Seroprevalencia de leptospirosis en grupos humanos en riesgo por factores ambientales, laborales o sociales / Seroprevalence of leptospirosis in human groups at risk due to environmental, labor or social conditions

Abstract Leptospirosis is important in Uruguay due to the economic loss caused by the diseases of production animals, mainly bovines, and also due to frequent human infection. We decided to study anti-Leptospira antibodies in the sera of dairy workers, rice laborers, veterinarians, suburban slum dwellers and garbage recyclers. Our aims were to estimate the seroprevalence of infection by Leptospira spp. in these people at risk, the relative importance of the known risk factors associated with infection, and the impact of human infections in each setting. Groups at risk were identified and 35 visits to their locations were made, conducting field surveys and exchange talks for information and education. Simple epidemiological questionnaires were administered and sera samples were taken from 308 persons. The microagglutination Technique (MAT) and the IgM Indirect Immunofluorescence (IIF) assay were employed to detect antibodies. Environmental water samples, canine and equine sera were also examined. More than 45% of human sera were reactive and the studied groups were confirmed to be widely exposed to infection. Female sera were frequently reactive, though most illnesses occur in men, and the most severe cases in elderly males; the emergence and evolution of the disease may strongly depend on the host condition and functions. Animal contact and unsafe water usage were the main identified risk factors to be considered in prevention. Fifty per cent of the studied horses showed a positive MAT reaction. The underdiagnosis of the illness and its long-term symptoms require further study, as well as greater health and social attention efforts.

Resumen La leptospirosis es importante en Uruguay por las pérdidas económicas que ocasionan las enfermedades en los animales de producción, principalmente en los bovinos, y a causa de la frecuente infección humana. Decidimos estudiar anticuerpos anti -Leptospira en trabajadores de tambo y de plantaciones de arroz, así como en veterinarios, habitantes de asentamientos y recicladores de residuos. Buscamos evaluar la importancia de distintos factores de riesgo conocidos asociados con la infección por Leptospira spp., y estimar la frecuencia y el impacto de las infecciones humanas en la población expuesta. Se efectuaron 35 visitas a colectivos de riesgo, realizando relevamientos de campo e intercambios educativos, llenando formularios epidemiológicos sencillos y tomando muestras de sangre a 308 personas. Se investigaron anticuerpos séricos con técnicas de microaglutinación (MAT) e inmunofluorescencia indirecta para IgM. Se examinaron también, muestras de agua ambiental, y sueros caninos y equinos. Más del 45% de los sueros humanos fueron reactivos y se confirmó que los grupos estudiados estaban ampliamente expuestos a la infección. Los sueros de mujeres fueron frecuentemente reactivos, aunque la mayoría de las enfermedades ocurren en varones, y los casos más graves en varones añosos. La emergencia y la evolución de la afección pueden depender fuertemente del estado del huésped y su respuesta. El contacto con animales y el uso de agua insegura fueron los principales factores de riesgo identificados para considerar en la prevención. El 50% de los sueros equinos fueron reactivos por MAT. Es necesario incrementar los esfuerzos de atención social y sanitaria en estos sectores, superar el subdiagnóstico y estudiar la evolución y la sintomatología a largo plazo de los pacientes.

Diagnosis of canine leptospirosis: evaluation of two PCR assays in comparison with the microagglutination test / Diagnóstico de leptospirose canina: avaliação de dois ensaios de PCR em comparação com o teste de microaglutinação

Canine leptospirosis is definitely diagnosed by demonstrating seroconversion in paired serum samples from the acute and convalescent period by the microagglutination test (MAT). However, the application of a polymerase chain reaction (PCR) assay can provide earlier confirmation of suspected cases. The objective of this study was to evaluate two PCR assays used in diagnosis of human leptospirosis (lipL32 real-time PCR and rrs conventional PCR) in cultured microorganisms and experimentally contaminated samples (whole blood, serum, urine), and investigate their applicability in clinical samples from dogs with presumptive diagnosis of leptospirosis by using the MAT as a reference. The analytical sensitivity of the lipL32 real-time PCR was 1 genome equivalent per reaction, whereas that for the rrs conventional PCR was 10 genome equivalents per reaction. Both assays amplified the pathogenic strains but were negative when evaluating the DNA of other microorganisms that may be present in clinical samples. The lipL32 real-time PCR detected 100 bacteria/mL in whole blood samples, 1000 bacteria/mL in serum samples and 10 bacteria/mL in urine samples, whereas the rrs conventional PCR detected 1000 bacteria/mL in whole blood and serum samples and 100 bacteria/mL in urine samples. Seven out of the 51 samples from dogs with presumptive diagnosis of leptospirosis were considered as confirmed cases. ThelipL32 real-time PCR detected positive results in six of the seven confirmed cases, whereas the rrs conventional PCR detected four. The PCR assays evaluated proved to be useful diagnostic tools in the confirmation of canine leptospirosis when used together with the MAT.(AU)

O diagnóstico definitivo da leptospirose canina é geralmente realizado demonstrando a seroconversão em amostras do paciente no período agudo e de convalescença por serologia. No entanto, a aplicação de técnicas de PCR pode contribuir para a confirmação de casos suspeitos num período de tempo mais curto. O objetivo deste estudo foi avaliar dois ensaios de PCR publicados em humanos (PCR-lipL32 em tempo real e PCR-rrs convencional) em culturas puras e em amostras de sangue com anticoagulante, soro e urina experimentalmente contaminados. Posteriormente, investigamos a utilidade de ambos os ensaios de PCR em amostras clínicas de cães com suspeita de leptospirose tomando a técnica de microaglutinação (MAT) como referência. A sensibilidade analítica foi de 1 e 10 genoma equivalente por reação para PCR-lipL32 em tempo real e para PCR-rrs convencional, respectivamente. Ambos os ensaios amplificaram corretamente as 14 estirpes patogênicas, mas foram negativos para avaliar o ADN de outros microrganismos que poderiam estar presentes em amostras clinicas. Em nas amostras experimentalmente contaminadas PCR-LipL32 em tempo real detectou 100 bactérias/mL em sangue total, 1000 bactérias/mL em soro e 10 bactérias/mL em urina. Enquanto o PCR-rrs convencional detectou 1000 bactérias/mL em sangue total e soro e 100 bactérias/mL na urina. Dos 51 cães suspeitos, sete foram considerados casos confirmados pela MAT. O PCR-lipL 32 em tempo real detectou seis dos sete casos confirmados, enquanto o PCR-rrs convencional foi positivo em quatro deles. As técnicas de PCR avaliadas provaram ser uma ferramenta de diagnóstico útil na confirmação de casos clínicos caninos quando utilizados em conjunto com a técnica MAT.(AU)

Occurrence of serological reactions for serogroup Sejroe (CTG and Prajtino) in female buffalo in the state of Pernambuco, Brazil

ABSTRACT The objective of this study was to evaluate the occurrence of anti-Leptospira spp. antibodies in female buffalo in the state of Pernambuco. A total of 123 female buffalo blood samples were collected from five properties distributed in the state of Pernambuco. The microscopic agglutination test was used to study anti-Leptospira spp. antibodies. The occurrence of anti-Leptospira spp. antibodies was 28.5% (35/123; CI 20.7-37.3%) and on different properties, the occurrence ranged from 28.6% to 80.0%, with 100% of the properties showing animals with positive results. The serovars of the serogroup Sejroe with a higher incidence were Hardjoprajtino (CTG strain, 49.1%) and Hardjo (Prajtino genotype, 43.2%), followed by serogroup Grippotyphosa with the Grippotyphosa serovar (3.9%), serogroup Pomona with the Pomona serovar (1.9%), and the Icterohaemorrhagiae serovar Copenhageni (1.9%). This was the first record of the occurrence of anti-Lepstospira spp. antibodies in female buffalo in the state of Pernambuco. Control measures are necessary to prevent health and economic losses, given that the agent involved affects animal reproduction, triggering drops in conception rates or even clinical cases of abortion.

Human leptospirosis: occurrence of serovars of Leptospira spp. in the state of Minas Gerais, Brazil, from 2008 to 2012

Abstract Background: Leptospirosis is an infectious and acute disease caused by Leptospira spp. that have high epidemic potential. This study verified the main Leptospira spp. serovars detected by MAT from serum of patients with suspicion of leptospirosis from 2008 to 2012 in Minas Gerais State. Methods: The laboratory received sera from 4654 patients. All serum were screened by IgM-ELISA according to the manufacturer's instructions. Each sample reactive or indeterminate were tested against twenty-four serovars of Leptospira by MAT. Results: In this study, 597 patients were classified as reactive on MAT. Only 301 patients were confirmed by laboratory test. It was not possible confirmation by laboratory diagnosis of 296 patients. Among the samples classified as reactive on MAT, 273 patients exhibited titers bigger than 800 for one or more serovars; seroconversion was detected in 28 cases. Percentage of 85.1% of the samples reactive on MAT corresponded to males, 39.4% corresponded to patients aged between 20 and 39 years old. The most common serovars found were Icterohaemorrhagiae, Andamana, Patoc, Tarassovi, Copenhageni, Hardjo and Australis. Concerning the samples that exhibited titers bigger than 800, serovar Icterohaemorrhagiae was also the most common, followed by Copenhageni, Andamana, Patoc, Tarassovi, Grippotyphosa and Canicola. In this study, 40% of the cases occurred to the metropolitan area, state capital and 34 neighboring towns. Conclusion: Our results show the possibly spreading serovars in Minas Gerais State and contribute to knowledge of human leptospirosis, aiming at improving the prevention, control of the disease, as well as the treatment of infected patients.

Seroprevalence and factors associated with Leptospira infection in an urban district of Cali, Colombia / Seroprevalencia y factores asociados a la infección por Leptospira en un distrito urbano de Cali, Colombia / Soroprevalência da infecção por Leptospira e fatores associados em um distrito urbano de Cali, Colômbia

Few studies have addressed Leptospira seroprevalence and risk factors in urban populations in Colombia. This study aimed to determine seroprevalence and factors associated with Leptospira infection in inhabitants of an urban district of Cali, Colombia. We collected sociodemographic and environmental data, as well as blood samples, from 353 subjects selected through a multistage cluster sampling design. We performed microagglutination test for the eight main Leptospira serogroups circulating in the region, considering a cut-off titer of ≥ 1:100. Most participants were female (226, 64.8%), with mean age 41.4 years, and 89 (32.6%) lived in low-low socioeconomic stratum (SES-1). Overall seroprevalence was 12.2% (95%CI: 10.3%-14.4%). Factors associated with Leptospira infection were SES 1, older age, single marital status, ethnic groups (Afro-Colombian and white/mestizo), school students, absence of toilet, barefoot walking, travel outside Cali in the previous month, and absence of skin and mucous-membrane lesions in the previous month. Our study suggests domestic and peridomiciliary transmission of Leptospira likely related to activities of daily living and inadequate environmental conditions. SES-1 is a major factor associated with Leptospira infection (adjusted OR = 4.08; 95%CI: 2.54-6.53; p < 0.001), suggesting that social and environmental conditions are key elements for endemicity of Leptospira infection in the study area. Epidemiological surveillance, improvement of environmental and sanitary conditions in various SES-1 areas, and community educational campaigns are recommended.

Pocos estudios se han centrado en la seroprevalencia por Leptospira y sus factores de riesgo en poblaciones urbanas de Colombia. Este estudio tuvo como meta determinar la seroprevalencia y los factores asociados a la infección por Leptospira en una población residente de un distrito urbano de Cali, Colombia. Recogimos datos sociodemográficos y ambientales, así como muestras de sangre, de 353 sujetos seleccionados a través de un diseño de muestreo por conglomerados en etapas múltiples. Se realizó un test de microaglutinación para los ocho serogrupos principales de Leptospira circulando en la región, considerando una zona corte de ≥ 1:100. La mayoría de los participantes fueron mujeres (226, un 64,8%), con un promedio de edad de 41,4 años, con 89 (32,6%) que vivían en condiciones socioeconómicas bajas o muy bajas (SES-1). La seroprevalencia global fue de un 12,2% (IC95%: 10,3%-14,4%). Los factores asociados con la infección por Leptospira fueron SES-1, edad más avanzada, estado civil soltera, grupo étnico (afrocolombiano y blanco/mestizo), estudiantes escolares, ausencia de baño, caminar descalzo, viajar fuera de Cali durante el mes previo al estudio, y ausencia de lesiones en la piel y membranas mucosas durante el mes previo al mismo. Nuestro estudio sugiere que la trasmisión doméstica y peridomiciliaria de la Leptospira está vinculada a actividades de la vida diaria y a condiciones ambientales inadecuadas. SES-1 es un factor importante, asociado a la infección por Leptospira (OR ajustada = 4,08; IC95%: 2,54-6,53; p < 0,001), sugiriendo que las condiciones sociales y ambientales son elementos clave para la endemicidad de la infección por Leptospira en el área de estudio. Se recomienda vigilancia epidemiológica, mejora de las condiciones ambientales y sanitarias en varias áreas SES-1, así como campañas educacionales dirigidas a la comunidad.

Poucos estudos trataram da soroprevalência para Leptospira e fatores de risco em populações urbanas da Colômbia. Este estudo teve como objetivo determinar a soroprevalência e fatores associados com a infecção por Leptospira nos habitantes de um distrito urbano de Cali, Colômbia. Os autores coletaram dados sociodemográficos e ambientais, além de amostras de sangue, de 353 indivíduos selecionados através de uma amostragem de aglomerados em múltiplas fases. Foi realizado o teste de microaglutinação para os oitos principais grupos sorológicos da Leptospira circulantes na região, considerando um título de ≥ 1:100. A maioria dos participantes era do sexo feminino (226, 64,8%), com média de idade de 41,4 anos; 89 (32,6%) pertenciam ao estrato socioeconômico mais baixo (SES-1). A soroprevalência global era 12,2% (IC95%: 10,3%-14,4%). Os fatores associados à infecção por Leptospira eram SES-1, idade, estado civil solteiro, grupo étnico (afro-colombiano e branco/mestiço), estudantes, ausência de privada no domicílio, andar descalço, viagem fora de Cali no mês anterior e ausência de lesões mucocutâneas no mês anterior. O estudo sugere a transmissão domiciliar e peridomiciliar da Leptospira, provavelmente associada a atividades cotidianas e condições ambientais adversas. SES-1 é um fator importante associado à infecção com Leptospira (OR ajustado = 4,08; IC95%: 2,54-6,53; p < 0,001), indicando que as condições sociais e ambientais são elementos importantes na endemicidade da leptospirose na área do estudo. Recomendamos a vigilância epidemiológica, melhora das condições ambientais e sanitárias em diversas áreas SES-1 e campanhas educativas comunitárias.

Seroprevalencia de leptospirosis y características asociadas en agricultores de arroz de una región tropical del Perú / Leptospirosis seroprevalence and associated features in rice farmers of tropical region of Peru

Objetivos . Estimar la seroprevalencia de leptospirosis en agricultores dedicados al cultivo de arroz del valle del Alto Mayo, región San Martín e identificar anticuerpos para los serovares circulantes y los factores asociados a la infección. Materiales y métodos. Se realizó un estudio transversal entre octubre y noviembre de 2010 en una muestra de 254 agricultores procedentes de las once comisiones de regantes del valle de Alto Mayo. Se recolectó una muestra de sangre y se aplicó un cuestionario que incluyó variables sociodemográficas, y características del hogar y del trabajo. Se determinó la presencia de anticuerpos contra leptospira usando la prueba de microaglutinación y ELISA IgM. Resultados. La seroprevalencia determinada por microaglutinación fue del 64,6% (IC 95%: 58,6-70,6). La prueba ELISA IgM fue reactiva en 15,0% (IC 95%: 10,5-19,5). Los tipos de serovar más frecuentes fueron Icterohaemorrhagiae, Autumnalis, Australis , Panama y Grippotyphosa. Los factores asociados independientemente fueron la manipulación de roedores (OR ajustado [ORa] de 7,9, IC 95%: 1,6-37,9), trabajar descalzo (ORa de 2,9, IC 95%: 1,2-6,8) y el sexo masculino (ORa de 4,5, IC 95%: 1,3-15,3). Conclusiones . El valle del Alto Mayo es un área hiperendémica de leptospirosis. Los factores asociados más importantes fueron la práctica de trabajar descalzo y la de manipular roedores en los campos de cultivo. En consecuencia, se recomienda implementar intervenciones que incidan en estos dos factores a fin de reducir el riesgo de infección en los cultivadores de arroz.

Objectives. To estimate the seroprevalence of leptospirosis in rice farmers of the Alto Mayo Valley in the Peruvian region of San Martín and to identify factors associated with infection. Materials and methods. A cross-sectional study was conducted between October and November of 2010 on a sample of 254 farmers from eleven irrigation committees in the Alto Mayo Valley. A blood sample was collected as well as sociodemographic, household and labor characteristics in the form of a questionnaire. The presence of antibodies against leptospira was determined using the microscopic agglutination test and the IgM ELISA. Results. The seroprevalence by agglutination was 64.6% (95% CI: 58.6-70.6). The IgM ELISA test was reactive in 15,0% (95% CI: 10.5-19.5). The most frequent serovar were Icterohaemorrhagiae, Autumnalis, Australis, Panama and Grippotyphosa. Independently associated factors were handling rodents (adjusted OR (aOR): 7.9; 95% CI: 1.6-37.9), working barefoot (aOR: 2.9; 95% CI: 1.2-6.8) and male sex (aOR: 4.5; 95% CI: 1.3-15.3). Conclusions. The Alto Mayo Valley is a hyperendemic for leptospirosis. The most important factors were associated with working barefoot and handling rodents in crop fields. Consequently, it is recommended to implement interventions that affect these two factors in order to reduce the risk of infection in rice farmers.

Immune responses to Leptospira infection: roles as biomarkers for disease severity

Various leptospiral components have been identified and shown to be involved in tissue destruction. In addition, immune responses to leptospires have been implicated in target organ damages in severe leptospirosis cases. Several inflammatory mediators were shown to be higher in susceptible animals than in resistant hosts. Moreover, cytokines/chemokines and serum proteins induced following Leptospira infection were suggested to be biomarkers for disease severity in human leptospirosis. This review focuses on the role of immune responses in the severity of leptospirosis. Studies in both animal models and humans are discussed.

Avaliação ambiental e do gradiente social nas infecções por leptospira em uma comunidade de Salvador-Bahia / Environmental and social gradient on leptospira infection in a community assessment of Salvador-Bahia

Introdução: A leptospirose tem emergido como um importante problema de saúde pública no mundo. Esta zoonose é responsável por epidemias anuais que acometem principalmente indivíduos residentes em comunidades negligenciadas como as existentes em Salvador. Poucos estudos longitudinais foram realizados com objetivo de identificar os fatores de risco para infecção, fontes de transmissão e compreender a real dimensão da leptospirose nessas comunidades. Objetivo: Identificar fatores de risco para infecção prévia e novas infecções por leptospiras no contexto ambiental e socioeconômico em uma comunidade em Salvador Bahia. Métodos: Estudos de soroprevalência e coorte foram conduzidos na comunidade de Pau da Lima, com a realização de entrevistas domiciliares, avaliação peridomiciliar, coleta de material biológico e análises espaciais para mensurar a associação epidemiológica entre fatores de risco ambientais e as infecções. O teste de microaglutinação foi utilizado para avaliar amostras sorológicas obtidas. Resultados: Residir próximo aos esgotos abertos e do fundo do vale proximidade do domicílio a acúmulo de lixo e baixa renda foram associados com as infecções. A incidência anual de infecções secundárias foi de 2,3 vezes maior que as infecções primárias. Conclusão: O presente estudo sugere que medidas preventivas devem focalizar nas deficiências de infraestrutura que servem como fontes de transmissão. Intervenções mais efetivas precisam se concentrar especialmente nos adultos jovens e nos grupos populacionais mais desfavorecidos nestas comunidades.

Introduction: Leptospirosis has emerged as an important public health problem in the world. This zoonosis is responsible for annual epidemics affecting mainly individuals living in disadvantaged communities as existing in Salvador. Few longitudinal studies have been conducted in order to identify risk factors for infection, transmission sources and understand the real dimension of leptospirosis in these communities. Objective: To identify risk factors for early infection and new infections by Leptospira in environmental and socioeconomic context in a community in Salvador Bahia. Methods: Seroprevalence and cohort studies were conducted in Pau da Lima community, conducting home interviews peridomicilary review, collection of biological material and spatial analysis to measure the epidemiological association between environmental risk factors and infections. The agglutination test was used to evaluate serum samples obtained. Results: Residing next to open sewers and the valley floor near the homes of waste accumulation and low income were associated with infections. The annual incidence of secondary infections was 2.3 times higher than primary infections. Conclusion: This study suggests that preventive measures should focus on infrastructure deficiencies that serve as sources of transmission. More effective interventions need to focus especially on young adults and the most disadvantaged population groups in these communities.

Etiología y caracterización epidemiológica del síndrome febril no palúdico en tres municipios del Urabá antioqueño, Colombia / Etiology and epidemiological characterization of non-malarial febrile syndrome in three municipalities of Urabá (Antioquia), Colombia

Introducción. La región de Urabá es endémica para varias enfermedades febriles agudas de origen infeccioso. Sin embargo, solo los pacientes con malaria pueden acceder a un diagnóstico oportuno y rápido, motivo por el cual muchos síndromes febriles no palúdicos quedan sin diagnóstico etiológico claro. Objetivo. Establecer la etiología, describir las manifestaciones clínicas y explorar algunos posibles factores de riesgo relacionados con los síndromes febriles agudos no palúdicos en pacientes procedentes de los municipios de Necoclí, Turbo y Apartadó. Materiales y métodos. Se tomaron muestras de suero en fase aguda y de convalecencia de 220 pacientes febriles negativos para malaria, provenientes de zonas rurales y urbanas de Necoclí, Turbo y Apartadó en los años 2007 y 2008. Se practicaron pruebas para diagnóstico de dengue (detección de anticuerpos IgM por ELISA), leptospirosis (detección de anticuerpos IgM e IgG por IFI), rickettsiosis (detección de anticuerpos IgG por IFI), hantavirus y arenavirus (detección de anticuerpos IgG por ELISA). Resultados. Se encontraron frecuencias de dengue, leptospirosis, rickettsiosis y arenavirus de 37,3 %, 14,1 %, 2,7 % y 0,5 %, respectivamente. Se presentaron 12 casos de coinfección de leptospirosis-dengue y uno de leptospirosis-rickettsiosis-dengue. El sexo masculino y la humedad relativa media, fueron factores de riesgo para dengue. El inicio de signos clínicos en febrero de 2008, se asoció tanto con la infección por dengue como por leptospirosis. Conclusión. Se reafirma la importancia del virus del dengue, Rickettsia spp. y Leptospira spp., como agentes causantes del síndrome febril en la región del Urabá.

Introduction: Urabá, a region on the northern coast of Colombia, is endemic to several acute febrile illnesses of infectious origin; however, only patients with malaria may have access to quick and effective diagnosis. For this reason, many non-malarial febrile patients go without a clear etiologic diagnosis. Aim: To establish the etiology and clinical signs of acute febrile non-malaria syndromes and explore some of the likely risk factors in patients originating in the municipalities of Necocli, Turbo and Apartado who exhibit these symptoms. Materials and methods: We obtained acute and convalescent sera from 220 non-malarial febrile patients from the rural and urban zones of Necocli, Turbo and Apartado during 2007 and 2008. Serologic tests for dengue (IgM by ELISA), leptospirosis (IgM and IgG by IFA), rickettsiosis (IgG by IFI), hanta and arenavirus (IgG by ELISA) were performed. Results: We found that the frequency of infection for dengue, leptospirosis, rickettsiosis and arenavirus, was 37.3%; 14.1%; 2.7% and 0.5%, respectively. There were 12 co-infection cases of leptospirosis-dengue and one of leptospirosis-rickettsiosis-dengue. Male gender and relative humidity were considered risk factors for dengue, and the beginning of clinical signs in February of 2008 was associated with the infection of dengue and leptospirosis. Conclusion: This study confirms previous records that underline the importance of Rickettsia spp, dengue virus and Leptospira spp as causal agents of febrile syndrome in this region of Colombia.

Ionic imbalance and lack of effect of adjuvant treatment with methylene blue in the hamster model of leptospirosis

Leptospirosis in humans usually involves hypokalaemia and hypomagnesaemia and the putative mechanism underlying such ionic imbalances may be related to nitric oxide (NO) production. We previously demonstrated the correlation between serum levels of NO and the severity of renal disease in patients with severe leptospirosis. Methylene blue inhibits soluble guanylyl cyclase (downstream of the action of any NO synthase isoforms) and was recently reported to have beneficial effects on clinical and experimental sepsis. We investigated the occurrence of serum ionic changes in experimental leptospirosis at various time points (4, 8, 16 and 28 days) in a hamster model. We also determined the effect of methylene blue treatment when administered as an adjuvant therapy, combined with late initiation of standard antibiotic (ampicillin) treatment. Hypokalaemia was not reproduced in this model: all of the groups developed increased levels of serum potassium (K). Furthermore, hypermagnesaemia, rather than magnesium (Mg) depletion, was observed in this hamster model of acute infection. These findings may be associated with an accelerated progression to acute renal failure. Adjuvant treatment with methylene blue had no effect on survival or serum Mg and K levels during acute-phase leptospirosis in hamsters. .

Haemoglobin and red cell counts in leptospirosis patients infected with different serovars

Introduction The aim of the study was to compare haemoglobin and red cell counts between patients known to be infected with a range of leptospiral serovars. Methods The study retrospectively compared the haemoglobin and red cell count results from the first blood samples taken from 207 patients at presentation to a Queensland Health hospital. Results Significant differences were observed in haemoglobin and red cell counts in those infected with Leptospira interrogans serovars Szwajizak and Canicola when compared with most of the other serovars. Conclusions These findings suggest that haemoglobin and red cell counts may be useful in differentiating leptospiral serovars in leptospirosis patients. .

Detecção de Espécies Reativas de Oxigênio no sangue periférico de pacientes com leptospirose grave / Detection of Reactive Oxygen Species in peripheral blood patients with severe leptospirosis

Leptospirose é uma zoonose que pode levar a graves complicações, como a síndrome de Weil e a síndrome pulmonar hemorrágica, porém os mecanismos patogênicos que levam ao desenvolvimento das formas graves da doença ainda são desconhecidos. Após a penetração no indivíduo, as leptospiras invadem a corrente sanguínea e se disseminam para os órgãos. Dessa forma, a leptospirose apresenta características semelhantes as da sepse, doença que tem o estresse oxidativo como um dos principais responsáveis pelo seu agravamento. Entretanto, pouco se sabe sobre o envolvimento do estresse oxidativo na leptospirose. O presente estudo teve como objetivo avaliar se a produção de espécies reativas de oxigênio (ROS) e os níveis do antioxidante glutationa (GSH) estão relacionados com as manifestações clínicas mais graves de pacientes hospitalizados com leptospirose. A produção de ROS e os níveis de GSH foram avaliados nas amostras de sangue de doze pacientes e nove indivíduos saudáveis através dos ensaios de quimioluminescência e de absorbância, respectivamente. Nós observamos que os níveis de ROS estavam aumentados (p=0.0012) e os de GSH diminuídos (p=0.0002) nos pacientes quando comparados com os indivíduos saudáveis. Dentre os pacientes, a diminuição de GSH estava correlacionada com a trombocitopenia (r=0.63) e com elevados níveis de creatinina (r= -0.64), enquanto que a produção de ROS estava fortemente correlacionada com os níveis elevados de potássio sérico (r=0.8). A compreensão da importância biológica de ROS e do GSH na leptospirose faz-se necessária, pois uma investigação mais detalhada pode levar ao desenvolvimento de terapias adjuvantes focadas no estresse oxidativo.

Leptospirosis is a zoonotic disease that causes severe manifestations such as Weil’s disease and pulmonary hemorrhage syndrome, however the underlying mechanisms that lead to the development of severe forms are not clear. Leptospires penetrate through skin, reach the bloodstream and disseminate to the organs. Thus, leptospirosis and sepsis have similar characteristics. Although there is vast literature demonstrating that oxidative stress play an important role in the severity of sepsis, none is known about it in leptospirosis. The aim of this study was to evaluate whether reactive oxygen species (ROS) production and antioxidant reduced glutathione (GSH) levels are related to complications in patients hospitalized with leptospirosis. ROS production and GSH levels were measured in blood samples of twelve patients and nine healthy controls using chemiluminescence and absorbance assays. We found that ROS production was higher (p=0.0012) and GSH levels were lower (p=0.0002) in leptospirosis patients compared with healthy individuals. Among patients, GSH depletion was correlated with thrombocytopenia (r=0.63) and elevated serum creatinine (r= -0.64), while a strong positive correlation was observed between ROS production and elevated serum potassium (r=0.8). Additional investigation of the biological significance of ROS production and GSH levels is warranted as they may guide the development of novel adjuvant therapies for leptospirosis targeting oxidative stress.

Inquérito sorológico para leptospirose em cães da Ilha da Marambaia, Rio de Janeiro, Brasil / Serologic survey for leptospirosis in dogs Marambaia Island, Rio de Janeiro, Brazil

A leptospirose é uma zoonose endêmica de distribuição mundial causada por bactérias do gênero Leptospira com inúmeros sorovares distintos, dificultando sua caracterização. A maioria dos casos cursa com sinais e sintomas inespecíficos, sendo muitas vezes confundida com viroses. Exibe caráter sazonal em regiões tropicais em que há alta incidência de períodos chuvosos, afetando tanto a população urbana quanto a rural. No Brasil a doença tem grande importância social e econômica. Acomete além do homem, animais silvestres e domésticos, sendo os roedores sinantrópicos os principais reservatórios urbanos e o cão, potencial fonte de infecção para o homem. O presente estudo teve como objetivo realizar o primeiro inquérito sorológico para leptospirose em cães na Ilha da Marambaia, município de Mangaratiba, Rio de Janeiro, onde não há registro de casos em humanos nem em animais além da busca de casos humanos nos registros do SINAN e também avaliar as características ambientais da região. Possíveis casos de leptospirose canina foram investigados a partir de fichas clínicas com dados dos animais. Foram analisadas 234 amostras sanguíneas de cães coletadas em dois períodos: No decorrer dos anos de 2009 e 2012 em inquérito sobre leishmaniose visceral na ilha. A investigação foi realizada a partir da técnica de aglutinação microscópica (MAT), considerada internacionalmente como o, “padrão ouro” para o diagnóstico de leptospirose. O procedimento foi executado no Laboratório Nacional de Referência de Leptospirose (LNRL-CC/OMS), localizado no instituto Oswaldo Cruz (FIOCRUZ), no Rio de Janeiro. Do total de amostras estudadas, 2,56% (6/234) apresentaram reação positiva ao MAT para os sorovares Australis, Copenhageni e Patoc, com titulações que variaram de 80 a 640. O sorovar mais prevalente foi o Australis 66,66% (04/06), seguido pelo Copenhageni (01/06) e Patoc (01/06), ambos com a mesma frequência de 16,67%.

Este foi um estudo preliminar na região e os dados indicam a possibilidade de circulação de Leptospira sp. embora não haja casos clínicos relatados. Os resultados encontrados podem indicar ainda possíveis reservatórios que devem ser confirmados em estudos posteriores. É importante frisar que além de detectarmos baixa incidência em cães, a região possui um ambiente propício para manutenção do micro-organismo. A precariedade do saneamento, a presença de animais silvestres, o movimento irrestrito de cães somados aos dados sorológicos encontrados sugerem a possibilidade de circulação de bactérias entre os cães e possíveis reservatórios no ambiente silvestre.

Avaliação da infecção por leptospiras patogênicas em primatas silvestres mantidos em cativeiro em Salvador, Bahia, Brasil / Evaluation of infection by pathogenic Leptospira in wild primates kept in captivity in Salvador, Bahia, Brazil

Estima-se que 70% das doenças infecciosas emergentes em humanos estão relacionados a exposição a animais silvestres. Estudos envolvendo infecções em primatas não humanos e o seu papel na epidemiologia da leptospirose são escassos.Uma instrução normativa do Ministério do Meio Ambiente(179 de 25/06/2008)recomenda o uso de teste de microaglutinação (MAT) para detecção de anticorpos aglutinantes anti-Leptospira em espécies silvestres em programas de reintrodução à vida livre. Neste contexto, o presente projeto propôs investigar a evidência de prévia exposição e a ocorrência do estado de portador de leptospira patogênicas em primatas silvestres residentes no Parque Zoobotânico Getúlio Vargas de Salvador (PZBGV) e recebidos pelo Centro de Triagem de Animais Silvestres Chico Mendes (CETAS). Foram analisados 42 amostras de soro e sangue total de 42 primatas do PZBGV e 16 amostras de soros de 16 primatas do CETAS pelo teste de aglutinação microscópica (MAT) e PCR respectivamente. Amostras de urina de 3 de primatas do PZBGV e 13 do CETAS também foram submetidas à PCR. A soroprevalência encontrada no PZGV foi de 2%(1/42)enquanto que no CETAS foi de 31%(5/16). O único primata do PZBGV positivo na MAT foi um Allouata caraya (bugio preto) fêmea, adulta, que apresentou reação mista para os sorogrupos Australis e Icterohaemorrhagiae. As cinco amostras positivas do CETAS ocorreram em macacos-prego(Cebus sp.)e foram distribuídos nos sorogrupos: Ballum(1:100), Semaranga (1:200), Grippotyphos (1:100),Cynopeteri(1:100) e uma reação mista Tarassovi / Autumnalis (1:100). Todas as amostras de sangue total e urina analisadas por PCR foram negativas. Conclui-se que a soroprevalência de anticorpos anti-Leptospira foi baixa no PZBGV de Salvador, apesar da alta frequência de roedores na área e endemicidade da leptospirose humana em Salvador. A prevalência elevada foi observada entre os animais resgatados do comércio ilegal no estado da Bahia e esta evidência sorológica de exposição sugere um risco potencial de transmissão da leptospirose ao se adotar estes primatas como animais de estimação

It is estimated that 70% of emerging infectious diseases in humans are related to exposure to wild animals. Studies involving infections in nonhuman primates and their role in the epidemiology of leptospirosis are scarce. A normative statement of the Ministry of the Environment (179 of 25/06/2008) recommends the use of microscopic agglutination test (MAT) for antibodies binding anti-Leptospira in wild species reintroduction programs in the wild. Positive tests indicate the need for quarantine and antimicrobial treatment. In this context, this project proposes to investigate the evidence of prior exposure and the occurrence of carrier status of pathogenic Leptospira in wild primates living in the Parque Vargas Zoobotânico Salvador (PZBGV) and received by the Center for Wildlife Screening Chico Mendes (CETAS). We analyzed 42 serum samples and 42 whole blood PZBGV primates and 16 sera from 16 primates CETAS by microscopic agglutination test (MAT) and PCR respectively. Urine samples of 3 primates PZBGV CETAS and 13 were also subjected to PCR. The seroprevalence in PZBGV was 2% (1/42) while the CETAS was 31% (5/16). The only positive was a primate Allouata caraya (black howler monkey) female, adult, which showed mixed reaction to serogroups Australis and Icterohaemorrhagiae. The five samples positive from CETAS occurred in monkeys (Cebus sp.) And were divided into serogroups: Ballum (1:100), Semaranga (1:200), Grippotyphosa (1:100), Cynopeteri (1:100) and mixed reaction Tarassovi / Autumnalis (1:100). All blood samples and urine samples were analyzed by PCR negative. It is concluded that the seroprevalence of anti- Leptospira antibodies was low in the Zoo of Salvador, despite the high frequency of rodents in the area and endemicity of leptospirosis in Salvador...

Diagnóstico de leptospirosis humana: evaluación de la aglutinación macroscópica en diferentes etapas de la enfermedad

OBJETIVO: Evaluar la aglutinación macroscópica con antígeno termorresistente (TR) como tamiz diagnóstico de leptospirosis humana en diferentes etapas de la enfermedad. MATERIAL Y MÉTODOS:La definición de casos se basó en la microaglutinación (MAT), recuento de leucocitos y neutrofilia. Se incluyeron 218 casos confirmados y 242 no casos. Cada muestra del banco de sueros del laboratorio del Instituto Nacional de Enfermedades Respiratorias de Santa Fe, Argentina, de 2008 a 2010, se clasificó según días de evolución en tres etapas: primera (<10 días), segunda (10- 25 días) y tercera (>25 días). RESULTADOS: La sensibilidad hallada fue: 71.1, 93.4 y 95.6% para etapas 1, 2 y 3 respectivamente. La especificidad varió de 79.0 a 69.2%. La variabilidad intra e interoperador fue moderada. CONCLUSIÓN: La variabilidad del TR, su baja sensibilidad en la primera etapa y baja especificidad en todas las etapas de la enfermedad sugieren que sería indispensable la incorporación de nuevos métodos diagnósticos de tamiz para la detección precoz de casos en nuestro país, y países donde aún se apliquen este tipo de métodos.

OBJECTIVE: To evaluate the macroscopic agglutination test using Temperature Resistant (TR) antigen as a screening test for the diagnosis of human leptospirosis in different stages of the disease. MATERIALS AND METHODS: The criteria for case definition were based on the results of the microscopic agglutination test (MAT), leukocyte counts and neutrophilia, resulting 218 confirmed cases and 242 non- cases. Each sample was classified according to the days of the disease progression in three stages: first (<10 days), second (10 - 25 days) and third (> 25 days). The design was cross-sectional observational. RESULTS: TR sensitivity was 71,1% on stage 1. 93.4% on stage 2 and 95.6% on stage 3. The specificity at different stages ranged from 79.0 to 69.2%. Intra and inter-operator variability was moderate. CONCLUSION: TR variability, low sensitivity in the first stage and low specificity found in all stages of the disease, suggest that it is essential to incorporate new diagnostic methods to screen for early detection of cases in our country and in countries that still apply such methods.

Evaluation and comparison of native and recombinant LipL21 protein-based ELISAs for diagnosis of bovine leptospirosis

A 21-kDa leptospiral lipoprotein (LipL21) was evaluated for its diagnostic potential to detect bovine leptospirosis by ELISA. Both native LipL21 (nLipL21) and recombinant LipL21 (rLipL21) proteins were tested and compared regarding diagnostic efficiency, and no statistically significant difference was observed. The sensitivity of rLipL21 ELISA for 62 microscopic agglutination test (MAT) positive sera was 100% and the specificity with 378 MAT negative sera was 97.09%. Thus, rLipL21 protein-based ELISA could be used as an alternative to MAT for the diagnosis of bovine leptospirosis.

Sistemas serológicos rápidos utilizados para la pesquisa de leptospirosis humana en Cuba / Rapid serological diagnosis systems for human leptospirosis screening in Cuba

Introducción: la leptospirosis humana necesita de un diagnóstico microbiológico rápido y oportuno por ser una enfermedad letal y frecuente en todo el mundo. Objetivo: incrementar la calidad del diagnóstico microbiológico de esta infección, ampliar el conocimiento sobre la circulación de serogrupos de leptospiras en Cuba y demostrar la utilidad de un sistema de aglutinación con partículas de látex cubano y los sistemas inmunocromatogénicos comerciales LEPTO Dipstick, Lepto Tek Lateral Flow, Lepto Tek Dri Dot y SD Leptospira IgM-IgG. Métodos: en esta investigación descriptiva se utilizaron sueros de casos controles positivos y negativos para evaluar y medir el valor diagnóstico de los sistemas serológicos rápidos con respecto al método de referencia de microaglutinación (MAT). Todas las técnicas utilizadas en este reporte aparecen descritas en el Manual de Operaciones y Procederes del Laboratorio de Leptospiras, del Instituto de Medicina Tropical "Pedro Kourí". Resultados: todos los sistemas estudiados presentaron aceptables valores de sensibilidad, especificidad y concordancia en comparación con el método de referencia internacional de microaglutinación con microrganismos vivos. Se constató la amplia selectividad (reactividad antigénica) y la fiabilidad diagnóstica de los sistemas, se destacan en particular el látex mezclado de producción nacional, el LEPTO Dipstick y el SD Leptospira IgM-IgG. Conclusiones: ninguno de los procedimientos utilizados fue superado en cuanto a su sencillez, rapidez, simplicidad técnica y grado de ejecución al comparárseles con los métodos tradicionales, incluido el de referencia, y todos resultaron útiles en la pesquisa de anticuerpos frente a leptospiras.

Introduction: human leptospirosis requires rapid and early microbiological diagnosis since it is a common lethal disease worldwide. Objectives: to increase the quality of microbiological diagnosis of this infection, to expand the knowledge on the circulation of groups of leptospiras in Cuba and to show the benefits of an agglutination assay using Cuban latex particles and of commercial immunochromatogenic systems LEPTO Dipstick, Lepto Tek Lateral Flow, Lepto Tek Dri Dot and SD Leptospira IgM-IgG. Methods: this descriptive research used sera from positive and negative control cases to evaluate and measure the diagnostic value of rapid serological diagnosis systems with respect to the microagglutination method of reference (MAT). All the techniques used in this report are described in the Manual of Operations and Procedures of the Leptospira Lab in "Pedro Kourí" Institute of Tropical Medicine. Results: all the studied diagnosis systems exhibited acceptable values of sensitivity, specificity and agreement when compared to the international microagglutination method of reference with live microorganisms. The great selectivity (antigen reactivity) and the diagnostic reliability of the diagnostic systems were confirmed; particularly the mixed Cuban-made latex, the LEPTO Dipstick and the SD Leptospira IgM-IgG. Conclusions: the procedures used in this research work exceeded the traditional methods including the microagglutination method of reference in terms of easiness, rapidity, technical simplicity and level of performance, and all were useful for the screening of antibodies to leptospiras.

Anticuerpos contra Leptospira sp. en primates neotropicales y trabajadores de un zoológico colombiano / Leptospiral antibodies in a Colombian zoo's Neotropical primates and workers

Objetivo Detectar anticuerpos contra Leptospira sp. en primates neotropicales y funcionarios de un zoológico colombiano e identificar factores de riesgo de la enfermedad. Métodos Se realizó un estudio transversal analítico en 65 primates y 20 funcionarios del Zoológico. Las muestras fueron procesadas mediante la técnica de Microaglutinación macroscópica (MAT) usando un cepario de referencia conformado por 21 serovares de Leptospira sp. Se aplicó un instrumento estructurado al personal evaluado para identificar factores de riesgo. Resultados La seroprevalencia de la infección por Leptospira sp. fue del 25 % (5/20) en el personal y 23,07 % (15/65) en los monos neotropicales. Los serovares más frecuentes entre los funcionarios fueron bataviae, gryppotyphosa y hurstbridge. En los monos neotropicales predominaron los serovares icterohaemorrhagiae, pomona y ranarum. Las especies mono araña negro (Ateles fusciceps), mono cariblanco (Cebus albifrons) y tití gris (Saguinus leucopus), presentaron mayor reactividad. La mayor proporción del personal usaba dotación de protección. Conclusiones Se evidenció el contacto de los primates neotropicales y del personal con diferentes serovares de Leptospira. El uso de la dotación de protección y el tiempo de experiencia de los funcionarios del zoológico se consideraron como factores protectores de la enfermedad. Se sugiere que existe un riesgo de transmisión de leptospirosis, en los animales del zoológico y el personal, siendo por lo tanto importante fortalecer la vigilancia epidemiológica activa e implementar programas de promoción y prevención.

Objective Detecting antibodies against Leptospira spp. in Neotropical primates and workers in a Colombian Zoo and identifying the risk factors associated with the disease. Methods A cross-sectional study was performed regarding 65 Neotropical primates and 20 zookeepers. The samples were processed by microagglutination test (MAT) using a reference strain collection consisting of 21 Leptospira serovars. The people being evaluated were given a structured survey to identify risk factors. Results There was 25 % (5/20) Leptospira spp. infection seroprevalence in the staff and 23.07 % (15/65) in Neotropical monkeys. The most frequently occurring serovars in workers were bataviae, gryppotyphosa and ranarum; icterohaemorrhagiae, pomona and ranarum were the predominant serovars in non-human primates. The black spider monkey (Ateles fusciceps), white-fronted capuchin (Cebus albifrons) and white-footed tamarin (Saguinus leucopus) showed the highest reactivity. Most of the personnel were using protective clothing. Conclusions The contact between primates and zookeepers involving different Leptospira sp. serovars was evident. Zoo personnel using protective clothing and their length of experience were considered to be protective factors for the disease. There may be a risk of Leptospira transmission between zoo animals and staff, and it is therefore important to strengthen active surveillance and implement promotion and prevention programs.

Human leptospirosis in the Caribbean, 1997-2005: characteristics and serotyping of clinical samples from 14 countries / Leptospirosis humana en el Caribe entre 1997 y 2005: características y serotipificación de muestras clínicas de 14 países

OBJECTIVE: To determine the frequency of human leptospirosis in the sera of suspected clinical cases sent by 14 Caribbean countries for diagnosis to a regional laboratory in 1997-2005. METHODS: All serum samples were initially tested using the immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) for leptospirosis. Demographic data (such as age and sex), month of the year and clinical manifestations that had been observed by the attending physician were related to seropositivity. The microscopic agglutination test (MAT) was used to serotype sera using a panel of 23 international serovars. RESULTS: Of 3 455 samples tested, 452 (13.1 percent) were seropositive for IgM antibodies to leptospirosis by the ELISA, with frequencies significantly (P < 0.05; χ2) different across countries and years. Among seropositive patients, the frequency of detection of leptospirosis (23.1 percent) was significantly higher in the age groups 1-20 years and 31-40 years combined compared with other age groups; and in male patients (72.1 percent) compared with female patients (19.7 percent) (P < 0.05; χ2). Chills, jaundice, vomiting, weakness, diarrhea, and kidney failure/problems were significantly (P < 0.05; χ2) exhibited at a higher frequency in seropositive, rather than seronegative patients. Using the MAT on 100 sera tested, 98 (98 percent) were seropositive, of which the serogroup Icterohaemorrhagiae was most prevalent with the detection of serovars Copenhageni (70 percent), Icterohaemorrhagiae (67 percent), and Mankarso (29 percent). CONCLUSIONS: Since only 13.1 percent of the suspected cases of leptospirosis were seropositive for IgM ELISA antibodies, other clinical conditions may have been responsible for the clinical manifestations observed, or the patient may have had chronic leptospirosis (IgG). In the Caribbean, serovars of the serogroup Icterohaemorrhagiae were responsible for most infections in the cases tested.

OBJETIVO: Determinar la frecuencia de leptospirosis humana en el suero de presuntos casos clínicos enviados por 14 países del Caribe a un laboratorio regional para la confirmación del diagnóstico entre 1997 y 2005. MÉTODOS: Todas las muestras de suero se analizaron inicialmente mediante el ensayo inmunoenzimático de adsorción (ELISA) para detectar inmunoglobulina M (IgM) contra Leptospira. Se relacionó la seropositividad con datos demográficos (como la edad y el sexo), el mes del año y las manifestaciones clínicas observadas por el médico a cargo. Se usó la prueba de aglutinación microscópica para serotipificar los sueros con un grupo de 23 serovariedades internacionales. RESULTADOS: De las 3 455 muestras analizadas por ELISA, 452 (13,1 por ciento) fueron seropositivas para anticuerpos IgM contra Leptospira, con frecuencias significativamente diferentes (P < 0,05; χ2) según el país y el año. En los pacientes seropositivos, la frecuencia de detección de leptospirosis (23,1 por ciento) fue significativamente mayor en los grupos etarios de 1 a 20 años y de 31 a 40 años combinados, en comparación con otros grupos de edad; y mayor en los varones (72,1 por ciento) en comparación con las mujeres (19,7 por ciento) (P < 0,05; χ2). Los escalofríos, la ictericia, los vómitos, la debilidad, la diarrea y la insuficiencia o los trastornos renales fueron significativamente más frecuentes (P < 0,05; χ2) en los pacientes seropositivos que en los seronegativos. De los 100 sueros que se analizaron con la prueba de aglutinación microscópica, 98 (98 por ciento) fueron seropositivos, y entre estos el serogrupo Icterohaemorrhagiae fue el más frecuente, con detección de las serovariedades Copenhageni (70 por ciento), Icterohaemorrhagiae (67 por ciento) y Mankarso (29 por ciento). CONCLUSIONES: Ya que solo 13,1 por ciento de los presuntos casos de leptospirosis fueron seropositivos por ELISA para anticuerpos IgM, las manifestaciones clínicas observadas pueden haberse debido a otras enfermedades, o el paciente puede haber tenido leptospirosis crónica (con anticuerpos IgG). En los casos analizados en el Caribe, las serovariedades del serogrupo Icterohaemorrhagiae causaron la mayoría de las infecciones.

Evidencia serológica de circulación de Leptospira spp en Rattus norvegicus naturalmente expuestos en una zona urbana colombiana / Serological evidence of Leptospira spp circulation in naturally-exposed rats (Rattusnorvegicus) in a Colombian urban area

Objetivo Determinar la frecuencia de anticuerpos dirigidos contra especies de Leptospira patógenas en reservorios naturales, con el propósito de establecer evidencia de su papel potencial en la dispersión ambiental de Leptospira y por consiguiente su actuación como agente diseminador de la infección tanto al humano como a otras especies susceptibles. Materiales y métodos El muestreo se llevó a cabo en la Plaza Minorista durante el periodo comprendido entre agosto de 2006 y abril de 2007, en el cual se capturaron 254 roedores Rattus norvegicus. Se obtuvo sangre de estos por punción cardiaca y el suero resultante se procesó con la prueba de Microaglutinación. Resultados El análisis serológico para verificar las serovariedades circulantes de Leptospira spp, dio como resultado que 64 roedores (25,2 por ciento, 95 por ciento CI=19,5-30,1) tuvieron títulos positivos para al menos una de las 11 serovariedades probadas. Conclusiones Los datos muestran que no solo la serovariedad Icterohaemorrhagiae está asociada con esta especie reservoria; también lo están otras serovariedades como Grippothyphosa y Canícola. El estudio permitió determinar la frecuencia de anticuerpos contra especies patógenas de Leptospira para reservorios procedentes de una zona urbana colombiana. Estos datos son relevantes para las entidades de salud pública por constituir la base para la implementación de campañas de control adecuadas para esta zona del país y como modelo de otros estudios similares en otras ciudades colombianas.

Objective Assessing the frequency of antibodies directed against pathogenic Leptospira species found in natural reservoirs for establishing evidence of their potential role in the environmental dispersion of Leptospira and consequent dissemination of the infection to humans as well as to other susceptible species. Material and methods A survey was carried out in the Plaza Minorista from August 2006 to April 2007 in which 254 rats (Rattusnorvegicus) were captured. Blood was obtained from these rodents by cardiac puncture and the resulting serum was used for microagglutination tests. Results Serological analysis for verifying Leptospira spp circulating serovars resulted in 64 rodents (25.2 percent;19.5-30.1 95 percentCI) having positive antibody titres for at least 11 of the serovars tested. Conclusions Frequency data regarding the antibodies so detected showed that the Icterohaemorrhagiae serovar was not the only one possibly associated with this reservoir species, but also with others such as the Grippothyphosa and Canícolaserovars. The study determined the frequency of antibodies against pathogenic Leptospira species for reservoirs from an urban area in Colombia. This data is relevant for public health authorities and might constitute the basis for implementing appropriate control campaigns for this area of the country and, likewise, this work could serve as a model for similar studies in other Colombian cities.