Performance of IFAT, ELISA, direct parasitological examination and PCR on lymph node aspirates for canine visceral leishmaniasis diagnosis

Canine visceral leishmaniasis (CVL) is endemic in numerous Brazilian regions. The greatest difficulty in controlling the disease is the diagnostic limitation. In the present study, the most common tests employed for visceral leishmaniasis diagnosis were compared: immunofluorescence antibody test (IFAT), immunoenzymatic assay (ELISA), direct parasitological examination and polymerase chain reaction (PCR). Samples of lymph node aspirates and blood were collected from 100 dogs that lived in an endemic area (Bauru city, São Paulo state) and from 100 negative controls from a non-endemic area (Botucatu city, São Paulo state). Specificity of both IFAT and PCR was 100 percent whereas ELISA was 99 percent. Sensitivities were 97.77, 93.33 and 91.11 percent respectively for IFAT, ELISA and PCR.

Experimental infection with Leishmania chagasi in immunosuppressed Balb/c mice: cytokines and parasite burdens

The immune response in leishmaniasis may result in a polarization of the T lymphocyte subpopulation, altering cell phenotype and resulting in immune protection or disease exacerbation. Leishmania may persist in the body either during asymptomatic infections or after treatment, which represents high risk under immunosuppression. The objective of this study was to evaluate the effect of infection with immunosuppression by dexamethasone associated with pentoxifylline on animal weight, spleen weight, spleen and hepatic parasitic load and immunopathology, as well as the IFN-ã and IL-10 production in spleen cell culture of Balb/c mice infected with Leishmania chagasi. The infection did not cause body weight gain in animals, but both the weight and size of the spleen were increased. The immunosuppression using dexamethasone associated with pentoxifylline affected body weight gain and spleen weight and size in both infected and non-infected animals. The immunosuppression did not significantly alter the course of the splenic or hepatic parasite burden. Dexamethasone and pentoxifylline significantly affected cytokine production, but did not influence the Th1/Th2 ratio in infected animals.(AU)

Aspectos epidemiológicos da leishmaniose visceral canina no município de Pedro Leopoldo, Minas Gerais, 2003 / Epidemiologic aspects of canine visceral leishmaniasis in Pedro Leopoldo district, Minas Gerais, 2003

Determinou-se a prevalência da leishmaniose visceral canina (LVC) no município de Pedro Leopoldo, MG, 2003, por meio de inquérito soro-epidemiológico. Coletaram-se amostras de sangue de 2.185 cães e aplicou-se questionário semi-estruturado em cada residência. Os animais foram divididos em quatro grupos, sendo o grupo A constituído de 1240 cães das áreas urbana e rural; o grupo B de 705 cães de áreas em torno dos focos; o grupo C, de 134 cães, cujas amostras foram coletadas durante o dia da vacinação anti-rábica oficial; e o grupo D composto de 111 cães errantes. Os dados foram armazenados em banco de dados EPIINFO 6.04b. Os 36 cães positivos foram localizados espacialmente com auxílio de GPS (Global Positioning System), e o georreferenciamento realizado por meio do programa AUTOCAD 2000. A prevalência global da LVC foi de 1,4 por cento e variou de 1,1 por cento na área urbana e 4,2 por cento na rural. Estes resultados permitiram concluir que Pedro Leopoldo, de acordo com a classificação oficial do Ministério da Saúde, é área silenciosa, receptiva e vulnerável para LVC. A distribuição espacial dos casos é diferenciada e requer medidas sanitárias de acordo com cada área de risco.

The prevalence of canine visceral leishmaniasis (CVL) in Pedro Leopoldo district, 2003 was evaluated. A serum-epidemic inquiry was accomplished by collecting blood samples of dogs and by applying a semi structured questionnaire, according to groups, in each visited residence: group A, constituted of 1240 dogs of the urban and rural areas; group B, constituted of 705 dogs sampled around the focuses; group C, constituted of 134 dogs, wich samples were collected during the canine/feline antirabic vaccination; and group D, constituted of 111 wandering dogs. The data were stored in the EPI INFO 6.04b database. Positive dogs were spatially located using GPS (Global Positioning System) and the geographycal reference was made through the AUTOCAD 2000 program. The district global prevalence for canine visceral leishmaniasis was of 1.4 percent, varying from 1.1 percent to 4.2 percent. These results allowed to conclude that Pedro Leopoldo is a silent area, receptive and vulnerable to CVL, in agreement with the Ministry of Health official classification. The spacial distribution of CVL is not homogeneous and it requires sanitary measures according to each risk area. The obtained knowledge allows to establish effective strategies for the control of CVL in that distric.