Diagnóstico de hepatozoon spp. en perros (Canis familiaris) y sus vectores en áreas rurales de los Estados Lara y Yaracuy-Venezuela / Diagnosis of hepatozoon spp. in dogs (Canis familiaris) and its vectors from rural areas of Lara and Yaracuy States, Venezuela

El objetivo de este trabajo fue diagnosticar Hepatozoon spp. en perros de áreas rurales en algunos municipios de los estados Lara y Yaracuy, así como su relación con los potenciales artrópodos vectores involucrados en su transmisión. Babesia canis vogeli, Ehrlichia canis y en menor frecuencia Hepatozoon canis son los agentes parasitarios más importantes en caninos teniendo todos ellos como vector a Rhipicephalus sanguineus. Estos hemotrópicos infectan frecuentemente a los animales sin causarles sintomatología clínica y en otros casos les causan enfermedad de gravedad variable. La asociación de estos agentes es muy común, lo que favorece la gravedad de los síntomas clínicos. Además de R. sanguineus, otros géneros de garrapatas pueden ser encontradas parasitando perros, como Amblyomma e Ixodes. Durante el estudio se realizaron frotis sanguíneos de sangre periférica de la oreja de 300 perros y se colectaron 604 garrapatas por medio de extracción manual. Estos ixódidos fueron identificados taxonómicamente en el Laboratorio de Parasitología con la ayuda de claves dicotómicas y luego fueron sometidas a disección en busca de fases evolutivas de Hepatozoon spp. Los resultados fueron analizados a través de estadísticas no paramétricas indicando la presencia o ausencia de Hepatozoon spp. y la identificación de los vectores involucrados. Se observó Hepatozoon spp. en las muestras de sangre periférica de 11 de los perros estudiados, correspondiendo a tres perros del estado Lara y ocho al estado Yaracuy. En relación a los vectores, se identificaron en el estado Lara, 557 Rhipicephalus sanguineus, 11 Amblyomma ovale y 10 Ixodes spp. y en el estado Yaracuy solamente se diagnosticaron 26 especímenes de Amblyomma ovale. Es importante destacar la presencia de Hepatozoon spp. en áreas rurales donde no se identificó R. sanguineus.

The purpose of this research was to diagnose Hepatozoon spp. in dogs from rural areas in some municipalities of the States of Lara and Yaracuy, Venezuela, and its relationship with potential arthropods vectors involved in its transmission. Babesia canis vogeli, Ehrlichia canis, and less frequently, Hepatozoon canis, are the most important hemoparasites of dogs, all having as a common vector Rhipicephalus sanguineus. These hemoparasites frequently infest both domestic and rural animals without overt clinical symptoms; in other cases, they cause diseases of varied severity. Coinfections by hemoparasites are very common, which favors the severity of clinical symptoms. Besides R. sanguineus, other tick genera like Amblyomma and Ixodes, can be found infesting dogs. To carry out this study, thin blood smears from peripheral ear veins of 300 dogs were performed; and 604 ticks were collected by manual extraction. These ixodids were taxonomically identified at the Parasitology Laboratory, with the help of dichotomous taxonomic keys. Then, they were subjected to dissections looking for evolutionary stages of Hepatozoon spp. Results obtained were analyzed through non-parametric statistics, showing the presence or absence of Hepatozoon spp. and the identification of the involved vectors. Hepatozoon spp. was found in samples of peripheral blood in 11 of the dogs studied, three from the State of Lara and eight from the State of Yaracuy. Regarding vectors, 557 Rhipicephalus sanguineus, 11 Amblyomma ovale and 10 Ixodes spp. were identified in Lara, whereas only 26 specimens of Amblyomma ovale were identified in Yaracuy. It is important to underscore the presence of Hepatozoon spp. in rural areas where R. sanguineus was not identified.

Morphology and morphometry of three Plasmodium juxtanucleare (Apicomplexa: Plasmodiidae) isolates.

In this work, three isolates of Plasmodium juxtanucleare have been analyzed based on morphological, morphometric and parasitic parameters. Each isolate was sampled from naturally infected adult chicken (Gallus gallus) from rural areas of three Brazilian municipalities: Seropédica (22 degrees 48' S; 43 degrees 41' W), in the state of Rio de Janeiro; Cruzeiro (22 degrees 33' S; 44 degrees 57' W), in the state of São Paulo; and Santa Bárbara do Tugúrio (21 degrees 15' S; 43 degrees 27' W), in the state of Minas Gerais. The blood samples taken from each infected chicken were inoculated in three groups of ten young chicken (21 days old). Blood smears of the experimentally infected chicken were sampled every two days until the 69th day in order to evaluate the parasitemia. For the morphological-descriptive and morphometric analyses, we measured 30 individuals from each of the intraerythocytic states, measures of the major (MD) and minor diameters (md), the estimation of morphometric index (Mi=md/MD) and size (T=pab, a=md/2; b=MD/2). The results indicated low and homogeneous parasitemia rates in the three strains, which showed differences among shape and size of the parasitic stadia displayed.

Morphology and morphometry of three Plasmodium juxtanucleare (Apicomplexa: Plasmodiidae) isolates / Morfologia e morfometria de três isolados de Plasmodium juxtanucleare (Apicomplexa: Plasmodiidae)

In this work, three isolates of Plasmodium juxtanucleare have been analyzed based on morphological, morphometric and parasitic parameters. Each isolate was sampled from naturally infected adult chicken (Gallus gallus) from rural areas of three Brazilian municipalities: Seropédica (22º 48' S; 43º 41'W), in the state of Rio de Janeiro; Cruzeiro (22º 33' S; 44º 57'W), in the state of São Paulo; and Santa Bárbara do Tugúrio (21º 15' S; 43º 27' W), in the state of Minas Gerais. The blood samples taken from each infected chicken were inoculated in three groups of ten young chicken (21 days old). Blood smears of the experimentally infected chicken were sampled every two days until the 69th day in order to evaluate the parasitemia. For the morphological-descriptive and morphometric analyses, we measured 30 individuals from each of the intraerythocytic states, measures of the major (MD) and minor diameters (md), the estimation of morphometric index (Mi=md/MD) and size (T=pab, a= md/2; b=MD/2). The results indicated low and homogeneous parasitemia rates in the three strains, which showed differences among shape and size of the parasitic stadia displayed.

Neste trabalho, três isolados de Plasmodium juxtanucleare foram analisados com base na morfologia, morfometria e parâmetros parasitológicos. Cada isolado foi coletado de aves (Gallus gallus) adultas infectadas naturalmente de áreas rurais de três municípios brasileiros: Seropédica (22º 48' S; 43º 41' W), no estado do Rio de Janeiro; Cruzeiro (22º 33' S; 44º 57' W), no estado de São Paulo; e Santa Bárbara do Tugúrio (21º 15' S; 43º 27' W), no estado de Minas Gerais. As amostras de sangue coletadas de cada ave infectada foram inoculadas em três grupos de dez aves (21 dias de idade). Esfregaços sangüíneos das aves infectadas experimentalmente foram realizados de dois em dois dias durante um período de 69 dias para avaliar a parasitemia. Para análises morfofisiológica e morfométrica, foram mensurados 30 indivíduos de cada estágio intraeritrocítico. Foram tomadas as medidas do diâmetro maior (DM) e diâmetro menor (dm), com os quais foi estimado o índice morfométrico (Mi=md/MD) e o tamanho (T=pab, a= md/ 2; b=MD/2). Os resultados indicaram uma parasitemia homogênea entre os três isolados, havendo diferenças apenas nas formas e tamanhos dos estádios parasitários.