Diffusion tensor imaging of the physis: the ABC's.

The physis, or growth plate, is the primary structure responsible for longitudinal growth of the long bones. Diffusion tensor imaging (DTI) is a technique that depicts the anisotropic motion of water molecules, or diffusion. When diffusion is limited by cellular membranes, information on tissue microstructure can be acquired. Tractography, the visual display of the direction and magnitude of water diffusion, provides qualitative visualization of complex cellular architecture as well as quantitative diffusion metrics that appear to indirectly reflect physeal activity. In the growing bones, DTI depicts the columns of cartilage and new bone in the physeal-metaphyseal complex. In this "How I do It", we will highlight the value of DTI as a clinical tool by presenting DTI tractography of the physeal-metaphyseal complex of children and adolescents during normal growth, illustrating variation in qualitative and quantitative tractography metrics with age and skeletal location. In addition, we will present tractography from patients with physeal dysfunction caused by growth hormone deficiency and physeal injury due to trauma, chemotherapy, and radiation therapy. Furthermore, we will delineate our process, or "DTI pipeline," from image acquisition to data interpretation.

Intraurban Geographic and Socioeconomic Inequalities of Mortality in Four Cities in Colombia.

Mortality inequalities have been described across Latin American countries, but less is known about inequalities within cities, where most populations live. We aimed to identify geographic and socioeconomic inequalities in mortality within the urban areas of four main cities in Colombia. We analyzed mortality due to non-violent causes of diseases in adults between 2015 and 2019 using census sectors as unit of analysis in Barranquilla, Bogotá, Cali, and Medellín. We calculated smoothed Bayesian mortality rates as main health outcomes and used concentration indexes (CInd) for assessing inequalities using the multidimensional poverty index (MPI) as the socioeconomic measure. Moran eigenvector spatial filters were calculated to capture the spatial patterns of mortality and then used in multivariable models of the association between mortality rates and quintiles of MPI. Social inequalities were evident but not consistent across cities. The most disadvantaged groups showed the highest mortality rates in Cali. Geographic inequalities in mortality rates, regardless of the adults and poverty distribution, were identified in each city, suggesting that other social, environmental, or individual conditions are impacting the spatial distribution of mortality rates within the four cities.

Incidence and Risk Factors Associated with Latent Tuberculosis Infection and Pulmonary Tuberculosis among People Deprived of Liberty in Colombian Prisons.

People deprived of liberty (PDL) are at high risk of acquiring Mycobacterium tuberculosis infection (latent tuberculosis infection [LTBI]) and progressing to active tuberculosis (TB). We sought to determine the incidence rates and factors associated with LTBI and active TB in Colombian prisons. Using information of four cohort studies, we included 240 PDL with two-step tuberculin skin test (TST) negative and followed them to evaluate TST conversion, as well as, 2,134 PDL that were investigated to rule out active TB (1,305 among people with lower respiratory symptoms of any duration, and 829 among people without respiratory symptoms and screened for LTBI). Latent tuberculosis infection incidence rate was 2,402.88 cases per 100,000 person-months (95% CI 1,364.62-4,231.10) in PDL with short incarceration at baseline, and 419.66 cases per 100,000 person-months (95% CI 225.80-779.95) in individuals with long incarceration at baseline (who were enrolled for the follow after at least 1 year of incarceration). The TB incidence rate among PDL with lower respiratory symptoms was 146.53 cases/100,000 person-months, and among PDL without respiratory symptoms screened for LTBI the incidence rate was 19.49 cases/100,000 person-months. History of Bacillus Calmette-Guerin vaccination decreased the risk of acquiring LTBI among PDL who were recently incarcerated. Female sex, smoked drugs, and current cigarette smoking were associated with an increased risk of developing active TB. This study shows that PDL have high risk for LTBI and active TB. It is important to perform LTBI testing at admission to prison, as well as regular follow-up to control TB in prisons.

Delayed HIV treatment, barriers in access to care and mortality in tuberculosis/HIV co-infected patients in Cali, Colombia / Retraso en el tratamiento para VIH, barreras en el acceso a la atención en salud y mortalidad en personas coinfectadas con tuberculosis y VIH en Cali, Colombia

Abstract Objective: To determine factors associated with mortality in tuberculosis/HIV co-infected patients in Cali, Colombia Methods: This retrospective cohort design included tuberculosis/HIV co-infected persons. Kaplan-Meier and Cox regression were used to estimate survival and risk factors associated with mortality. Results: Of the 279 tuberculosis/HIV co-infected participants, 27.2% died during the study. Participants mainly were adults and males. CD4 count information was available for 41.6% (the median count was 83 cells/mm3), and half were subject to tuberculosis susceptibility testing. The median time between HIV diagnosis and antiretroviral therapy initiation was 372 days. HIV was identified prior to tuberculosis in 53% and concurrent HIV-tuberculosis were diagnosed in 37% of patients. 44.8% had tuberculosis treatment success. Body mass index above 18 kg/m2, initiation of tuberculosis treatment within two weeks, having any health insurance coverage and CD4 count information conferred a survival advantage. Conclusions: Delays in treatment initiation and factors associated with limited health care access or utilization were associated with mortality. As HIV and tuberculosis are both reportable conditions in Colombia, strategies should be focused on optimizing treatment outcomes within both tuberculosis and HIV programs, particularly improving early HIV diagnosis, early antiretroviral therapy treatment initiation, and adherence to tuberculosis treatment.

Resumen Objetivo: Determinar factores asociados con mortalidad en personas con co-infeccion Tuberculosis/VIH en Cali, Colombia. Métodos: Este diseño de cohorte retrospectiva incluyó personas co-infectadas con tuberculosis /VIH. Se utilizó Kaplan Meier y regresion de Cox para estimar supervivencia y factores de riesgo asociados con mortalidad. Resultados: De los 279 participantes coinfectados con tuberculosis/VIH, el 27.2% falleció durante el estudio. Los participantes fueron principalmente adultos y hombres. Se dispuso de información de recuento de CD4 en el 41.6% (la mediana del recuento fue 83 células/mm3), y en la mitad se realizaron pruebas de susceptibilidad para tuberculosis. La mediana de tiempo entre el diagnóstico de VIH e inicio de terapia antirretroviral fue 372 días. Se identificó VIH previo a tuberculosis en un 53%, e infección concurrente tuberculosis-VIH en el 37% de los pacientes. El 44.8% presentó éxito en el tratamiento para tuberculosis. Un índice de masa corporal superior a 18 kg/m2, inicio del tratamiento para TB dentro de las primeras dos semanas, contar con aseguramiento en salud y con recuento de CD4 se asociaron con mayor supervivencia. Conclusiones: Retraso en el inicio de tratamiento y factores relacionados con brechas en el acceso a atención en salud se asociaron con mortalidad. Dado que VIH y tuberculosis son enfermedades de notificación obligatoria en Colombia, las estrategias deben centrarse en optimizar los desenlaces del tratamiento dentro de ambos programas, en particular mejorar el diagnóstico temprano de VIH, el inicio temprano de la terapia antirretroviral y fomentar la adherencia al tratamiento para tuberculosis.

Leptospirosis en pediatría, un diagnóstico a tener en cuenta / Leptospirosis in pediatrics, a diagnosis to be considered

Resumen La leptospirosis humana es una importante causa de enfermedad febril aguda que afecta con mayor frecuencia las zonas tropicales. Su principal reservorio es los roedores por lo que la infección está vinculada con factores de pobreza, déficit sanitario, actividades recreativas y laborales que favorecen el contacto con la orina de animales infectados, agua o suelos contaminados. Las infecciones por Leptospira spp tienen una presentación inespecífica desde cuadros asintomáticos hasta un compromiso multisistémico con alta mortalidad, siendo la sospecha clínica y la presencia de factores de riesgo las variables iniciales para el diagnóstico de la enfermedad. Entre los métodos disponibles para el diagnóstico microbiológico se destaca la observación directa, el cultivo, la reacción de polimerasa en cadena y la serología que permiten la confirmación de éste. El tratamiento de leptospirosis en niños se basa en medidas de soporte y en el inicio de antimicrobianos β-lactámicos o macrólidos. Las medidas de prevención de la enfermedad son fundamentales en la población expuesta al riesgo siendo recursos esenciales intervenciones generales, quimioprofilaxis y vacunación. El conocimiento, la consideración diagnóstica y el tratamiento oportuno en el paciente pediátrico, acelera la recuperación y limita la aparición de complicaciones que pueden impactar en la calidad de vida.

Abstract Human leptospirosis is an important cause of acute febrile disease that most frequently affects tropical areas. Its main reserve is rodents, so the infection is limited by factors of poverty, health deficit, recreational and work activities that favor contact with the urine of infected animals, contaminated water or soil. Leptospira spp infections have a non-specific presentation, ranging from asymptomatic to multisystem compromise with high mortality; being the clinical suspicion and the presence of risk factors the initial variables for the diagnosis of the disease. Among the available methods for microbiological diagnosis, direct observation, culture, polymerase chain reaction and serology that allows confirmation of this are highlighted. The treatment of leptospirosis in children is based on clinical support measures and the antibiotic initiation of β-lactams or macrolides. Disease prevention measures are fundamental in the population exposed to risk being essential resources general interventions, chemoprophylaxis and vaccination. The knowledge, diagnostic consideration, and timely treatment in pediatric patients accelerate recovery and limit the appearance of complications that can impact the quality of life

Cultura de la seguridad del paciente en seis centros quirúrgicos de Antioquia / Patient Safety Culture Observed at Six Surgical Centers in Antioquia / Colombia Cultura da segurança do paciente em seis centros cirúrgicos em Antioquia

Introducción: Colombia, como otros países promueve políticas de seguridad al paciente para reducir y, de ser posible, eliminar la ocurrencia de eventos adversos. Objetivo: identificar la cultura de seguridad en seis centros quirúrgicos de Antioquia a través de las dimensiones descritas por el instrumento Hospital Survey on Patient Safety Culture. Materiales y Métodos: Estudio multicéntrico transversal descriptivo realizado en instituciones de 2, 3 y 4 nivel complejidad del departamento de Antioquia; de noviembre de 2016 a noviembre de 2018. Se aplicó el instrumento Hospital Survey on Patient Safety Culture propuesto por la Agency for Healthcare Research and Quality (AHRQ) a 514 trabajadores del área de la salud. Resultados: En una escala de cero a diez, el promedio del clima de seguridad en los servicios de cirugía es 8. El 62% de las respuestas sobre la percepción de la cultura de la seguridad fue positiva. Las de mayor puntuación fueron: aprendizaje organizacional/mejora continua en 82,94% de los trabajadores; en el trabajo en equipo en el servicio, 82,94%. Las de menor puntuación fueron: respuesta no punitiva a errores 46,25%; y franqueza en comunicación 45,38%. Discusión: las dimensiones con mayor y menor puntuación reportadas en la investigación son comparables con las reportadas en otros estudios y requiere atención del sistema de salud y de las direcciones de las instituciones. Conclusión: Se detectaron fortalezas y debilidades en la cultura de seguridad de los pacientes. En cuanto a las Fortalezas: el Aprendizaje organizacional/mejora continua y el Trabajo en equipo en la Unidad/Servicio.

Introduction: Colombia, just like other countries, promotes patient safety policies to reduce and, if possible, eliminate the occurrence of adverse events. Objective: To identify the patient safety culture at six surgical centers located in Antioquia using the dimensions described in the Hospital Survey on Patient Safety Culture instrument. Materials and Methods: A descriptive cross-sectional multicenter study was conducted at different healthcare institutions providing secondary, tertiary and quaternary levels of care between November 2016 and November 2018 in the department of Antioquia. The Hospital Survey on Patient Safety Culture instrument proposed by the Agency for Healthcare Research and Quality (AHRQ) was applied to 514 health workers. Results: On a scale of zero to ten, the average safety perception in surgical services is 8. 62% of the responses regarding the perception of safety culture were positive. The highest scores were organizational learning/continuous improvement in 82.94% of the workers and service teamwork in 82.94%. The lowest scores were a nonpunitive response to errors in 46.25% and communication openness in 45.38%. Discussion: The dimensions with the highest and lowest scores reported in the research are comparable to those reported in other studies and require attention from the healthcare system and the directors of the institutions. Conclusion: Strengths and weaknesses in the patient safety culture were detected. The strengths were organizational learning/continuous improvement and teamwork at the unit/service.

Introduction: Colombia, just like other countries, promotes patient safety policies to reduce and, if possible, eliminate the occurrence of adverse events. Objective: To identify the patient safety culture at six surgical centers located in Antioquia using the dimensions described in the Hospital Survey on Patient Safety Culture instrument. Materials and Methods: A descriptive cross-sectional multicenter study was conducted at different healthcare institutions providing secondary, tertiary and quaternary levels of care between November 2016 and November 2018 in the department of Antioquia. The Hospital Survey on Patient Safety Culture instrument proposed by the Agency for Healthcare Research and Quality (AHRQ) was applied to 514 health workers. Results: On a scale of zero to ten, the average safety perception in surgical services is 8. 62% of the responses regarding the perception of safety culture were positive. The highest scores were organizational learning/continuous improvement in 82.94% of the workers and service teamwork in 82.94%. The lowest scores were a nonpunitive response to errors in 46.25% and communication openness in 45.38%. Discussion: The dimensions with the highest and lowest scores reported in the research are comparable to those reported in other studies and require attention from the healthcare system and the directors of the institutions. Conclusion: Strengths and weaknesses in the patient safety culture were detected. The strengths were organizational learning/continuous improvement and teamwork at the unit/service.

Is tuberculosis elimination a feasible goal in Colombia by 2050?

Colombia has an underreporting of 30% of the total cases, according to World Health Organization (WHO) estimations. In 2016, successful tuberculosis (TB) treatment rate was 70%, and the mortality rate ranged between 3.5% and 10%. In 2015, Colombia adopted and adapted the End TB strategy and set a target of 50% reduction in incidence and mortality by 2035 compared with 2015. The aims of this study were: To evaluate whether Colombia will be able to achieve the goals of TB incidence and mortality by 2050, using the current strategies; and whether the implementation of new screening, diagnosis and TB treatment strategies will allow to achieve those WHO targets. An ecological study was conducted using TB case-notification, successful treatment and mortality rates from the last 8 years (2009-17). System dynamics analysis was performed using simulated scenarios: (1) continuation with the same trends following the trajectory of the last 8 years (Status quo) and (2) modification of the targets between 2017 through 2050, assuming the implementation of multimodal strategies to increase the screening, to improve the early diagnosis and to improve the treatment adherence. Following the current strategies, it is projected that Colombia will not achieve the End TB strategy targets. Achieving the goal of TB incidence of 10/100 000 by 2050 will only be possible by implementing combined strategies for increasing screening of people with respiratory symptoms, improving access to rapid diagnostic tests and improving treatment adherence. Therefore, it is necessary to design and implement simultaneous strategies according to the population needs and resources, in order to stride towards the End TB targets.

Inflammatory Cell Differentiation and Chemotaxis and Extracellular Tissue Repair Markers Are Correlated with Pulmonary Dysfunction in HIV Infected Individuals Presenting with Community-Acquired Pneumonia.

Prior studies have shown that HIV patients develop permanent pulmonary dysfunction following an episode of community-acquired pneumonia (CAP). However, the mechanism causing pulmonary dysfunction remains an enigma. HIV patients experience chronic inflammation. We hypothesized that CAP exacerbates inflammation in HIV patients resulting in an accelerated decline in lung function. A prospective cohort pilot study enrolled HIV patients hospitalized in Medellin, Colombia, with a diagnosis of CAP. Sixteen patients were eligible for the study; they were split into 2 groups: HIV and HIV+CAP. Plasma, sputum, and pulmonary function test (PFT) measurements were retrieved within 48 h of hospital admission and at 1 month follow-up. The concentrations of 13 molecules and PFT values were compared between the 2 cohorts. The HIV+CAP group had lower lung function compared to the HIV group; forced vital capacity (FVC)% predicted and forced expiratory volume in 1 s (FEV1)% predicted decreased, while FEV1/FVC remained constant. APRIL, BAFF, CCL3, and TIMP-1 correlated negatively with FVC% predicted and FEV1% predicted; the relationships however were moderate in strength. Furthermore, the concentrations of BAFF, CCL3, and TIMP-1 were statistically significant between the 2 groups (P ≤ 0.05). Our results indicate that HIV patients with CAP have a different inflammatory pattern and lower lung function compared to HIV patients without CAP. BAFF, CCL3, and TIMP-1 were abnormally elevated in HIV patients with CAP. Future studies with larger cohorts are required to verify these results. In addition, further investigation is required to determine if BAFF, CCL3, and TIMP-1 play a role in the process causing pulmonary dysfunction.

Risk of infection and disease progression in children exposed to tuberculosis at home, Colombia / Riesgo de infección y progresión de la enfermedad en niños expuestos a tuberculosis en el hogar, Colombia

Abstract Aim: To assess the risk of tuberculosis (infection and disease) in children less than 15 years' old who are household contacts of pulmonary tuberculosis patients in three Colombian cities (Medellín, Cali, and Popayán). Methods: A cohort of 1,040 children household contacts of 380 adults with smear-positive pulmonary tuberculosis was followed up for 24 months. Study period 2005-2009. Results: Tuberculin skin test was positive (≥10 mm) in 43.7% (95% CI: 39.2-48.2). Tuberculin skin test positivity was associated with age 10-14 years (Prevalence Ratio -PR= 1.43, 95% CI: 1.1-1.9), having a BCG vaccine scar (PR= 1.52, 95% CI: 1.1-2.1), underweight, closer proximity to the index case and exposure time >3 months. The annual risk of infection (tuberculin skin test induration increase of 6 mm or more per year) was 17% (95% CI: 11.8-22.2) and was associated with a bacillary load of the adult index case (Relative Risk -RR= 2.12, 95% CI: 1.0-4.3). The incidence rate of active tuberculosis was 12.4 cases per 1,000 persons-year. Children <5 years without BCG vaccine scar had a greater risk of developing active disease (Hazard Ratio -HR= 6.00, 95% CI: 1.3-28.3) than those with scar (HR= 1.33, 95% CI: 0.5-3.4). The risk of developing active tuberculosis augmented along with the increase from initial tuberculin skin test (tuberculin skin test 5-9 mm HR= 8.55, 95% CI: 2.5-29.2; tuberculin skin test ≥10 mm HR= 8.16, 95% CI: 2.0-32.9). Conclusions: There is a need for prompt interruption of adult-to-children tuberculosis transmission within households. Conducting proper contact investigation and offering chemoprophylaxis to infected children could reduce tuberculosis transmission.

Resumen Objetivo: Evaluar el riesgo de tuberculosis (infección y enfermedad) en niños menores de 15 años de edad convivientes de pacientes con tuberculosis pulmonar en tres ciudades colombianas (Medellín, Cali y Popayán). Métodos: Se siguió durante 24 meses una cohorte de 1,040 niños convivientes de 380 adultos con tuberculosis pulmonar bacilífera. Periodo de estudio 2005-2009. Resultados: La prueba de tuberculina fue positiva (≥10 mm) en el 43.7% (IC 95%: 39.2-48.2), y estuvo asociada con la edad de 10-14 años (Razón de Prevalencia-RP= 1.43, IC 95%: 1.1-1.9), tener cicatriz de la vacuna BCG (RP= 1.52, IC 95%: 1.1-2.1). El riesgo anual de infección (aumento de la induración en la prueba de tuberculina de 6 mm o más al año) fue 17% (IC 95%: 11.8-22.2), y estuvo asociado con mayor carga bacilar en el adulto con tuberculosis pulmonar (Riesgo Relativo-RR= 2.12, IC 95%: 1.0-4.3). La tasa de incidencia de tuberculosis activa fue de 12.4 casos por 1,000 años-persona de seguimiento. Los niños menores de 5 años sin cicatriz de vacuna BCG tuvieron un mayor riesgo de desarrollar tuberculosis activa (Razón de Peligro -HR= 6.00, IC 95%: 1.3-28.3), que quienes tenían cicatriz (HR= 1.33, IC 95%: 0.5-3.4). El riesgo de desarrollar tuberculosis activa aumentó conforme el aumento de la prueba de tuberculina inicial (prueba de tuberculina 5-9 mm HR= 8.55, IC 95%: 2.5-29.2; prueba de tuberculina ≥10 mm HR= 8.16, IC 95%: 2.0-32.9). Conclusión: Es necesario interrumpir rápidamente la transmisión de tuberculosis de adultos a niños en los hogares. Realizar investigaciones de contacto apropiadas y ofrecer quimioprofilaxis a los niños infectados podría reducir la transmisión de la tuberculosis.

Guards in Prisons: A Risk Group for Latent Tuberculosis Infection.

To determine the prevalence and incidence of LTBI among prison guards and to the risk factors associated with infection. Two male prisons in Medellín and Itaguí, Colombia. A cohort study was conducted in adult prison guards that consented to participate. Exclusion criteria included: previous or current active TB, or conditions that preclude TST administration. We screened 194 guards and completed 155 TST administrations. The prevalence of LTBI was 55.8% in prison one, and 39.1% in prison two. The risk factors associated with LTBI diagnosis included drug use at least once in a lifetime (PR: 1.75; 95% CI 1.42-2.15) and male sex (PR: 2.16; 95% CI 1.01-4.62). The cumulative incidence of TST conversion over 6 months was 3.2%. All conversions occurred in prison 1. Our findings suggest an occupational risk for LTBI prevalence and incidence among guards (different prevalence and incidence according to the prison they work).

Monitoring delays in diagnosis of pulmonary tuberculosis in eight cities in Colombia / Supervisión del retraso en el diagnóstico de la tuberculosis pulmonar en ocho ciudades de Colombia

ABSTRACT Objective To measure time between onset of tuberculosis (TB) symptoms and start of treatment, and to identify factors associated with delay in eight Colombian cities. Methods Operational research with a retrospective analytical cohort design was conducted in 2014 using routinely collected data about new smear-positive pulmonary TB patients from eight cities in Colombia (Barranquilla, Bogotá, Bucaramanga, Cali, Cúcuta, Medellín, Pereira, and Villavicencio). Date of symptom onset was sourced from TB surveillance databases. Data on all other variables came from National TB Program (NTP) registers. Results There were 2 545 new cases of smear-positive pulmonary TB, but a plausible date of symptom onset was available for only 1 456 (57%). Median number of days between symptom onset and treatment start was 51 days (interquartile range: 27–101). A total of 72% of patients had a delay (> 30 days between symptom onset and treatment start), and 28% had a 3+ bacillary load at diagnosis. Based on multiple logistic regression, three factors were significantly associated with delay: being uninsured (odds ratio (OR): 1.30; 95% confidence interval (CI): 1.01–1.68) and having an unknown HIV status (OR: 1.81; CI: 1.04–3.17), which increased risk, and coming from a neighborhood with NTP-employed community health workers, which decreased risk (OR: 0.56; CI: 0.34–0.90). Conclusions Delays still prevent timely TB diagnosis and treatment in Colombia. As the country aims for TB elimination, delays must be reduced, especially in cities and vulnerable neighborhoods, to stop community transmission. The NTP should focus not only on the number of cases detected but also on how long it takes to detect them. To monitor interventions designed to reduce delays, additional dates in the process should be recorded routinely. In addition, reliability and completeness of data are crucial for monitoring.

RESUMEN Objetivo Medir el lapso entre la aparición de los síntomas de tuberculosis y el comienzo del tratamiento y reconocer los factores que se asocian con este retraso en ocho ciudades de Colombia. Métodos Investigación operativa con un estudio de cohortes analítico retrospectivo realizado en el 2014, a partir de los datos corrientes consignados en los casos nuevos de tuberculosis pulmonar con baciloscopia positiva en ocho ciudades de Colombia (Barranquilla, Bogotá, Bucaramanga, Cali, Cúcuta, Medellín, Pereira y Villavicencio). La fecha de aparición de los síntomas se obtuvo de las bases de datos de vigilancia de la tuberculosis. Los datos sobre todas las demás variables provinieron de los registros de Programa Nacional contra la Tuberculosis. Resultados Se registraron 2 545 casos nuevos de tuberculosis pulmonar con baciloscopia positiva, pero solo se contó con una fecha verosímil de aparición de los síntomas en 1 456 casos (57%). La mediana del número de días entre la aparición de los síntomas y el comienzo del tratamiento fue 51 días (intervalo intercuartil: de 27 a 101). En 72% de los pacientes se comprobó un retraso (más de 30 días entre la aparición de los síntomas y el comienzo del tratamiento) y en 28% de los casos se observó una carga bacilar de 3+ en el momento del diagnóstico. Según el análisis de regresión logística multivariante, tres factores se asociaron de manera significativa con el retraso, a saber: la falta de seguro de enfermedad (razón de posibilidades [OR]: 1,30; intervalo de confianza [IC] de 95%: de 1,01 a 1,68) y el desconocimiento de la situación frente al virus de la inmunodeficiencia humana (OR: 1,81; IC de 95%: de 1,04 a 3,17), factores que aumentaron el riesgo de retraso y el hecho de provenir de un vecindario donde operan agentes sanitarios de la comunidad empleados por el Programa Nacional contra la Tuberculosis, que disminuyó el riesgo (OR: 0,56; IC: de 0,34 a 0,90). Conclusiones Los retrasos todavía obstaculizan el diagnóstico y el tratamiento oportuno de la tuberculosis en Colombia. Al buscar la eliminación de la tuberculosis en el país es preciso disminuir los retrasos, sobre todo en las ciudades y los vecindarios vulnerables, con el objeto de interrumpir la transmisión en la comunidad. El Programa Nacional contra la Tuberculosis debe prestar atención no solo al número de casos detectados, sino también al tiempo que precisa su detección. Con el propósito de llevar a cabo un seguimiento de las intervenciones encaminadas a disminuir los retrasos, es necesario registrar de manera sistemática otras fechas de la evolución clínica. Además, la fiabilidad y la integridad de los datos registrados constituyen aspectos primordiales del seguimiento.

Use and evaluation of a line probe assay in patients with tuberculosis in Peru: 2011 and 2013 / Utilización y evaluación de un ensayo con sondas en línea en los pacientes con diagnóstico de tuberculosis en el Perú del 2011 al 2013

ABSTRACT Objective To determine the use and performance of a line probe assay (LPA) compared with conventional culture and drug sensitivity testing (CDST) in patients registered with tuberculosis (TB) under routine program conditions in Peru in 2011–2013. Methods This was a descriptive, operational research, cross-sectional study of sputum specimens from patients with smear-positive pulmonary TB and mycobacterial cultures from patients with smear-negative or positive TB. Drug resistance to rifampicin and/or isoniazid detected by LPA was compared to CDST. Sensitivity, specificity, and predictive values were calculated and reliability for detecting drug resistance was assessed through kappa coefficient, with values 0.61–0.80 showing substantial correlation, and 0.81 or above showing almost-perfect correlation. Results In 2011–2013, there were 16 169 LPA tests performed, with the proportion of TB patients receiving the test increasing from 3.2% to 30.2%. In all, 2 905 LPA test results were compared to CDST. For LPA in sputum specimens, sensitivity for rifampicin was 92%; isoniazid, 94%; and MDR-TB, 88%; while specificity for rifampicin was 92%; isoniazid, 92%; and MDR-TB, 95%. For LPA in mycobacterial cultures, sensitivity for rifampicin was 95%; isoniazid, 96%; and MDR-TB, 90%; while specificity for rifampicin was 85%; isoniazid, 91%; and MDR-TB, 94%. Kappa coefficients were at 0.81 or above for all comparisons of LPA with CDST using sputum specimens and cultures, except for isoniazid in cultures, which was at 0.79. Conclusions This study suggests that LPA is a reliable and rapid screening test for drug-resistant TB and should be considered suitable for routine use and scale up in Peru.

RESUMEN Objetivo Definir la utilización de un ensayo con sondas en línea y evaluar su desempeño, en comparación con el método convencional de cultivo y antibiograma, en los pacientes registrados con tuberculosis en condiciones programáticas en el Perú del 2011 al 2013. Métodos Investigación operativa descriptiva con un estudio transversal de las muestras de esputo de los pacientes con diagnóstico de tuberculosis pulmonar y baciloscopia positiva y de los cultivos de micobacterias de los pacientes con tuberculosis y baciloscopia positiva o negativa. La farmacorresistencia a la rifampicina, la isoniacida o a ambas, detectada mediante el ensayo con sondas en línea, se comparó con los resultados obtenidos por el método de cultivo y antibiograma. Se calculó la sensibilidad, la especificidad y los valores predictivos del ensayo con sondas en línea y se evaluó su fiabilidad en la detección de la farmacorresistencia mediante el coeficiente k, cuyos valores de 0,61 a 0,80 correspondían a una fuerte correlación y los valores de 0,81 o superiores reflejaban una correlación casi perfecta. Resultados Del 2011 al 2013 se practicaron 16 169 ensayos con sondas en línea, y la proporción de pacientes con diagnóstico de tuberculosis en quienes se practicaba aumentó de 3,2% a 30,2%. En total, se compararon 2 905 resultados del ensayo molecular con el método convencional. En las muestras de esputo, el ensayo molecular ofreció una sensibilidad de 92% para la resistencia a la rifampicina, 94% a la isoniacida y 88% para la tuberculosis multirresistente; su especificidad fue 92% con respecto a la rifampicina, 92% a la isoniacida y 95% a la tuberculosis multirresistente. En los cultivos de micobacterias, el ensayo con sondas en línea mostró una sensibilidad de 95% para la resistencia a la rifampicina, 96% a la isoniacida y 90% para la tuberculosis multirresistente; la especificidad fue 85% para la rifampicina, 91% para la isoniacida y 94% para la tuberculosis multirresistente. El coeficiente k fue 0,81 o superior en todas las comparaciones del ensayo molecular con el método tradicional cuando se usaron muestras de esputo y cultivo, excepto con la isoniacida en cultivo, cuyo coeficiente fue 0,79. Conclusiones Los resultados del presente estudio indican que el ensayo con sondas en línea constituye una prueba de detección fiable y rápida para la tuberculosis multirresistente, y se debe considerar apropiada su utilización en la práctica de rutina y la ampliación de su empleo en el Perú.

Contrasting trends of tuberculosis in the cities of San Pedro Sula and Tegucigalpa, Honduras, 2005 and 2014 / Tendencias discordantes de tuberculosis en San Pedro Sula y Tegucigalpa, Honduras, del 2005 al 2014

ABSTRACT Objective To 1) describe and compare the trends of tuberculosis (TB) case notification rates (CNRs) and treatment outcomes in the two largest cities in Honduras (San Pedro Sula and Tegucigalpa) for the period 2005–2014 and 2) identify possible related socioeconomic and health sector factors. Methods This retrospective ecological operational research study used aggregated data from the National TB Program (socioeconomic and health sector information and individual data from the 2014 TB case notification report). Results TB CNRs declined steadily over the study period in Tegucigalpa (from 46 to 28 per 100 000 inhabitants) but remained high in San Pedro Sula (decreasing from 89 to 78 per 100 000 inhabitants). Similar trends were observed for smear-positive TB. While presumptive TB cases examined were similar for both cities, in San Pedro Sula the proportions of presumptive cases with a positive smear; (7.7% versus 3.6%) relapses (8.9% versus 4.2%); and patients lost to follow-up (10.9% versus 2.7%) were significantly higher, and the treatment success lower (75.7% versus 87.0%). San Pedro Sula had lower annual income per capita, fewer public sector health workers and facilities, and a higher and increasing homicide index. The 2014 TB case data from San Pedro Sula showed a significantly lower median age and a higher proportion of assembly plant workers, prisoners, drug abusers, and diabetes. Conclusions The TB rate was higher and treatment success lower, and health care resources and socio-demographic indicators less favorable, in San Pedro Sula versus Tegucigalpa. City authorities, the NTP, and the health sector overall should strengthen early case detection, treatment, and infection control, involving both public and private health sectors.

RESUMEN Objetivo Describir y comparar las tendencias de las tasas de notificación de casos de tuberculosis y los desenlaces terapéuticos en las dos principales ciudades de Honduras (San Pedro Sula y Tegucigalpa) durante el período del 2005 al 2014; y reconocer los posibles factores socioeconómicos y del sector de la salud que se relacionan con estos resultados. Métodos Estudio ecológico retrospectivo de investigación operativa con datos agregados del Programa Nacional contra la Tuberculosis. La información socioeconómica y del sector de la salud y los datos individuales se obtuvieron del informe de notificación de casos de tuberculosis del 2014. Resultados Las tasas de notificación de casos de tuberculosis disminuyeron en forma sostenida durante el período del estudio en Tegucigalpa (de 46 a 28 por 100 000 habitantes) pero permanecieron altas en San Pedro Sula (disminuyeron de 89 a 78 casos por 100 000 habitantes). Se observaron tendencias análogas en los casos de tuberculosis con baciloscopia positiva. Si bien el número de casos con presunción clínica de tuberculosis examinados en ambas ciudades fue equivalente, en San Pedro Sula los casos con baciloscopia positiva, las recaídas (8,9% frente a 4,2%) y los pacientes perdidos durante el seguimiento (10,9% frente a 2,7%) fueron significativamente más frecuentes y la tasa de éxito terapéutico fue más baja (75,7% frente a 87,0%). En San Pedro Sula se observó un ingreso anual por habitante más bajo, menos personal y establecimientos de salud en el sector público, y un índice más alto y creciente de homicidios. Los datos sobre los casos de tuberculosis del 2014 en San Pedro Sula revelaron una mediana de edad de los pacientes significativamente menor y una mayor proporción de trabajadores de instalaciones de montaje, prisioneros, consumidores de drogas y pacientes con diabetes. Conclusiones En San Pedro Sula la tasa de tuberculosis fue más alta, la tasa de éxito terapéutico fue inferior y los indicadores sobre los recursos de atención de salud y los aspectos sociodemográficos fueron menos favorables en comparación con Tegucigalpa. Las autoridades municipales, el Programa Nacional contra la Tuberculosis y el sector sanitario en general deben fortalecer la detección temprana de casos, el tratamiento y el control de la infección mediante la participación del sector público y el sector privado de la salud.

Hallazgos nefro-urológicos postnatales de pacientes con diagnóstico prenatal de hidronefrosis evaluados en un hospital de cuarto nivel de complejidad / Postnatal nephro-urology findings of patients with prenatal diagnosis of hydronephrosis

No es clara la repercusión clínica de la hidronefrosis. Este estudio busca determinar las características de las imágenes diagnósticas de los pacientes con hidronefrosis prenatal y determinar si el valor del diámetro anteroposterior de la pelvis renal puede identificar la presencia de malformaciones urológicas posnatales y la necesidad de cirugía. Materiales y métodos: estudio transversal en el que se revisaron las historias clínicas de todos los pacientes con edades entre 0 y 5 años de edad, con diagnóstico prenatal de hidronefrosis, quienes consultaron a un hospital de cuarto nivel de complejidad en la ciudad de Medellín - Colombia. Cada unidad renal se evaluó en forma independiente. Resultados: en total se estudiaron 135 unidades renales de 97 pacientes. No se encontró hidronefrosis posnatal en el 17,8 %. Al seguimiento, el 85 % de los pacientes con estenosis pieloureteral y 90 % de los pacientes con valvas de uretra posterior fueron clasificados prenatalmente como hidronefrosis moderada a grave. Por el contrario, el 41,4 % de los riñones con diagnóstico de reflujo vesico-ureteral fueron clasificados como hidronefrosis leve, 34,5 % moderada y 24,1 % grave. El 56,3 % de los riñones necesitaron algún tipo de cirugía. El 26 % de las hidronefrosis clasificadas como leves necesitaron algún procedimiento quirúrgico. Un diámetro anteroposterior de la pelvis renal de 10,5 mm tuvo una sensibilidad de 67 % y una especificidad de 71,2 % para la detección de malformaciones nefro-urológicas. Conclusión: la hidronefrosis prenatal, independiente de su grado, puede ser indicativa de malformaciones del tracto genitourinario. Se recomienda un seguimiento estricto en los pacientes con hidronefrosis, incluso en los casos leves, para así detectar tempranamente la presencia o no de malformaciones nefro-urológicas que requieran algún tipo de intervención.

Currently, we do know the clinical repercussions of prenatal hydronephrosis. This study aims to assess the imaging features of hydronephrosis patients and to determine whether the renal pelvis value in the prenatal ultrasound correlates with the presence of urologic malformations and the need for surgery. Materials and methods: Cross sectional study. We evaluated the medical records of all patients almost 5 years old with prenatal hydronephrosis who had consulted during 2006-2010. Results: we analyzed 97 patients, for a total of 135 kidneys. 17.8 % had not hydronephosis; 85.1 % of the patients with pyeloureteral junction stenosis and 90 % of those with posterior urethral valves had been prenatally classified as having mild to severe hydronephrosis. Conversely, 41.4 % of kidneys with vesicouretral reflux were classified as having mild hydronephrosis, 34.5 % moderate and 24.14 % severe. Furthermore, 56.3 % of the evaluated kidneys needed some type of surgery. It is also worth mentioning that it was necessary to perform surgical procedures on 26 % of the kidneys with mild hydronephrosis. Finally, the analysis of the ROC curve made it possible to find that, when the pelvis has an anteroposterior diameter of 10.5 mm, the sensitivity for the detection of nephro-urologic malformations is 67 % and the specificity 71.2 %. Conclusion: prenatal hydronephrosis, regardless of its degree, may be an indication of malformations in the urinary tract. We recommend performing strict follow-ups on the patients to determine the presence of nephro-urologic malformations requiring some kind of intervention.

Parálisis cordal izquierda asociada a aneurisma aórtico. Reporte de un caso / Aortic aneurysm associated to left vocal cord palsy. Case report

La parálisis del nervio laríngeo recurrente izquierdo puede estar motivada por múltiples causas, y las de origen vascular son las que con mayor frecuencia se asocian a esta patología. Presentamos un caso poco frecuente de parálisis cordal izquierda, producida por un aneurisma de aorta. Para su diagnóstico se realizó una nasofaringolaringoscopia, así como una tomografía y angiorresonancia de cuello y tórax. Se encontró un aneurisma sacular en la porción ascendente de la aorta, y un trombo intramural, motivo por el cual el paciente fallece en dos semanas, por un episodio agudo de hematemesis. La lesión del nervio laríngeo recurrente, en los aneurismas de la aorta torácica, se produce por alargamiento o estiramiento del nervio, debido al aumento en el diámetro del cayado aórtico. El estudio radiológico torácico de los pacientes con parálisis laríngea puede ayudar al diagnóstico precoz de los aneurismas de la aorta...

Left recurrent laryngeal nerve palsy may be due to multiple causes, being vascular origin the most frequent. We report an infrequent case of left vocal cord palsy caused by an aortic aneurysm. A video nasolaryngoscopy, neck and thoracic tomography and nuclear resonance were performed. A sacular aneurysm and intramural thrombus were found in the ascending aorta portion. The patient died because of aneurysm rupture two weeks later. Impairment of the recurrent laryngeal nerve in thoracic aortic aneurysm is due to elongation or stretching of the nerve. Radiologic study of the thorax in vocal cord palsy patients may be helpful for doing an early diagnosis of aortic aneurysm...

Glomus carotídeo bilateral. Reporte de un caso / Bilateral glomus caroticum. case report

Los glomus o paragangliomas carotídeos son tumores de crecimiento lento, hipervascularizados, poco frecuentes, derivados del cuerpo carotídeo. El objetivo es presentar un caso poco frecuente de tumores glómicos carotídeos bilaterales. Para su diagnóstico se realizó angiorresonancia magnética y angiografía de cuello. Se encontró una tumoración bilateral hipervascularizada a nivel de la división de la arteria carótida común, con signo de la lira...

Carotid glomus or paragangliomas are slow growing tumors, highly vascularized, rare, originated from the carotid body. The objective is to present a very rare case of bilateral carotid glomic tumors. Neck angioresonance was performed for diagnosis. A highly vascularized tumor was found bilaterally in the bifurcation of the common carotid artery, showing the lyre sign...

Costo-efectividad de un tratamiento antituberculoso alternativo: seguimiento a convivientes residenciales de los pacientes / Cost-effectiveness of an alternative tuberculosis treatment: home-based guardian monitoring of patients

Objetivo. Estimar la relación de costo-efectividad del tratamiento de corta duración bajoobservación directa (DOTS), comparándolo con una variación de dicho tratamiento, que incluyeun mayor seguimiento a los convivientes residenciales de los pacientes (DOTS-R) parael tratamiento de tuberculosis (TB).Métodos. Tomando una perspectiva social que incluye los costos para las institucionesde salud, para los pacientes y sus familiares, y para otras entidades que contribuyen a hacerefectiva la operación del programa, se evaluaron los costos incurridos con cada una de las dosestrategias y se estimaron razones costo-efectividad adoptando las medidas de efecto usadas porlos programas de control. La estimación de los costos de cada una de las dos estrategias incluyelos correspondientes a las instituciones de salud que administran el tratamiento, los pacientesy sus familiares, y los de la secretaría de salud que gestiona los programas de salud pública anivel municipal. Con base en estos costos y el número de casos curados y tratamientos terminadoscomo medidas de resultado de cada una de las estrategias evaluadas, se calcularon lasrazones costo-efectividad y costo incremental.Resultados. El DOTS-R se halló más costo-efectivo para lograr tratamientos exitosos queel DOTS. El DOTS-R registró costos de entre US$ 1 122,4 y US$ 1 152,7 por caso curado,comparados con valores de entre US$ 1 137,0 y US$ 1 494,3 correspondientes al DOTS. Laproporción de casos tratados con éxito fue mayor con DOTS-R que con DOTS.Conclusiones. El DOTS-R es una alternativa costo-efectiva promisoria para mejorar elcontrol de la TB en sitios endémicos. Se recomienda a las autoridades del sector salud incorporaren su gestión institucional del programa contra la TB, acciones de seguimiento de losconvivientes de pacientes, con la participación del personal de salud y los recursos físicos yfinancieros que apoyan actualmente dicho programa.

Objective. Estimate the cost-effectiveness ratio of the directly observed treatmentshort course (DOTS) for treatment of tuberculosis (TB), comparing it to a variation ofthis treatment that includes increased home-based guardian monitoring of patients(DOTS-R).Methods. Taking a social perspective that includes the costs for the healthinstitutions, the patients, and their family members, and for other entities thatcontribute to making operation of the program effective, the costs incurred with eachof the two strategies were evaluated and the cost-effectiveness ratios were estimatedadopting the measures of effect used by the control programs. The estimate of the costof each of the two strategies includes the cost to the health institutions that administertreatment, the patients and their family members, and the cost to the Ministry ofHealth that manages public health programs on the municipal level. Based on thesecosts and the number of cases cured and treatments completed as outcome measuresof each of the strategies evaluated, the cost-effectiveness ratio and incremental costwere calculated.Results. The DOTS-R was found to be more cost-effective for achievement ofsuccessful treatments than the DOTS. The DOTS-R recorded costs of US$ 1 122.40 toUS$ 1 152.70 for each case cured compared to values of US$ 1 137.00 to US$ 1 494.30for the DOTS. The percentage of cases treated successfully was higher with DOTS-Rthan with DOTS.Conclusions. The DOTS-R is a promising cost-effective alternative for improvedcontrol of TB in endemic areas. It is recommended that the health authorities includehome-based guardian monitoring of patients in their institutional management of theTB program, with the participation of health workers and the physical and financialresources that currently support this program.

Sistemas de microscopía virtual: análisis y perspectivas: [revisión] / Virtual microscopy systems: analysis and perspectives: [review]

Desde finales del siglo XX la microscopía se ha venido transformando, incluyendo nuevos recursos que mejoran y perfeccionan su práctica. Entre ellos se destaca el microscopio virtual, la sinergia entre disciplinas como la patología, la histología, la informática médica y el análisis de imágenes. Esta tecnología ha cambiado muchos paradigmas en la investigación, el diagnóstico, la educación y el entrenamiento médico. Los sistemas de microscopía virtual requieren de la digitalización de una placa con el uso de microscopios robotizados, antes del procesamiento de la imagen y después de él, compresión, transmisión por la red y visualización. En este artículo se hace un análisis extenso de cada uno de estos procesos, y se presentan las principales características de los microscopios virtuales, junto con el impacto de estos sistemas en actividades de interpretación y diagnóstico.

Virtual microscopy systems: Analysis and perspectives Microscopy has been constantly evolving since the end of the Twentieth Century, with the introduction of new resources which have improved its practice. For example, the use of the virtual microscope has reached a high level of maturity; it is a synergy among disciplines such as pathology, histology, medical informatics and image analysis. This technology has moved forward many paradigms in research, diagnosis, education and medical training. The virtual microscopy systems require the digitalization of a physical slide, using motorized microscopes, pre and post image processing, compression, transmission and visualization. This article provides an extensive analysis of each of these processes. The main characteristics of virtual microscopy are presented as well as the impact of these systems in image interpretation and in diagnostic activities.

Quality of life in persons living with HIV–AIDS in three healthcare institutions of Cali, Colombia / Calidad de vida en personas con VIH-SIDA en tres instituciones de salud de Cali, Colombia

Antecedents: The Human Immunodeficiency Virus is currently considered a chronic disease; hence, quality of life is an important goal for those suffering the disease or living with someone afflicted by the virus. Objectives: We sought to measure the quality of life in individuals living with acquired immunodeficiency syndrome virus and establish its relationship with socio-demographic and clinical variables. Methods: This is a cross-sectional, descriptive study with a sample of 137 HIV-infected individuals attending three healthcare institutions in the city of Cali, Colombia. Quality of life was measured via the HIV/AIDS-Targeted Quality of Life (HAT-QoL) instrument. The descriptive analyses included mean and standard deviation calculations. To determine the candidate variables, we used the student t test and the Pearson correlation. The response variable in the multiple linear regression was the score for quality of life. Results: Some 27% of the sample were women and 3% were transgender; the mean age of the sample was 35 + 10.2 years; 88% had some type of health insurance; 27% had been diagnosed with AIDS, and 64% were taking antiretroviral medications at the time of the study. Quality of life was measured through a standard scale with scores from 0 to 100. Participants’ global quality of life mean was 59 + 17.8. The quality-of-life dimensions with the highest scores were sexual function, satisfaction with the healthcare provider, and satisfaction with life. The highest quality-of-life scores were obtained by participants who received antiretroviral therapy, had health insurance, lower symptoms of depression, low frequency and intensity of symptoms, and no prior reports of sexual abuse. Eight variables explained 53% of the variability of the global quality of life...

Antecedente: Hoy en día se considera el VIH como una enfermedad crónica; por tanto,la calidad de vida es una meta importante de alcanzar en las personas que viven y conviven con el virus.Objetivos: Medir la calidad de vida en personas que viven con el virus del sida y establecer la relación con variables socio-demográficas y clínicas. Métodos: Estudio transversal, descriptivo, con muestra no probabilística de 137 personas con VIH que asistieron a tres instituciones de salud de Cali, Colombia. La calidad de vida se midió con el instrumento Hiv/Aids-Targeted Quality of Life (HAT-QoL). El análisis descriptivo incluyó los cálculos de promedio y desviación estándar. Para determinar las variables candidatas se utilizaron la prueba t de Student y la correlación de Pearson. La variable respuesta en la regresión lineal múltiple fue el puntaje de calidad de vida. Resultados: De los encuestados 27% eran mujeres y 3% transgéneros; la edad promedio fue 35 + 10.2 años; 88% tenían algún tipo de seguro de salud; 27% con diagnóstico de Sida y 64% con tratamiento antirretroviral en el momento del estudio. La calidad de vida se midió con una escala estandarizada de 0 a 100; el promedio de calidad de vida global fue de 59 + 17.8; las dimensiones de calidad de vida que mayor puntaje obtuvieron fueron la función sexual, la satisfacción con el proveedor de cuidados de salud y la satisfacción con la vida. Los puntajes más altos en calidad de vida los obtuvieron personas que recibieron tratamiento antirretroviral, con acceso a algún seguro de salud, menor sintomatología depresiva, baja frecuencia e intensidad de síntomas y sin antecedentes de abuso sexual. Ocho variables explicaron 53% de la variabilidad de la calidad de vida...

Características de la contratación entre aseguradores y prestadores de servicios de salud, Medellín, 2007-2008 / Características da contratação entre administradoras de planos de benefício e prestadores de serviços de saúde, Medellín, 2007-2008 / Characteristics of the Contracting out process between insurers and hospitals; Medellín 2007-2008

Objetivo: describir las características del proceso de contratación de servicios de salud entre las entidades administradoras de planes de beneficio - EAPB (Entidades Promotoras de Salud (EPS) y entes territoriales) con los Institutos Promotores de Salud (IPS) públicas y privadas en la ciudad de Medellín, entre los años 2007 y 2008. Metodología: se realizó un estudio descriptivo exploratorio; se analizó una muestra de minutas de contratos firmados entre EAPB e IPS, y se realizaron entrevistas en profundidad para identificar los aspectos relevantes del proceso de negociación y de las relaciones entre contratantes y contratistas. Hallazgos relevantes: las minutas de los contratos son muy diversas, se observa un desbalance en las obligaciones de las partes y hay constantes tensiones interinstitucionales relacionadas con la posición dominante de las EAPB.

Objective: to describe the characteristics of the health service contracting out process betweenAdministrator Entities of Benefit Plans – health Promoting Entities and Territorial Entities- with public and private Health Service Providers of Medellin city, between 2007 and 2008. Methodology:a descriptive, exploratory methodological approach was used to analyze a sample of the contract’s minutes and a qualitative approach to identify the relevant aspects of the negotiation process and the relationship between contractors and contracting parties in the development ofthe contracts. Main finding: the contract is a source of ongoing inter-institutional stress during the negotiation, development, and ending phases affected by the exercise of the underwriter´s dominant position of the health insurers opposed to the purpose of willing agreement guaranteeing effective access to health service.

Objetivo: descrever as características do processo de contratação de serviços de saúde entre as entidades administradoras de planos de benefício – EAPB (Entidades Promotoras de Saude(EPS) e entidades territoriais) com as organizações prestadoras (IPS) públicas e privadas na cidade de Medellín, entre os anos 2007 e 2008. Metodologia: realizou-se um estudo descritivo e exploratório; analisou-se um mostra de minutas de contratos assinados entre as entidadesadministradoras (EAPB) e as organizações prestadoras (IPS), e realizaram-se entrevistas aprofundidade para identificar os aspectos relevantes do processo de negociação e das relaçõesentre contratantes e contratados. Descobrimentos relevantes: as minutas dos contratos são muito diversas, observa-se um desequilíbrio nas obrigações das partes e há contastes tensões interinstitucionais relacionadas com a posição dominante das entidades administradoras (EAPB).