Leishmaniose visceral canina: comparação de métodos sorológicos em cães de área indene do Rio Grande do Sul no Brasil / Canine visceral leishmaniasis: Comparison of serological methods in dogs of unsurveyed area of Rio Grande do Sul in Brazil

Neste estudo foi realizado um levantamento da presença de cães soropositivos em canis de 12municípios do Rio Grande do Sul, comparando-se métodos e protocolos de diagnóstico. Comisso, pode-se detectar precocemente uma possível disseminação da doença e, consequentemente,incentivar campanhas de controle e prevenção e evitar futuros surtos. Este estudo foi realizadoem uma área do RS sem diagnóstico de leishmaniose visceral canina (LVC), sendo avaliado umtotal de 165 cães. A pesquisa sorológica foi realizada por meio das técnicas de imunofluorescênciaindireta (IFI), ensaio imunoenzimático (ELISA) e Dual Plate Plataform (DPP). Constataram-setaxas de 33,9 por cento (56/165) na IFI, 6,7 por cento (11/165) no DPP, 3,0 por cento (5/165) na IFI e DPP e 6,1 por cento (10/165)no ELISA. Dentre os resultados confirmados no ELISA, cinco (5/10) foram reagentes na IFI, dosquais, desconsiderando-se os dois que foram soropositivos apenas no ELISA e IFI, resultaram trêscães (3/10) soropositivos no DPP e ELISA, conforme o protocolo atual preconizado pelo Ministérioda Saúde. Também foi feita a comparação entre os testes de diagnóstico para verificar acurácia evalor kappa. Ao considerar somente resultados positivos no DPP e IFI, a acurácia aumentou para94,6 por cento, com um valor Kappa=0,375, ou seja, com uma concordância considerável. Conclui-se quea pesquisa em áreas do RS sem diagnóstico de LVC revelou a presença de cães sororreagentes emquatro municípios do estado: Cachoeira do Sul (2), São Francisco de Assis (1), Dom Pedrito (1) eRio Grande (1)...

This study surveyed the presence of seropositive dogs in kennels of twelve municipalities of RioGrande do Sul (RS), comparing methods and diagnostic protocols. Using this approach we coulddetect a possible spread of the disease, consequently encouraging prevention and control campaigns,and preventing future outbreaks. This study was conducted in an undiagnosed area for caninevisceral leishmaniasis (CVL) of RS and a total of 165 dogs were evaluated. Serological analysiswas performed using the indirect immunofluorescence (IIF), enzyme-linked immunosorbent assay(ELISA) and Dual Plate Platform (DPP). A rate of 33.9 percent (56/165) in the IIF, 6.7 percent (11/165) inDPP, 3.0 percent (5/165) in IIF and DPP and 6.1 percent (10/165) in ELISA was observed. Among the resultsconfirmed by ELISA, five (5/10) were positive by IIF, of which, disregarding two of these five thatwere seropositive only by ELISA and IIF, three dogs (3/10) were seropositive by DPP and ELISA,according to the current protocol recommended by the Ministry of Health. Comparisons betweenthe diagnostic tests to verify accuracy and kappa value were also made. When considering onlythe results positive in DPP and IIF, the accuracy increased to 94.6 percent, with a kappa value of 0.375,therefore, with considerable agreement. It is concluded that the research in undiagnosed areas of RSrevealed the presence of seropositive dogs in four municipalities of the State: Cachoeira do Sul (2),São Francisco de Assis (1) Dom Pedrito (1) and Rio Grande (1)...

Characterization of a virulent Leptospira interrogans strain isolated from an abandoned swimming pool

Pathogenic Leptospira spp. are the etiological agents of leptospirosis, an important disease of both humans and animals. In urban settings, L. interrogans serovars are the predominant cause of disease in humans. The purpose of this study was to characterize a novel Leptospira isolate recovered from an abandoned swimming pool. Molecular characterization through sequencing of the rpoB gene revealed 100% identity with L. interrogans and variable-number tandem-repeat (VNTR) analysis resulted in a banding pattern identical to L. interrogans serogroup Icterohaemorrhagiae, serovar Copenhageni or Icterohaemorrhagiae. The virulence of the strain was determined in a hamster model of lethal leptospirosis. The lethal dose 50% (LD50) was calculated to be two leptospires in female hamsters and a histopathological examination of infected animals found typical lesions associated with severe leptospirosis, including renal epithelium degeneration, hepatic karyomegaly, liver-plate disarray and lymphocyte infiltration. This highly virulent strain is now available for use in further studies, especially evaluation of vaccine candidates.