Seroprevalence and risk factors of antibodies against Leptospira spp. in ovines from Uberlândia municipality, Minas Gerais state, Brazil

The objectives of the present study were to verify the seroprevalence of anti-Leptospira spp. antibodies, identify the most frequent serovars and the risk factors associated with the infection in Uberlândia, Minas Gerais, Brazil . A total of 334 ovines blood samples were collected in 12 farms from Uberlândia municipality to be evaluated by means the Microscopic Agglutination Test (MAT) against 22 serovars of Leptospira spp. and an epidemiologic questionnaire was applied for each farm in order to correlate with risk factors of leptospirosis: sex, age and breed as well as contact with cattle, contact with dogs and presence of rodents. The prevalence of seropositive to MAT was found in seventy four ovines (22.2 percent; CI 95 percent 17.6-26.4 percent), with titers ranging from 100 to 3200. The most frequent serovars identified were: Hardjo, Autumnalis, Hardjo and Wolffi association and Grippotyphosa. Statistically significant differences were found in males, pure breeds and presence of rodents (p<0.05). The prevalence of anti-Leptospira spp. antibodies found in the present study demonstrated that this bacterium occurs in ovines of Uberlândia municipality, MG, Brazil . The need for the adoption of efficient management for the control of rodents and infection in ovines in order to avoid leptospirosis in the local flocks and future transmission to humans.

Cinética da resposta imune humoral de cães jovens imunizados contra Leptospira interrogans / Kinetics of the humoral immune response of dogs young immunized with Leptospira interrogans

Objetivou-se analisar a resposta imune humoral contra Leptospira interrogans mediante a utilização da prova de soroaglutinação microscópica (SAM) em 26 cães jovens, sendo 17 de raça definida (Grupo A) e nove sem raça (Grupo B), de ambos os sexos, pertencentes a canis e ambientes domiciliares em Uberlândia, Minas Gerais. Os cães foram vacinados com bacterina inativada comercial polivalente com os sorovares Canicola, Grippotyphosa, Icterohaemorrhagiae e Pomona. O esquema vacinal baseou-se em três imunizações. A primovacinação foi realizada aos quarenta e cinco dias de idade, considerado dia zero, e após dois reforços com intervalos de trinta dias cada. Sete colheitas sanguíneas de cada cão foram efetuadas do dia zero até aos 180 dias pós-vacinais, com intervalos de trinta dias cada. Não foram detectados títulos pré-vacinais para os sorovares Canicola, Icterohaemorrhagiae e Grippotyphosa no dia zero. Apenas um cão do grupo A foi reagente com título 1:100 contra o sorovar Pomona na primeira colheita. Não houve diferença estatística entre os títulos de anticorpos aglutinantes entre os Grupos A e B (p>0,05), induzidos pela bacterina comercial utilizada, exceto na colheita II (p<0,05), na qual o grupo B apresentou títulos para o sorovar Autumnalis em todos os cães avaliados, enquanto que, no grupo A, 64,7 por cento dos cães não foram reagentes a nenhum sorovar testado. No dia 30, títulos para o sorovar Autumnalis que persistiram até os 180 dias pós-vacinais, em ambos os grupos, variando apenas a intensidade da resposta imunológica sem diferença estatística significativa. Para avaliação da eficiência vacinal da bacterina anti-Leptospira, a presente pesquisa alerta para os ricos à infecção que os cães vacinados anualmente estão submetidos.

The objective was to analyze the humoral immune response against Leptospira interrogans using the microscopic agglutination test (MAT) in 26 young dogs, and 17 mixed breed (Group A) and nine mixed breed (Group B) of both sexes, pertaining to kennels and home environments in Uberlandia, Minas Gerais. Dogs were vaccinated with commercial inactivated polyvalent bacterin with Canicola, Grippotyphosa, Icterohaemorrhagiae and Pomona serovars. The immunization schedule was based on three immunizations. The first vaccination was performed at forty-five days of age, considered day zero, and after two boosters at intervals of thirty days each. Seven blood samples from each dog were made from time zero up to 180 days post-vaccination, at intervals of thirty days each. Titles have not been detected pre-vaccination against serovars Canicola, and Icterohaemorrhagiae Grippotyphosa on day zero. Only one dog in group A was reactive with a titer of 1:100 against Pomona in the first harvest. There was no statistical difference between the agglutinating titers between Groups A and B (p>0.05) induced by commercial vaccine used, except at harvest II (p<0.05), in which the group B presented evidence to serovar Autumnalis in all dogs evaluated, whereas in group A, 64.7 percent of dogs were not reactive to any serovar tested. There were on the 30th title to serovar Autumnalis that persisted until 180 days post-vaccination in both groups, varying only the intensity of immune response without significant statistical difference. To assess the efficiency of vaccine culture anti-Leptospira this research to warn the risks infection that dogs are vaccinated annually submitted.