Vaccine effectiveness and use of collar impregnated with insecticide for reducing incidence of Leishmania infection in dogs in an endemic region for visceral leishmaniasis, in Brazil.

Although a national programme for control of visceral leishmaniosis (VL) is being run in Brazil, the disease continues to spread. This programme is essentially based on culling infected dogs from endemic regions. Thus, there is an urgent need to develop other control measures against VL to deter its advance. Here, a subunit vaccine, a recombinant vaccine, an insecticide-impregnated collar and the associations between these measures were evaluated for reducing the incidence of Leishmania infection in dogs. This was through a cohort study conducted in an endemic region of Brazil, considering the incidence and time of total exposure over a period of 1 year. The incidence of VL was estimated by means of serological and molecular diagnostic tests, 180 and 360 days after the application of the control measures. The estimates of the effectiveness (EF) were not significant in any cohort. The EF of the subunit vaccine, the recombinant vaccine and the collar were 26.4%, 32.8% and 57.7% and the upper limit of the 95% confidence interval for EF were 63.7%, 67.9% and 82.5%, respectively. In conclusion, under the conditions of this study, none of the immunogens for VL control was sufficiently effective to protect dogs against infection. On the other hand, use of collars impregnated with insecticide seems to constitute a method with better prognosis, corroborating other studies in this field.

Serological and molecular diagnostic tests for canine visceral leishmaniasis in Brazilian endemic area: one out of five seronegative dogs are infected.

Euthanasia of infected dogs is one of the measures adopted in Brazil to control visceral leishmaniasis (VL) in endemic areas. To detect infected dogs, animals are screened with the rapid test DPP® Visceral Canine Leishmaniasis for detection of antibodies against K26/K39 fusion antigens of amastigotes (DPP). DPP-positives are confirmed with an immunoenzymatic assay probing soluble antigens of promastigotes (ELISA), while DPP-negatives are considered free of infection. Here, 975 dogs from an endemic region were surveyed by using DPP, ELISA and real-time PCR (qPCR) for the diagnosis of VL. When DPP-negative dogs were tested by qPCR applied in blood and lymph node aspirates, 174/887 (19·6%) were positive in at least one sample. In a second sampling using 115 cases, the DPP-negative dogs were tested by qPCR in blood, lymph node and conjunctival swab samples, and 36/79 (45·6%) were positive in at least one sample. Low-to-moderate pairwise agreement was observed between all possible pair of tests. In conclusion, the official diagnosis of VL in dogs in Brazilian endemic areas failed to accuse an expressive number of infected animals and the impact of the low accuracy of serological tests in the success of euthanasia-based measure for VL control need to be assessed.

Evaluation of an Immunochromatographic Test to the Diagnosis of Canine Brucellosis Caused by Brucella canis.

This study evaluated the performance of an immunochromatographic test (ICT) for the diagnosis of canine brucellosis caused by Brucella canis, comparing its results with that of the rapid slide agglutination test with and without the use of 2-mercaptoethanol and the agar gel immunodiffusion test (AGID). The microbiological culture, PCR and clinical examination were used as reference. According to the results obtained in clinical examination, blood culture, culture of semen and vaginal swab and PCR in blood, semen and vaginal swab, a total of 102 dogs were divided into three groups: B. canis-infected dogs (Group 1), B. canis-non-infected dogs (Group 2) and dogs with suspected brucellosis (Group 3). The diagnostic sensitivity of RSAT, 2ME-RSAT, AGID and ICT in Group 1 was, respectively, 75%, 37.5%, 27.8% and 89.58%. The diagnostic specificity of RSAT, 2ME-RSAT, AGID and ICT in Group 2 was, respectively, 91%, 100%, 100%, and 100%. In dogs with suspected brucellosis, 9.67% were RSAT positive, none was positive by 2ME-RSAT, 3.22% were AGID positive and 6.45% were ICT positive. The main drawback concerning canine brucellosis diagnosis is the lack of a highly sensitive serological assay to be used as a screening test to the rapid identification of infected animals. The ICT showed a high diagnostic specificity and a diagnostic sensitivity value greater than that observed in the RSAT, 2ME-RSAT and AGID. However, 10.41% of infected dogs had negative results by ICT. These dogs were positive by microbiological culture and/or PCR, indicating active infection and consequently a higher potential of spreading Brucella. Although rapid and simple to perform, the ICT lacked sensitivity to be used as a screening test.

Serum protein profile as a biomarker in diagnosing leishmaniosis and monocytic ehrlichiosis in dogs / Perfil sérico de proteínas como biomarcador nos diagnósticos da leishmaniose e da erliquiose monocítica em cães

Diagnosing Canine Visceral Leishmaniosis is challenging for veterinarians given that its hematological and biochemical abnormalities greatly resemble those of other illnesses of dogs, such as canine ehrlichiosis, which is caused by Ehrlichia canis and is highly prevalent with high pathogenicity. The aim of this study was to determine occurrences of serological positivity for the antigens of Ehrlichia canis and Leishmania infantum and its relationship to globulin concentrations in samples from dogs. Out of 93 samples tested, 12.9% were negative for the antigens of both L. infantum and E. canis; 33.3% were seropositive for both antigens. Discordant results were found from 18.3% that were positive only for L. infantum, while 35.5% were positive only for E. canis. Hyperglobulinemia was observed in 88.2% and the statistical analysis showed that there was a significant relationship between the high levels of globulins and seropositivity for the antigen of E. canis. However, the relationship between positivity for the antigen of L. infantum and hyperglobulinemia, showed that there was no statistically significant relationship between the two laboratory findings. From these results, it can be concluded that concomitant infections occur frequently and that hyperglobulinemia is more closely related to ehrlichiosis than to leishmaniosis, in dogs.

O diagnóstico da leishmaniose canina é um desafio ao Médico Veterinário visto que anormalidades hematológicas e bioquímicas muito se assemelham à outras enfermidades dos cães, como a erliquiose canina, causada pela Ehrlichia canis, muito prevalente e de alta patogenicidade. O objetivo deste estudo foi determinar a positividade sorológica frente aos antígenos de Ehrlichia canis e Leishmania infantum e a sua relação com as concentrações de globulinas em amostras de cães. Das 93 amostras testadas, 12,9% foram negativas frente aos antígenos de E. canis e L. infantum e 33% foram soropositivas. Resultados discordantes foram encontradas em 18,3% positivas apenas para L. infantum, enquanto que 35,5% reagiram apenas frente a E. canis. Hiperglobulinemia foi observada em 88,2% das amostras e a análise estatística mostrou haver relação significante entre a soropositividade frente aos antígenos de E. canis e a hiperglobulinemia, e em contrapartida, a relação entre esse aumento de globulinas e a positividade para L. infantum foi insignificante. Pelos resultados apresentados, pode-se concluir que as infecções concomitantes são frequentes e que a hiperglobulinemia está mais intimamente relacionada a erliquiose quando comparada à leishmaniose em cães.

Serum protein profile as a biomarker in diagnosing leishmaniosis and monocytic ehrlichiosis in dogs / Perfil sérico de proteínas como biomarcador nos diagnósticos da leishmaniose e da erliquiose monocítica em cães

Diagnosing Canine Visceral Leishmaniosis is challenging for veterinarians given that its hematological and biochemical abnormalities greatly resemble those of other illnesses of dogs, such as canine ehrlichiosis, which is caused by Ehrlichia canis and is highly prevalent with high pathogenicity. The aim of this study was to determine occurrences of serological positivity for the antigens of Ehrlichia canis and Leishmania infantum and its relationship to globulin concentrations in samples from dogs. Out of 93 samples tested, 12.9% were negative for the antigens of both L. infantum and E. canis; 33.3% were seropositive for both antigens. Discordant results were found from 18.3% that were positive only for L. infantum, while 35.5% were positive only for E. canis. Hyperglobulinemia was observed in 88.2% and the statistical analysis showed that there was a significant relationship between the high levels of globulins and seropositivity for the antigen of E. canis. However, the relationship between positivity for the antigen of L. infantum and hyperglobulinemia, showed that there was no statistically significant relationship between the two laboratory findings. From these results, it can be concluded that concomitant infections occur frequently and that hyperglobulinemia is more closely related to ehrlichiosis than to leishmaniosis, in dogs.(AU)

O diagnóstico da leishmaniose canina é um desafio ao Médico Veterinário visto que anormalidades hematológicas e bioquímicas muito se assemelham à outras enfermidades dos cães, como a erliquiose canina, causada pela Ehrlichia canis, muito prevalente e de alta patogenicidade. O objetivo deste estudo foi determinar a positividade sorológica frente aos antígenos de Ehrlichia canis e Leishmania infantum e a sua relação com as concentrações de globulinas em amostras de cães. Das 93 amostras testadas, 12,9% foram negativas frente aos antígenos de E. canis e L. infantum e 33% foram soropositivas. Resultados discordantes foram encontradas em 18,3% positivas apenas para L. infantum, enquanto que 35,5% reagiram apenas frente a E. canis. Hiperglobulinemia foi observada em 88,2% das amostras e a análise estatística mostrou haver relação significante entre a soropositividade frente aos antígenos de E. canis e a hiperglobulinemia, e em contrapartida, a relação entre esse aumento de globulinas e a positividade para L. infantum foi insignificante. Pelos resultados apresentados, pode-se concluir que as infecções concomitantes são frequentes e que a hiperglobulinemia está mais intimamente relacionada a erliquiose quando comparada à leishmaniose em cães.(AU)

Occurrence of infectious and parasitic diseases in association with the outdoor habits of household dogs and cats a case-control study / Estudo caso-controle da ocorrência de doenças infecto-parasitárias associadas aos hábitos semi-domiciliados de cães e gatos domésticos

Many owners believe to act in their pets best interest by allowing them to go outside, with or without supervision. However, outdoor exposure greatly increases the risk of disease and accidents. In this study, we evaluated the association between infectious and parasitic diseases and the outdoor habits of pet dogs and cats. Epidemiological data were obtained from the records of dogs and cats treated at the Teaching Clinic and Hospital Unit of Veterinary Medicine in the city of Pirassununga, state of São Paulo, Brazil. Pets with any form of infection were included in the case study group, and pets with no infectious or parasitic diseases were used as controls. Animals were further divided according to their habits into indoor animals, indoor animals taken for walks, and outdoor animals. The odds ratio of having a disease was calculated from the comparisons among these groups using the MedCalc Statistical Software. We found an increased risk for the occurrence of infectious or parasitic diseases in outdoor dogs and cats when compared to indoor animals (OR of 4.735) and to those taken for walks (OR of 2.303). In light of our results, we suggest that awareness campaigns should also focus on the benefits of keeping pets indoors.

Muitos proprietários acreditam agir no melhor interesse de seus animais de estimação permitindo-os o acesso ao ambiente externo, com ou sem supervisão. Entretanto, isso aumenta consideravelmente o risco para a ocorrência de doenças e acidentes. Neste estudo, foi avaliada a associação entre doenças infecciosas e parasitárias com relação aos hábitos semi-domiciliados de cães e gatos. Dados epidemiológicos foram obtidos de arquivo de prontuários de cães e gatos atendidos na Unidade Didática Clínico Hospitalar (UDCH) do curso de Medicina Veterinária da FZEA/USP no município de Pirassununga, estado de São Paulo, Brasil. Animais de estimação que apresentaram doenças infecto-parasitárias foram incluídos no grupo de casos; animais sem tais doenças, controles. Os animais foram ainda divididos de acordo em domiciliados, domiciliados frequentemente levados a passeios e semi-domiciliados. A razão de chances para a ocorrência de doenças infecciosas foi calculada a partir da comparação dos grupos supracitados, fazendo uso do software estatístico MedCalc. Encontrou-se um risco aumentado para a ocorrência de doenças infecto-parasitárias em cães e gatos semi-domiciliados quando comparados aos animais domiciliados (OR de 4.735) e quanto aos domiciliados guiados em passeios (OR de 2.303). À luz dos resultados se sugere que campanhas de conscientização foquem também nos benefícios da criação domiciliada de animais de estimação.

Occurrence of infectious and parasitic diseases in association with the outdoor habits of household dogs and cats a case-control study / Estudo caso-controle da ocorrência de doenças infecto-parasitárias associadas aos hábitos semi-domiciliados de cães e gatos domésticos

Many owners believe to act in their pets best interest by allowing them to go outside, with or without supervision. However, outdoor exposure greatly increases the risk of disease and accidents. In this study, we evaluated the association between infectious and parasitic diseases and the outdoor habits of pet dogs and cats. Epidemiological data were obtained from the records of dogs and cats treated at the Teaching Clinic and Hospital Unit of Veterinary Medicine in the city of Pirassununga, state of São Paulo, Brazil. Pets with any form of infection were included in the case study group, and pets with no infectious or parasitic diseases were used as controls. Animals were further divided according to their habits into indoor animals, indoor animals taken for walks, and outdoor animals. The odds ratio of having a disease was calculated from the comparisons among these groups using the MedCalc Statistical Software. We found an increased risk for the occurrence of infectious or parasitic diseases in outdoor dogs and cats when compared to indoor animals (OR of 4.735) and to those taken for walks (OR of 2.303). In light of our results, we suggest that awareness campaigns should also focus on the benefits of keeping pets indoors.(AU)

Muitos proprietários acreditam agir no melhor interesse de seus animais de estimação permitindo-os o acesso ao ambiente externo, com ou sem supervisão. Entretanto, isso aumenta consideravelmente o risco para a ocorrência de doenças e acidentes. Neste estudo, foi avaliada a associação entre doenças infecciosas e parasitárias com relação aos hábitos semi-domiciliados de cães e gatos. Dados epidemiológicos foram obtidos de arquivo de prontuários de cães e gatos atendidos na Unidade Didática Clínico Hospitalar (UDCH) do curso de Medicina Veterinária da FZEA/USP no município de Pirassununga, estado de São Paulo, Brasil. Animais de estimação que apresentaram doenças infecto-parasitárias foram incluídos no grupo de casos; animais sem tais doenças, controles. Os animais foram ainda divididos de acordo em domiciliados, domiciliados frequentemente levados a passeios e semi-domiciliados. A razão de chances para a ocorrência de doenças infecciosas foi calculada a partir da comparação dos grupos supracitados, fazendo uso do software estatístico MedCalc. Encontrou-se um risco aumentado para a ocorrência de doenças infecto-parasitárias em cães e gatos semi-domiciliados quando comparados aos animais domiciliados (OR de 4.735) e quanto aos domiciliados guiados em passeios (OR de 2.303). À luz dos resultados se sugere que campanhas de conscientização foquem também nos benefícios da criação domiciliada de animais de estimação.(AU)

Neospora caninum: avaliação de anticorpos e problemas reprodutivos em vacas de corte até 60 dias de gestação / Neospora caninum: evaluation of antibodies and reproductive problems in beef cows with up to 60 days of pregnancy

O presente trabalho teve como objetivo identificar anticorpos anti-Neospora caninum em fêmeas bovinas da raça Nelore pelos métodos sorológicos de Imunoabsorbância Ligada a Enzima (ELISA) e Imunofluorescência Indireta (RIFI) e buscar associação entre a soropositividade e o histórico reprodutivo até 60 dias de gestação. Adicionalmente, nas amostras positivas foram realizados testes de ELISA-Avidez e ELISA para anticorpos anti-Toxoplama gondii. Para isto, foi constituído um banco de 375 amostras de soros, categorizados em três grupos, de acordo com o histórico reprodutivo de cada fêmea até os 60 dias após a Inseminação Artificial (I.A). Para a análise estatística utilizou-se o teste de Qui-Quadrado de Pearson (X²) e índice Kappa (k). Foram encontrados 8% (30/375) e 5,07% (19/375) de soros positivos para N. caninum pelo ELISA e RIFI, respectivamente, com o ELISA apresentando concordância alta com a RIFI (k = 0,67). A infecção encontrada nesse rebanho, revelado pelo ELISA-Avidez, foi considerada crônica. Nesse estudo, 9,08% das fêmeas soropositivas pela RIFI e 17,25% das fêmeas positivas pelo ELISA apresentaram algum problema reprodutivo. Entretanto, não foi encontrada associação significativa entre a soropositividade das vacas, com o retorno ao cio ou a ocorrência de aborto, observados até 60 dias de gestação (p>0,05). Não foi observado nenhum animal co-infectado por N. caninum e T. gondii.

This study aimed to identify anti-Neopora caninum antibodies in cows by serological methods Imunoabsorbância Linked Enzyme (ELISA) and Indirect Immunofluorescence Antibody Test (IFAT) and seek association between seropositivity and the reproductive history up to 60 days of gestation. In addition, in positive samples were performed ELISA-Avidity and ELISA tests for anti-Toxoplasma gondii antibodies. For this, was constituted a bank of 375 serum samples categorized in three groups according to the reproduction history of each female until 60 days after the Artificial Insemination (AI). Statistical we used the Pearson’s Chi-square test (X²) and Kappa index (k). Found 8% (30/375) and 5,07% (19/375) of positive sera for N. caninum by IFAT and ELISA, respectively, with the ELISA showing high correlation with IFAT (k = 0,67). The infection found in this flock, revealed by ELISA-Avidity was considered chronic. In this study, 9,08% of positive females by IFAT and 17,25% of females positive by ELISA showed some reproductive problem. However, there was no statistically significant association between seropositivity of cows, with the return to estrus or the occurrence of abortion, observed up to 60 days of gestation (p>0,05). There was no co-infected animal by N. caninum and T. gondii.

Neospora caninum: avaliação de anticorpos e problemas reprodutivos em vacas de corte até 60 dias de gestação / Neospora caninum: evaluation of antibodies and reproductive problems in beef cows with up to 60 days of pregnancy

O presente trabalho teve como objetivo identificar anticorpos anti-Neospora caninum em fêmeas bovinas da raça Nelore pelos métodos sorológicos de Imunoabsorbância Ligada a Enzima (ELISA) e Imunofluorescência Indireta (RIFI) e buscar associação entre a soropositividade e o histórico reprodutivo até 60 dias de gestação. Adicionalmente, nas amostras positivas foram realizados testes de ELISA-Avidez e ELISA para anticorpos anti-Toxoplama gondii. Para isto, foi constituído um banco de 375 amostras de soros, categorizados em três grupos, de acordo com o histórico reprodutivo de cada fêmea até os 60 dias após a Inseminação Artificial (I.A). Para a análise estatística utilizou-se o teste de Qui-Quadrado de Pearson (X²) e índice Kappa (k). Foram encontrados 8% (30/375) e 5,07% (19/375) de soros positivos para N. caninum pelo ELISA e RIFI, respectivamente, com o ELISA apresentando concordância alta com a RIFI (k = 0,67). A infecção encontrada nesse rebanho, revelado pelo ELISA-Avidez, foi considerada crônica. Nesse estudo, 9,08% das fêmeas soropositivas pela RIFI e 17,25% das fêmeas positivas pelo ELISA apresentaram algum problema reprodutivo. Entretanto, não foi encontrada associação significativa entre a soropositividade das vacas, com o retorno ao cio ou a ocorrência de aborto, observados até 60 dias de gestação (p>0,05). Não foi observado nenhum animal co-infectado por N. caninum e T. gondii.(AU)

This study aimed to identify anti-Neopora caninum antibodies in cows by serological methods Imunoabsorbância Linked Enzyme (ELISA) and Indirect Immunofluorescence Antibody Test (IFAT) and seek association between seropositivity and the reproductive history up to 60 days of gestation. In addition, in positive samples were performed ELISA-Avidity and ELISA tests for anti-Toxoplasma gondii antibodies. For this, was constituted a bank of 375 serum samples categorized in three groups according to the reproduction history of each female until 60 days after the Artificial Insemination (AI). Statistical we used the Pearsons Chi-square test (X²) and Kappa index (k). Found 8% (30/375) and 5,07% (19/375) of positive sera for N. caninum by IFAT and ELISA, respectively, with the ELISA showing high correlation with IFAT (k = 0,67). The infection found in this flock, revealed by ELISA-Avidity was considered chronic. In this study, 9,08% of positive females by IFAT and 17,25% of females positive by ELISA showed some reproductive problem. However, there was no statistically significant association between seropositivity of cows, with the return to estrus or the occurrence of abortion, observed up to 60 days of gestation (p>0,05). There was no co-infected animal by N. caninum and T. gondii.(AU)

Detection of Leishmania (L.) chagasi in canine skin.

Canine visceral leishmaniasis (CVL) is caused by a protozoa parasite of the specie Leishmania (L.) chagasi endemic for humans and dogs in many regions of Brazil. The purpose of the present study was the detection of (L.) chagasi in canine skin tissues from three different groups of clinical signs: asymptomatic, oligosymptomatic and polysymptomatic Leishmania-infected dogs. Lesional or non-lesional skin tissue samples from 34 naturally infected dogs were obtained and processed by histochemistry (HE) and immunohistochemistry (IMHC) for direct parasitological examination and the results were compared with a polymerase chain reaction (PCR) method. IMHC and HE methods detected intact Leishmania-amastigote parasites in lesional and no lesional skin, particularly in asymptomatic and oligosymptomatic dogs. 50% of skin samples collected from asymptomatic and 21.4% from oligosymptomatic dogs had parasites in their skins even though with mild inflammatory reaction or without any macroscopic dermatological alterations. On the other hand, 100% of polysymptomatic dogs showed several forms of clinical dermatological alterations and 91.7% had intact amastigotes with parasite load ranging from mild to intense. By PCR, DNA of Leishmania spp. was detected in 97.8% skin samples regardless clinical status of the dogs or IMHC/HE test results. PCR on skin was a sensitive procedure for CVL diagnosis, but direct observation of intact parasite in skin biopsies, particularly by IMHC, may be also considered to support the diagnosis.

Neospora caninum: AVALIAÇÃO DE ANTICORPOS E PROBLEMAS REPRODUTIVOS EM VACAS DE CORTE ATÉ 60 DIAS DE GESTAÇÃO

O presente trabalho teve como objetivo identificar anticorpos anti-Neospora caninum em fêmeas bovinas da raça Nelore pelos métodos sorológicos de Imunoabsorbância Ligada a Enzima (ELISA) e Imunofluorescência Indireta (RIFI) e buscar associação entre a soropositividade e o histórico reprodutivo até 60 dias de gestação. Adicionalmente, nas amostras positivas foram realizados testes de ELISA-Avidez e ELISA para anticorpos anti-Toxoplama gondii. Para isto, foi constituído um banco de 375 amostras de soros, categorizados em três grupos, de acordo com o histórico reprodutivo de cada fêmea até os 60 dias após a Inseminação Artificial (I.A). Para a análise estatística utilizou-se o teste de Qui-Quadrado de Pearson (X²) e índice Kappa (k). Foram encontrados 8% (30/375) e 5,07% (19/375) de soros positivos para N. caninum pelo ELISA e RIFI, respectivamente, com o ELISA apresentando concordância alta com a RIFI (k = 0,67). A infecção encontrada nesse rebanho, revelado pelo ELISA-Avidez, foi considerada crônica. Nesse estudo, 9,08% das fêmeas soropositivas pela RIFI e 17,25% das fêmeas positivas pelo ELISA apresentaram algum problema reprodutivo. Entretanto, não foi encontrada associação significativa entre a soropositividade das vacas, com o retorno ao cio ou a ocorrência de aborto, observados até 60 dias de gestação (p>0,05). Não foi observado nenhum animal co-infectado por N. caninum

SERUM PROTEIN PROFILE AS A BIOMARKER IN DIAGNOSING LEISHMANIOSIS AND MONOCYTIC EHRLICHIOSIS IN DOGS

Diagnosing Canine Visceral Leishmaniosis is challenging for veterinarians given that its hematological and biochemical abnormalities greatly resemble those of other illnesses of dogs, such as canine ehrlichiosis, which is caused by Ehrlichia canis and is highly prevalent with high pathogenicity. The aim of this study was to determine occurrences of serological positivity for the antigens of Ehrlichia canis and Leishmania infantum and its relationship to globulin concentrations in samples from dogs. Out of 93 samples tested, 12.9% were negative for the antigens of both L. infantum and E. canis; 33.3% were seropositive for both antigens. Discordant results were found from 18.3% that were positive only for L. infantum, while 35.5% were positive only for E. canis. Hyperglobulinemia was observed in 88.2% and the statistical analysis showed that there was a significant relationship between the high levels of globulins and seropositivity for the antigen of E. canis. However, the relationship between positivity for the antigen of L. infantum and hyperglobulinemia, showed that there was no statistically significant relationship between the two laboratory findings. From these results, it can be concluded that concomitant infections occur frequently and that hyperglobulinemia is more closely related to ehrlichiosis than to leishmaniosis, in dogs.