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Leptospirosis is an infectious zoonotic disease of special importance in tropical regions of the world and is closely related to climatic conditions. In Mexico, at least eight Leptospira serogroups are known to affect sheep, but little is known about their distribution. The aim was to analyse the spatial distribution of seroreactive sheep to eight serogroups of Leptospira spp. through ecological niche modelling from the state of Veracruz. We carried out a cross-sectional, multistage, and stratified epidemiological study, sampling 405 sheep in different regions of the state (north, center, and south). The sera were analysed using the microscopic agglutination test (MAT) to identify seropositivity to eight Leptospira serogroups (Icterohaemorrhagiae, Pyrogenes, Grippotyphosa, Canicola, Pomona, Hardjo, Wolffi, and Tarassovi). Management variables in the sampled herds were evaluated through a survey among the producers, which was analysed using the chi-squared test for cross-tabulation. Geospatial modelling was conducted using MAXENT and 19 climatic variables, and validation was carried out using the area under the curve (AUC). No positive animals were found for Pomona in any area of Veracruz, and there was only one case of seroreactivity to Grippotyphosa. The total seroprevalence found was 53.83% (95% confidence interval [CI] 48.84-58.75). The main serogroup found was Sejroe (55.31%, 95% CI 50.32-60.20%), followed by Canicola (8.64%, 95% CI 6.17-11.92%), Icterohaemorrhagiae (4.69%, 95% CI 2.93-7.36%), Tarassovi (3.95%, 95% CI 2.35-6.47%), Pyrogenes (2.47%, 95% CI 1.26-4.64%), Australis (0.99%, 95% CI 0.32-2.69%), and Grippotyphosa (0.25%, 95% CI 0.01-1.59%). The predictive model for Australis was not significant. Acceptable predictive models (AUC > 0.7-0.8) were found for Canicola, Icterohaemorrhagiae, Pyrogenes, and Tarassovi, while for Sejroe, it was excellent (AUC > 0.85); consequently, the climatic variables that most contributed to the model were those related to precipitation. The potential distribution of Pyrogenes, Icterohaemorrhagiae, and Canicola was located to a greater extent in the three regions; Pyrogenes and Tarassovi were distributed mostly in the north and central regions, and Sejroe was mostly located in the center and south of the state. Ecological niche modelling could support epidemiological control and surveillance programs for affected sheep herds in the state of Veracruz.

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In 2015 and 2016, Zika virus (ZIKV) swept through dengue virus (DENV) endemic areas of Latin America. These viruses are of the same family, share a vector and may interact competitively or synergistically through human immune responses. We examine dengue incidence from Brazil and Colombia before, during, and after the Zika epidemic. We find evidence that dengue incidence was atypically low in 2017 in both countries. We investigate whether subnational Zika incidence is associated with changes in dengue incidence and find mixed results. Using simulations with multiple assumptions of interactions between DENV and ZIKV, we find cross-protection suppresses incidence of dengue following Zika outbreaks and low periods of dengue incidence are followed by resurgence. Our simulations suggest correlations in DENV and ZIKV reproduction numbers could complicate associations between ZIKV incidence and post-ZIKV DENV incidence and that periods of low dengue incidence are followed by large increases in dengue incidence.

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Triatoma brasiliensis e Triatoma pseudomaculata são vetores do Trypanosoma cruzi, agente da doença de Chagas, na Caatinga do nordeste do Brasil. Na natureza, essas espécies ocupam diferentes ecótopos e exploram diferentes hospedeiros. T. brasiliensis é terrestre e está associado a afloramentos rochosos (e cactos em algumas áreas) frequentemente compartilhados por roedores, enquanto T. pseudomaculata é arbóreo e parece alimentar-se principalmente de aves. Ambas as espécies, no entanto, podem infestar habitats feitos pelo homem, onde a possibilidade surge para a competição sobre os principais recursos - abrigo e sangue. Determinamos a ocorrência / coocorrência de T. brasiliensis e T. pseudomaculata em 412 ecótopos artificiais (91 habitações) para investigar padrões de segregação de espécies e investigar dois candidatos a processos subjacentes: (a) partição de recursos (T. brasiliensis preferindo ecótopos minerais ou ocupados por roedores e T. pseudomaculata preferindo ecótopos ocupados por vegetação ou aves) e (b) competição interespecífica verdadeira (cada espécie efetivamente evitando a outra). Usamos modelos lineares mistos generalizados (GLMMs) para identificar correlatos de ocorrência específica, incluindo a coocorrência de outras espécies. Ambas as espécies co-ocorreram em quatro ecótopos (0,97%). T. brasiliensis (12,9% de ocorrência geral) foi mais comum que T. pseudomaculata em ecótopos minerais (17,9% vs. 3,46%) e em ecótopos utilizados por roedores (74,1% vs. 11,1%); o melhor desempenho do T. brasiliensis GLMM estimou um forte efeito positivo da disponibilidade de roedores na ocorrência desses insetos (ßroedor = 3,55 ± 0,57EP)

Em contraste, T. pseudomaculata foi mais rara (7,1%) e ocorreu mais frequentemente que T. brasiliensis em ecótopos vegetais (13,6% vs. 6,8%) e em ecótopos utilizados por aves (19,3% vs 6,4%); o melhor desempenho de T. pseudomaculata GLMM estimou o efeito da presença de aves na ocorrência de insetos como ßaves = 2,30 ± 0,48EP. Os GLMMs não revelaram nenhuma evidência de que a ocorrência de uma espécie afetou a probabilidade de que o outro co-ocorresse no mesmo ecótopo, após o ajuste para as características do ecótopo e a disponibilidade do hospedeiro. Esses achados sugerem que as espécies de estudo mantêm a segregação espacial em ambientes humanos associando-se preferencialmente com os vertebrados que exploram na natureza. Assim, conclue-se que a partição de recursos, e não a verdadeira competição interespecífica, provavelmente impulsiona a segregação ecológica de T. brasiliensis e T. ix pseudomaculata em habitats criados pelo homem. Elucidar os mecanismos subjacentes ao particionamento de recursos exigirá abordagens experimentais. (AU)

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Background: Zika virus is an emerging Flaviviridae virus, which has spread rapidly in the last few years. It has raised concern because it has been associated with fetus microcephaly when pregnant women are infected. The main vector is the mosquito Aedes aegypti , distributed in tropical areas. Methods: Niche modelling techniques were used to estimate the potential distribution area of A. aegypti. This was overlapped with human population density, determining areas of potential transmission risk worldwide. Afterwards, we quantified the population at risk according to risk level. Results: The vector transmission risk is distributed mainly in Asia and Oceania on the shores of the Indian Ocean. In America, the risk concentrates in the Atlantic coast of South America and in the Caribbean Sea shores in Central and North America. In Africa, the major risk is concentrated in the Pacific and Atlantic coasts of Central and South Africa. The world population under high and very high risk levels includes 2.261 billion people. Conclusions: These results illustrate Zika virus risk at the global level and provide maps to target the prevention and control measures especially in areas with higher risk, in countries with less sanitation and poorer resources. Many countries without previous vector reports could become active transmission zones in the future, so vector surveillance should be implemented or reinforced in these areas.

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Introduction: an exponential law has been found for chaotic dynamic cardiac systems, making it possible to quantify the differences between normal and pathological cardiac dynamics. Methodology: 120 electrocardiographic records were analyzed, 40 corresponded to subjects within the limits of normality and 80 with different pathologies. For each holter the attractors generated with the data during 18 hours and throughout the dynamics were analyzed. The fractal dimension of the attractor and its spatial occupation were calculated. To these measures was applied the diagnosis mathematical evaluation previously developed, comparing the evaluation for 18 hours and for the whole registry; sensitivity, specificity and Kappa coefficient were finally calculated. Results: For the normal dynamics, the occupancy spaces in the Kp grid were between 200 and 381 for the evaluation of the whole holter, and between 201 and 384 in the evaluation during 18 hours, showing the closeness in the measurements, which allows that the decrease in the time of the evaluation is consistent, this same proximity was observed for the diseased and acute dynamics. Conclusion: It was evidenced the clinical applicability in 18 hours of the exponential law in the chaotic cardiac dynamics associated with arrhythmias showing to be useful for the prediction of the evolution towards acute states of the dynamics

Introducción: una ley exponencial se ha hallado para los sistemas dinámicos caóticos cardiacos, logrando cuantificar las diferencias entre dinámicas cardiacas normales y patológicas. Metodología: Se analizaron 120 registros electrocardiográficos, 40 correspondían a sujetos dentro de los límites de normalidad y 80 con diferentes patologías. Para cada holter se analizaron los atractores generados con los datos durante 18 horas y durante toda la dinámica. Se calculó la dimensión fractal del atractor y su ocupación espacial. A estas medidas se aplicó la evaluación matemática diagnostica desarrollada previamente, comparando la evaluación para 18 horas y para todo el registro; finalmente se calculó la sensibilidad, especificidad y coeficiente Kappa. Resultados: Para las dinámicas normales los espacios de ocupación en la rejilla Kp estuvieron entre 200 y 381 en la evaluación de la totalidad del holter, y entre 201 y 384 en la evaluación durante 18 horas, mostrando la cercanía en las medidas, lo que permite que la disminución en el tiempo de la evaluación sea consistente, esta misma cercanía se observó para las dinámicas enfermas y agudas. Conclusión: Se evidenció la aplicabilidad clínica en 18 horas de la ley exponencial en la dinámica cardiaca caótica asociada a arritmias mostrando ser de utilidad para la predicción de la evolución hacia estados agudos de la dinámica.

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Este trabalho testa a ocorrência de interação estratégica entre os gastos municipais motivados por spillover no ano de 2012. Para tanto, foram estimadas as curvas de reação para dez categorias de despesa utilizando o método generalized spatial two-stage least squares (GS2SLS). Os resultados indicaram que as curvas de reação são relevantes e positivamente inclinadas para nove entre dez tipos de serviços públicos, apontando relação de complementaridade entre despesas de municípios próximos. Com relação à intensidade dos coeficientes de interação, sugere-se que sua maior magnitude esteja relacionada ao maior poder discricionário do governo local. Assim, existe maior liberdade para se efetuar mudanças nos dispêndios com cultura e segurança pública, em face da elevada magnitude no coeficiente de interação. Todavia, despesas com educação, saúde e administração pública são pouco reativas a mudanças dos municípios vizinhos, em virtude da existência de restrições legais que limitam o poder de manobrar essas variáveis. Argumenta-se que a intensidade da interação estratégica pode ser um vetor importante de indução à expansão das despesas governamentais

This work tests for the presence of strategic interaction in municipal spendings motivated by spillover in 2012. To accomplish this goal, the reaction functions of ten spending categories were estimated by generalized spatial two-stage least squares (GS2SLS). The results showed that reaction functions are relevant and positively sloped to nine of ten categories of public services, indicating complementarity relationship between expenditure in neighboring municipalities. With regard to the intensity of the interaction coefficients, higher values seem to be related to greater discretionary power of local government. Thus, it follows that there is more freedom to make changes in expenditures for culture and public safety, due to the sizeable magnitude of the interaction coefficient. On the other hand, expenditure on education, health and publica dministration are poorly responsive to changes in neighboring municipalities, because of the existence of legal restrictions that limit the power to manipulate these variables. It is argued that the intensity of strategic interaction can be an important vector of induction to the expansion of government expenditure

El trabajo pone a prueba la existencia de la interacción estratégica entre el gasto municipal motivados por spillover en 2012. Por lo tanto, las curvas de reacción son estimadas para diez categorías de gastos utilizando el método generalized spatial two-stage least squares (GS2SLS). Los resultados indicaron que las curvas de reacción son relevantes e inclinadas positivamente a nueve de cada diez tipos de servicios públicos, entre ellos relación de complementariedad entre los costos de municipios cercanos. Mientras a la intensidad de los coeficientes de interacción, se sugiere que su mayor magnitud está relacionada con la mayor discreción del gobierno local. Por lo tanto, hay una mayor libertad de hacer cambios en los gastos para la cultura y seguridad pública, a causa de gran magnitud en el coeficiente de interacción. Sin embargo, el gasto en educación, la salud y la administración pública son poco sensibles a los cambios en los municipios vecinos, debido a la existencia de restricciones legales que limitan el poder de manejar estas variables. Se argumenta que la intensidad de la interacción estratégica puede ser un vector importante de la inducción a la expansión del gasto público

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