Early-life external exposome in children 2-5 years old in Colombia.

Exposome studies are advancing in high-income countries to understand how multiple environmental exposures impact health. However, there is a significant research gap in low- and middle-income and tropical countries. We aimed to describe the spatiotemporal variation of the external exposome, its correlation structure between and within exposure groups, and its dimensionality. A one-year follow-up cohort study of 506 children under 5 in two cities in Colombia was conducted to evaluate asthma, acute respiratory infections, and DNA damage. We examined 48 environmental exposures during pregnancy and 168 during childhood in eight exposure groups, including atmospheric pollutants, natural spaces, meteorology, built environment, traffic, indoor exposure, and socioeconomic capital. The exposome was estimated using geographic information systems, remote sensing, spatiotemporal modeling, and questionnaires. The median age of children at study entry was 3.7 years (interquartile range: 2.9-4.3). Air pollution and natural spaces exposure decreased from pregnancy to childhood, while socioeconomic capital increased. The highest median correlations within exposure groups were observed in meteorology (r = 0.85), traffic (r = 0.83), and atmospheric pollutants (r = 0.64). Important correlations between variables from different exposure groups were found, such as atmospheric pollutants and meteorology (r = 0.76), natural spaces (r = -0.34), and the built environment (r = 0.53). Twenty principal components explained 70%, and 57 explained 95% of the total variance in the childhood exposome. Our findings show that there is an important spatiotemporal variation in the exposome of children under 5. This is the first characterization of the external exposome in urban areas of Latin America and highlights its complexity, but also the need to better characterize and understand the exposome in order to optimize its analysis and applications in local interventions aimed at improving the health conditions and well-being of the child population and contributing to environmental health decision-making.

Delineating the Seasonality of Varicella and Its Association With Climate in the Tropical Country of Colombia.

BACKGROUND: Varicella causes a major health burden in many low- to middle-income countries located in tropical regions. Because of the lack of surveillance data, however, the epidemiology of varicella in these regions remains uncharacterized. In this study, based on an extensive dataset of weekly varicella incidence in children ≤10 during 2011-2014 in 25 municipalities, we aimed to delineate the seasonality of varicella across the diverse tropical climates of Colombia. METHODS: We used generalized additive models to estimate varicella seasonality, and we used clustering and matrix correlation methods to assess its correlation with climate. Furthermore, we developed a mathematical model to examine whether including the effect of climate on varicella transmission could reproduce the observed spatiotemporal patterns. RESULTS: Varicella seasonality was markedly bimodal, with latitudinal changes in the peaks' timing and amplitude. This spatial gradient strongly correlated with specific humidity (Mantel statistic = 0.412, P = .001) but not temperature (Mantel statistic = 0.077, P = .225). The mathematical model reproduced the observed patterns not only in Colombia but also México, and it predicted a latitudinal gradient in Central America. CONCLUSIONS: These results demonstrate large variability in varicella seasonality across Colombia and suggest that spatiotemporal humidity fluctuations can explain the calendar of varicella epidemics in Colombia, México, and potentially in Central America.

Characterization of the external exposome and its contribution to the clinical respiratory and early biological effects in children: The PROMESA cohort study protocol.

BACKGROUND: Air pollution contains a mixture of different pollutants from multiple sources. However, the interaction of these pollutants with other environmental exposures, as well as their harmful effects on children under five in tropical countries, is not well known. OBJECTIVE: This study aims to characterize the external exposome (ambient and indoor exposures) and its contribution to clinical respiratory and early biological effects in children. MATERIALS AND METHODS: A cohort study will be conducted on children under five (n = 500) with a one-year follow-up. Enrolled children will be followed monthly (phone call) and at months 6 and 12 (in person) post-enrolment with upper and lower Acute Respiratory Infections (ARI) examinations, asthma development, asthma control, and genotoxic damage. The asthma diagnosis will be pediatric pulmonologist-based and a standardized protocol will be used. Exposure, effect, and susceptibility biomarkers will be measured on buccal cells samples. For environmental exposures PM2.5 will be sampled, and questionnaires, geographic information, dispersion models and Land Use Regression models for PM2.5 and NO2 will be used. Different statistical methods that include Bayesian and machine learning techniques will be used for the ambient and indoor exposures-and outcomes. This study was approved by the ethics committee at Universidad Pontificia Bolivariana. EXPECTED STUDY OUTCOMES/FINDINGS: To estimate i) The toxic effect of particulate matter transcending the approach based on pollutant concentration levels; ii) The risk of developing an upper and lower ARI, based on different exposure windows; iii) A baseline of early biological damage in children under five, and describe its progression after a one-year follow-up; and iv) How physical and chemical PM2.5 characteristics influence toxicity and children's health.

Understanding how socioeconomic inequalities drive inequalities in COVID-19 infections.

Across the world, the COVID-19 pandemic has disproportionately affected economically disadvantaged groups. This differential impact has numerous possible explanations, each with significantly different policy implications. We examine, for the first time in a low- or middle-income country, which mechanisms best explain the disproportionate impact of the virus on the poor. Combining an epidemiological model with rich data from Bogotá, Colombia, we show that total infections and inequalities in infections are largely driven by inequalities in the ability to work remotely and in within-home secondary attack rates. Inequalities in isolation behavior are less important but non-negligible, while access to testing and contract-tracing plays practically no role because it is too slow to contain the virus. Interventions that mitigate transmission are often more effective when targeted on socioeconomically disadvantaged groups.

SARS-CoV-2 Drive/Walk-Thru screening centers in Colombia: The CoVIDA Project / Centros de tamizaje masivo para SARS COV-2 en Colombia: Proyecto CoVIDA

Abstract Objective: The CoVIDA project is a public-private collaboration led by Universidad de los Andes that contributed to the SARS-CoV-2 epidemiological surveillance in Bogotá and nearby municipalities. We aimed to describe the development and performance of the Drive/Walk-through free RT- PCR for SARS-CoV-2 testing strategy implemented by CoVIDA. Material and method: We performed a descriptive analysis of the characteristics and performance of the CoVIDA Drive/Walk-through testing centers. The model and the process indicators to assess the model's performance were based on international experiences and scientific literature. Two screening centers were imple mented in shopping centers in the north and south of Bogotá. We reported the number of tests taken, the number of positive tests, and the number of participants that used the model by the type of occupations. Results: In total, 36,689 nasopharyngeal RT-PCR tests for SARS-CoV-2 were performed with a 5.75% cumulative positivity. Process indicators showed an excellent performance and an important contribution in reducing barriers to access to testing. Conclusions: the CoVIDA Drive/Walk-through testing centers supported the epidemiological surveillance in asymptomatic or mild-symptomatic population in Bo gotá. Low and middle-income countries can use this model as a cost-effective and innovative solution strategy to intensify testing and help mitigate the pandemic.

Resumen Objetivo: El proyecto CoVIDA es una colaboración público-privada liderada por la Universidad de los Andes que contribuyó a la vigilancia epidemiológica del SARS-CoV-2 en Bogotá y municipios cercanos. Nuestro objetivo fue describir el desarrollo y rendimiento de la estrategia de tamizaje gratuito con RT-PCR mediante un modelo Drive/Walk through para SARS-CoV-2 implementado por CoVIDA. Materiales y métodos: Realizamos un análisis descriptivo de las características y desempeño de los centros de tamizaje Drive/Walk through de CoVIDA. El modelo y los indicadores de proceso para evaluar el desempeño del modelo se basaron en experiencias internacionales y la literatura científica. Se implementaron dos cen tros de tamizaje en centros comerciales del norte y sur de Bogotá. Se reportó la cantidad de pruebas tomadas, pruebas positivas y de participantes que utilizaron el modelo de acuerdo con el tipo de ocupaciones. Resultados : En total, se realizaron 36,689 pruebas RT-PCR nasofaríngeas para SARS-CoV-2 con una positividad acumulada del 5,75%. Los indicadores de proceso mostraron un excelente desempeño y una contribución importante en la reducción de las barreras de acceso a las pruebas. Conclusiones: los centros de tamizaje con modelo Drive/Walk through de CoVIDA apoyaron la vigilancia epidemiológica en población asintomática o con síntomas leves en Bogotá. Los países de ingresos bajos y medianos pueden utilizar este modelo como una estrategia innovadora y rentable para aumentar la realización de las pruebas y ayudar a mitigar la pandemia.

COVID-19 spread, detection, and dynamics in Bogota, Colombia.

Latin America has been severely affected by the COVID-19 pandemic but estimations of rates of infections are very limited and lack the level of detail required to guide policy decisions. We implemented a COVID-19 sentinel surveillance study with 59,770 RT-PCR tests on mostly asymptomatic individuals and combine this data with administrative records on all detected cases to capture the spread and dynamics of the COVID-19 pandemic in Bogota from June 2020 to early March 2021. We describe various features of the pandemic that appear to be specific to a middle income countries. We find that, by March 2021, slightly more than half of the population in Bogota has been infected, despite only a small fraction of this population being detected. The initial buildup of immunity contributed to the containment of the pandemic in the first and second waves. We also show that the share of the population infected by March 2021 varies widely by occupation, socio-economic stratum, and location. This, in turn, has affected the dynamics of the spread with different groups being infected in the two waves.

La educación como determinante social de la salud y el impacto de la COVID-19: avances y desafíos / Education as a social determinant of health and the impact of COVID-19: progress and challenges

Webinar N° 10 del ORAS-CONHU, realizado el 09 de julio de 2020, se realizó un webinar con el objetivo de analizar los avances y desafío que tiene la región andina en cuanto a las acciones y medidas multi e intersectoriales tomadas para garantizar educación para todos en tiempos de covid-19. Al reconocer que la educación es uno de los determinantes sociales de la salud, nos vemos en la necesidad de analizar tanto la dimensión global de esta relación, como cada una de las interacciones que se producen con otras variables del desarrollo humano, para dar respuesta a la Agenda Mundial en materia de salud y educación AL 2030. Conferencistas del webinar: Fernando Berríos, Coordinador de Unesco Perú, Luis Jorge Hernández Flores, Profesor Universidad de los Andes de Colombia, Fabián León Tamariz, Decano de la Facultad de Ciencias Químicas de la Universidad de Cuenca, Ecuador y José Ferrer Vicerrector de la Universidad de las Ciencias de la Salud de Venezuela.

An asbestos contaminated town in the vicinity of an asbestos-cement facility: The case study of Sibaté, Colombia.

INTRODUCTION: The asbestos industry began operations in Colombia in 1942, with an asbestos-cement facility located in the municipality of Sibaté. In recent years residents from Sibaté have been complaining about what they consider is an unusually large number of people diagnosed with asbestos-related diseases in the town. A study to analyze the situation of Sibaté started in 2015, to verify if the number of asbestos related diseases being diagnosed were higher than expected, and to identify potential asbestos exposure sources in the town. METHODS: A health and socioeconomic survey was implemented door-to-door to identify potential asbestos-related diseases. Several self-reported mesothelioma cases were identified, and for confirmation purposes, copies of the medical record with the histopathology report were obtained. A panel of six physicians analyzed the medical records. Information of validated cases was used to estimate the male and female age-adjusted incidence rate for Sibaté. Based on reports of the existence of potential asbestos-contaminated landfills, topographic maps, a digital elevation model, and current satellite images were crossed using a geographic information system to identify potential landfilled areas, and soils samples were collected in some of these areas. RESULTS: A total of 355 surveys were completed, and 29 self-reported mesothelioma cases were identified. Twenty-five of these cases have been persons who had lived at some moment of their lives in Sibaté. It was possible to obtain copies of the medical diagnosis for 17 cases. Of these, the panel of physicians classified 15 cases as certain pleural mesothelioma, one as probable, and one as not mesothelioma. Based on this information, the estimated age-adjusted incidence rate of mesothelioma in Sibaté was 3.1 × 105 persons-year for males and 1.6 × 105 persons-year for females. These rates are high in comparison to those reported in other cities, regions, and countries of the world. Using geographic information systems, landfilled zones in the urban area of Sibaté were identified, on top of which a school and different sports facilities were built. The analysis of four soil samples collected in landfilled zones, confirmed the existence of an underground layer of friable and non-friable asbestos. CONCLUSION: The collected evidence suggests the presence of a malignant pleural mesothelioma cluster in Sibaté.

El modelo de la OMS como orientador en la salud pública a partir de los determinantes sociales / The WHO model as a guideline for public health based on social determinants

RESUMEN El desarrollo de la salud pública ha tenido múltiples enfoques, a partir desde los lineamientos de los sistemas de salud, la comunidad o el individuo. El presente análisis identificar los modelos conceptuales de la salud pública que surgen de analizar las categorías de salud o enfermedad y el nivel al cual se da la respuesta social: el individuo o familia, biofísico y el ambiente social; el modelo higienista o preventivo. Partiendo del concepto de modelo más allá de una representación de la realidad, como una postura ontológica de cómo entender la sociedad y el Estado, cualquier modelo se inscribe en una teoría y está en conjunto con otras teorías, hace parte de un marco de análisis. Se presentan entonces, tres modelos de proceso salud-enfermedad, el modelo canadiense que establece cuatro determinantes: estilo de vida, ambiente, factores biológicos y los servicios de salud. El modelo de determinantes sociales de la Organización Mundial de la Salud (OMS) con tres determinantes, el estructural, el intermedio y el proximal, basados en enfoque de riesgo. Por último el modelo histórico-social o de determinación social, buscando las raíces de las desigualdades sociales que inciden en la salud. El desarrollo del Sistema de Salud Colombia en su momento ha pasado por estos modelos en salud, actualmente la Política de Atención Integral en Salud con el Modelo de Atención Integral de Salud basa su enfoque dentro de un modelo de determinantes cado por la OPS.(AU)

ABSTRACT Public health has developed based on multiple approaches, including the guidelines of the health systems, the community or the individuals. This paper intends to identify the conceptual models of public health that arise after analyzing health or disease categories, as well as the level at which social response occurs: the individual or a family, biophysical and social environment; hygienist or preventive mode. Considering that the concept of model is not only a representation of reality, but an ontological position that allows to understand society and the State, all models are part of a theory and converge with other theories to create a framework of analysis. In consequence, three models of the health-disease process are presented. First, the Canadian model that establishes four determinants -lifestyle, environment, biological factors and health services-. Second, the social determinants model of the World Health Organization (WHO) that establishes three determinants based on risk approach: structural, intermediate and proximal. Finally, the historical-social or social determination model, which looks for the roots of social inequalities that affect health. The development of the Colombia Health System has considered these health models. Today, the Comprehensive Health Care Policy, and its Comprehensive Health Care Model, bases its approach within a model of determinants established by the PAHO.(AU)

[The WHO model as a guideline for public health based on social determinants]. / El modelo de la OMS como orientador en la salud pública a partir de los determinantes sociales.

Public health has developed based on multiple approaches, including the guidelines of the health systems, the community or the individuals. This paper intends to identify the conceptual models of public health that arise after analyzing health or disease categories, as well as the level at which social response occurs: the individual or a family, biophysical and social environment; hygienist or preventive mode. Considering that the concept of model is not only a representation of reality, but an ontological position that allows to understand society and the State, all models are part of a theory and converge with other theories to create a framework of analysis. In consequence, three models of the health-disease process are presented. First, the Canadian model that establishes four determinants -lifestyle, environment, biological factors and health services-. Second, the social determinants model of the World Health Organization (WHO) that establishes three determinants based on risk approach: structural, intermediate and proximal. Finally, the historical-social or social determination model, which looks for the roots of social inequalities that affect health. The development of the Colombia Health System has considered these health models. Today, the Comprehensive Health Care Policy, and its Comprehensive Health Care Model, bases its approach within a model of determinants established by the PAHO.

El desarrollo de la salud pública ha tenido múltiples enfoques, a partir desde los lineamientos de los sistemas de salud, la comunidad o el individuo. El presente análisis identificar los modelos conceptuales de la salud pública que surgen de analizar las categorías de salud o enfermedad y el nivel al cual se da la respuesta social: el individuo o familia, biofísico y el ambiente social; el modelo higienista o preventivo. Partiendo del concepto de modelo más allá de una representación de la realidad, como una postura ontológica de cómo entender la sociedad y el Estado, cualquier modelo se inscribe en una teoría y está en conjunto con otras teorías, hace parte de un marco de análisis. Se presentan entonces, tres modelos de proceso salud-enfermedad, el modelo canadiense que establece cuatro determinantes: estilo de vida, ambiente, factores biológicos y los servicios de salud. El modelo de determinantes sociales de la Organización Mundial de la Salud (OMS) con tres determinantes, el estructural, el intermedio y el proximal, basados en enfoque de riesgo. Por último el modelo histórico-social o de determinación social, buscando las raíces de las desigualdades sociales que inciden en la salud. El desarrollo del Sistema de Salud Colombia en su momento ha pasado por estos modelos en salud, actualmente la Política de Atención Integral en Salud con el Modelo de Atención Integral de Salud basa su enfoque dentro de un modelo de determinantes cado por la OPS.

[Respiratory symptoms associated with air pollution in five localities of Bogotá, 2008-2011, a dynamic cohort study]. / Síntomas respiratorios asociados con la exposición a la contaminación del aire en cinco localidades de Bogotá, 2008-2011, estudio en una cohorte dinámica.

INTRODUCTION: High levels of air pollution increase respiratory morbidity in children under five years of age. OBJECTIVE: To know the incidence of respiratory symptoms and its associated factors in five localities of Bogota. MATERIALS AND METHODS: A dynamic cohort study was undertaken with a sample size of 3,278 children from five localities split into two groups according to the degree of exposure to particulate matter. Monitoring was conducted at the outbreak of ten respiratory symptoms through a diary of those symptoms. Statistical analysis included incidence rate ratio (IRR) calculations and Poisson regression models for each assessed symptom. RESULTS: Cough was more frequent in the highly exposed group (lRR=1.23, Cl 95% 1.13-1.34). The most exposed group had higher incidence of expectoration (lRR=1.64, Cl= 95% 1.47-1.84). Wheezing was associated with high exposure to particulate matter (RR=2.29, Cl 95% 1.78-3.00), cottage industries (RR=1.29, Cl 95% 1.01-1.68) and age (RR=0.95, Cl 95% 0.94-0.96). Risk attributable to air pollution exposure fluctuated according to symptoms from 37% for nocturnal wheezing (Cl 95% 26-47.8) to 10.6 for cough (Cl 95% 6.3-15%). CONCLUSION: Extradomiciliary air pollution effects are potentiated by socioeconomic living and working conditions of people in Bogota. A broader conceptual public health approach and the strengthening of intersector actions are required to reduce health effects of air pollution.

Síntomas respiratorios asociados con la exposición a la contaminación del aire en cinco localidades de Bogotá, 2008-2011, estudio en una cohorte dinámica / Respiratory symptoms associated with air pollution in five localities of Bogotá, 2008-2011, a dynamic cohort study

Introducción. En Bogotá, la morbilidad por enfermedad respiratoria en menores de cinco años aumenta a medida que lo hace la contaminación del aire. Objetivo. El objetivo de este estudio fue conocer la incidencia de los síntomas respiratorios en cinco localidades de Bogotá y su asociación con otros factores, entre 2008 y 2011. Materiales y métodos. Se hizo un estudio de cohorte dinámica. El tamaño de la muestra fue de 3.278 niños de cinco localidades, divididos en dos grupos de acuerdo con la exposición a material en partículas. Se hizo el seguimiento de la aparición de diez síntomas respiratorios mediante un diario de registro. El análisis estadístico incluyó el cálculo de la razón de tasas de incidencia (RTI) y la regresión de Poisson para cada síntoma evaluado. Resultados. La tos se presentó con mayor frecuencia en los niños más expuestos (RTI=1,23; IC 95% 1,13-1,34) y la incidencia de expectoración fue mayor en ellos (RTI=1,64; IC 95% 1,47-1,84). En cuanto a las sibilancias, se observó una asociación con la exposición a material en partículas (RR=2,29; IC 95% 1,78-3,00), la presencia de fábricas en la vivienda (RR=1,29; IC 95% 1,01-1,68) y la edad (RR=0,95; IC 95% 0,94-0,96). La proporción de riesgo atribuible a la exposición a la contaminación del aire, fluctuó según los síntomas entre 37 % para las sibilancias nocturnas (IC 95% 26-47,8) y 10,6 % para la tos (IC 95% 6,3-15). Conclusión. Los efectos de la contaminación del aire extramuros se vieron potenciados por las condiciones socioeconómicas en las que vive y trabaja la población de Bogotá. Es necesario adoptar una aproximación conceptual más amplia desde la perspectiva de la salud pública y fortalecer la acción intersectorial para reducir los efectos de la contaminación del aire en la salud de la población.

Introduction: High levels of air pollution increase respiratory morbidity in children under five years of age. Objective: To know the incidence of respiratory symptoms and its associated factors in five localities of Bogota. Materials and methods: A dynamic cohort study was undertaken with a sample size of 3,278 children from five localities split into two groups according to the degree of exposure to particulate matter. Monitoring was conducted at the outbreak of ten respiratory symptoms through a diary of those symptoms. Statistical analysis included incidence rate ratio (IRR) calculations and Poisson regression models for each assessed symptom. Results: Cough was more frequent in the highly exposed group (lRR=1.23, Cl 95% 1.13-1.34). The most exposed group had higher incidence of expectoration (lRR=1.64, Cl= 95% 1.47-1.84). Wheezing was associated with high exposure to particulate matter (RR=2.29, Cl 95% 1.78-3.00), cottage industries (RR=1.29, Cl 95% 1.01-1.68) and age (RR=0.95, Cl 95% 0.94-0.96). Risk attributable to air pollution exposure fluctuated according to symptoms from 37% for nocturnal wheezing (Cl 95% 26-47.8) to 10.6 for cough (Cl 95% 6.3-15%). Conclusion: Extradomiciliary air pollution effects are potentiated by socioeconomic living and working conditions of people in Bogota. A broader conceptual public health approach and the strengthening of intersector actions are required to reduce health effects of air pollution.

[Evaluation of results and impact of the first phase of a community based mental health model in localities in Bogotá, D.C]. / Evaluación de resultados e impactos de un modelo de salud mental basadoen la comunidad en localidades de Bogotá, DC.

OBJECTIVES: The results and impact of the first phase of a Community Based Mental Health Model, developed in the South network by the Bogota Health authority and the Tunjuelito hospital during 2002 were evaluated. The first phase of the program included the formation of health community agents, communitary screening of mental health done through home visits, referrals to the services network and an increase in the nodes of the network of good treatment. METHODS: The indicators of before (year 2001) and after (year 2002) the application of the model were compared, as well as the variations between the study groups (South network) and the control group (Central-Eastern network). RESULTS: The mental health model increased the notification of cases of family violence (23.8% in the study group vs. 15.3% in the control group), the followup of cases of family violence (80% vs. 25%) and the conectivity of the networks of good treatment. In the localities in which the mental health component of the Basic Attention Plan is strengthened, the mental health model showed a better performance. CONCLUSIONS: The results suggest that the implementation of a community based mental health model favors the notification of cases of family violence, their followup and a greater community composition in the social networks of good treatment.

Sífilis activa como predictor de riesgo para infección VIH en embarazadas de Santa Fe de Bogotá, 1998-1999 / Active syphilis as a predictor of risk for HIV infection in pregnant women in Santa Fe de Bogotá, 1998-1999

Justificación y propósito Colombia se ubica en el cuarto lugar entre los países continentales de América Latina en cuanto al número total de casos reportados de VIH-SIDA, lo cual ha afectado la percepción de riesgo que significan las otras ETS, en especial las ulcerativas como sífilis y gonorrea, no sólo en la población general, sino también en los equipos de salud que atienden estas patologías. A tal punto ha llegado la situación que varias de ellas casi han desaparecido de los registros de notificación, aunque no del medio como han probado varias investigaciones recientes. Lo más lamentable de esta situación es que la prevención y el control de estas patologías se puede hacer con medios específicos, tratamientos relativamente baratos y efectivos, que además disminuyen el riesgo y la transmisión del VIH porque al realizar intervenciones de prevención en ETS también se previene el VIH-SIDA. Un ejemplo típico es el de la sífilis, que varios estudios del exterior y del país han probado que constituye un factor de riesgo para infección VIH y una infección indicadora del SIDA. No obstante, la respuesta a los esfuerzos para implementar el programa de erradicación de la sífilis con- génita antes del año 2000 que actualmente adelantan el Ministerio de Salud y la Secretaría de Salud de Bogotá, ha sido muy pobre. En estas circunstancias hay que buscar estrategias novedosas que favorezcan el control de las otras ETS a través de las que están en curso para VIH y viceversa. Este proyecto fue desarrollado para evaluar la magnitud del reservorio de sífilis en embarazadas de Bogotá, con un estudio simultáneo de infección VIH, intentando desarrollar algoritmos de diagnóstico y predicción de riesgo en los cuales se use la detección rutinaria a partir de la serología positiva confirmada para sífilis para detectar casos de infección VIH. Objetivos Evaluar la frecuencia de Infecciones por T. pallidum en el grupo de embarazadas seleccionadas de la dudad de Bogotá, al Igual que la frecuencia de infecciones por VIH, con miras a establecer la importancia de los posibles algoritmos de diagnóstico que permitan la detección de las dos patologías tanto en la madre como en sus hijos, iniciando por el estudio de la infección por T. pallidum. Evaluar la sensibilidad, especificidad, valor predictivo positivo y negativo de las pruebas que actualmente se tienen disponibles en Bogotá para la detección de estas patologías en el grupo de pacientes mencionados. Metodología Entre octubre de 1998 y octubre de 1999 se tomaron muestras de sangre, en el momento del parto, a las embarazadas que asistieron a los hospitales Simón Bolívar, Clínica Corpas, La Victoria, La Perseverancia, La Granja. La Samaritana, Clínica El Bosque y el Centro de Atención de Cafam en Ciudad Bolívar en Santa Fe de Bogotá. La muestra de embarazadas fue no probabilística y se les practicaron pruebas rápidas y convencionales para sífilis e infección VIH; además se obtuvieron datos sobre variables demográficas, clínicas y de laboratorio, y una muestra de suero para Nasba carga viral, pruebas no treponémicas y Elisa IgM trepónemica para detección de anticuerpos contra el T. pallidum. Para propósitos de comparación y validación de las pruebas usadas ante dudas que surgieron fuera del grupo de trabajo durante su ejecución, se incluyeron muestras obtenidas de trabajadoras sexuales durante un proyecto diferente en el Hospital de La Perseverancia y muestras de sangre de trabajadoras sexuales embarazadas que han asistido a consulta también al Hospital de La Perseverancia, tanto positivas como negativas. A estas últimas pacientes se le realizaron también pruebas convencionales deVDRL para sífilis en el Instituto de Virología y Elisa para VIH en el Hospital de La Perseverancia; una prueba no trepónemica para sífilis (RPR), Elisa IgM treponémica para detección de anticuerpos contra el T. pallidum, Elisa y Western Blot para VIH y Nasba carga viral.También se les llenó una ficha prediseñada donde se tomaron datos demográficos, clínicos y epidemiológicos, y una muestra de sangre que se procesó en forma similar a las de los hospitales ya mencionados. Resultados Se examinaron un total de 567 muestras procedentes de los hospitales mencionados. Se encontró un total de 2 (0.4%) muestras positivas para VIH y un total de 14 (2.5%) reactivas por VDRL y/o RPR; de ellas se confirmaron 9 (1.6%) por Elisa IgM para sífilis que corresponden al 30% de las que fueron inicialmente reactivas por VDRL y RPR. Conclusiones De acuerdo con los resultados de este estudio la frecuencia de infecciones confirmadas por T. pallidum es de 1.6% en el grupo de embarazadas estudiadas, lo cual corresponde a la literatura; esto podría deberse a la acumulación de casos por factores diferentes a los de riesgo. La frecuencia de infecciones por VIH estuvo en 0.4% que no corresponde a lo informado para la población general en Bogotá y no se correlacionó con la seropositividad para sífilis. Se evidenció también alta frecuencia de falsos reactivos o falsos positivos para sífilis en el embarazo que son detectados por las pruebas no treponémicas como VDRL y RPR, lo que hace obligatorio la confirmación por métodos más específicos como la ¡nmunofluorescencia y el Elisa IgM con antígenos treponémicos.

Justification and purpose Colombia ranks fourth among the continental countries of Latin America in terms of the total number of reported cases of HIV-AIDS, which has affected the perception of risk posed by other STDs, especially ulcerative STDs such as syphilis and gonorrhea, not only in the general population, but also in the health teams that treat these pathologies. The situation has reached such a point that several of them have almost disappeared from the notification records, although not from the environment, as several recent investigations have proven. The most regrettable aspect of this situation is that the prevention and control of these pathologies can be done with specific means, relatively cheap and effective treatments, which also reduce the risk and transmission of HIV because by carrying out STD prevention interventions, HIV-AIDS is also prevented. A typical example is syphilis, which several studies from abroad and at home have proven to be a risk factor for HIV infection and an AIDS indicator infection. However, the response to the efforts to implement the program to eradicate syphilis before the year 2000, currently being carried out by the Ministry of Health and the Secretariat of Health of Bogota, has been very poor. In these circumstances, it is necessary to look for novel strategies that favor the control of other STDs through those that are underway for HIV and vice versa. This project was developed to evaluate the magnitude of the syphilis reservoir in pregnant women in Bogota, with a simultaneous study of HIV infection, trying to develop diagnostic and risk prediction algorithms in which routine screening from confirmed positive serology for syphilis is used to detect cases of HIV infection. Objectives To evaluate the frequency of T. pallidum infections in the group of selected pregnant women in the city of Bogotá, as well as the frequency of HIV infections, in order to establish the importance of possible diagnostic algorithms that allow the detection of both pathologies in the mother and her children, starting with the study of T. pallidum infection. To evaluate the sensitivity, specificity, positive and negative predictive value of the tests currently available in Bogota for the detection of these pathologies in the aforementioned group of patients. Methodology Between October 1998 and October 1999, blood samples were taken at the time of delivery from pregnant women attending the following hospitals: Simón Bolívar, Clínica Corpas, La Victoria, La Perseverancia, La Granja, La Samaritana, Clínica El Bosque and the Cafam Care Center in Ciudad Bolívar in Santa Fe, Bogotá. La Samaritana, Clínica El Bosque and the Cafam Care Center in Ciudad Bolívar in Santa Fe de Bogotá. The sample of pregnant women was non-probabilistic and they underwent rapid and conventional tests for syphilis and HIV infection; in addition, data on demographic, clinical and laboratory variables were obtained, as well as a serum sample for Nasba viral load, non-treponemal tests and Elisa IgM treponemal for detection of antibodies against T. pallidum. For purposes of comparison and validation of the tests used in case of doubts that arose outside the working group during its execution, samples obtained from sex workers during a different project at the Hospital de La Perseverancia and blood samples from pregnant sex workers who have also attended the Hospital de La Perseverancia, both positive and negative, were included. The latter patients also underwent conventionalVDRL tests for syphilis at the Instituto de Virología and Elisa for HIV at the Hospital de La Perseverancia; a non-treponemal test for syphilis (RPR), Elisa IgM treponemal for detection of antibodies against T. A pre-designed form was also filled out where demographic, clinical and epidemiological data were collected, and a blood sample was processed in a similar way to those of the aforementioned hospitals. Results A total of 567 samples from the aforementioned hospitals were examined. A total of 2 (0.4%) samples were found to be positive for HIV and a total of 14 (2.5%) reactive by VDRL and/or RPR; of these, 9 (1.6%) were confirmed by IgM Elisa for syphilis, corresponding to 30% of those initially reactive by VDRL and RPR. Conclusions According to the results of this study, the frequency of confirmed T. pallidum infections is 1.6% in the group of pregnant women studied, which corresponds to the literature; this could be due to the accumulation of cases due to factors other than risk factors. The frequency of HIV infection was 0.4%, which does not correspond to that reported for the general population in Bogotá, and did not correlate with seropositivity for syphilis. There was also a high frequency of false reactive or false positives for syphilis in pregnancy that are detected by non-treponemal tests such as VDRL and RPR, which makes confirmation by more specific methods such as ¡nmunofluorescence and IgM Elisa with treponemal antigens mandatory.