Seroprevalência anti-Leptospira spp. anticorpos e fatores de risco em bovinos da savana tropical do oriente da Colômbia

A leptospirose é uma zoonose de distribuição ampla e endêmica na zona tropical. A condição epidemiologia da doença é complexa, intervém diferentes fatores do hospedeiro, tipo de sorovar, reservatórios, ambiente e as práticas agrícolas. Em bovinos a doenças causa danos significativos ao setor pecuário, e as condições ambientais podem influenciar a sua dinâmica. O objetivo deste estudo foi determinar a seroprevalência anti-Leptospira spp. anticorpos e os fatores de risco em bovinos na savana tropical do leste da Colômbia. Foi coletado sangue das veias coccígeas de 1.000 animais e foi utilizada a técnica MAT (Microagglutination) para a identificação do sorogrupo Autumnalis, Bataviae, Bratislava, Canicola, Copenhagen, Cynopteri, Grippotyphosa, Sejroe, Mini, Pomona, Shermani, Tarassovi, e Celledoni. Estudos de fatores de risco foram realizados de acordo com o sorovar por meio do cálculo de X2 e OR. A seroprevalência de Leptospira spp foi de 34,2% com 92,3% dos rebanhos. Pomona teve a maior frequência de 7,9%, seguida por Sejroe com 7,0% e Grippotyphosa com 6,2%. A aglutinação de anticorpos com mais de um sorovar foi observada em 102 (29,8%) das amostras, o sorogrupo com as maiores correlações foi Pomona e Harjo.Leptospirosis is a zoonotic disease in the tropical zone with a broad and endemic distribution. The condition is complex, where different host factors, serovar type, reservoirs, environment, and agricultural practices intervene. In cattle, the disease causes significant damage to the livestock sector, and the surrounding conditions can influence its dynamics. This study aimed to determine the seroprevalence of anti-Leptospira spp. antibodies and the risk factors in cattle in the tropical savannah from eastern Colombia. Blood was taken from the coccygeal veins of 1,000 animals. The MAT (Microagglutination) technique was used for the identification of the serogroup Autumnalis, Bataviae, Bratislava, Canicola, Copenhagen, Cynopteri, Grippotyphosa, Sejroe, Mini, Pomona, Shermani, Tarassovi, and Celledoni. Studies of risk factors were carried out according to the serovar through the calculation of X2 and OR. Seroprevalence of Leptospira spp. was 34.2% with 92.3% of herds. Pomona had the highest frequency of 7.9%, followed by Hardjo prajit with 7.0% and Grippotyphosa with 6.2%. Antibody agglutination with more than one serovar was seen in 102 (29.8%) samples. The serogroup with the highest correlations were Pomona and Hardjo prajit.

Leptospira seroprevalence in colombian dairy herds

Leptospirosis in cattle has important economic effects on the infected farms. Moreover, livestock farming is considered a major occupational risk factor for the transmission of Leptospira infection to humans. A survey was performed to determine the overall and within-herd seroprevalence and mapping of different Leptospira serovars in dairy cattle from farms located in some municipalities of the Colombian department of Boyacá. Nine hundred and fifty-nine animals, from 20 unvaccinated and one vaccinated herd, were included in the study. Anti-Leptospira serum antibodies were detected by the microscopic agglutination test (MAT). Only one herd was seronegative. Overall seroprevalence to at least one serovar of Leptospira was 24.1% for unvaccinated animals and 62.3% for animals from the vaccinated herd. A very high within-herd seroprevalence (>60%) was present in 20% of the unvaccinated herds. The presence in the vaccinated herd of 20/398 animals showing high titers, between 1000 and 4000, to at least one serovar of Leptospira suggest that some animals could have been infected. Moreover, due to the presence of seronegative animals, a failure of vaccination immunity or the presence of unvaccinated animals in the vaccinated herd cannot be excluded. In all farms, domestic animals other than cattle were present. Considering the farming practices occurring on dairy farms in the study area, higher hygienic standards and stricter biosecurity measures are suggested

CURRENT STATUS AND FUTURE STRATEGIES IN THE EPIDEMIOLOGY OF LEPTOSPIROSIS IN THE CANTON OF PORTOVIEJO, PROVINCE OF MANABÍ, ECUADOR

El objetivo del presente trabajo fue realizar un análisis observacional descriptivo del estado actual y la ocurrencia de casos de leptospirosis en la población del cantón Portoviejo en la provincia de Manabí, Ecuador. Además del planteamiento de estrategias futuras que se llevarán a cabo para mejorar la prevención y control de la enfermedad en animales y humanos. Se determinó la incidencia de casos de leptospirosis por semanas epidemiológicas y años, en una serie de tiempo que abarcó el periodo comprendido entre el 2014–2017. Se realizó un análisis de la ocurrencia de casos, con el objetivo de describir las características de su tendencia, estacionalidad y el canal de comportamiento habitual. Se concluye que en la provincia de Manabí la incidencia de leptospirosis en la población humana es relativamente baja teniendo en cuenta la cantidad de habitantes por cantón, durante el año 2014 se registra la mayor cantidad de brotes y es evidente en el último periodo del 2017 el incremento del número de casos. El grupo etario con mayor número de casos es de 20 a 49 años, con predominio del sexo femenino, durante el año 2015. La leptospirosis manifiesta un comportamiento estacional con mayor ocurrencia en los meses de febrero, marzo, abril y junio. El canal endémico de la ocurrencia de la leptospirosis en el territorio estudiado es de uno a seis casos mensuales; evidenciándose un incremento de la ocurrencia durante el año 2017 con varios meses en zona de alerta.The objective of the present work was to perform a descriptive observational analysis of the current status and occurrence of cases of leptospirosis in the population of the canton of Portoviejo in the province of Manabí, Ecuador. In addition, the approach of future strategies that will be carried out to improve the prevention and control of the disease in animals and humans was developed. The incidence of cases of leptospirosis was determined by epidemiological weeks and years, in a time series that covered the 2014-2017 period. An analysis of the occurrence of cases was carried out, with the aim of describing the characteristics of their tendency, seasonality and the channel of habitual behavior. It is concluded that in the province of Manabí the incidence of leptospirosis in the human population is relatively low taking into account the number of inhabitants per canton. The highest number of outbreaks was recorded during 2014 and the increase in the number of cases is evident in the last period of 2017. The age group with the highest number of cases is 20 to 49 years old, with a predominance of females, during 2015. Leptospirosis manifests a seasonal behavior with greater occurrence in the months of February, March, April and June. The endemic pathway of the occurrence of leptospirosis in the studied territory is from one to six monthly cases; evidencing an increase in the occurrence during 2017 with several months in the alert zone

Delineating host-pathogen interaction of pathogenic Leptospira spp.

Delineating host-pathogen interaction of pathogenic Leptospira spp. Abstract Leptospirosis is a highly infectious, global, zoonotic disease affecting the majority of the mammalian species. Leptospirosis is caused by pathogenic bacteria, Leptospira spp., with more than >250 serovars identified. Cattle are one of the most susceptible hosts where the infection is commonly caused by serovar Hardjobovis. Bovine leptospirosis (BL) causes severe reproductive disorders and is a significant public health risk. Commercially available BL vaccines are typically bacterin and considered limited as they are serovar-specific and confer temporary protection. Bacterial outer membrane proteins (OMPs) are extensively studied as potential vaccine candidates for infectious diseases due to their ability to stimulate robust immune responses and induce cross-protective immunity. Here, seven novels OMPs from L. borgpetersenii serovar Hardjobovis L550 were identified using a reverse vaccinology approach. Four OMP genes were successfully cloned, expressed and purified as recombinant proteins. Subsequent functional in vitro binding assays showed that these OMPs could adhere to various host components and two OMPs of 37 and 49 kDa with significant binding results were re-assigned as ‘Leptospiral adhesin’ (Lsa) together with molecular weights as Lsa37 and Lsa49. Immunological evaluation of antibody titres against the OMPs in cattle bulk milk suggests these proteins are expressed by the bacteria and interact with the host immune system with two OMPs, OmpL1 and rLBL0375 exhibiting better discrimination with disease status. Several leptospiral OMPs exhibit molecular diversity through comparative sequence analysis. Here, two groups of OMP variants, OmpL1 and Lsa49 across five pathogenic genomospecies were selected via phylogenetic analysis to evaluate their functional binding diversities towards various host components. OmpL1 exhibited significant binding variation against various host components, compared to Lsa49. The diversity is strongly correlated with variations on predicted OmpL1 surface-exposed loops contributing to functional loss and gain via molecular evolution, which resulted in binding preferential towards specific host molecules. Immunological evaluation of cattle sera showed that these OMPs are expressed and exposed to the host immune system, and had a strong association against one another. This suggests that these OMPs may have similar structural epitopes that allow antibody binding, and indicates conserved immunogenicity across species. In a final study, we investigated whether the ruminant gastrointestinal (GI) tract was a carriage site for Leptospira. Through PCR surveys of ruminant gingival and rectal tissues, the presence of leptospires was identified as extremely low, thus indicating the GI tract does not appear to be an important leptospire carriage site. In conclusion, here we have identified several novel bovine leptospire OMPs, which may be useful vaccine or diagnostic components for bovine leptospirosis in the future. Additionally, the functional diversity between leptospiral OMP variants identifies OMP genetic evolution resulting in addition or loss of binding function, highlighting the complex host-pathogen interaction of leptospirosis. Lastly, this study does not suggest a role for the ruminant GI tract in leptospire carriage, indicating disease transmission through this route is unlikely

Central and South America

The chapter is divided into two main sections. The first section follows an integrative approach in which hazards, exposure, vulnerability, impacts and risks are discussed following the eight climatically homogeneous sub-regions described in WGI AR6 (Figure 12.1). The second section assesses the implemented and proposed adaptation practices by sector; in doing so, it connects to the WGII AR6 crosschapter themes. The storyline is then a description of the hazards, exposure, vulnerability and impacts providing as much detail as is available in the literature at the sub-regional level, followed by the identification of risks as a result of the interaction of those aspects. This integrated sub-regional approach ensures a balance in the text, particularly for countries that are usually underrepresented in the literature but that show a high level of vulnerability and impacts, such as those observed in CA. The sectoral assessment of adaptation that follows is useful for policymakers and implementers, usually focused and organised by sectors, government ministries or secretaries that can easily locate the relevant adaptation information for their particular sector. To ensure coherence in the chapter, a summary of the assessed adaptation options by key risks is presented, followed by a feasibility assessment for some relevant adaptation options. The chapter closes with case studies and a discussion of the knowledge gaps evidenced in the process of the assessment.EEA Santa CruzFil: Castellanos, Edwin J. Universidad del Valle de Guatemala; Guatemala.Fil: Lemos, Maria Fernanda. Pontifical Catholic University of Rio de Janeiro; Brasil.Fil: Astigarraga, Laura. Universidad de la República; Uruguay.Fil: Chacón, Noemí. Instituto Venezolano de Investigaciones Científicas; Venezuela.Fil: Cuvi, Nicolás. Facultad Latinoamericana de Ciencias Sociales (FLACSO); Ecuador.Fil: Huggel, Christian. University of Zurich; Switzerland.Fil: Miranda Sara, Liliana Raquel. Foro Ciudades para la Vida; Peru.Fil: Moncassim Vale, Mariana. Federal University of Rio de Janeiro; Brasil.Fil: Ometto, Jean Pierre. National Institute for Space Research; Brasil.Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Postigo, Julio C. Indiana University; Estados Unidos.Fil: Ramajo Gallardo, Laura. Adolfo Ibanez University; Chile.Fil: Roco, Lisandro. Catholic University of The North; Chile.Fil: Rusticucci, Matilde Monica. Universidad de Buenos Aires; Argentina

Epidemiology behavior of leptospirosis in Ciénaga de Oro, Córdoba (Colombia)

The purpose of this study was to determine the epidemiology of leptospirosis in rural areas of Ciénaga de Oro, Córdoba, Colombia, a convenience sampling was carried out on 13 farms. The sample size was 325 reproductive age cows, 11 canine samples, and 20 humans. The samples were subjected to MAT analysis with 11 serogroups of Leptospira interrogans sensu lato. Once the MAT results were received, urine samples were collected from 78 cows, along with 39 water samples, for bacteriological cultures and PCR for the 16S rRNA gene in L. interrogans sensu lato. Positive PCR samples were sequenced to determine the possible genome species. The leptospirosis seroprevalence was 74.5% in the cattle, 70.0% in the dogs, and 45.5% in the humans. Although isolation was not achieved, L. interrogans sensu lato was detected by PCR in three urine samples and in a sample of wastewater. The sequencing confirmed the circulation of pathogenic species. The high prevalence of antibodies for L. interrogans sensu lato and the molecular evidence led to the inference that the rural areas of Ciénaga de Oro are endemic and that cattle can act as renal carriers and contaminate water sources, which increases the risk of contracting leptospirosis