Transmission of Leishmania infantum from cats to dogs / Transmissão de Leishmania infantum de gatos para cães

Abstract Leishmania infantum infection in cats has been reported in several countries, including Brazil. However, the transmission of visceral leishmaniasis (VL) from cats to another host has not been proven yet. Therefore, the aim of this study was to verify the possibility of L. infantum transmission from cats to dogs. In order to verify the possibility of VL transmission from the cat to the dog, xenodiagnosis was carried out in a VL-positive cat, using 55 female Lutzomyia longipalpis. Five days later, 40 insects were dissected to verify Leishmania infection. The remaining 15 females were fed in a healthy dog. The potential infection of the dog was verified through clinical, serological, parasitological examinations, and PCR, at three, six, and twelve months post-infection. All 55 L. longipalpis females became visibly engorged. Leishmania promastigotes were detected in 27.5% of the dissected insects. Leishmania infection in the dog was confirmed upon first evaluation. DNA sequencing of the parasite isolated from the cat confirmed L. infantum infection and showed 99% similarity with the L. infantum DNA sequences from the dogs. Through this study, it was possible to confirm the L. infantum experimental transmission from a domestic cat to a domestic dog through its biological vector L. longipalpis.

Resumo A infecção por Leishmania infantum em gatos tem sido relatada em vários países, incluindo o Brasil. No entanto, a transmissão da leishmaniose visceral (LV) de gatos para outro hospedeiro ainda não foi comprovada. Portanto, o objetivo deste estudo foi verificar a possibilidade de transmissão de L. infantum de gatos para cães. Para verificar a possibilidade de transmissão da LV do gato para o cão, foi realizado xenodiagnóstico em um gato com LV, utilizando-se 55 fêmeas de Lutzomyia longipalpis. Cinco dias depois, 40 insetos foram dissecados para verificar a infecção por Leishmania. As 15 fêmeas restantes foram alimentadas em um cão saudável. A possível infecção no cão foi verificada por meio de exames clínicos, sorológicos, parasitológicos e PCR, três, seis e doze meses após a infecção. Todas as 55 fêmeas de L. longipalpis ficaram visivelmente ingurgitadas. Promastigotas de Leishmania foram detectadas em 27,5% dos insetos dissecados. A infecção por Leishmania no cão foi confirmada na primeira avaliação. O sequenciamento do DNA do parasito isolado do gato confirmou a infecção por L. infantum e apresentou 99% de similaridade com sequências de DNA de L. infantum de cães. Através deste estudo, foi possível confirmar a transmissão experimental de L. infantum de um gato doméstico para um cão doméstico através do seu vetor biológico L. longipalpis.

Avaliação da infectividade parasitária a Lutzomyia longipalpis por xenodiagnóstico em cães tratados para leishmaniose visceral naturalmente adquirida / Evaluation of parasite infectivity for Lutzomyia longipalpis by xenodiagnosis in dogs treated for natural visceral leishmaniasis

O efeito de um protocolo quimioterápico multidrogas contra a leishmaniose visceral (LV) canina, sobre a capacidade de transmissão de Leishmania infantum ao vetor, foi analisado por meio de xenodiagnóstico. Trinta e cinco cães naturalmente infectados foram avaliados antes e durante o tratamento com a combinação de metronidazol, cetoconazol e alopurinol a cada três meses por até um ano. Em cada avaliação, os cães foram individualmente submetidos ao xenodiagnóstico e quantificação da carga parasitária por PCR quantitativa. O tratamento foi eficaz em bloquear a transmissibilidade parasitária do cão para o flebotomíneo (p= 0,011) nos cães avaliados. Houve significante correlação entre recuperação clínica e infectividade: cães com melhora clínica mais evidente apresentaram menores chances de transferir L. infantum ao Lutzomyia longipalpis via xenodiagnóstico (r=0,528, p= 0,002). Esses resultados demonstram que o tratamento canino com o protocolo proposto pode representar uma alternativa ao sacrifício de cães no Brasil como medida de controle da doença, uma vez que as drogas utilizadas não são aplicadas ao tratamento da LV humana em áreas endêmicas.(AU)

The outcome of a multidrug chemotherapeutic protocol against canine visceral leishmaniasis (VL) has been evaluated for its effect on dogs' capacity of transferring Leishmania infantum to sand flies by xenodiagnosis. Thirty-five naturally infected dogs were examined before and during treatment with a combination of metronidazole, ketoconazole, and allopurinol, at every three months up to one year. For each evaluation, treated dogs were individually submitted to xenodiagnosis and quantitative PCR to quantify parasite load in sand flies. The treatment was effective in blocking parasite transmission from host to sand flies (p=0.011) in the assessed dogs. There was a significant correlation between clinical improvement and sand fly infectivity: dogs that achieved better clinical conditions showed a lower chance of L. infantum transference to vector by xenodiagnosis (r=0.528, p=0.002). These results demonstrate that the treatment of dogs with the proposed protocol may represent an alternative to dog culling in Brazil for disease control, since these drugs are not used for treating human VL in endemic areas.(AU)

Estudio seroepidemiológico de la enfermedad de Chagas en la comunidad Copey-El Guayabillo, Estado Carabobo, Venezuela / Seroepidemiological study of Chagas disease in the community of Copey-El Guayabillo, State of Carabobo, Venezuela

Introducción: la enfermedad de Chagas, causada por Trypanosoma cruzi y transmitida por insectos de la familia Reduviidae, es considerada un problema de salud pública dada su magnitud y trascendencia; es una de las enfermedades transmisibles de más amplia distribución en el continente americano. Dentro de los factores que intervienen en el ciclo de transmisión se encuentran la calidad de las viviendas, el material de las paredes y los techos, la presencia de otros reservorios del parásito, la endofilia o exofilia del vector, y la presencia de árboles y otros hábitats. Objetivo: determinar la seroprevalencia de esta enfermedad en la comunidad de Copey-El Guayabillo, del estado Carabobo. Métodos: se estudiaron 115 pacientes, distribuidos en 36 viviendas, a los que se les aplicó una encuesta epidemiológica, 3 pruebas serológicas (ELISA [enzyme-linked immunosorbent assay] y hemoaglutinación indirecta, e inmunofluorescencia indirecta). Resultados: se obtuvo una prevalencia general de 6,09 por ciento en personas mayores a 40 años, con predominancia en el sexo masculino (71 por ciento ) y la ocupación de agricultor (57,14 por ciento ). El tipo de vivienda más frecuente de los pacientes seropositivos correspondió con el rancho de zinc (71,43 por ciento ). El 85,71 por ciento presentó anexos (gallinero, depósito de leña y cochinera). Adicionalmente, no se encontraron rastros fecales, huevos, exuvias, ni ejemplares vivos o muertos (ninfas o adultos) de vectores en el interior de las viviendas encuestadas. De la misma forma, se analizaron 18 animales mediante xenodiagnóstico, con resultados negativos. Conclusión: estos resultados indican que no existía una transmisión activa de la enfermedad en la comunidad para el momento del desarrollo de esta investigación(AU)

Introduction: Chagas disease, caused by Trypanosoma cruzi and transmitted by insects of the family Reduviidae, is considered to be a public health problem due to its magnitude and impact. It is one of the communicable diseases most broadly distributed in the American continent. The factors involved in its transmission cycle include the poor quality of housing, the material of which walls and roofs are built, the presence of other reservoirs of the parasite, the endophilia and exophilia of the vector, and the presence of trees and other habitats. Objective: determine the seroprevalence of the disease in the community of Copey-El Guayabillo, State of Carabobo. Methods: a study was conducted of 115 patients from 36 households, who were given an epidemiological survey, 3 serological tests (ELISA [enzyme-linked immunosorbent assay], indirect hemagglutination and indirect immunofluorescence). Results: overall prevalence was 6.09 percent for people over 40, with a predominance of the male sex (71 percent) and the occupation of agricultural worker (57.14 percent). Most seropositive patients (71.43 percent) lived in huts with laminated metal covers. 85.71 percent of the houses had annexed structures (henhouses, woodsheds and pigpens). No fecal traces, eggs, exuviae, or living or dead specimens (nymphs or adults) of the vector were found inside the houses surveyed. Eighteen animals were tested by xenodiagnosis with negative results. Conclusion: these results indicate that there was no active transmission of the disease in the community at the time of the research(AU)

Estudio seroepidemiológico de la enfermedad de Chagas en la comunidad Copey-El Guayabillo, Estado Carabobo, Venezuela / Seroepidemiological study of Chagas disease in the community of Copey-El Guayabillo, State of Carabobo, Venezuela

Introducción: la enfermedad de Chagas, causada por Trypanosoma cruzi y transmitida por insectos de la familia Reduviidae, es considerada un problema de salud pública dada su magnitud y trascendencia; es una de las enfermedades transmisibles de más amplia distribución en el continente americano. Dentro de los factores que intervienen en el ciclo de transmisión se encuentran la calidad de las viviendas, el material de las paredes y los techos, la presencia de otros reservorios del parásito, la endofilia o exofilia del vector, y la presencia de árboles y otros hábitats. Objetivo: determinar la seroprevalencia de esta enfermedad en la comunidad de Copey-El Guayabillo, del estado Carabobo. Métodos: se estudiaron 115 pacientes, distribuidos en 36 viviendas, a los que se les aplicó una encuesta epidemiológica, 3 pruebas serológicas (ELISA [enzyme-linked immunosorbent assay] y hemoaglutinación indirecta, e inmunofluorescencia indirecta). Resultados: se obtuvo una prevalencia general de 6,09 % en personas mayores a 40 años, con predominancia en el sexo masculino (71 %) y la ocupación de agricultor (57,14 %). El tipo de vivienda más frecuente de los pacientes seropositivos correspondió con el rancho de zinc (71,43 %). El 85,71 % presentó anexos (gallinero, depósito de leña y cochinera). Adicionalmente, no se encontraron rastros fecales, huevos, exuvias, ni ejemplares vivos o muertos (ninfas o adultos) de vectores en el interior de las viviendas encuestadas. De la misma forma, se analizaron 18 animales mediante xenodiagnóstico, con resultados negativos. Conclusión: estos resultados indican que no existía una transmisión activa de la enfermedad en la comunidad para el momento del desarrollo de esta investigación.

Introduction: Chagas disease, caused by Trypanosoma cruzi and transmitted by insects of the family Reduviidae, is considered to be a public health problem due to its magnitude and impact. It is one of the communicable diseases most broadly distributed in the American continent. The factors involved in its transmission cycle include the poor quality of housing, the material of which walls and roofs are built, the presence of other reservoirs of the parasite, the endophilia and exophilia of the vector, and the presence of trees and other habitats. Objective: determine the seroprevalence of the disease in the community of Copey-El Guayabillo, State of Carabobo. Methods: a study was conducted of 115 patients from 36 households, who were given an epidemiological survey, 3 serological tests (ELISA [enzyme-linked immunosorbent assay], indirect hemagglutination and indirect immunofluorescence). Results: overall prevalence was 6.09% for people over 40, with a predominance of the male sex (71 %) and the occupation of agricultural worker (57.14 %). Most seropositive patients (71.43 %) lived in huts with laminated metal covers. 85.71 % of the houses had annexed structures (henhouses, woodsheds and pigpens). No fecal traces, eggs, exuviae, or living or dead specimens (nymphs or adults) of the vector were found inside the houses surveyed. Eighteen animals were tested by xenodiagnosis with negative results. Conclusion: these results indicate that there was no active transmission of the disease in the community at the time of the research.