannia) braziliensis and L. (L.) chagasi antigens for the detection of anti-Leishmania IgG, IgG1 and IgG2. The use of L. (V.) braziliensis antigens for the detection of IgG and IgG2 yielded the best results. Using L. (L.) chagasi antigen, the sensitivity and specificity for the detection of IgG were 82.4% and 100%, respectively, whereas both sensitivity and specificity were 97.1% with the L. (V.) braziliensis antigen. No improvement in the performance of the test was observed when IgG2 was analyzed separately. The IgG1 assays presented low accuracy, irrespective of the antigen used: sensitivity and specificity of 58.8% and 60% for L. (V.) braziliensis and of 64.7% and 77.1% for L. (L.) chagasi, respectively. The present results suggest that IgG ELISA using the L. (V.) braziliensis shows the best performance for the diagnosis of ATL, permitting the discrimination between cases of ATL and sporotrichosis in dogs.

First encounter of subclinical human Leishmania (Viannia) infection in State of Rio Grande do Sul, Brazil.

The objective of the present study was to evaluate the specificity of the Montenegro skin test (MST) in an area in Brazil, state of Grande do Sul State (RS), which was considered to be non-endemic for leishmaniasis. Sixty subjects presented a positive MST and were reevaluated by clinical examination, serology and polymerase chain reaction (PCR) of peripheral blood for the detection of subclinical Leishmania infection. None of the subjects presented clinical signs or symptoms of current leishmaniasis or a history of the disease. Leishmania (Viannia) DNA was detected in blood by PCR and hybridization in one subject. The PCR skin test-positive individual remained asymptomatic throughout the study. Clinical examination showed no scars suggestive of past cutaneous leishmaniasis. Human subclinical infection with Leishmania (Viannia) in RS was confirmed by PCR. This is the first report of subclinical infection with this parasite in the human population of this area.

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.

Post mortem parasitological evaluation of dogs seroreactive for Leishmania from Rio de Janeiro, Brazil.

A parasitological study was conducted on 66 dogs seroreactive for Leishmania captured as a control measure of visceral leishmaniasis in the State of Rio de Janeiro, Brazil. Biological samples from different anatomical sites were collected during autopsy of the animals and cultured on biphasic medium (NNN/Schneider). The Leishmania isolates were characterized by isoenzyme electrophoresis. Leishmania was isolated from 80.3% of the animals: 12 animals with Leishmania (Viannia) braziliensis isolated exclusively from cutaneous lesions, 39 with L. (L.) chagasi isolated from different sites in the same animal, and 2 with simultaneous isolation of L. (V.) braziliensis from cutaneous lesions and L. (L.) chagasi from different sites. Isolation in culture revealed the absence of Leishmania parasites in 13 animals. The results obtained confirm the existence of mixed infections in dogs in Rio de Janeiro and indicate the need to complement the investigation of seroreactive dogs using methods for the parasitological diagnosis and identification of Leishmania species.

Is Leishmania (Viannia) braziliensis preferentially restricted to the cutaneous lesions of naturally infected dogs?

Nineteen dogs naturally infected with Leishmania (Viannia) braziliensis were studied in order to determine the presence of the parasite outside cutaneous lesions. Eleven (57.9%) animals showed single cutaneous or mucosal lesions and eight (42.1%) presented two or three lesions. Twenty-eight active lesions were biopsied. Isolation in culture and characterization by enzyme electrophoresis were possible in 100% of cases and amastigote forms were visualized upon histopathological examination in three samples (n=25, 12%). Isolation of the parasite in culture from peripheral blood and intact skin fragments obtained from the scapular region was negative in all animals, as was the histopathological analysis of skin from this region. Serological reactivity determined by an immunofluorescent antibody test and/or enzyme-linked immunosorbent assay was demonstrated in 15 animals. The results obtained suggest that L. braziliensis preferentially remains at the site of lesion, in contrast to the systemic distribution of parasites observed in dogs infected with L. (Leishmania) chagasi. A better understanding of this aspect may help direct diagnostic and control strategies applicable to areas characterized by the simultaneous occurrence of the cutaneous and visceral forms of leishmaniasis, as is the case for the Municipality of Rio de Janeiro, Brazil.

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

OBJECTIVE: To evaluate characteristics of a large epidemic of sporotrichosis in cats. DESIGN: Retrospective study. ANIMALS: 347 cats with naturally acquired infection with Sporothrix schenckii. PROCEDURE: Medical records were reviewed for data regarding clinical, mycologic, histopathologic, and routine hematologic and serum biochemical findings; assays for FIV-specific antibodies and FeLV antigen; antifungal treatment; and follow-up. RESULTS: Lesions varied from small papules to extensive zones of necrosis. Ten cats had no skin lesions, 114 had skin lesions at a single site, 86 had skin lesions in 2 sites, and 137 had skin lesions in 3 or more sites. Respiratory tract signs were observed in 154 cats and were the most frequent extracutaneous sign. Anemia, leukocytosis with neutrophilia, hypoalbuminemia, and hyperglobulinemia were the main blood abnormalities. Antibodies against FIV were detected in 28 cats, FeLV antigen was detected in 2 cats, and both were detected in 1 cat among 142 cats tested. During the study, 118 cats were lost to follow-up and 124 died. Of 266 cats that were treated, 68 were cured. Complete healing of the lesions was observed regardless of the presence of extracutaneous signs, general condition, treatment schedule, or coinfection with FIV. CONCLUSIONS AND CLINICAL RELEVANCE: Feline sporotrichosis was evident in subclinical to severe forms; however, cats can respond well to regular and prolonged antifungal treatment.