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Abstract Age-stratified serosurvey data are often used to understand spatiotemporal trends in disease incidence and exposure through estimating the Force-of-Infection (FoI). Typically, median or mean FoI estimates are used as the response variable in predictive models, often overlooking the uncertainty in estimated FoI values when fitting models and evaluating their predictive ability. To assess how this uncertainty impact predictions, we compared three approaches with three levels of uncertainty integration. We propose a performance indicator to assess how predictions reflect initial uncertainty. In Colombia, 76 serosurveys (1980–2014) conducted at municipality level provided age-stratified Chagas disease prevalence data. The yearly FoI was estimated at the serosurvey level using a time-varying catalytic model. Environmental, demographic and entomological predictors were used to fit and predict the FoI at municipality level from 1980 to 2010 across Colombia. A stratified bootstrap method was used to fit the models without temporal autocorrelation at the serosurvey level. The predictive ability of each model was evaluated to select the best-fit models within urban, rural and (Amerindian) indigenous settings. Model averaging, with the 10 best-fit models identified, was used to generate predictions. Our analysis shows a risk of overconfidence in model predictions when median estimates of FoI alone are used to fit and evaluate models, failing to account for uncertainty in FoI estimates. Our proposed methodology fully propagates uncertainty in the estimated FoI onto the generated predictions, providing realistic assessments of both central tendency and current uncertainty surrounding exposure to Chagas disease.

Abstract Chagas disease remains a major neglected disease in Colombia. We aimed to characterize Trypanosoma cruzi transmission networks in the Sierra Nevada de Santa Marta (SNSM) region, to shed light on disease ecology and help optimize control strategies. Triatomines were collected in rural communities and analyzed for blood feeding sources, parasite diversity and gut microbiota composition through a metagenomic and deep sequencing approach. Triatoma dimidiata predominated, followed by Rhodnius prolixus, Triatoma maculata, Rhodnius pallescens, Panstrongylus geniculatus and Eratyrus cuspidatus. Twenty-two species were identified as blood sources, resulting in an integrated transmission network with extensive connectivity among sylvatic and domestic host species. Only TcI parasites were detected, predominantly from TcIb but TcIa was also reported. The close relatedness of T. cruzi strains further supported the lack of separate transmission cycles according to habitats or triatomine species. Triatomine microbiota varied according to species, developmental stage and T. cruzi infection. Bacterial families correlated with the presence/absence of T. cruzi were identified. In conclusion, we identified a domestic transmission cycle encompassing multiple vector species and tightly connected with sylvatic hosts in the SNSM region, rather than an isolated domestic transmission cycle. Therefore, integrated interventions targeting all vector species and their contact with humans should be considered.

Background: Chagas disease is one of the leading causes of heart failure (HF) in Latin Americans, and there are limited data available that examine related costs of care for patients with HF. This study aimed to compare healthcare resource utilization and related costs for patients with HF, with and without Chagas disease. Methods: A prospective matched-cohort study comparing the healthcare costs for patients with HF with Chagas disease and care costs for patients with HF without Chagas disease was conducted between January 2019 and December 2019. Only direct costs have been estimated, including hospitalization costs, medications and other cardiovascular interventions, and clinical and laboratory follow-up for up to 1 year. Results: A total of 80 patients with chronic HF were included in the study. Of the 80 patients, 40 patients in the Chagas cohort and 40 patients in the non-Chagas cohort were matched for age, insurer and sex. From a social security system perspective, the total costs for the two cohorts during the study period were U$970,136. Specifically, the healthcare costs for the Chagas cohort were greater than the total healthcare costs for the non-Chagas group (U$511,931 versus U$458,205; p = 0.6183) Most costs were associated with hospitalizations (65.5% versus 59.6%), with averages of U$12,798.5 and U$11,455.1 per person in the Chagas and non-Chagas groups, respectively. In both the Chagas (51.6%) and non-Chagas cohorts (54.5%), causes of readmission unrelated to HF outweighed causes of readmission related to HF. High incidences of hospital admissions were observed during the rainy (cold) season for both cohorts Conclusions: Over a 12-month follow-up period, patients with chronic HF and Chagas consume as many healthcare resources as those with chronic HF and without Chagas. These data highlight the considerable and growing economic burden of HF on the Colombian health system.

BackgroundChagas disease is a long-lasting disease with a prolonged asymptomatic period. Cumulative indices of infection such as prevalence do not shed light on the current epidemiological situation, as they integrate infection over long periods. Instead, metrics such as the Force-of-Infection (FoI) provide information about the rate at which susceptible people become infected and permit sharper inference about temporal changes in infection rates. FoI is estimated by fitting (catalytic) models to available age-stratified serological (ground-truth) data. Predictive FoI modelling frameworks are then used to understand spatial and temporal trends indicative of heterogeneity in transmission and changes effected by control interventions. Ideally, these frameworks should be able to propagate uncertainty and handle spatiotemporal issues.Methodology/principal findingsWe compare three methods in their ability to propagate uncertainty and provide reliable estimates of FoI for Chagas disease in Colombia as a case study: two Machine Learning (ML) methods (Boosted Regression Trees (BRT) and Random Forest (RF)), and a Linear Model (LM) framework that we had developed previously. Our analyses show consistent results between the three modelling methods under scrutiny. The predictors (explanatory variables) selected, as well as the location of the most uncertain FoI values, were coherent across frameworks. RF was faster than BRT and LM, and provided estimates with fewer extreme values when extrapolating to areas where no ground-truth data were available. However, BRT and RF were less efficient at propagating uncertainty.Conclusions/significanceThe choice of FoI predictive models will depend on the objectives of the analysis. ML methods will help characterise the mean behaviour of the estimates, while LM will provide insight into the uncertainty surrounding such estimates. Our approach can be extended to the modelling of FoI patterns in other Chagas disease-endemic countries and to other infectious diseases for which serosurveys are regularly conducted for surveillance.

ABSTRACT Background: Mother-to-child transmission of Chagas disease (CD) has become a relevant problem in both endemic and non-endemic areas. Methods: Description of the CUIDA Chagas Project - Communities United for Innovation, Development and Attention for Chagas disease’. Results: Through innovative and strategic research, this project will provide improved diagnostic and treatment options as well as replicable implementation models that are adaptable to different contexts. Conclusions: By integrating test, treat and care actions for CD into primary health care practices, the burden of CD on people and health systems may be significantly reduced.

Background: In Colombia, communities living in the Andean region are the most affected by Chagas disease due to the presence of the main vectors, the environmental and risk factors associated with house infestation. Triatoma venosa is classified as a secondary vector that is frequently found in the departments of Boyaca and Cundinamarca, but epidemiological information and its association with risk factors in domestic and peridomestic areas is unknown. The study aimed to evaluate housing and environmental characteristics associated with domestic and peridomestic infestation by T. venosa and a risk map was estimated. Methods: A cross-sectional study was conducted in municipalities of Boyaca and Cundinamarca, Colombia. From March to July 2015, triatomine infestation screening surveys were conducted in 155 households. Multivariate analysis was performed to evaluate associations with the infestation and ecological niche modeling was estimated using environmental variables. Results: No statistical association was found with any of the housing variables in the adjusted multivariate analysis. However, in raw relationship infestation was associated with bushes

The family Tymoviridae comprises positive-sense RNA viruses, which mainly infect plants. Recently, a few Tymoviridae-like viruses have been found in mosquitoes, which feed on vertebrate sources. We describe a novel Tymoviridae-like virus, putatively named, Guachaca virus (GUAV), isolated from Culex pipiens and Culex quinquefasciatus species of mosquitoes and collected in the rural area of Santa Marta, Colombia. After a cytopathic effect was observed in C6/36 cells, RNA was extracted and processed through the NetoVIR next-generation sequencing protocol, and data were analyzed through the VirMAP pipeline. Molecular and phenotypic characterization of the GUAV was achieved using a 5′/3′ RACE, transmission electron microscopy, amplification in vertebrate cells, and phylogenetic analysis. A cytopathic effect was observed in C6/36 cells three days post-infection. The GUAV genome was successfully assembled, and its polyadenylated 3′ end was corroborated. GUAV shared only 54.9% amino acid identity with its closest relative, Ek Balam virus, and was grouped with the latter and other unclassified insect-associated tymoviruses in a phylogenetic analysis. GUAV is a new member of a family previously described as comprising plant-infecting viruses, which seem to infect and replicate in mosquitoes. The sugar- and blood-feeding behavior of the Culex spp., implies a sustained contact with plants and vertebrates and justifies further studies to unravel the ecological scenario for transmission.

Background: Identifying risk factors for Triatominae infestation is essential for the development of vector control interventions. Methods: To determine the intra- and peridomiciliary risk factors associated with triatomine infestation, a cross-sectional analytical study was carried out with random cluster sampling in two stages, which included the identification of risk factors by survey and direct observation, as well as the search and capture of triatomines. The detection of trypanosomes in triatomines was carried out by observing the rectal content and then by conventional polymerase chain reaction (PCR). Results: In 21 of the 207 houses inspected, 13 specimens of R. colombiensis and 19 specimens of P. geniculatus were found. Entomological indices included: dispersion 36%, infestation 10%, infection 65%, colonization 4.7%, density 15%, and concentration 152%. An association was found between the presence of Triatominae and the existence of branches and fissures in the floors, as well as with the presence of accumulated objects and with knowledge about Chagas disease. The risk of having triatomines in urban homes is 5.7 times higher than the risk in rural areas [confidence interval (CI) 0.508–67.567]; 6.6 times in houses with cracked soil (CI 0.555–81.994), 6 times in houses located near caneys (CI 0.820–44.781), and 6.16 times with accumulated objects (CI 1.542–39.238). Conclusion: Chagas disease is a complex problem that requires control based on the vector’s elimination or surveillance, which implies identifying species and their distribution, generating alerts, knowledge, and awareness in the population. It is necessary to intensify surveillance activities for the event, especially in changing aspects of Chagas diseases’ transmission dynamics, such as urbanization and the type of housing associated with the vector’s presence.

ABSTRACT A few studies have carried out the taxonomic and molecular characterization of sylvatic mosquito species in Latin America, where some species have been incriminated as vectors for arboviruses and parasites transmission. The present study reports the molecular characterization of mosquito species in the Sierra Nevada de Santa Marta, a natural ecosystem in the Northern coast of Colombia. Manual capture methods were used to collect mosquitoes, and the specimens were identified via classical taxonomy. The COI marker was used for species confirmation, and phylogenetic analysis was performed using the neighbor-joining method, with the Kimura-2-Parameters model. Aedes serratus , Psorophora ferox , Johnbelkinia ulopus , Sabethes chloropterus , Sabethes cyaneus , Wyeomyia aporonoma , Wyeomyia pseudopecten , Wyeomyia ulocoma and Wyeomyia luteoventralis were identified. We assessed the genetic variability of mosquitoes in this area and phylogenetic reconstructions allowed the identification at the species level. Classical and molecular taxonomy demonstrated to be useful and complementary when morphological characteristics are not well preserved, or the taxonomic group is not represented in public molecular databases.

Aedes aegypti is the main vector of the dengue virus in Colombia. Some factors have been associated with its presence; however, in the local context, it has not been sufficiently evaluated. The present study seeks to identify the socioeconomic, environmental, and behavioral factors associated with the presence and abundance of A. aegypti in urban dwellings in the municipality of Castilla la Nueva. A cross-sectional cohort study was conducted in houses in the urban area of the municipality of Castilla la Nueva, where 307 houses were sampled by systematic random sampling during May 2018. A multifactorial survey was used to measure the socioeconomic, environmental, and behavioral factors as explanatory variables. The infestation and relative abundance were established by the presence of larval stages and ovitraps. The associated factors for the presence and abundance of A. aegypti were identified using negative binomial and logistic regression models. A positive housing infestation of 33.2% was identified by direct inspection and 78.5% with ovitraps. The main factors positively associated with the presence and abundance of A. aegypti were one-story homes (PR = 2.26; 95% CI: 1.31–3.87), the storage of water for domestic use (PR = 1.91; 95% CI: 1.18–3.09), and local conditions such as disorganized backyard (PR = 79.95; 95% CI: 10.96–583.24) and the proportion of shade greater than 50% of the backyard (PR = 62.32; 95% CI: 6.47–600.32). And, it is negatively associated with residential gas service (PR = 0.3; 95% CI: 0.16–0.58) and self-administered internal fumigation (PR = 0.37; 95% CI: 0.2–0.69). The presence and abundance of A. aegypti were explained by interrelated socioeconomic, environmental, and behavioral factors where local conditions and habits such as the organization of the patio, knowledge about vector biology, and cleaning containers are identified as main topics for future prevention strategies for the transmission of dengue in the local and national context.

Introducción. Las especies del complejo Amblyomma cajennense, potenciales vectores implicados en la transmisión de Rickettsia rickettsii en Centroamérica y Suramérica, presentan una amplia distribución geográfica en el neotrópico. En Colombia, todavía es incipiente el conocimiento sobre las especies de este complejo, su distribución y su ecología. Objetivo. Explorar la ecología del complejo A. cajennense en Colombia a partir del estudio de su selección de hábitat y la generación de modelos potenciales de distribución geográfica y climática. Materiales y métodos. Se utilizaron registros únicos de la presencia de estas garrapatas en el estudio de sus patrones de selección del hábitat, mediante el análisis factorial del nicho ecológico (Ecological Niche Factor Analysis, ENFA), y se construyeron modelos de distribución potencial con las metodologías MaxEnt y GARP. Resultados. El complejo A. cajennense se encontró en las cinco regiones naturales de Colombia, con 64,71 % de los registros procedentes de los departamentos de Antioquia, Cundinamarca y Huila. La selección del hábitat evidenció que estas garrapatas escogen preferentemente las áreas geográficas (ENFA: 96,03 %) según sus condiciones de índice de estabilidad térmica y de precipitación en el trimestre más seco del año. Los modelos de distribución potencial indicaron la idoneidad del hábitat en 31 a 51 % del área del país dependiendo del algoritmo empleado. Conclusiones. En Colombia, el complejo A. cajennense presenta una distribución muy influenciada por el comportamiento en la selección del hábitat climático, característica que facilitó la creación de modelos de distribución. En futuros estudios de campo, se podrían validar los modelos presentados; se requieren, además, otros estudios genéticos para la identificación de especies del complejo y el manejo de sus potenciales zonas de hibridación en el país.

Introducción: Ae. aegypti es una especie adaptada a ambientes urbanos, es el vector de varias enfermedades virales, entre ellas el dengue, zika y chikungunya. Objetivo: Determinar los factores demográficos, socioeconómicos, ambientales y de conocimientos y costumbres, asociados a la infestación domiciliaria por Ae. aegypti, en el corregimiento El Manzanillo del municipio de Itagüí en el año 2015. Metodología: Estudio cuantitativo de tipo observacional entre octubre y diciembre del 2015. La población de estudio estuvo conformada por las viviendas de las ocho veredas del corregimiento. Se realizó una encuesta sobre los factores demográficos, socioeconómicos, ambientales, de conocimientos y costumbres y medición de índices Aedicos con la técnica (LIRAa). Resultados: Se analizaron 400 encuestas. La mayoría de personas encuestadas eran mujeres entre los 18 y 33 años, que convivían en unión libre, afiliadas al régimen contributivo. La mayor proporción de viviendas eran propias entre los estratos 1 y 2, en las cuales habitaban entre 1 y 4 personas. Las personas encuestadas no tenían mayor conocimiento sobre el dengue o participación en campañas de prevención. De las ocho veredas El Ajizal presentó los índices aédicos más altos. Los principales factores potencialmente asociados a la infestación domiciliaria por Ae. aegypti fueron vivir cerca de un sitio de disposición de inservibles, almacenamiento de agua en la vivienda y el control de agua almacenada. Conclusiones: Se requiere concertar programas de educación comunitaria con participación activa y consciente de los habitantes con énfasis en medidas que reduzcan la infestación de las viviendas.

Triatoma dimidiata es un importante vector de la enfermedad de Chagas en Centroamérica y en los países del norte de Suramérica. En Colombia, tiene una amplia distribución y su presencia se ha reportado en 14 departamentos de las regiones Andina, Caribe, de los Llanos Orientales y del Alto Magdalena, en las cuales ocupa diferentes ecótopos naturales y artificiales. La especie está clasificada como secundaria para la transmisión de Trypanosoma cruzi; sin embargo, su presencia en el ambiente silvestre, peridoméstico y doméstico en la región Andina, y su capacidad de movilizarse entre ellos, le han permitido escapar al control basado en la aspersión con piretroides y ello resalta su importancia en el mantenimiento de la transmisión del parásito debido a la potencial reinfestación de las viviendas. La comprensión de las relaciones de T. dimidiata con su hábitat, así como el empoderamiento de la comunidad, contribuyen al desarrollo de sistemas de control efectivos y perdurables. El propósito de esta revisión fue describir la distribución, los factores de riesgo, la ecología, las características entomológicas y los hábitats de las poblaciones de T. dimidiata en Colombia, y proponer alternativas de intervención acordes con las características particulares de esta especie.

Introduction: Due to the lack of information regarding biophysical and spatio-temporal conditions (hydrometheorologic and vegetal coverage density) in areas with Triatoma dimidiata in the Colombian departments of Santander and Boyacá, there is a need to elucidate the association patterns of these variables to determine the distribution and control of this species. Objective: To make a spatio-temporal analysis of biophysical variables related to the distribution of T. dimidiate observed in the northeast region of Colombia. Materials and methods: We used the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (IPCC SRES) data bases registering vector presence and hydrometheorologic data. We studied the variables of environmental temperature, relative humidity, rainfall and vegetal coverage density at regional and local levels, and we conducted spatial geostatistic, descriptive statistical and Fourier temporal series analyses. Results: Temperatures two meters above the ground and on covered surface ranged from 14,5°C to 18,8°C in the areas with the higher density of T. dimidiata. The environmental temperature fluctuated between 30 and 32°C. Vegetal coverage density and rainfall showed patterns of annual and biannual peaks. Relative humidity values fluctuated from 66,8 to 85,1%. Conclusions: Surface temperature and soil coverage were the variables that better explained the life cycle of T. dimidiata in the area. High relative humidity promoted the seek of shelters and an increase of the geographic distribution in the annual and biannual peaks of regional rainfall. The ecologic and anthropic conditions suggest that T. dimidiata is a highly resilient species.

Ecoepidemiological scenarios for Chagas disease transmission are complex, so vector control measures to decrease human-vector contact and prevent infection transmission are difficult to implement in all geographic contexts. This study assessed the geographic abundance patterns of two vector species of Chagas disease: Triatoma maculata (Erichson, 1848) and Rhodnius pallescens (Barber, 1932) in Latin America. We modeled their potential distribution using the maximum entropy algorithm implemented in Maxent and calculated distances to their niche centroid by fitting a minimum-volume ellipsoid. In addition, to determine which method would accurately explain geographic abundance patterns, we compared the correlation between population abundance and the distance to the ecological niche centroid (DNC) and between population abundance and Maxent environmental suitability. The potential distribution estimated for T. maculata showed that environmental suitability covers a large area, from Panama to Northern Brazil. R. pallescens showed a more restricted potential distribution, with environmental suitability covering mostly the coastal zone of Costa Rica and some areas in Nicaragua, Honduras, Belize and the Yucatán Peninsula in Mexico, northern Colombia, Acre, and Rondônia states in Brazil, as well as a small region of the western Brazilian Amazon. We found a negative slope in the relationship between population abundance and the DNC in both species. R. pallecens has a more extensive potential latitudinal range than previously reported, and the distribution model for T. maculata corroborates previous studies. In addition, population abundance increases according to the niche centroid proximity, indicating that population abundance is limited by the set of scenopoetic variables at coarser scales (non-interactive variables) used to determine the ecological niche. These findings might be used by public health agencies in Latin America to implement actions and support programs for disease prevention and vector control, identifying areas in which to expand entomological surveillance and maintain chemical control, in order to decrease human-vector contact.

Introducción. Aedes albopictus se encuentra ampliamente distribuido en el mundo. Su introducción en las Américas ocurrió en 1985 y se le considera vector potencial de los virus del dengue y uno de los principales vectores del virus del chikungunya. En Colombia, su primer reporte fue en Leticia, Amazonas, en 1998, seguido de Buenaventura, Valle del Cauca, en 2001, Barrancabermeja, Santander, en 2010 y Medellín, Antioquia, en 2011. La especie se ha reportado en diez departamentos del país. Objetivo. Notificar el hallazgo de A. albopictus en el municipio de Istmina, Chocó, y dar cuenta de su importancia en salud pública. Materiales y métodos. En enero de 2015 se inspeccionaron criaderos de los barrios de San Agustín, Santa Genoveva y Subestación del municipio de Istmina para la detección de formas inmaduras de Aedes spp. Las larvas recolectadas fueron identificadas en la Unidad de Entomología del Laboratorio de Salud Pública Departamental de Chocó y confirmadas en el Laboratorio de Entomología de la Red Nacional de Laboratorios del Instituto Nacional de Salud en Bogotá. Resultados. Se encontraron doce larvas de A. albopictus en criaderos ubicados en los barrios Subestación y San Agustín en el municipio de Istmina. Conclusión. La detección de A. albopictus en el municipio de Istmina resalta la importancia del fortalecimiento de las estrategias de vigilancia entomológica continua a nivel municipal y departamental en el país, y especialmente en Istmina y los municipios aledaños.

Introduction This study was conducted in Brazil and Colombia,where dengue is endemic and vector control programs use chemical insecticides. Methods We identified knowledge, attitudes, and practices about dengue and determined the infestation levels of Aedes aegypti in one Brazilian and four Colombian communities. Results The surveys show knowledge of the vector, but little knowledge about diagnosis, prognosis, and treatment. Vector infestation indices show Brazil to have good relative control, while Colombia presents a high transmission risk. Conclusions Given the multidimensionality of dengue control, vertical control strategies are inadequate because they deny contextualized methods, alternative solutions, and local empowerment.

Introducción. El dengue es una enfermedad viral de transmisión vectorial de importancia en salud pública. La ausencia de una vacuna ha llevado a que las acciones de control se enfoquen principalmente en la disminución del mosquito vector. Sin embargo, estas estrategias tienen costos elevados. Las ovitrampas letales podrían contribuir de forma práctica en estrategias costo-efectivas para el control vectorial. Objetivo. Determinar el tipo de ovitrampas letales más eficiente para el control vectorial de Aedes aegypti, combinando diferentes tipos de insecticidas, sustrato de ovipostura e infusión atrayente. Materiales y métodos. El estudio se llevó a cabo en dos etapas. En la primera, se evaluaron en el laboratorio 18 ovitrampas diferentes provenientes de la combinación de insecticidas (deltametrina y permetrina), sustratos de ovipostura (toalla, dacrón y franela) e infusiones atrayentes (infusión de heno al 10 y 20 % y agua declorada). Para esta evaluación, las ovitrampas se colocaron en el interior de una jaula de evaluación y se liberaron 100 hembras grávidas de A. aegypti. Se seleccionaron las seis mejores ovitrampas con base en la mayor cantidad de oviposturas y en la menor emergencia larvaria. La segunda etapa consistió en evaluar las seis mejores ovitrampas en condiciones de campo. Resultados. Se observó una diferencia estadística entre las 18 ovitrampas en el laboratorio. Las que tenían deltametrina fueron las que presentaron los mejores resultados. En campo se observó que la ovitrampa más eficiente fue la compuesta por deltametrina, toalla e infusión de heno al 10 %. Conclusiones. La combinación de deltametrina, toalla y solución de heno al 10 % fue la más eficiente para la reducción vectorial de A. aegypti.

Introducción. Aedes (Stegomyia) aegypti es el principal vector del dengue. En el control del mosquito se han usado insecticidas químicos contra los cuales ha desarrollado resistencia. Es necesaria la evaluación de estrategias alternativas que sean eficientes, económicas y de fácil aplicación, como las ovitrampas con Bacillus thuringiesis var. israeliensis. Objetivo. Evaluar el impacto de ovitrampas con B. thuringiesis var. israeliensis sobre los índices aédicos tradicionales, como estrategia para la vigilancia y el control de A. aegypti. Materiales y métodos. Se seleccionaron ocho barrios de los municipios de Apartadó y Carepa, Antioquia, de los cuales se escogieron dos barrios para la intervención y dos para el control en cada municipio. La intervención consistió en la instalación de una ovitrampa con B. thuringiesis var. israeliensis en cada una de las viviendas. Las ovitrampas se visitaron mensualmente entre septiembre de 2009 y marzo de 2010. Se obtuvieron los índices aédicos tradicionales y se hicieron comparaciones entre los barrios. Se calculó el índice de ovitrampas positivas y el de densidad de huevos, y se generaron los mapas de densidad. Resultados. Se colocaron 519 ovitrampas muestreadas mensualmente. Se hicieron 3.114 muestreos, con un porcentaje de registros positivos de 76,4 %. Se recolectaron 501.425 huevos. En Apartadó se observaron diferencias significativas entre el índice de infestación de viviendas, el índice de infestación de depósitos y el índice de Breteau en los barrios intervenidos comparados con los barrios de control. El índice de ovitrampas positivas evidenció un alto riesgo de infestación por A. aegypti y, los índices tradicionales, niveles de riesgo medio y bajo. Conclusiones. Las ovitrampas tuvieron impacto sobre los índices tradicionales y demostraron ser estrategias útiles en la vigilancia de A. aegypti en el Urabá antioqueño.

Irrigation schemes and dams have posed a great concern on public health systems of several countries, mainly in the tropics. The focus of the present review is to elucidate the different ways how these human interventions may have an effect on population dynamics of anopheline mosquitoes and hence, how local malaria transmission patterns may be changed. We discuss different studies within the three main tropical and sub-tropical regions (namely Africa, Asia and the Pacific and the Americas). Factors such as pre-human impact malaria epidemiological patterns, control measures, demographic movements, human behaviour and local Anopheles bionomics would determine if the implementation of an irrigation scheme or a dam will have negative effects on human health. Some examples of successful implementation of control measures in such settings are presented. The use of Geographic Information System as a powerful tool to assist on the study and control of malaria in these scenarios is also highlighted.

Introducción. Los estudios encaminados a conocer los parámetros ecológicos de las poblaciones de mosquitos selváticos, permiten establecer el riesgo de transmisión de arbovirus y aportar recomendaciones sobre prevención, vigilancia y control a las autoridades de salud. Objetivo. Determinar la diversidad y abundancia de mosquitos nocturnos y crepusculares, potenciales vectores de arbovirus en zonas rurales de Apartadó y Turbo, Antioquia. Materiales y métodos. Se realizaron muestreos trimestrales. Para la recolección de mosquitos se usaron trampas CDC, Shannon y cebo humano protegido, en fragmentos de bosque, entre las 18:00 y las 06:00 horas. Se estimaron los índices de diversidad y abundancia de especies. Resultados. Se capturaron 583 mosquitos de 10 géneros y 27 especies. Las especies más abundantes fueron Coquilletidia venezuelensis (14,6 %), Aedes scapularis (14,08 %), Psorophora ferox (10,82 %) y Culex quinquefasciatus (10,3 %). La riqueza específica y los índices ecológicos calculados fueron mayores en Turbo; el fragmento de bosque estudiado en Turbo se considera de mayor riqueza y uniformidad de especies. El hallazgo de Cx. pedroi, Ae. scapularis, Ae. angustivittatus, Cq. venezuelensis, Cx. nigripalpus, Cx. quinquefasciatus, Cx. declarator, Mansonia titillans, Ma. pseudotitillans, Ps. ferox y Trichiprosopon digitatum reportados como vectores de arbovirus, alerta sobre la posibilidad de transmisión en la zona. Conclusión. La diversidad y abundancia de mosquitos en la zona de estudio son altas. Los análisis ecológicos más los reportes previos de capacidad vectorial de algunas de las especies registradas, permiten concluir que en la zona se pueden presentar brotes de arbovirosis. doi: http://dx.doi.org/10.7705/biomedica.v32i2.667

Algunas especies de artrópodos son causantes de enfermedades en humanos, animales domésticos y silvestres, actuando como vectores biológicos y mecánicos de importantes patógenos; además de los daños directos que ocasionan por sus hábitos alimenticios y de fijación en diferentes partes del cuerpo de sus hospederos. El objetivo de este trabajo fue identificar las diferentes especies de ectoparásitos presentes en las aves silvestres ingresadas al Centro de Atención y Valoración de Fauna Silvestre (CAV) del área metropolitana del Valle de Aburrá. Se realizó un estudio descriptivo longitudinal, en el cual se analizaron 43 aves infestadas con ectoparásitos que ingresaron al centro, durante el periodo de octubre de 2006 a noviembre de 2007. Se colectaron 202 ectoparásitos de los órdenes Pthiraptera, Diptera y ácaros del orden Parasitiformes (Arachnida). El orden Phthiraptera presentó la mayor diversidad, con 18 especies, todas del grupo Mallophaga. Del orden Diptera se identificó una especie y diez larvas de la familia Muscidae, mientras que en los ácaros se identificaron tres géneros, de los subórdenes: Astigmata y Mesostigmata. Los resultados de este estudio permiten ampliar el rango de hospederos del género Bonnetella a la especie Ramphastos citroelaemus. Además se registra la presencia de Menacanthus eurysternus y Colpocephalum turbinatum en Pelecanus occidentalis y Buteo platypterus. Se recomienda realizar estudios microbiológicos y parasitológicos para identificar las especies patógenas presentes en estos ectoparásitos, que permitan establecer el riesgo de transmisión de enfermedades y proponer medidas de prevención y control de enfermedades zoonóticas.Algumas espécies de artrópodes são causadores de doenças tanto para os humanos como para animais domésticos e silvestres, atuando como vetores biológicos e mecânicos de patogenias importantes, além de causar danos diretos por seus hábitos alimentares e a sua fixação em diferentes partes do corpo do hospedeiro. O objetivo foi identificar as diferentes espécies de ectoparasitas hachados em aves silvestres do "Centro de Atención y Valoración de Fauna Silvestre del area metropolitana del Valle de Aburrá". Foi feito um estudo descritivo longitudinal em 43 aves as quais ingressaram ao Centro infestadas com ectoparasitas desde outubro de 2006 até novembro de 2007. Coletaram-se 202 ectoparasitas das ordens Phthiraptera, Diptera e ácaros da ordem Parasitiformes (Arachnida). A ordem Phthiraptera apresentou a maior diversidade, com 18 espécies todas do grupo Mallophaga, Da ordem Díptera identificou-se uma espécie e dez larvas da família Muscidae, enquanto nos ácaros identificaram-se três gêneros das subordens Astigmata y Mesostigmata. Os resultados do estudo permitem ampliar o rango dos hospedeiros do gênero Bonnetella á espécie Ramphastos citroelaemus. Alem de mais se registra a presencia de Menacanthus eurysternus y Colpocephalum turbinatum em Pelecanus occidentalis y Buteo platypterus. Recomenda-se realizar estudos microbiológicos e parasitológicos para identificar as espécies patogenias presentes nestes ectoparasitas que permitam estabelecer o risco de transmissão de doenças e propor medidas de prevenção e controle de zoonoses.Some arthropod species are vectors of diseases to human's beings, domestic and sylvatic animals acting as biological or mechanical vectors of important pathogens. They produce direct damage due to feeding habits and attachment to different parts of animals and humans bodies. The aim of this study was to identify different species of ectoparasites from wild birds located at "Centro de Atención y Valoración de Fauna Silvestre del area metropolitana del Valle de Aburrá". From October 2006 to November 2007 a descriptive longitudinal study was done in 43 birds infested with ectoparasites. A total of 202 ectoparasites belonging to Diptera and Phthiraptera (Insecta) orders and Parasitiformes mites (Arachnida: Acari) were found.The Phtiraptera order shows the highest diversity with 18 species all of them belonging to Mallophaga group. From Diptera order, one specie was identified and ten larvae from Muscidae family was identified too, from Acari three genera of the Astigmata and Mesostigmata soborders was identified. The results of this study allow us to expand the host range of Bonnetella genera to Ramphastos citroelaemus specie. Also the presence of Menacanthus eurysternus and Colpocephalum turbinatum is registered in Pelecanus occidentalis and Buteo platypterus. The development of microbiological and parasitological studies to identify pathogen species in these ectoparasites is recommended to establish disease transmission risk and prevention and control strategies of zoonotic diseases.

Introducción. Triatoma dimidiata es el segundo vector más importante de la enfermedad de Chagas en Colombia, después de Rhodnius prolixus. El conocimiento de la composición genética y la diferenciación de poblaciones es fundamental para el adecuado diseño e implementación de estrategias de control y vigilancia vectorial. Objetivo. Determinar el nivel de variabilidad y diferenciación genética en tres poblaciones colombianas de T. dimidiata provenientes de distintas localidades y hábitats, mediante el análisis molecular de un fragmento del gen mitocondrial ND4. Materiales y métodos. Se analizó el nivel de polimorfismo y la estructura genética de dos poblaciones silvestres de los departamentos de La Guajira (n=10) y Santander (n=10), y de una población intradomiciliaria (n=15) y peridomiciliaria (n=5) del Cesar. Para tal fin, se analizaron las secuencias de nucleótidos de un fragmento del gen mitocondrial ND4. Resultados. T. dimidiata en Colombia demostró tener gran diversidad genética, tanto a nivel de nucleótidos (π: 0,034) como de haplotipo (Hd: 0,863), además de una significativa estructuración de población (fST: 0,761) con un bajo número de migrantes (Nm: 0,157). Las distancias genéticas y las diferencias en los niveles de variabilidad genética entre las tres poblaciones fueron coherentes con una posible subdivisión de población. Conclusión. Este trabajo demostró diferenciación genética entre las poblaciones de T. dimidiata de La Guajira, Cesar y Santander. Se sugiere una posible relación entre tal subdivisión y algunas características eco-epidemiológicas que posee T. dimidiata en el centro-oriente y en el norte de Colombia. Finalmente, este trabajo describe, por primera vez, la utilidad del ND4 como un marcador molecular para el estudio de poblaciones naturales de T. dimidiata.

Ecological niche modeling of Triatominae bugs allow us to establish the local risk of transmission of the parasite Trypanosoma cruzi, which causes Chagas disease. This information could help to guide health authority recommendations on infection monitoring, prevention, and control. In this study, we estimated the geographic distribution of triatomine species in Colombia and identified the relationship between landscape structure and climatic factors influencing their occurrence. A total of 2451 records of 4 triatomine species (Panstrongylus geniculatus, Rhodnius pallescens, R. prolixus, and Triatoma maculata) were analyzed. The variables that provided more information to explain the ecologic niche of these vectors were related to precipitation, altitude, and temperature. We found that the species with the broadest potential geographic distribution were P. geniculatus, R. pallescens, and R. prolixus. In general, the models predicted the highest occurrence probability of these vectors in the eastern slope of the Eastern Cordillera, the southern region of the Magdalena valley, and the Sierra Nevada of Santa Marta.

Chagas disease is transmitted by the parasite, Trypanosoma cruzi. Acute infection is characterized by acute myocarditis, although it is largely asymptomatic. Initial cardiac insult could be a determinant to the posterior development of chronic Chagasic cardiomyopathy, usually after 10 years in only approximately 30% of chronically infected patients. Herein, we characterized the acute gene expression profiling in heart tissue of two strains of mice infected with T. cruzi (tulahuen strain) at 4 weeks and their respective controls. Gene sequence data are available at NCBI under GEO accession number: GSE63847. The output of the genes expression suggests differences in involvement of protein kinase B (AKT), NCAM1, HLA-DRA, and ubiquitin C genes networks. These gene activation differences may correlate with myocardial contractility during the acute infection.

To determine the incidence of dengue infection, we established active surveillance of febrile episodes in a cohort of schoolchildren from three schools in Medellin, Colombia. We followed a cohort of 2,379 schoolchildren in 2010 and followed 1,840 of these children the following year. During the follow-up time, 264 schoolchildren displayed 297 febrile episodes; of these, 23 episodes (7.7%) were caused by acute dengue infection. All four dengue serotypes were found, and all of the cases were mild. The most common symptoms in the dengue cases compared with those in other febrile illness were asthenia (96% versus 87%), anorexia (78% versus 57%), rhinorrhea (65.2% versus 58%), abdominal pain (56.5% versus 47.8%), arthralgia (43% versus 33%), and positive tourniquet test (13% versus 3%). This difference was not statistically significant. Pulse was elevated, and systolic arterial pressure was lower in dengue cases compared with other febrile illness (P