Emergence of Dengue Virus Serotype 2 Cosmopolitan Genotype, Colombia.

Using Oxford Nanopore technologies and phylogenetic analyses, we sequenced and identified the cosmopolitan genotype of dengue virus serotype 2 isolated from 2 patients in the city of Villavicencio, Meta department, Colombia. This identification suggests the emergence of this genotype in the country, which warrants further surveillance to identify its epidemic potential.

Cryptic transmission and novel introduction of Dengue 1 and 2 genotypes in Colombia.

Dengue fever remains as a public health challenge in Colombia, standing as the most prevalent infectious disease in the country. The cyclic nature of dengue epidemics, occurring approximately every 3 years, is intricately linked to meteorological events like El Niño Southern Oscillation (ENSO). Therefore, the Colombian system faces challenges in genomic surveillance. This study aimed to evaluate local dengue virus (DENV) transmission and genetic diversity in four Colombian departments with heterogeneous incidence patterns (department is first-level territorial units in Colombia). For this study, we processed 266 serum samples to identify DENV. Subsequently, we obtained 118 genome sequences by sequencing DENV genomes from serum samples of 134 patients infected with DENV-1 and DENV-2 serotypes. The predominant serotype was DENV-2 (108/143), with the Asian-American (AA) genotype (91/118) being the most prevalent one. Phylogenetic analysis revealed concurrent circulation of two lineages of both DENV-2 AA and DENV-1 V, suggesting ongoing genetic exchange with sequences from Venezuela and Cuba. The continuous migration of Venezuelan citizens into Colombia can contribute to this exchange, emphasizing the need for strengthened prevention measures in border areas. Notably, the time to most recent common ancestor analysis identified cryptic transmission of DENV-2 AA since approximately 2015, leading to the recent epidemic. This challenges the notion that major outbreaks are solely triggered by recent virus introductions, emphasizing the importance of active genomic surveillance. The study also highlighted the contrasting selection pressures on DENV-1 V and DENV-2 AA, with the latter experiencing positive selection, possibly influencing its transmissibility. The presence of a cosmopolitan genotype in Colombia, previously reported in Brazil and Peru, raises concerns about transmission routes, emphasizing the necessity for thorough DENV evolution studies. Despite limitations, the study underscores genomic epidemiology's crucial role in early detection and comprehension of DENV genotypes, recommending the use of advanced sequencing techniques as an early warning system to help prevent and control dengue outbreaks in Colombia and worldwide.

Seroprevalencia de la infección por Trypanosoma cruzi y factores asociados en población de Cumaral, Meta, Colombia / Seroprevalence of infection with Trypanosoma cruzi and associated factors in a population of Cumaral, Meta, Colombia

Introducción: La Enfermedad de Chagas es una zoonosis parasitaria causada porTrypanosoma cruzi, un protozoario que se transmite principalmente de manera vectorial al ser humano. Estudios de campo predicen que un tercio de un estimado de 18 millones de personas infectadas en Latinoamérica morirán de Enfermedad de Chagas. Objetivo: El objetivo de este estudio fue determinar la seroprevalencia de la infección por Trypanosoma cruzi y factores asociados en población del municipio de Cumaral, Meta, Colombia. Material y Métodos: Se realizó un estudio descriptivo de tipo transversal, en el cual se recolectaron sueros de toda persona habitante del municipio de Cumaral por más de seis meses y que habitara en área urbana o rural. Se utilizó el método de ELISA de extractos totales (Primera prueba) para la detección de IgG antiTripanosoma cruzy; a los positivos se les realizó prueba confirmatoria por ELISA recombinante; los resultados dudosos fueron enviados al Instituto Nacional de Salud para su confirmación mediante la inmunofluorescencia indirecta. Para el análisis de la información se utilizó el paquete estadístico Prism versión 8.2.1 para MacOS. Resultados: En la tamización de la prueba para Chagas del presente estudio, resultó positivo 2,7 por ciento de los evaluados; al contrastar los sujetos con resultado positivo con los negativos, se observaron diferencias en la edad, la escolaridad y el material de las paredes de sus viviendas. Conclusiones: Los resultados proporcionan información útil de condiciones de vivienda y seroprevalencia de la enfermedad, que ayudan a evaluar la efectividad del acuerdo que facilita y fortalece el acceso al diagnóstico y tratamiento de la enfermedad(AU)

Introduction: Chagas disease is a parasitic zoonosis caused byTrypanosoma cruzi, a vector-born protozoan that is transmitted to humans. Field studies predict that one-third of around 18 millionT cruzi-infected humans will die of Chagas disease in Latin America. Objective: To determine the seroprevalence of the infection with Trypanosoma cruzi and to identify some risk factors associated with this condition in Cumaral, Meta, Colombia. Material and Methods: A descriptive, cross-sectional study was conducted. Blood samples were collected from subjects that had been living in urban and rural areas of Cumaral municipality for more than six months. An ELISA-IgG method with total extracts (first test) was used for the detection of Trypanosoma cruzy IgG. A recombinant-based ELISA was performed as a confirmatory test. Doubtful results were sent to the National Institute for Health for confirmation by indirect immunofluorescence assay. Prism 8 for MacOS (version 8.2.1) was used for statistical analysis. Results: In the screening for Chagas disease, 2,7 percent of all the cases tested were positive. When comparingsubjects with positiveandnegative results, differences between age, scholarship and materials used in the construction of house walls were evidenced. Conclusions: The results provide useful information about housing conditions and seroprevalence of the disease that help to evaluate the effectiveness of the arrangement that provides and strengthens the access to the diagnosis and treatment of the disease(AU)