Differentials in the epidemiological profile of canine visceral leishmaniasis in the semi-arid region of Paraíba, Brazil / Diferenciais no perfil epidemiológico da leishmaniose visceral canina no semiárido da Paraíba, Brasil

The objective of this study was to estimate the prevalence of canine visceral leishmaniasis (CVL) and to identify the differences in associated factors to its occurrence in urban area and countrysides in the municipality of Santa Luzia located in the semi-arid region of Paraíba. In the years 2015 and 2016, 779 blood samples from dogs were collected. The prevalence was determined by three serological techniques, ELISA-S7® Kit, DPP® Rapid Test and EIE-LVC® Kit, considering positive the samples that reacted in at least two assays. Associated factors were determined by univariate and multivariate analyzes of the guardians' responses to the epidemiological questionnaire. The prevalence of anti-Leishmania infantum antibodies in the studied municipality was 15.00% (117/779), being higher in the urban area (15.20%) than in the countryside (13.60%). The neighborhood with the highest prevalence was Frei Damião with 26.40% (33/125), being considered a hotspot (OR 1.245, p=0.007). Other associated factors were the semi-domiciliary breeding (OR 1.798, p=0.025), in the urban area, and hunting dog (OR 18.505, p=0.016), contact with cattle (OR 17.298, p=0.022) and environment where the dog is raised (OR 4.802, p=0.024) in the countryside. In the municipality of Santa Luzia, the prevalence of canine visceral leishmaniasis is high and the disease is widely distributed. Epidemiological differences between urban area and the countryside could be observed demonstrating the need for more adequate control measures for each locality and proving the urbanization process.(AU)

O objetivo desta pesquisa foi estimar a prevalência da leishmaniose visceral canina (LVC) e identificar as diferenças nos fatores relacionados à sua ocorrência nas zonas urbana e rural do município de Santa Luzia, localizado no semiárido paraibano. Nos anos de 2015 e 2016, coletaram-se 779 amostras de sangue de cães. A prevalência foi determinada através de três técnicas sorológicas, Kit ELISA-S7®, teste rápido DPP® e Kit EIE-LVC®, considerando positivas as amostras que reagiram em, pelo menos, dois ensaios. Os fatores relacionados foram determinados por meio das análises estatísticas uni e multivariada das respostas dos tutores ao questionário epidemiológico. A prevalência de anticorpos anti-Leishmania infantum encontrada no município estudado foi de 15,00% (117/779), sendo maior na zona urbana (15,20%) do que na rural (13,60%). O bairro que apresentou maior prevalência foi o Frei Damião com 26,40% (33/125), sendo considerado um hotspot (OR 1,245; p=0,007). Outros fatores relacionados encontrados foram a criação semidomiciliar (OR 1,798; p=0,025), na zorna urbana, e cão de caça (OR 18,505; p=0,016), contato com bovinos (OR 17,298; p=0,022) e ambiente onde o cão é criado (OR 4,802; p=0,024), na zona rural. Verifica-se a elevada prevalência da leishmaniose visceral canina e a sua ampla distribuição no município de Santa Luzia. Diferenças epidemiológicas entre as zonas urbana e rural puderam ser observadas, demonstrando a necessidade de medidas de controle mais adequadas para cada localidade e comprovando o processo de urbanização.(AU)

Information technology by mobile communication for the notification of canine visceral leishmaniasis / Tecnologia da informação por comunicação móvel para notificação de leishmaniose visceral canina

Visceral leishmaniasis is the most severe form of a human and animal disease complex entitled leishmaniasis, which is endemic to 70 countries. It is imperative to develop and offer technologies capable of increasing the resolution ability of control programs of this zoonosis. In the search for technological innovations in health, especially in environmental surveillance, the objective is to develop a mobile application (App) for smartphones in order to facilitate and systematize the notification of positive cases of canine visceral leishmaniasis (CVL) by veterinarians working in clinics for assisting the municipal health surveillance in the management of this zoonosis. Thus, we developed an App, C7 LVC - Canine Visceral Leishmaniasis Notification System, with formatting based on the CR Campeiro 7® software. The technology created enables the filling of important gaps in information systems, facilitating the transmission of data and the use of this data by public management bodies to take CVL prevention and control actions.(AU)

A leishmaniose visceral é a forma mais grave de um complexo de doenças humanas e animais, denominado leishmaniose, endêmica em 70 países. É imprescindível desenvolver e oferecer tecnologias capazes de aumentar a capacidade de resolução dos programas de controle desta zoonose. Na busca por inovações tecnológicas em saúde, principalmente na vigilância ambiental, o objetivo é desenvolver um aplicativo móvel (App) para smartphones a fim de facilitar e sistematizar a notificação de casos positivos de leishmaniose visceral canina (LVC) por médicos veterinários que atuam em clínicas auxiliando a vigilância sanitária municipal, na gestão desta zoonose. Para tanto, foi desenvolvido um App, C7 LVC - Sistema de Notificação da Leishmaniose Visceral Canina, com formatação baseada no software CR Campeiro 7®. A tecnologia criada possibilita o preenchimento de lacunas importantes nos sistemas de informação, facilitando a transmissão de dados e a utilização desses dados pelos órgãos da gestão pública para a tomada de ações de prevenção e controle da LVC.(AU)

Detection of Leishmania infantum amastigotes in neutrophil from peripheral blood in a naturally infected dog / Detecção de formas amastigotas de Leishmania infantum em neutrófilos do sangue periférico de cão naturalmente infectado

Abstract Canine visceral leishmaniasis (CVL) is a zoonotic disease of high lethality caused by Leishmania infantum in the Americas. In the infected dog, the amastigotes are scarce in blood, especially in the late phase of the disease. This study aimed to report a rare case of L. infantum amastigotes found in neutrophils from peripheral blood of a naturally infected dog in terminal phase of CVL, also describing its clinical status before and after treatment with miltefosine 2%. The dog, which presented as polysymptomatic and with classical signs and symptoms of CVL was submitted to the following tests: Dual Path Platform (DPP) rapid test, ELISA and parasitological examination of peripheral blood. Hematological and biochemical parameters were obtained before and after treatment. All diagnostic tests were positive for CVL. The identification of L. infantum amastigotes inside neutrophils from peripheral blood was confirmed through microscopy, and the species was confirmed by molecular analysis. At the end of the treatment, peripheral parasitemia was not detected, and improvements were observed in clinical and laboratorial parameters. Finally, this atypical finding can be used as example to raise discussions about the real immunological role of neutrophils in late phases of CVL and its clinical/therapeutic implications.

Resumo A leishmaniose visceral canina (LVC) é uma doença zoonótica de alta letalidade causada por Leishmania infantum nas Américas. No cão infectado, as formas amastigotas são escassas no sangue, principalmente na fase tardia da doença. Este estudo teve como objetivo relatar um caso raro de amastigotas de L. infantum encontradas em neutrófilos do sangue periférico de um cão naturalmente infectado e terminal da LVC, descrevendo também seu estado clínico antes e após o tratamento com miltefosina a 2%. O cão, que se apresentou como polissintomático e com sinais e sintomas clássicos da LVC foi submetido aos seguintes testes: teste rápido Dual Path Platform (DPP), ELISA e exame parasitológico de sangue periférico. Os parâmetros hematológicos e bioquímicos foram obtidos antes e após o tratamento. Todos os testes diagnósticos foram positivos para LVC. A identificação de formas amastigotas de L. infantum, dentro de neutrófilos do sangue periférico foi confirmada por microscopia, e a espécie foi confirmada por análise molecular. Ao final do tratamento, não foi detectada parasitemia periférica, observando-se melhora dos parâmetros clínicos e laboratoriais. Por fim, esse achado atípico pode ser usado como exemplo para levantar discussões sobre o real papel imunológico dos neutrófilos nas fases tardias da LVC e suas implicações clínicas/terapêuticas.

Information technology by mobile communication for the notification of canine visceral leishmaniasis

ABSTRACT: Visceral leishmaniasis is the most severe form of a human and animal disease complex entitled leishmaniasis, which is endemic to 70 countries. It is imperative to develop and offer technologies capable of increasing the resolution ability of control programs of this zoonosis. In the search for technological innovations in health, especially in environmental surveillance, the objective is to develop a mobile application (App) for smartphones in order to facilitate and systematize the notification of positive cases of canine visceral leishmaniasis (CVL) by veterinarians working in clinics for assisting the municipal health surveillance in the management of this zoonosis. Thus, we developed an App, C7 LVC - Canine Visceral Leishmaniasis Notification System, with formatting based on the CR Campeiro 7® software. The technology created enables the filling of important gaps in information systems, facilitating the transmission of data and the use of this data by public management bodies to take CVL prevention and control actions.

RESUMO: A leishmaniose visceral é a forma mais grave de um complexo de doenças humanas e animais, denominado leishmaniose, endêmica em 70 países. É imprescindível desenvolver e oferecer tecnologias capazes de aumentar a capacidade de resolução dos programas de controle desta zoonose. Na busca por inovações tecnológicas em saúde, principalmente na vigilância ambiental, o objetivo é desenvolver um aplicativo móvel (App) para smartphones a fim de facilitar e sistematizar a notificação de casos positivos de leishmaniose visceral canina (LVC) por médicos veterinários que atuam em clínicas auxiliando a vigilância sanitária municipal, na gestão desta zoonose. Para tanto, foi desenvolvido um App, C7 LVC - Sistema de Notificação da Leishmaniose Visceral Canina, com formatação baseada no software CR Campeiro 7®. A tecnologia criada possibilita o preenchimento de lacunas importantes nos sistemas de informação, facilitando a transmissão de dados e a utilização desses dados pelos órgãos da gestão pública para a tomada de ações de prevenção e controle da LVC.

Differentials in the epidemiological profile of canine visceral leishmaniasis in the semi-arid region of Paraíba, Brazil

ABSTRACT: The objective of this study was to estimate the prevalence of canine visceral leishmaniasis (CVL) and to identify the differences in associated factors to its occurrence in urban area and countrysides in the municipality of Santa Luzia located in the semi-arid region of Paraíba. In the years 2015 and 2016, 779 blood samples from dogs were collected. The prevalence was determined by three serological techniques, ELISA-S7® Kit, DPP® Rapid Test and EIE-LVC® Kit, considering positive the samples that reacted in at least two assays. Associated factors were determined by univariate and multivariate analyzes of the guardians responses to the epidemiological questionnaire. The prevalence of anti-Leishmania infantum antibodies in the studied municipality was 15.00% (117/779), being higher in the urban area (15.20%) than in the countryside (13.60%). The neighborhood with the highest prevalence was Frei Damião with 26.40% (33/125), being considered a hotspot (OR 1.245, p=0.007). Other associated factors were the semi-domiciliary breeding (OR 1.798, p=0.025), in the urban area, and hunting dog (OR 18.505, p=0.016), contact with cattle (OR 17.298, p=0.022) and environment where the dog is raised (OR 4.802, p=0.024) in the countryside. In the municipality of Santa Luzia, the prevalence of canine visceral leishmaniasis is high and the disease is widely distributed. Epidemiological differences between urban area and the countryside could be observed demonstrating the need for more adequate control measures for each locality and proving the urbanization process.

RESUMO: O objetivo desta pesquisa foi estimar a prevalência da leishmaniose visceral canina (LVC) e identificar as diferenças nos fatores relacionados à sua ocorrência nas zonas urbana e rural do município de Santa Luzia, localizado no semiárido paraibano. Nos anos de 2015 e 2016, coletaram-se 779 amostras de sangue de cães. A prevalência foi determinada através de três técnicas sorológicas, Kit ELISA-S7®, teste rápido DPP® e Kit EIE-LVC®, considerando positivas as amostras que reagiram em, pelo menos, dois ensaios. Os fatores relacionados foram determinados por meio das análises estatísticas uni e multivariada das respostas dos tutores ao questionário epidemiológico. A prevalência de anticorpos anti-Leishmania infantum encontrada no município estudado foi de 15,00% (117/779), sendo maior na zona urbana (15,20%) do que na rural (13,60%). O bairro que apresentou maior prevalência foi o Frei Damião com 26,40% (33/125), sendo considerado um hotspot (OR 1,245; p=0,007). Outros fatores relacionados encontrados foram a criação semidomiciliar (OR 1,798; p=0,025), na zorna urbana, e cão de caça (OR 18,505; p=0,016), contato com bovinos (OR 17,298; p=0,022) e ambiente onde o cão é criado (OR 4,802; p=0,024), na zona rural. Verifica-se a elevada prevalência da leishmaniose visceral canina e a sua ampla distribuição no município de Santa Luzia. Diferenças epidemiológicas entre as zonas urbana e rural puderam ser observadas, demonstrando a necessidade de medidas de controle mais adequadas para cada localidade e comprovando o processo de urbanização.

Validation of ELISA with recombinant antigens in serological diagnosis of canine Leishmania infantum infection

BACKGROUND Dogs are the main peridomiciliary reservoir of Leishmania infantum thus the correct diagnosis of infection is essential for the control of the transmission and treatment as well. However, the diagnosis is based on serological assays that are not fully effective. OBJECTIVE We aimed to establish an effective serological assay for the diagnosis of L. infantum infected dogs using Leishmania-derived recombinant antigens. METHODS Leishmania derived rK39-, rK28-, rKR95-based enzyme-linked immunosorbent assay (ELISA) was standardized using symptomatic and asymptomatic L. infantum-infected dogs. Then 2,530 samples from inquiry in endemic areas for VL were evaluated and the results compared with recommended assays by the Brazilian Ministry of Health (MH algorithm). Further samples from a cohort of 30 dogs were searched. FINDINGS For rK39-, rK28- and rKR95-ELISA the sensitivity was around 97% and specificity 100%. The positivity of these three ELISA in the inquiry samples was 27-28%, around 10% higher than the assays currently in use. When cohort samples were searched, we observed likely false-negative results (> 65%) with supposedly negative samples that turned positive six months later with the assays in use (MH algorithm). MAIN CONCLUSIONS For the diagnosis of L. infantum-infected dogs, rK39-based ELISA showed better diagnostic performance than other assays in use in Brazil and worldwide.

Evaluation of the euthanasia of seropositive dogs for canine visceral leishmaniasis as the only method of controling the disease in the enzootic area in the Midwestern Minas Gerais / Avaliação da eutanásia de cães soro reagentes para leishmaniose visceral canina como único método de controle da doença em área enzoótica no Centro Oeste de Minas Gerais

Human Visceral Leishmaniasis (VL) is expanding, and it is distributed in the five geographic regions of Brazil, with the Northeast being the region that presents the most significant number of registered cases. The main urban reservoir of the etiological agent of VL is the domestic dog, and it is known that canine cases precede human cases. One of the control actions of VL, recommended by the Ministry of Health, is performing the euthanasia of seropositive dogs. In 2013, in the municipality of Iguatama/MG, the first canine serological survey was carried out in the city, with a prevalence of 8.3% of seropositive dogs for Leishmania infantum. Of the seropositive animals for Canine Visceral Leishmaniasis (CVL) in this survey, 84% were euthanized, and 16% died within two years after diagnosis. No other control measures for CVL were taken in the municipality. The objectives of the present study were to determine the current prevalence of seropositive dogs for CVL in the municipality of Iguatama and to observe the impact of euthanasia of seropositive dogs to VL as the only control measure performed in this municipality, which is considered an enzootic area of the disease. For this, a new canine epidemiological survey was carried out in the municipality of Iguatama, following the guidelines of the Manual of Surveillance and Control of Visceral Leishmaniasis. Blood samples were collected from 270 dogs and tested by DPP® immunochromatographic test and by Enzyme-Linked Immunosorbent Assay (ELISA). The animals that presented inconclusive results had new blood samples collected and analyzed. The only animal that showed a positive result in DPP® and undetermined in the ELISA, in the first evaluation, became seropositive four months later, so this study reinforces the recommendation of the Ministry of Health to reassess dogs that present inconclusive results for CVL. From a total of 270 samples, 21 (7.8%) were reagents in both tests. Thus, the prevalence of seropositive dogs for CVL, in 2017, in the urban area of the municipality of Iguatama was 7.8%. The Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) molecular technique confirmed infection by L. infantum in the ten dogs sampled with CVL-positive serology. The comparison between the current prevalence (after euthanasia) with that found in 2013 (8.3%), there was no significant difference (p=0.764). The prevalence of CVL in the urban area of the municipality of Iguatama is still high, making it possible to presume that the euthanasia of seropositive dogs for CVL, and the absence of monitoring or other interventions measures, did not contribute to decrease the transmission of the parasite and was not sufficient for the control of CVL in the municipality of Iguatama, an area considered as non-endemic to CVL until 2013.(AU)

A Leishmaniose visceral humana (LV) está em franca expansão e distribuída nas cinco regiões geográficas do Brasil, o Nordeste sendo a região em que há o maior número de casos registrados. O principal reservatório urbano do agente etiológico da LV é o cão doméstico e sabe-se que casos caninos antecedem o aparecimento de casos humanos. Uma das ações de controle da LV, preconizada pelo Ministério da Saúde, é a eutanásia dos cães soro reagentes. Em 2013, no município de Iguatama/MG, foi realizado o primeiro inquérito sorológico canino na cidade, sendo constatada uma prevalência de 8,3% de cães soro reagentes para Leishmania infantum. Dos animais com sorologia positiva para Leishmaniose visceral canina (LVC), neste inquérito, 84% foram eutanasiados e 16% foram a óbito em, no máximo, dois anos após o diagnóstico. Nenhuma outra medida de controle para LVC foi realizada no município. Os objetivos deste estudo foram determinar a prevalência atual de cães soro reagentes para LVC no município de Iguatama e observar o impacto das eutanásias de cães soro reagentes para LV como única medida de controle realizada neste município, considerado área enzoótica para a doença. Para isso, foi realizado um novo inquérito epidemiológico canino no município de Iguatama, seguindo as normas do Manual de Vigilância e Controle da Leishmaniose Visceral. Foram colhidas amostras sanguíneas de 270 cães que foram examinadas pelo teste imunocromatográfico DPP® e pelo ensaio imunoenzimático (ELISA). Os animais que apresentaram resultados inconclusivos tiveram novas amostras de sangue coletadas e analisadas. O único animal que apresentou resultado positivo no DPP® e indeterminado no ELISA, na primeira avaliação, soro converteu quatro meses depois, o que reforça a recomendação do Ministério da Saúde de reavaliar os cães que apresentam resultado inconclusivo para LVC. Do total das 270 amostras, 21 foram reagentes nos dois testes. Portanto, a prevalência de cães soro reagentes para LVC, em 2017, na área urbana do município de Iguatama foi igual a 7,8%. A infecção pela espécie Leishmania infantum foi confirmada através da técnica molecular de PCR-RFLP em 10 cães amostrados com sorologia positiva para LVC. A comparação entre a prevalência atual (depois das eutanásias) com a encontrada em 2013 (8,3%), não mostrou diferença significativa (p=0,764). Uma vez que a soro prevalência de LVC na área urbana do município de Iguatama ainda é alta, pode-se supor que a eutanásia dos cães soro reagentes para LVC, somada à ausência de monitoramento e de outras medidas de intervenção, não contribuiu para a diminuição da transmissão do parasito, e não foi suficiente para o controle de LVC no município de Iguatama, uma área considerada, até 2013, indene para LVC.(AU)

A cross-sectional approach including dog owner characteristics as predictors of visceral leishmaniasis infection in dogs

BACKGROUND Visceral leishmaniasis (VL) is relevant for human and animal public health. Several factors have been associated with the risk of Leishmania infantum infection in dogs. However, dog owner characteristics have been rarely explored. OBJECTIVES To estimate the prevalence and to identify the associated factors for VL infection including dog owners characteristics. METHODS A cross-sectional study was conducted including dogs from an endemic canine visceral leishmaniasis (CVL) region in the Federal District, Brazil. The infection was detected using parasitological, serological, and molecular methods. The associated factors were identified through Poisson regression modelling. FINDINGS The prevalence of infection was 26.25% [95% confidence interval (CI): 20.05 to 33.57]. The associated factors were: short coat prevalence ratio (PR) = 2.33 (95% CI: 1.02 to 5.22); presence of backyard with predominance of soil and/or vegetation PR = 4.15 (95% CI: 1.35 to 12.77); and highest gross family income score PR = 2.03 (95% CI: 1.16 to 3.54). MAIN CONCLUSION This is the first study that relates higher socioeconomic status of dog owners as an independent factor associated with higher prevalence of VL infection, along with other strongly associated factors related to receptive environment for phlebotomines. Our findings strengthen the need for exploration of the biological and behavioural bases linking dog owner characteristics to the risk of canine infection in prospective cohort studies.

Molecular detection of Leishmania infantum DNA according to clinical stages of leishmaniasis in dog / Deteção molecular de DNA de Leishmania infantum em diferentes estágios clínicos da leishmaniose em cães

Abstract The aim of this study was to compare molecular tests used to diagnose Leishmania spp. in dogs with different stages of infection. Blood and conjunctival swab (CS) samples from dogs classified in four clinical stages were subjected to different PCR protocols (13A/13B, MC1/MC2, LITSR/L5.8S and LEISH-1/LEISH-2 primers). To the study, 22.3% (48/215) of dogs were classified as without clinical signs, 67.5% (145/215) stage I (mild disease), 7.0% (15/215) stage II (moderate disease) and 3.2% (7/215) stage III (severe disease). The results showed that in blood samples, 13A/13B detected a significant higher number of positive dogs in stage I (25/145) and in total (42/215) (p≤0.05). However, when CS samples were tested, no difference was observed (p>0.05). On the other hand, in blood samples, MC1/MC2 detected significantly fewer positive dogs classified as without clinical signs (0/48), in stage I (0/145) and in total (1/215) (p≤0.05). Likewise, in CS samples, this primers showed also lower detection (1/215) (p≤0.05). So than, we can conclude that PCR on blood samples with 13A/13B primers has greater capacity to detect positive dogs, mainly at the initial of clinical disease than do other primers and MC1/MC2 are not a good choice to detect Leishmania infantum infection in dogs.

Resumo O objetivo deste estudo foi comparar testes moleculares usados para diagnosticar Leishmania spp., em cães apresentando diferentes estágios de infecção. Amostras de sangue e suabe conjuntival (SC) de cães classificados em quatro estágios clínicos foram submetidas a diferentes PCRs (primers 13A/13B, MC1/MC2, LITSR/L5.8S e LEISH-1/LEISH-2). Para o estudo, 22,3% (48/215) dos cães foram classificados como sem sinais clínicos, 67,5% (145/215) estágio I (doença leve), 7,0% (15/215) estágio II (doença moderada) e 3,2% (7/215) estágio III (doença grave). Os resultados mostraram que, em amostras de sangue, 13A/13B detectou número significativamente maior de cães positivos no estágio I (25/145) e no total (42/215) (p≤0,05). No entanto, quando as amostras de SC foram testadas, nenhuma diferença foi observada (p>0,05). Por outro lado, no sangue, MC1/MC2 detectou significativamente menos cães positivos sem sinais clínicos (0/48), em estágio I (0/145) e no total (1/215) (p≤0,05). Da mesma forma, em amostras de SC, MC1/MC2 também apresentou menor detecção (1/215) (p≤0,05). Assim, a PCR em amostras de sangue com 13A/13B tem maior capacidade de detectar cães positivos, principalmente no início da doença do que outros primers, e o par de primers MC1/MC2 não é uma boa escolha para detectar infecção por Leishmania infantum em cães.

Improving the reference standard for the diagnosis of canine visceral leishmaniasis: a challenge for current and future tests

BACKGROUND Studies aimed at validating canine visceral leishmaniasis diagnostic tests present heterogeneous results regarding test accuracy, partly due to divergences in reference standards used and different infection evolution periods in animals. OBJECTIVE This study aimed to evaluate the accuracy of the rapid test-dual path platform (TR-DPP) (Biomanguinhos®), EIE-Leishmaniose-Visceral-Canina-Biomanguinhos (EIE-LVC) (Biomanguinhos®), enzyme-linked immunosorbent assay (ELISA) rK39 (in-house), and the direct agglutination test (DAT-Canis) against a reference standard comprising parasitological and molecular techniques. METHODS A phase II/III validation study was carried out in sample sera from 123 predominantly asymptomatic dogs living in an area endemic for visceral leishmaniasis. FINDINGS Sixty-nine (56.1%) animals were considered infected according to the reference standard. For each test, the sensitivity and specificity, respectively, were as follows: TR-DPP, 21.74% [confidence interval (CI)95% 13.64% to 32.82%] and 92.59% (CI95% 82.45% to 97.08%); EIE-LVC, 11.59% (CI95% 5.9% to 21.25%) and 90.74% (CI95% 80.09% to 95.98%); ELISA rK39, 37.68% (CI95% 27.18% to 49.48%) and 83.33% (CI95% 71.26% to 90.98%); and DAT-Canis, 18.84% (CI95% 11.35% to 29.61%) and 96.30% (CI95% 87.46% to 98.98%). CONCLUSION We concluded that improving the sensitivity of serum testing for diagnosing asymptomatic dogs must constitute a priority in the process of developing new diagnostic tests to be used in the visceral leishmaniasis control program in Brazil.

Evaluation of DPP® and SNAP® Rapid Tests for diagnosis of Leishmania infantum canine infections

Abstract INTRODUCTION: Visceral leishmaniasis is a disease that affects humans, wildlife, and domestic species. Since dogs play a key role in urban Leishmania spp. transmission, the Brazilian government maintains the Monitoring and Control Program of Visceral Leishmaniasis (VLMCP) in endemic regions, which promotes awareness campaigns aiming to enhance the control of the infection. The VLMCP recommends the Dual Path Platform (DPP®) canine visceral leishmaniasis test (Bio-Manguinhos, Brazil) for screening and enzyme-linked immunosorbent assay to confirm the infection. The DPP® test is produced and distributed by the Health Ministry to the Municipal Health Centers responsible for the local VLMCP. The test is not available to all the clinics, forcing some veterinarians to use other rapid tests for screening and diagnosis of this disease in their daily routine. METHODS: The present study was conducted to compare the performance of the DPP® and SNAP® tests using sera from the dogs with confirmed infections of L. infantum and from the dogs with no previous testing, residing in areas with a low Leishmania infection. RESULTS: There was 97.0% agreement between the two tests. Sensitivity and specificity of the SNAP® test were 96.3% and 100%, respectively. Agreement between both the antibody tests and the parasitological detection methods was 96.8%. The DPP® test had 95.8% sensitivity and 100% specificity. CONCLUSIONS: The SNAP® and the DPP® tests were virtually equivalent in terms of detection of canine antibodies against L. infantum, and both the tests demonstrated high and similar levels of sensitivity and specificity.

Neutrophils, eosinophils, and mast cells in the intestinal wall of dogs naturally infected with Leishmania infantum / Neutrófilos, eosinófilos e mastócitos na parede intestinal de cães naturalmente infectados com Leishmania infantum

Abstract Visceral leishmaniasis (VL) is a disease caused by the protozoa Leishmania infantum and can cause an inflammatory reaction in the gastrointestinal tract, however the role of granulocytic cells (neutrophils, eosinophils, and mast cells) in the intestine of dogs infected is not fully understood. We performed a quantitative analysis these cells in the intestinal wall of dogs with canine visceral leishmaniasis (CVL). Twenty dogs were assigned to one of three groups: group 1 (G1, n=8), dogs with CVL and L. infantum amastigotes in the intestine; group 2 (G2, n=9), dogs with CVL but without intestinal amastigotes; and group 3 (G3, n=3), uninfected dogs (control group). Granulocytic cells were counted in the crypt-villus unit (mucosa), submucosa, and muscle layer of the intestinal mucosa. Cell counts were higher in the intestinal wall of dogs from G2 followed by G1 and G3 (p≤0.05). In G1, there was a low inverse correlation between parasite burden of the small intestine and granulocyte counts (r= -0.1, p≤0.01). However, in G2 dogs, mast cell and eosinophil numbers showed positive correlation (r=0.85, p≤0.01). The granulocytic cell hyperplasia observed in the intestine of L. infantum-infected dogs suggests that these cells may be involved in the cell-mediated immune response for parasite elimination.

Resumo A leishmaniose visceral (LV) é uma doença causada pelo protozoário Leishmania infantum e pode causar uma reação inflamatória no trato gastrointestinal, entretanto o papel das células granulocíticas (neutrófilos, eosinófilos e mastócitos) no intestino de cães infectados não é totalmente compreendido. Neste estudo realizamos uma análise quantitativa dessas células na parede intestinal de cães com LV. Vinte cães foram distribuídos em três grupos: grupo 1 (G1, n=8), cães com LV e amastigotas de L. infantum no intestino; grupo 2 (G2, n=9), cães com LV, mas sem amastigotas intestinais; e grupo 3 (G3, n=3), não infectados (grupo controle). Células granulocíticas foram contadas na unidade cripta-vilo (mucosa), submucosa e camada muscular da mucosa intestinal. Observamos hiperplasia dessas células na parede intestinal de cães do G2, seguidas das G1 em relação ao G3 (p≤0,05). No G1, houve uma correlação inversa baixa entre a carga parasitária do intestino delgado e a contagem de granulócitos (r= -0,1; p≤0,01). No entanto, nos cães do G2, os números de mastócitos e eosinófilos apresentaram correlação positiva (r=0,85; p≤0,01). A hiperplasia de células granulocíticas observada no intestino de cães infectados por L. infantum sugere que essas células podem estar envolvidas na resposta imune mediada por células para a eliminação do parasita.

PCR sensitivity of peripheral blood of dogs co-infected with Leishmania spp. and Ehrlichia spp. in endemic area of Brazil

Abstract INTRODUCTION Peripheral blood of 400 dogs infected with Leishmania and Ehrlichia were analyzed using polymerase chain reaction (PCR), and clinical signs were characterized. METHODS PCR and parasitological tests were conducted. RESULTS PCR was positive for Leishmania in 84.75%, and parasitological tests showed that 63.25% and 31.75% were positive for Leishmania and Ehrlichia, respectively. All animals showed more than three clinical signs. PCR results were negative for Leishmania in 15.25% of the samples. CONCLUSIONS Conventional PCR of peripheral blood can be used for diagnosing canine visceral leishmaniasis in combination with other techniques, especially in uncertain cases that need species identification.

First autochthonous case of canine visceral leishmaniasis in Rondônia, Brazil, a region with no history of visceral leishmaniasis

Abstract This report describes the first autochthonous case of canine visceral leishmaniasis in Rondônia, northern Brazil. A canine resident of the municipality of Cacoal, with clinical signs and symptoms of visceral leishmaniasis, was treated by a veterinarian. Samples were analyzed by a reference laboratory. Dual-path platform (DPP) assay, indirect immunofluorescence technique (IIT), enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), isolation in a culture medium, and direct parasitological analysis were performed. DPP assay, IIT, and ELISA revealed positive results for Leishmania; PCR identified the species as Leishmania infantum. Based on the clinical presentation and test results, canine visceral leishmaniasis was diagnosed.

Molecular and serological detection of Leishmania spp. in horses from an endemic area for canine visceral leishmaniasis in southeastern Brazil / Detecção molecular e sorológica de infecção por Leishmania (Leishmania) infantum em cavalos na região Sudeste do Brasil

This study aimed to verify the occurrence of Leishmania spp. and Leishmania (Leishmania) infantum in horses from a visceral leishmaniasis endemic area in Brazil. DNA samples from blood and conjunctival swab (CS) were tested by PCR and Indirect Immunofluorescence Antibody Test (IFAT). Although none of the horses was clinically sick, animals infected by Leishmania spp. were found and some could be characterized as infected by L. (L.) infantum. From 40 horses, 100% of the animals were positive by blood PCR, 90% (36/40) by CS PCR, and 2.5% (01/40) in serodiagnosis, by IFAT. Six from these 40 horses were L. (L.) infantum positive by blood PCR. Direct sequencing and analysis of amplicons resulted in a sequence to evolutionary analysis. Results indicate the presence of Leishmania spp. and L. (L.) infantum infecting healthy horses in Brazil. The presence of Leishmania spp. and L. (L.) infantum DNA in asymptomatic horses suggests that they can be important reservoirs of these parasites, a highly relevant finding for the epidemiological surveillance of the diseases they cause.(AU)

O estudo objetivou verificar a ocorrência de Leishmania spp. e Leishmania (Leishmania) infantum em cavalos de uma região endêmica para leishmaniose visceral do Brasil. Amostras de DNA de sangue e suabe conjuntival (SC) foram testadas pela PCR e pela Reação de Imunofluorescência Indireta (RIFI). Embora nenhum cavalo estivesse clinicamente doente, animais infectados por Leishmania spp. e L. (L.) infantum foram encontrados em Ilha Solteira/SP. Dos 40 cavalos, 100% (40/40) foram positivos pela PCR de sangue, 90% (36/40) pela PCR de SC, e 2,5% (01/40) no sorodiagnóstico, pela RIFI. Seis desses 40 cavalos foram positivos para L. (L.) infantum pela PCR de sangue. O sequenciamento direto e a análise dos amplicons resultaram em uma sequência para análise evolutiva. Os resultados indicam a presença de Leishmania spp. e L. (L.) infantum infectando cavalos saudáveis no Brasil. A presença de DNA de Leishmania spp. and L. (L.) infantum em cavalos saudáveis sugere que eles podem ser importantes reservatórios desses parasitas, um achado altamente relevante para a vigilância epidemiológica das doenças que causam.(AU)

Evaluation of Cardiopulmonary biomarkers during different stages of Canine Visceral Leishmaniasis / Evaluación de biomarcadores cardiopulmonares durante diferentes etapas de Leishmaniasis visceral canina

ABSTRACT Objective. The purpose of the present study was to test the hypothesis that cardiac alterations participate within different stages of CVL. Materials and methods. Dogs were diagnosed with CVL, were classified as follows; group I (mild disease), group II (moderate disease), group III (severe disease), group IV (very severe disease) and group V included healthy controls. Results. Ig G antibodies against Leishmaniasis in group as tested by IFAT, were deemed 1/64 to 1/16000 among infected groups. Considering the cTnI levels, there were significant differences (p=0.018) between stage IV (group IV) and healthy control group, besides between group IV and group I. Considering D-dimer levels, there was difference between healthy control group and group II, III and IV (p=0.005). Regareing NT-pro BNP levels, there were differences between healthy control group and stage III, IV, besides between stage I with stage III, IV (p=0.000). Conclusions. The results showed that levels of cTnI, Nt pro-BNP and D-dimer were higher in dogs infected with CVL in contrast to healthy dogs, in which levels of those biomarkers were below detection limits. Obtained results suggested the possibility of cTnI and NT pro-BNP as markers for cardiac damage and D-dimer as a supportive tool for a diagnosis of probable thromboembolism in dogs with CVL.

RESUMEN Objetivo. El propósito del presente estudio fue probar la hipótesis de que las alteraciones cardíacas participan en diferentes estadios de CVL. Materiales y métodos. Perros fueron diagnosticados con CVL, se clasificaron de la siguiente manera; Grupo I (enfermedad leve), grupo II (enfermedad moderada), grupo III (enfermedad grave), grupo IV (enfermedad muy grave) y grupo V controles sanos incluidos. Resultados. Los anticuerpos Ig G contra la leishmaniasis en el grupo como probado por IFAT, se consideraron 1/64 a 1/16000 entre los grupos infectados. Considerando los niveles de cTnI, hubo diferencias significativas (p=0.018). Entre el grupo IV y el grupo control sano, además entre el grupo IV y el grupo I. Considerando los niveles D-dímero, hubo diferencia entre el grupo control sano y el grupo II, III y IV (p=0.005). Teniendo en cuenta los niveles de NT-proBNP, hubo diferencia estadística entre el grupo de control sano y el estadio III, IV, además entre la etapa I con estadio III, IV (p=0.000). Conclusiones. Los resultados mostraron que los niveles de cTnI, Nt pro-BNP y D-dímero fueron mayores en perros infectados con CVL en contraste con perros sanos, en los que los niveles de estos biomarcadores estaban por debajo de los límites de detección. Los resultados obtenidos sugirieron la posibilidad de que cTnI y NT pro-BNP como marcadores de daño cardíaco y D-dímero como una herramienta de apoyo para un diagnóstico de tromboembolismo probable en perros con CVL.

Potential application of rLc36 protein for diagnosis of canine visceral leishmaniasis

Visceral leishmaniasis (VL) is fatal if left untreated. Infected dogs are important reservoirs of the disease, and thus specific identification of infected animals is very important. Several diagnostic tests have been developed for canine VL (CVL); however, these tests show varied specificity and sensitivity. The present study describes the recombinant protein rLc36, expressed by Leishmania infantum, as potential antigen for more sensitive and specific diagnosis of CVL based on an immunoenzymatic assay. The concentration of 1.0 μg/mL of rLc36 enabled differentiation of positive and negative sera and showed a sensitivity of 85% and specificity of 71% (with 95% confidence), with an accuracy of 76%.

Evaluation of the presence of Leishmania infantum in bone stored in glycerol or sterilized by autoclave for cortical bone grafting / Avaliação da presença de Leishmania infantum em ossos armazenados em glycerol ou esterilizados em autoclave para enxertia óssea cortical

This study was performed to evaluate the effects of autoclaving and storage in 85% glycerol on cortical bone from dogs infected with Leishmania sp. We used 42 cadavers with leishmaniasis. The dogs were evaluated for the presence of Leishmania sp. in culture of bone marrow and by culturing cortical bone. From the infected animals, we harvested 42 diaphysis of the right femur for culture of cortical bone before and after autoclaving or storage in glycerol. There was no significant difference in growth of the parasite in culture of bone marrow or cortical bone. There was no growth of Leishmania sp. in culture of samples after autoclaving or storage in glycerol. Both treatments were effective in preventing the growth of the parasite in vitro, so it was considered viable for grafting.(AU)

Este estudo teve por objetivo avaliar os efeitos da esterilização em autoclave e do armazenamento em glicerol a 85% no osso cortical de cães infectados por Leishmania sp. Foram utilizados 42 cadáveres de cães com leishmaniose. Os cães foram avaliados para a presença de Leishmania sp. em cultura de medula óssea e de osso cortical. Foram coletadas 42 diáfises do fêmur direito para cultura do osso cortical antes e após a esterilização e o armazenamento em glicerol. Não houve diferença significativa no crescimento do parasito em cultura utilizando-se medula óssea ou osso cortical. Não houve crescimento de Leishmania sp. em cultura de amostras de osso cortical após a autoclavagem ou o armazenamento em glicerol. Ambos os tratamentos foram eficazes na prevenção do crescimento do parasita in vitro, de modo que foram considerados viáveis para enxerto.(AU)

Addressing the recent dispersion of urban visceral leishmaniasis in the border of Argentina, Brazil, Paraguay + Uruguay + Bolivia ­ Project IDRC

The territory located in the border of Argentina, Brazil and Paraguay is endemic for tegumentary leishmaniasis (TL). However, Lutzomyia longipalpis first report in the area was in 2010-Argentina, in 2012-Brazil, and no records in the Paraguayan border despite of reports of human visceral leishmaniasis (VL) cases. Therefore, we developed a research from 2014 to 2017 to study VL in the three-country border at locality level; Uruguay-2015, and Bolivia-2016 joined latter due to the alerts of VL in the Argentinean borders. The space-time distributions of vectors, infected dogs and environmental variables were recorded and associated at three progressive scales, while anthropological surveys were performed. Three scenarios were characterized based on canine VL prevalence, vector presence-abundance and the spatial distribution consistency between them: settled VL, incipient VL, and steady TL with imported canine VL. The vector abundance was clustered in 'hot spots' persistent in time that could act as 'source populations'. The clustering distribution was associated with environmental variables at the different scales studied. Therefore, the vector distribution (proxy of human-dog exposure) could be modeled in recent southern scenarios to focus the surveillance and interventions on predicted 'hot spots', in order to increase the effectiveness and efficiency of program activities. (AU)

O território localizado na fronteira da Argentina, Brasil e Paraguai é endêmico para leishmaniose tegumentar (LT). Entretanto, o primeiro relato de Lutzomyia longipalpis na área foi em 2010-Argentina, em 2012-Brasil, sem registros na fronteira em Paraguai apesar dos casos de leishmaniose visceral humana (LV). Portanto, desenvolvemos uma pesquisa de 2014 a 2017 para estudar a LV na tríplice fronteira em nível de localidades; Uruguai-2015 e Bolívia-2016 aderiram mais tarde devido aos alertas de LV nas fronteiras argentinas. As distribuições espaço-temporais de vetores, cães infectados e as variáveis ambientais foram registradas e associadas em três escalas progressivas, enquanto se realizou o inquérito antropológico. Três cenários foram caracterizados com base na prevalência de LV canina, na abundância-presença de vetores, e a coerência da distribuição espacial entre eles: LV instalada, LV incipiente e LT estável com LV canina importada. A abundância de vetores foi agrupada em "pontos quentes" persistentes no tempo que poderiam atuar como "populações fonte". A distribuição de agrupamento foi associada a variáveis ambientais nas diferentes escalas. Portanto, a distribuição vetorial (proxy da exposição humana a cães) poderia ser modelada em cenários recentes do sul para focar a vigilância e as intervenções nos "pontos quentes" previstos, a fim de aumentar a eficácia e a eficiência das atividades do programa. (AU)

Addressing the recent dispersion of urban visceral leishmaniasis in the border of Argentina, Brazil, Paraguay + Uruguay + Bolivia – Project IDRC / Abordando a recente dispersão da leishmaniose visceral urbana nas fronteiras da Argentina, Brasil e Paraguai + Uruguai + Bolívia - Projeto IDRC

The territory located in the border of Argentina, Brazil and Paraguay is endemic for tegumentary leishmaniasis (TL). However, Lutzomyia longipalpis first report in the area was in 2010-Argentina, in 2012-Brazil, and no records in the Paraguayan border despite of reports of human visceral leishmaniasis (VL) cases. Therefore, we developed a research from 2014 to 2017 to study VL in the three-country border at locality level; Uruguay-2015, and Bolivia-2016 joined latter due to the alerts of VL in the Argentinean borders. The space-time distributions of vectors, infected dogs and environmental variables were recorded and associated at three progressive scales, while anthropological surveys were performed. Three scenarios were characterized based on canine VL prevalence, vector presence-abundance and the spatial distribution consistency between them: settled VL, incipient VL, and steady TL with imported canine VL. The vector abundance was clustered in ‘hot spots’ persistent in time that could act as ‘source populations’. The clustering distribution was associated with environmental variables at the different scales studied. Therefore, the vector distribution (proxy of human-dog exposure) could be modeled in recent southern scenarios to focus the surveillance and interventions on predicted ‘hot spots’, in order to increase the effectiveness and efficiency of program activities.

O território localizado na fronteira da Argentina, Brasil e Paraguai é endêmico para leishmaniose tegumentar (LT). Entretanto, o primeiro relato de Lutzomyia longipalpis na área foi em 2010-Argentina, em 2012-Brasil, sem registros na fronteira em Paraguai apesar dos casos de leishmaniose visceral humana (LV). Portanto, desenvolvemos uma pesquisa de 2014 a 2017 para estudar a LV na tríplice fronteira em nível de localidades; Uruguai-2015 e Bolívia-2016 aderiram mais tarde devido aos alertas de LV nas fronteiras argentinas. As distribuições espaço-temporais de vetores, cães infectados e as variáveis ambientais foram registradas e associadas em três escalas progressivas, enquanto se realizou o inquérito antropológico. Três cenários foram caracterizados com base na prevalência de LV canina, na abundância-presença de vetores, e a coerência da distribuição espacial entre eles: LV instalada, LV incipiente e LT estável com LV canina importada. A abundância de vetores foi agrupada em “pontos quentes” persistentes no tempo que poderiam atuar como “populações fonte”. A distribuição de agrupamento foi associada a variáveis ambientais nas diferentes escalas. Portanto, a distribuição vetorial (proxy da exposição humana a cães) poderia ser modelada em cenários recentes do sul para focar a vigilância e as intervenções nos “pontos quentes” previstos, a fim de aumentar a eficácia e a eficiência das atividades do programa.