Hydatid disease (HD) is a parasitic infection caused by the larvae of a tapeworm that is endemic to many regions around the world-South America, Africa, and Asia, in particular. Humans are infected as intermediate hosts in the parasite's life cycle; thus, HD can be seen in persons living in areas where animal husbandry is practiced. However, owing to the varied patterns of migration and immigration during the past several decades, HD can be diagnosed in individuals living anywhere. The liver is the most common organ involved, with hepatic HD accounting for the majority of published cases. However, HD can affect multiple organs and tissues other than the liver, including the spleen, kidneys, lungs, heart, peritoneum, muscles, and brain. Knowledge of the route of spread, clinical findings at presentation, and possible complications involving each extrahepatic location can be useful for the radiologist when evaluating imaging findings in patients suspected of having HD. The ultrasonographic, computed tomographic, and magnetic resonance imaging findings of extrahepatic hydatid lesions frequently simulate those of hepatic HD, as long as rupture, bleeding, and/or superimposed bacterial infection has not occurred. Specific features of HD seen at different extrahepatic sites can help tailor the diagnosis. The differential diagnoses that can mimic HD at every nonhepatic location should be considered, as many of these entities are common, especially in nonendemic areas. RSNA, 2017.
U n objetivo en todo estudio epidemiológico, en el que se desea conocer la frecuencia con la que ocurre un evento o estimar la asociación entre un factor de riesgo y una enfermedad, debe ser el de medir y calcular con la mayor precisión y exactitud posibles dichas determinaciones. En otras palabras, la validez del conocimiento derivado de cualquier estudio epidemiológico dependerá, en gran medida, de la ausencia de error y de la capacidad de estimar o predecir el parámetro verdadero en la población blanco. En el contexto de la epidemiología, la validez se refiere a la ausencia de sesgo o error. A lo largo del presente trabajo se hace referencia a dos tipos de validez: a) la validez interna, que se refiere principalmente a los errores cometidos durante el proceso de selección de la población de estudio, durante las mediciones que se realizan en dicha población o a errores ocasionados por la falta de comparabilidad de los grupos estudiados, y b) la validez externa, que se refiere a la capacidad del estudio de generalizar los resultados observados en la población en estudio hacia la población blanco. Es importante notar que la validez externa depende de que exista la interna, es decir, es necesario cumplir con los requisitos necesarios de validez interna para poder extrapolar lo resultados, por esta razón en los diferentes estudios epidemiológicos se privilegian acciones que maximizan la validez interna, aun comprometiendo, en cierta medida, la validez externa. Sesgos en estudios epidemiológicosMauricio Hernández-Avila, Ph.D., (1) Francisco Garrido, M.C., M. en C., (2) Eduardo Salazar-Martínez, Dr. en C. (1) Todo estudio epidemiológico está sujeto a un cierto margen de error, por lo que será muy importante conocer cuáles son sus fuentes principales y los diferentes procedimientos que pueden ser utilizados para minimizar su impacto en los resultados. Los errores se pueden clasificar en dos grandes tipos: los errores no aleatorios o sistemáticos y los errores aleatorios (no sistemáticos); ambos tipos de error, de no controlarse adecuadamente, pueden comprometer la validez del estudio. El error aleatorio (no sistemá-tico) ocurre cuando las mediciones repetidas, ya sean en un mismo sujeto o en diferentes miembros de la población en estudio, varían de manera no predecible, mientras que el error sistemático (no aleatorio) ocurre cuando estas medidas varían de manera predecible y, por lo tanto, se tiende a sobre o subestimar el valor verdadero en medidas repetidas. La analogía que se utiliza para describir ambos conceptos es la práctica de "tiro al blanco" donde el punto medio del objetivo es el valor verdadero en la población blanco y los "disparos" son las diferentes mediciones que se realizan en la población en estudio para estimar dicho valor verdadero. Un buen tirador cuya arma no está bien calibrada apuntará al blanco equivocado, podrá ser muy preciso (todos los disparos dan en el mismo lugar), pero ninguno de ellos da en el blanco correcto. Esto corresponde al error sistemático. Por otra parte, un tirador con mano ...
In 1988 the Mexican General Directorate of Epidemiology and the Mexican Institute of Psychiatry carried out the first National Addiction Survey that provided prevalence estimates at national and regional levels of alcohol consumption, tobacco smoking, and several other drugs use. In addition, a questionnaire included questions regarding alcohol consumption during pregnancy and adverse outcomes. According to the results of logistic regression, women classified as suffering from Alcohol Dependence Syndrome had a very high risk of low birth weight and/or preterm delivery: Odds ratio = 12.1 with a 95% confidence interval of (1.3, 108.9) and p = .026. After controlling for several confounding variables, the findings remained basically the same.
Objective. To describe the availability of some essential drugs at the primary health care units of the Ministry of Health of Tamaulipas, Mexico. Material and methods. Between September and October 1998, all first level healthcare units of Tamaulipas' three sanitary jurisdictions were surveyed. Drug availability was assessed. The measurement instrument was a checklist of 56 drugs and 10 different supplies. For each drug and input the absolute number and the proportion of units with this drug or input was calculated. In the units where the drugs were available, the medians were calculated. The median of the total number of drugs available in all units was used as a global indicator. This same exercise was developed for each unit. Comparisons between the availability of these inputs in the units and stockrooms were also done. Stata 5.0 was used for statistical analysis. Results. None of the inspected units had full availability of all checklist drugs. The highest percentage of drug availability was 84% and the lowest was 32%. There was limited availability of antibiotics, antihypertensive, hypoglycemic, and iron deficiency drugs. The availability of oral rehydration salts and contraceptive and vaccine agents was acceptable. Conclusions. Healthcare organizations must find alternative ways to improve access to drugs nationwide, in general, and availability of essential drugs in first level healthcare units, in particular. Two recent initiatives provide an optimistic outlook: decentralization of health services for the uninsured and the Generic Exchangeable Drugs Program, established nationwide in 1998.
This paper reports on the prevalence of lead poisoning in children between 1 and 5 years of age living in a marginal area to the north of Mexico City and also includes an evaluation of sources of exposure to this metal in the same area. The results show that 67.5% of the children studied have blood lead (PbB) levels > or = 10 micrograms/100 ml. Twenty-one percent of these children (1987) had PbB levels that required medical evaluation (> or = 20 micrograms/100 ml- < or = 40 micrograms/100 ml), and 112 children needed medical treatment (PbB > or = 40 micrograms/100 ml). In addition, the study found that the probability of higher blood lead levels (> or = 20 micrograms/dl) corresponds to children whose mothers use lead-glazed pottery dishes (OR = 2.80; CI 95%, 1.55-5.07) and to children who habitually bite colored pencils (OR = 2.05; CI 95%, 1.13-3.71) compared, respectively, with children whose mothers do not use that type of dishes and children who do not bite pencils. Our results provide baseline information for estimating the impact and costs of population-based interventions aimed at these populations and also confirm the need to strengthen health education programs to promote the reduction of lead exposure in the general population.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.