Leptospirose Canina: Estudo sero-epidemiológico de casos com quadro clínico compatível com a doença
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2019-05-14
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A leptospirose é uma zoonose de distribuição mundial, causada pela infeção por bactérias patogénicas do género Leptospira. Os canídeos domésticos e selvagens constituem importantes fontes de infeção para humanos e outras populações animais, que habitam o mesmo ecossistema, criando riscos de saúde pública e problemas em termos de sanidade animal. O presente estudo teve como principais objetivos determinar a taxa de seropositividade anti-Leptospira em canídeos domésticos presentes à consulta com sinais compatíveis com a doença, utilizando a técnica de aglutinação microscópica (TAM). Adicionalmente, foram determinados os serogrupos presuntivos das estirpes mais prevalentes na população alvo, e analisadas estaticamente as características demográficas, a taxa vacinal, bem como os sinais clínicos observados e os exames complementares realizados. Foi também efetuado um protocolo de amplificação de ADN usando a técnica da reação em cadeia da polimerase (PCR), baseado em “primers” específicos para leptospiras patogénicas cujo alvo é o gene que codifica a proteína de membrana LipL32. Este teste foi realizado em algumas amostras de canídeos seronegativas à TAM e suspeitos de se encontrarem na fase aguda da doença. O estudo serológico da população alvo, 80 canídeos da região Norte de Portugal suspeitos de leptospirose, revelou que cerca de 79% possuíam anticorpos anti-Leptospira. Destes, 70% tinham título de anticorpos compatíveis com doença ativa, enquanto os restantes foram classificados como duvidosos (13,8%), sem anticorpos (10%) ou com anticorpos mas sem evidência de doença ativa (6,3%). Os títulos de anticorpos obtidos variaram entre 50-6.400, sendo o título de 400 o mais frequentemente observado na TAM. Os serogrupos para os quais se obtiveram as principais reatividades foram, por ordem decrescente, os serogrupos Icterohaemorrhagiae, Pomona, Canicola, Ballum, Australis, Autumnalis e Grippotyphosa. As seis amostras negativas pela TAM analisadas por PCR foram negativas. Relativamente às variáveis demográficas, verificou-se que a maioria dos animais presentes à consulta por suspeita de leptospirose eram do sexo masculino, de raça indeterminada, tinham 24 ou 36 meses, provinham de zonas rurais, encontravam-se imunizados para a leptospirose e haviam tomado antibióticos. Quanto aos sinais clínicos, a maioria apresentava-se normotérmico, com depressão, anorexia e vómito, apresentando com menor frequência hipertermia, fraqueza muscular, diarreia, sangue nas fezes, conjuntivite, mucosas anémicas, icterícia, e com uma frequência reduzida hemorragias/petéquias, polidipsia/poliúria, uveíte e alterações neurológicas. A larga maioria dos animais realizaram algum tipo de exame complementar. A presença de anemia, leucocitose, trombocitopenia, aumento da concentração de ureia e creatinina no sangue apresentaram valores de frequência relevantes. A presença de alterações hepáticas e de alterações compatíveis com insuficiência renal, foram também frequentemente observadas.
Leptospirosis is a zoonosis of worldwide distribution, caused by infection with pathogenic bacteria of the Leptospira genus. Domestic and wild dogs are important sources of infection for humans and other animal populations, which inhabit the same ecosystem, creating public health risks and animal health problems. The objective of this study was to determine the seropositivity rate against Leptospira in domestic dogs presented for consultation with signs compatible with the disease, using the microscopic agglutination technique (MAT). Additionally, the presumptive serogroups of the most prevalent strains in the studied population were determined, and the demographic characteristics, the vaccination rate, the observed clinical signs and the complementary tests were statistically analyzed. A DNA amplification protocol was also performed using the polymerase chain reaction technique (PCR), based on specific primers for pathogenic leptospires whose target is the gene encoding the LipL32 membrane protein. This test was performed in some samples of dogs that were seronegative by MAT and suspected of being in the acute phase of the disease. The serological study of the target population, 80 dogs from the Northern and Southern regions of Portugal suspected of leptospirosis, revealed that about 79% had leptospiral antibodies. Of these, 70% had antibody titers compatible with active disease, while the remainder were classified as borderline (13.8%), without antibodies (10%) or with antibodies but without evidence of current disease (6.3%). Antibody titers ranged from 50-6,400, with the titer of 400 being the most frequently observed in MAT. The serogroups for which the main reactivities were obtained were, in descending order, serogroups Icterohaemorrhagiae, Pomona, Canicola, Ballum, Australis, Autumnalis and Grippotyphosa. All six MAT-negative samples were also negative by PCR. Regarding the demographic variables, it was verified that most of the animals present at the consultation due to suspected leptospirosis were male, of undetermined breed, were 24 or 36 months old, came from rural areas, were immunized for leptospirosis and had taken antibiotics. As for clinical signs, most animals were normothermic and presented depression, anorexia and vomiting, less frequently hyperthermia, muscular weakness, diarrhea, blood in the stools, conjunctivitis, anemic mucous membranes, jaundice, and with reduced frequency hemorrhages/petechiae, polydipsia/polyuria, uveitis, and neurological disorders. Most animals did other complementary test. The presence of anemia, leukocytosis, thrombocytopenia, increased urea and creatinine concentrations in the blood were common findings. The presence of hepatic alterations and changes compatible with renal insufficiency were also frequently observed.
Leptospirosis is a zoonosis of worldwide distribution, caused by infection with pathogenic bacteria of the Leptospira genus. Domestic and wild dogs are important sources of infection for humans and other animal populations, which inhabit the same ecosystem, creating public health risks and animal health problems. The objective of this study was to determine the seropositivity rate against Leptospira in domestic dogs presented for consultation with signs compatible with the disease, using the microscopic agglutination technique (MAT). Additionally, the presumptive serogroups of the most prevalent strains in the studied population were determined, and the demographic characteristics, the vaccination rate, the observed clinical signs and the complementary tests were statistically analyzed. A DNA amplification protocol was also performed using the polymerase chain reaction technique (PCR), based on specific primers for pathogenic leptospires whose target is the gene encoding the LipL32 membrane protein. This test was performed in some samples of dogs that were seronegative by MAT and suspected of being in the acute phase of the disease. The serological study of the target population, 80 dogs from the Northern and Southern regions of Portugal suspected of leptospirosis, revealed that about 79% had leptospiral antibodies. Of these, 70% had antibody titers compatible with active disease, while the remainder were classified as borderline (13.8%), without antibodies (10%) or with antibodies but without evidence of current disease (6.3%). Antibody titers ranged from 50-6,400, with the titer of 400 being the most frequently observed in MAT. The serogroups for which the main reactivities were obtained were, in descending order, serogroups Icterohaemorrhagiae, Pomona, Canicola, Ballum, Australis, Autumnalis and Grippotyphosa. All six MAT-negative samples were also negative by PCR. Regarding the demographic variables, it was verified that most of the animals present at the consultation due to suspected leptospirosis were male, of undetermined breed, were 24 or 36 months old, came from rural areas, were immunized for leptospirosis and had taken antibiotics. As for clinical signs, most animals were normothermic and presented depression, anorexia and vomiting, less frequently hyperthermia, muscular weakness, diarrhea, blood in the stools, conjunctivitis, anemic mucous membranes, jaundice, and with reduced frequency hemorrhages/petechiae, polydipsia/polyuria, uveitis, and neurological disorders. Most animals did other complementary test. The presence of anemia, leukocytosis, thrombocytopenia, increased urea and creatinine concentrations in the blood were common findings. The presence of hepatic alterations and changes compatible with renal insufficiency were also frequently observed.
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Dissertação de Mestrado Integrado em Medicina Veterinária
Palavras-chave
Zoonose , leptospirose , Leptospira , canídeos