Tuberculosis activa en trabajadores de salud en Colombia 2011 – 2017

RESUMEN: Introducción: La tuberculosis (TB) afecta a los trabajadores de salud (TS) de Colombia y el mundo. Objetivo: Determinar el patrón geográfico de la incidencia de TB activa en Colombia y explorar la dinámica de su transmisión entre 2011 y 2017. Metodología: Se condujo un estudio de corte. Se realizó ajuste por edad de las tasas de incidencia de TB activa en los TS en los departamentos colombianos y se estudió su distribución por oficios. Se determinó la distribución geográfica de las tasas y se realizó el análisis de clúster propuesto por Kulldorff (modelo de Poisson). La relación de algunas variables individuales y clínicas con la TB activa en los TS, se realizó mediante análisis bivariado y multivariado (regresión binomial y análisis de correspondencias múltiples). Se calculó la fracción de la incidencia atribuible (FAP) a los TS mediante el método de Levin y mediante el número reproductivo básico R obtenido por varios experimentos teóricos. Resultados: Se registraron 715 casos de TB activa en los TS en Colombia y 114 en Medellín. La tasa de incidencia fue de 39,3/100.000 TS (IC95% 31,3 - 47,2) a nivel nacional y en departamentos como el Chocó hasta 909,6 casos/100.000 TS. Los casos nacionales se agruparon en los departamentos del norte y occidente del país (IRR de 3,71 y 6,25). Las auxiliares de enfermería y odontología (n=260, 36,4%), los médicos (n=144, 20,1%) y los enfermeros (n=110, 15,4%) aportaron el mayor número de casos. Las mujeres trabajadoras tuvieron un riesgo mayor de TB activa (RPa: 6,29 IC95% 5,05 – 7,84). La mayor FAP en Colombia fue de 0,45%. Se estimó un R de 1,35 para Medellín en el 2015, indicando una transmisión en curso de la TB en la ciudad. Conclusiones: Nuestro estudio contribuye a mejorar el conocimiento de las características de la TB activa en los TS en Colombia: se trata de una enfermedad que afecta principalmente a las mujeres TS, localizadas en departamentos específicos y con un peso poblacional conocido. El retraso en el diagnóstico en la comunidad y la ausencia de medidas de control en el ambiente hospitalario requieren - a partir de esas características - reflexión y concertación por los encargados de los programas nacionales y locales de TB y de salud en el trabajo. Palabras Claves: Personal de salud, análisis espacial, modelos teóricos, número reproductivo básico, incidencia.ABSTRACT: Background: Tuberculosis (TB) affects healthcare workers (HCWs) in Colombia and the world. Objective: To determine the geographic pattern of the incidence of active TB in Colombia and explore the dynamics of its transmission between 2011 and 2017. Methods: A cross-sectional study was conducted. The incidence rates of active TB in HCWs in Colombian departments were adjusted by age and its distribution by occupations was determined. We determined the geographical distribution of the rates and performed the cluster analysis proposed by Kulldorff (Poisson model). The relationship of some individual and clinical variables with active TB in the HCWs was estimated by bivariate and multivariate analysis (binomial regression and multiple correspondence analysis). The population attributable fraction (PAF) to HCWs was calculated by the Levin method and by the basic reproductive number R obtained by several theoretical experiments. Results: 715 cases of TB in HCWs were registered in Colombia and 114 in Medellin. The incidence rate was 39.3/100,000 HCWs (95% CI 31.3 - 47.2) for the country, and up to 909,6 cases/100,000 HCWs in the department of Chocó. National cases are grouped in the northern and western departments of the country (IRR of 3.71 and 6.25). Nursing and dental assistants (n = 260, 36.4%), doctors (n = 144, 20.1%) and nurses (n = 110, 15.4%) contributed the highest number of cases. Female HCWs had a higher risk of active TB (PRa: 6.29 95% CI 5.05 - 7.84). The highest PAF in Colombia was 0.45%. An R of 1.35 was estimated for Medellin in 2015, indicating an ongoing transmission of TB in the city. Conclusions: Our study contributes to improve the knowledge of the characteristics of active TB in HCWs in Colombia: the disease affects mainly female HCWs, it is located in specific departments, and it has a known population weight. The delay in diagnosis in the community and the absence of control measures in the hospital environment require – from the aforementioned characteristics – the consideration and discussion of those in charge of the national and local TB programs and the occupational health programs. Keywords: Health Personnel, Spatial Analysis, theoretical models, basic reproduction number, incidence

Algorithmic methods for investigating equilibria in epidemic modeling

The calculation of threshold conditions for models of infectious diseases is of central importance for developing vaccination policies. These models are often coupled systems of ordinary differential equations, in which case the computation of threshold conditions can be reduced to the question of stability of the disease-free equilibrium. This paper shows how computing threshold conditions for such models can be done fully algorithmically using quantifier elimination for real closed fields and related simplification methods for quantifier-free formulas. Using efficient quantifier elimination techniques for special cases that have been developed by Weispfenning and others, we can also compute whether there are ranges of parameters for which sub-threshold endemic equilibria exist

Algorithmic Methods for Investigating Equilibria in Epidemic Modeling

The calculation of threshold conditions for models of infectious diseases is of central importance for developing vaccination policies. These models are often coupled systems of ordinary differential equations, in which case the computation of threshold conditions can be reduced to the question of stability of the disease-free equilibrium. This paper shows how computing threshold conditions for such models can be done fully algorithmically using quantifier elimination for real closed fields and related simplification methods for quantifier-free formulas. Using efficient quantifier elimination techniques for special cases that have been developed by Weispfenning and others, we can can also compute whether there are ranges of parameters for which sub-threshold endemic equilibria exist