Background: Dengue, chikungunya and Zika are viral infections transmitted by Aedes aegypti mosquitoes, and present major public health challenges in tropical regions. Traditional vector control methods have been ineffective at halting disease transmission. The World Mosquito Program has developed a novel approach to arbovirus control using Ae. aegypti stably transfected with the Wolbachia bacterium, which have significantly reduced ability to transmit dengue, Zika and chikungunya in laboratory experiments. Field releases in eight countries have demonstrated Wolbachia establishment in local Ae. aegypti populations. Methods: We describe a pragmatic approach to measuring the epidemiological impact of city-wide Wolbachia deployments in Bello and Medellín, Colombia. First, an interrupted time-series analysis will compare the incidence of dengue, chikungunya and Zika case notifications before and after Wolbachia releases, across the two municipalities. Second, a prospective case-control study using a test-negative design will be conducted in one quadrant of Medellín. Three of the six contiguous release zones in the case-control area were allocated to receive the first Wolbachia deployments in the city and three to be treated last, approximating a parallel two-arm trial for the >12-month period during which Wolbachia exposure remains discordant. Allocation, although non-random, aimed to maximise balance between arms in historical dengue incidence and demographics. Arboviral disease cases and arbovirus-negative controls will be enrolled concurrently from febrile patients presenting to primary care, with case/control status classified retrospectively following laboratory diagnostic testing. Intervention effect is estimated from an aggregate odds ratio comparing Wolbachia-exposure odds among test-positive cases versus test-negative controls. Discussion: The study findings will add to an accumulating body of evidence from global field sites on the efficacy of the Wolbachia method in reducing arboviral disease incidence, and can inform decisions on wider public health implementation of this intervention in the Americas and beyond. Trial registration: ClinicalTrials.gov: NCT03631719. Registered on 15 August 2018.

Background: Dengue, chikungunya and Zika are viral infections transmitted by Aedes aegypti mosquitoes, and present major public health challenges in tropical regions. Traditional vector control methods have been ineffective at halting disease transmission. The World Mosquito Program has developed a novel approach to arbovirus control using Ae. aegypti stably transfected with the Wolbachia bacterium, which have significantly reduced ability to transmit dengue, Zika and chikungunya in laboratory experiments. Field releases in eight countries have demonstrated Wolbachia establishment in local Ae. aegypti populations. Methods: We describe a pragmatic approach to measuring the epidemiological impact of city-wide Wolbachia deployments in Bello and Medellín, Colombia. First, an interrupted time-series analysis will compare the incidence of dengue, chikungunya and Zika case notifications before and after Wolbachia releases, across the two municipalities. Second, a prospective case-control study using a test-negative design will be conducted in one quadrant of Medellín. Three of the six contiguous release zones in the case-control area were allocated to receive the first Wolbachia deployments in the city and three to be treated last, approximating a parallel two-arm trial for the >12-month period during which Wolbachia exposure remains discordant. Allocation, although non-random, aimed to maximise balance between arms in historical dengue incidence and demographics. Arboviral disease cases and arbovirus-negative controls will be enrolled concurrently from febrile patients presenting to primary care, with case/control status classified retrospectively following laboratory diagnostic testing. Intervention effect is estimated from an aggregate odds ratio comparing Wolbachia-exposure odds among test-positive cases versus test-negative controls. Discussion: The study findings will add to an accumulating body of evidence from global field sites on the efficacy of the Wolbachia method in reducing arboviral disease incidence, and can inform decisions on wider public health implementation of this intervention in the Americas and beyond. Trial registration: ClinicalTrials.gov: NCT03631719. Registered on 15 August 2018.

Wild population management programs require determining some fundamental aspects for conservation, including population structure, flow between populations, evolutionary history and kinship, among others. Since sample collection from wild mammals for DNA extraction is a complex task, conservation genetics has developed non-invasive sampling techniques, which allow obtaining DNA without the need to capture individuals. For the genetic characterization of otter populations, stools are frequently used as source of DNA for amplification of molecular markers (microsatellites, mitochondrial segments and sequences for determining sex) in studies on genetic diversity, phylogeography, population structure and size, among others. This review summarizes the application of non-invasive sampling techniques in genetic studies of otter species. Genetic characterization studies that use stools as source of DNA support the usefulness of this material to get amplified markers in the genotyping of individuals. They also suggest the use of fresh samples and appropriate conservation methods to avoid DNA degradation, as well as quantify the potential errors in genotyping, such as false and null alleles. En los programas de manejo de poblaciones silvestres es necesario conocer algunos aspectos fundamentales para su conservación como la estructura poblacional, el flujo entre poblaciones, la historia evolutiva y el parentesco, entre otros. Dado que en mamíferos silvestres es difícil acceder a muestras para la extracción de ADN, la genética de la conservación ha desarrollado técnicas de muestreo no invasivas, que permiten obtener ADN sin necesidad de capturar los individuos. En la caracterización genética de poblaciones de nutrias se emplean frecuentemente las heces como fuente de ADN para la amplificación de marcadores moleculares (microsatélites, segmentos mitocondriales y secuencias para la determinación del sexo) en estudios de diversidad genética, filogeografía, estructura y tamaño de las poblaciones, entre otros. En ésta revisión se presenta una síntesis de la aplicación de técnicas de muestreo no invasivas en los estudios genéticos de las especies de nutria. Los estudios de caracterización genética, utilizando heces como fuente de ADN, coinciden en la utilidad de este material para obtener amplificados de calidad en la genotipificación de individuos. También sugieren el uso de muestras frescas y la aplicación de métodos de conservación apropiados para evitar la degradación del ADN y cuantificar los posibles errores de genotipificación como los alelos falsos y nulos. ADN mitocondrial, diversidad genética, microsatélites, marcadores moleculares, muestreos no invasivos, nutrias.

No abstract