Serological cross-reactivity of Trypanosoma cruzi, Ehrlichia canis, Toxoplasma gondii, Neospora caninum and Babesia canis to Leishmania infantum chagasi tests in dogs.

INTRODUCTION: The aim of this study was to evaluate the serological cross-reactivity between Leishmania sp. and other canine pathogens. METHODS: Positive serum samples for Ehrlichia canis, Babesia canis, Toxoplasma gondii, Neospora caninum and Trypanosoma cruzi were tested using three serological methods enzyme linked immunosorbent assay (ELISA), indirect immunofluorescent antibody test (IFAT) and Kalazar Detect™, for canine visceral leishmaniasis. RESULTS: Of the 57 dog samples tested, 24 (42.1%) tested positive using one of the three serological methods: 10/57 (17.5%) for ELISA, 11/57 (19.3%) for IFAT and 3/57 (5.3%) for Kalazar Detect™. CONCLUSIONS: Our results demonstrated that the presence of other infectious agents may lead to cross-reactivity on leishmaniasis serological tests.

Serological cross-reactivity of Trypanosoma cruzi, Ehrlichia canis, Toxoplasma gondii, Neospora caninum and Babesia canis to Leishmania infantum chagasi tests in dogs

Introduction: The aim of this study was to evaluate the serological cross-reactivity between Leishmania sp. and other canine pathogens. Methods: Positive serum samples for Ehrlichia canis, Babesia canis, Toxoplasma gondii, Neospora caninum and Trypanosoma cruzi were tested using three serological methods enzyme linked immunosorbent assay (ELISA), indirect immunofluorescent antibody test (IFAT) and Kalazar Detect™, for canine visceral leishmaniasis. Results: Of the 57 dog samples tested, 24 (42.1%) tested positive using one of the three serological methods: 10/57 (17.5%) for ELISA, 11/57 (19.3%) for IFAT and 3/57 (5.3%) for Kalazar Detect™. Conclusions: Our results demonstrated that the presence of other infectious agents may lead to cross-reactivity on leishmaniasis serological tests. .

Coinfection of Leishmania chagasi with Toxoplasma gondii, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in cats from an endemic area of zoonotic visceral leishmaniasis.

The aim of the present study was to determine the coinfection of Leishmania sp. with Toxoplasma gondii, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in a population of cats from an endemic area for zoonotic visceral leishmaniasis. An overall 66/302 (21.85%) cats were found positive for Leishmania sp., with infection determined by direct parasitological examination in 30/302 (9.93%), by serology in 46/302 (15.23%) and by both in 10/302 (3.31%) cats. Real time PCR followed by amplicon sequencing successfully confirmed Leishmania infantum (syn Leishmania chagasi) infection. Out of the Leishmania infected cats, coinfection with FIV was observed in 12/66 (18.18%), with T. gondii in 17/66 (25.75%) and with both agents in 5/66 (7.58%) cats. FeLV was found only in a single adult cat with no Leishmania infection. A positive association was observed in coinfection of Leishmania and FIV (p<0.0001), but not with T. gondii (p>0.05). In conclusion, cats living in endemic areas of visceral leishmaniasis are significantly more likely to be coinfected with FIV, which may present confounding clinical signs and therefore cats in such areas should be always carefully screened for coinfections.

Estudo da imunopatogenia das lesões no sistema nervoso central de cães naturalmente acometidos por leishmaniose visceral / Study of the immunopathogenesis of central nervous system lesions in dogs naturally affected by visceral leishmaniasis

A Leishmaniose visceral em cães é descrita como uma doença de caráter crônico na qual os principais sintomas são perda progressiva de peso, caquexia e lesões dermatológicas. Recentemente, a doença tem sido relacionada com alterações neurológicas. Um total de 40 cães portadores de leishmaniose visceral foi dividido em dois grupos. O primeiro composto por cães sem sintomas neurológicos (n=30) e o segundo grupo composto por cães com sintomas neurológicos (n=10). Amostras de encéfalo foram coletadas e armazenadas em formalina tamponada, para realização de imunoistoquímica para a pesquisa de formas amastigotas de Leishmania (Leishmania) infantum chagasi, linfócitos T CD3+, CD4+ e CD8+ e macrófagos. A reação de imunoistoquímica não revelou formas amastigotas do parasita. Linfócitos T estavam presentes em 24/30 (80%) dos cães sem sintomas neurológicos e em todos os cães do segundo grupo (p=0,0011). Linfócitos CD4+ e CD8+ raramente foram observados, apresentando imunomarcação para CD4+ em 10/40 (25%) dos cães e em metade dos animais do grupo neurológico (p=0,0090). A presença de CD8+ foi detectada em 4/10 (40%) cães com doenças neurológicas (p=0,0021). Macrófagos foram observados em 38/40 (95%) cães, sem diferença estatística significante entre os dois grupos (p= 0,7664).

Visceral leishmaniasis in dogs is described as a chronic disease whose main symptoms are progressive weigth loss, cachexy and dermatologic lesions. Recently, the disease has been associated to neurologic disorders. A total of 40 dogs with visceral leishmaniasis were divided into two groups. The first composed of dogs without neurological signs (n=30) and the second by dogs with neurological disorders (n=10). Brain samples were collected, stored in 10% buffered formalin and subjected to immunohistochemical examination for amastigotes forms of Leishmania (Leishmania) infantum chagasi, CD3+, CD4+ and CD8+ T lymphocytes and macrophages. Imunnohistochemistry evaluation revealed no amastigote forms of the parasite. CD3+ T lymphocytes were present in 24/30 (80%) dogs without neurological signs and in all dogs from the second group (p=0.0011). CD4+ and CD8+ were rarely observed, with CD4+ immunostaining in 10/40 (25%) dogs, from which half of them had neurological disease (p=0.0090). The presence of CD8+ was detected only in 4/10 (40%) dogs from neurological group (p=0.0021). Macrophages were detected in 38/40 (95%) dogs, without significant differences between groups (p=0.7664).

Leishmania chagasi infection in cats with dermatologic lesions from an endemic area of visceral leishmaniosis in Brazil.

Although dogs are considered the main domestic reservoirs for Visceral Leishmaniosis (VL), which is caused in the Americas by Leishmania chagasi, infected cats have also been recently found in endemic areas of several countries and became a public health concern. Accordingly, the purpose of this study was to evaluate cats with dermatologic lesions from an endemic area of VL and the natural infection of L. chagasi. A total of 55 cats were selected between April 2008 and November 2009 from two major animal shelters of Araçatuba, Southeastern Brazil. All cats underwent general and dermatologic examinations, followed by direct parasitological examination of lymphoid organs, immunosorbent assay (ELISA) and indirect immunofluorescence (IFAT). In addition, detection of amastigotes was performed by immunohistochemistry (IHC) in skin lesions of all cats. VL was diagnosed in 27/55 (49.1%) cats with dermatological problems. Amastigotes were found in lymphoid organs of 10/27 (37.0%) cats; serology of 14/27 (51.9%), 6/27 (22.2%) and 5/27 (18.5%) cats was positive for ELISA, IFAT and both, respectively. The IHC identified 9/27 (33.3%) cats; 5/27 (18.5%) were positive only for IHC and therefore increased the overall sensitivity. Specific FIV antibodies were found in 6/55 (10.9%) cats, of which 5/6 (83.3%) had leishmaniosis. Real time PCR followed by amplicon sequencing successfully confirmed L. chagasi infection. In conclusion, dermatological lesions in cats from endemic areas was highly associated to visceral leishmaniosis, and therefore skin IHC and differential diagnosis of LV should be always conducted in dermatological patients in such areas.

Sorofrequência de infecção pelo vírus da imunodeficiência felina e vírus da leucemia felina em gatos do município de Araçatuba, São Paulo / Serofrequency of feline immunodeficiency virus and feline leukemia virus in cats of Araçatuba, São Paulo

imunodeficiência viral felina e a leucemia viral felina representam importantes doenças infecciosas causadas por retrovírus. O presente estudo teve por objetivos investigar a sorofrequência da infecção pelo vírus da imunodeficiência felina (FIV) e pelo vírus da leucemia felina (FeLV) em gatos provenientes do município de Araçatuba, Estado de São Paulo. Amostras de sangue de 302 gatos foram colhidas e testadas quanto à presença de anticorpos antivírus da imunodeficiência felina e do antígeno do vírus da leucemia felina por meio do ELISA Snap-Combo®FIV-FeLV (IDEXX Laboratories). A frequência de positividade para FIV foi de 5,63% (17/302) e para FeLV de 0,33% (1/302). Dos 17 gatos infectados pelo FIV, nove (52,94%) eram sintomáticos. Houve um predomínio da infecção pelo FIV em machos (p = 0,0316) e em gatos com idade variando entre um e três anos (p = 0,0324).

Feline immunodeficiency virus and feline leukemia represent important infectious diseases caused by retroviruses. This study aimed to investigate the prevalence of infection by feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) in cats from the municipality of Araçatuba, São Paulo. Blood samples from 302 cats were collected and tested for the presence of antibodies against feline immunodeficiency virus and antigen of feline leukemia virus by ELISA ® Snap- Combo FIV-FeLV (IDEXX Laboratories). The frequency of FIV positivity was 5.63% (17/302) and of FeLV was 0.33% (1/302). Of the 17 cats infected with FIV, nine (52.94%) were symptomatic. There was a prevalence of FIV infection in males (p = 0.0316) and cats aged between one and three years (p = 0.0324).

Ocorrência de leishmaniose em gatos de área endêmica para leishmaniose visceral / Occurrence of leishmaniasis in cats from endemic area for visceral leishmaniasis

Apesar da descrição de vários casos de leishmaniose felina no mundo, pouco se sabe sobre a importância do gato como um reservatório da doença. O objetivo do presente estudo foi determinar a ocorrência de leishmaniose em gatos provenientes de uma área endêmica para leishmaniose visceral no Brasil. Duzentos gatos foram incluídos no estudo. A presença de infecção foi determinada por meio do achado de formas amastigotas do parasita em esfregaços obtidos por punção biópsia aspirativa de linfonodos, medula óssea, baço e fígado, e pela presença de anticorpos anti-L. chagasi pelo teste de ELISA indireto. Nossos resultados demonstraram uma prevalência de infecção em 14,5% (31/200) dos gatos na população estudada, sendo 4% (8/200) por diagnóstico parasitológico e 11,5% (23/200) por sorologia.

Despite the description of several cases of feline leishmaniasis around the world, little information is available about the importance of the cat as a reservoir of the disease. The aim of the present study was to determine the occurrence of leishmaniasis in cats from an endemic area for visceral leishmaniasis in Brazil. Two hundred cats were included in this study. Infection was evaluated through the presence of amastigotes in stained smears from fine-needle aspirates of lymph nodes, bone marrow, spleen and liver, and by antibody reactivity against Leishmania chagasi using indirect ELISA. Our results showed a prevalence of infection in 14.5% (31/200) of the feline population studied, with 4% (8/200) of positivity by parasitological diagnosis and 11.5% (23/200) by serology.