Audiometric findings of printing press workers exposed to noise and organic solvents.

OBJECTIVE: To determine if exposure to organic solvents and noise is associated with audiometric results among workers from a printing press in Mexico City. DESIGN: Cross-sectional study. STUDY SAMPLE: One hundred and seventy-six male workers at a printing press in Mexico City exposed to noise and organic solvents, including xylene, and 103 non-exposed male workers as reference group. Hearing thresholds were assessed with pure-tone audiometry. RESULTS: Poorer hearing thresholds were observed among printing workers than non-exposed controls, particularly among groups with over 5 years of exposure. Hearing thresholds differences were observed in the frequencies above 500 Hz, especially in 4000 Hz in all exposure groups compared to the reference. Adjusted models for age and previous exposure to noise and organic solvents showed worse hearing thresholds as years of seniority increased -ß coefficients (95% CI): ≤5 years: 3.06 dB (0.01, 6.10); >5-10 years: 4.51 dB (1.13, 7.89); >10 years: 4.58 dB (1.20, 7.96). Further analyses showed no interaction between noise and organic solvents on hearing thresholds, considering both current and previous occupational exposures. CONCLUSION: Exposure to noise levels that were below recommended exposure limits and organic solvents were associated with poorer hearing thresholds than those observed among non-exposed study participants. This suggests that workers exposed to solvents should be included in hearing conservation programmes, even when noise exposures are below 85 dB. If only noise levels were taken into consideration in the risk assessment of this worker population, the risk of hearing effects could have been overlooked.

Ototoxicity effects of low exposure to solvent mixture among paint manufacturing workers.

OBJECTIVE: To evaluate auditory function in a group of workers exposed to organic solvent mixture at a paint factory. DESIGN: Cross-sectional study. STUDY SAMPLE: One hundred and sixty-one workers were studied, 77 exposed to solvents and 84 unexposed. Fourteen solvents were measured, including toluene, xylene, and n-hexane. Pure-tone audiometry and brainstem auditory-evoked potentials (BAEP) were performed. Industrial noise was < 85 dBA and exposure levels to organic solvents were low. RESULTS: The exposed group showed a hearing impairment in both ears compared with the unexposed workers. Multiple linear regression models adjusted by age, chronic pathologies, and environmental noise for frequency means between 125 and 8000 Hz produced the following results: for the left ear, R(2) = 33.3%, exposed vs. unexposed ß = 4.1 (p < 0.001); and for the right ear, R(2) = 38%, exposed vs. unexposed ß = 4.8 (p < 0.001). Adjusted for age and chronic pathologies, waves III and V, and interpeak interval latencies were increased (p < 0.05) in both ears in the exposed group. CONCLUSIONS: Although solvent mixture concentrations and noise levels were low, our results demonstrate that there may be a concurrent ototoxicity and neurotoxicity condition and emphasize the importance of including BAEP analysis for comprehensive assessments. Future studies that include otoacoustic emissions assessments to monitor cochlear function and central auditory processing tests are imperative.

Are Mexican agricultural farmlands PCDD/F soil reservoirs?

Our aim was to identify polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzo-p-furans (PCDFs) in agricultural farmland soils in the Northwest of Mexico. We obtained ≈50 g of soil in five Yaqui Valley (VY) agricultural fields in the north-western Mexican State of Sonora and in five Culiacán Valley (VC) agricultural fields in the north-western Mexican State of Sinaloa. Fields with minimal tillage, with ferti-irrigation, and those with intensive aerial and manual tillage were included. All soil samples were subjected to the chemical activated luciferase gene expression (CALUX(®)) test to determine PCDD/F. On average, samples contained 4.2 ± 1.2 PCDD/F ppt TEQ; VY soil samples contained 4.72 ± 1.23 PCDD/F ppt TEQ, while VC soil samples showed 3.6 ± 1.1 PCDD/F ppt TEQ (p = 0.47). On considering tillage-type, in agricultural fields catalogued as intensive tillage, PCDD/F concentrations were 4.40 ± 0.43 in agricultural fields catalogued as intensive tillage, while in farmlands of another tillage-type these concentrations were slightly higher (5.53 ± 0.8).

[Clinical aptitude in occupational medicine residents]. / Aptitud clínica en residentes de medicina del trabajo.

OBJECTIVE: To determine clinical aptitude (AC) in occupational medicine residents. METHODS: An instrument based on real clinical cases was built and validated to assess AC, which was composed by surveillance indicators of the workers health (SIWH) and occupational-medical evaluation indicators (0ME) In the study participated 22 undergraduate students (UE), 40 residents of first year (R1) and 36 of second year (R2). The instrument was validated by experts. RESULTS: Internal consistency of the instrument was 0.93 by Kuder-Richardson. Regarding global AC, 96 % of UE were situated in a random level and 4 % in a very low level. 15 % of R1 was situated in a random level, 50 % in a very low level, 30 % low level and 5 % in medium level; whereas R2 3 % was positioned in a random level, 28 % in a very low level, 50 % in low level and 19 % in medium level. A significant difference was found between R1 and R2 in occupational-medical evaluation (p < 0.009), but not in SIWH. Two centers showed statistical difference in both indicators.

[Occupational exposure-associated hematological and immunologic manifestations to the benzene-toluene-xylene (Btx) mixture]. / Exposición ocupacional a mezcla de benceno-tolueno-xileno. Manifestaciones hematoinmunológicas.

Despite, the idea promoted to study occupational exposure to benzene and its mixture with toluene and xylene (BTX) because it appears to determine its toxicity and probably the production of additive effects, it persists interest to recognizing its hematological and immunotoxic effects. The fact that exposure to a sole substance in the occupational field is infrequent. Available contributions that analyze these implications are scarce, with contradictory results, and in their majority are limited to the fraction of benzene. Epidemiologic studies that have evaluated occupational exposure to any of the BTX fractions have been based on personal monitoring, while others have characterized this heterogeneously and are accompanied by weaker proposals. The conformation of specific methods to stimulate occupational exposure to the BTX mixture would contribute to its homogenization and allow for a more integral view in terms of determining BTX exposure. On the other hand, the application of BTX exposure biomarkers has been questioned in studies contemplating the specific biological effects of reference-associated chronic exposure. Analysis of the hematological and immunologic manifestations associated BTX mixture is based on information that is unclear, controversial, or even speculative to date.

[Reliability and validity of a generic job exposure matrix applied on a small-business]. / Matriz de expocición ocupacional genérica. Consistencia y validez al aplicarla en una pequeña empresa.

OBJECTIVE: to evaluate the reliability and validity of a generic job exposure matrix (JEM) applied in a small business. METHODOLOGY: procedures to evaluate a JEM integrated by six sections: the number of exposed workers per area, frequency of exposure, time of exposure time, level of exposure, safety controls, and proximity to source of exposure, was evaluated. The JEM also obtains information about possible health effects from exposure to occupational/environment agents. Two observers estimated the risk of exposure to epoxy resins on 31 workers of an epoxy resin facility in Mexico City. The rater agreements between the two observers were assessed through percent agreement (PA), weighted kappa (kappa(w)) and the intraclass correlation coefficient (ICC). RESULTS: disagreements were greater for the number of exposed workers (PA = 61.3, kappa(w) = 0.24, ICC = 0.33), level of exposure (PA= 66.7, kappa(w) = 0.25, ICC= 0.56), and safety controls (PA = 54.8, kappa(w) = 0.23, ICC = 0.69) sections. Percent agreement and kappa(w) were 64% and 0.58, respectively. In accordance with Landis and Koch, Altman, Fleiss, and Byrt classifications for the interpretation of kappa value, the weighted kappa (0.58) ranged from moderate to a fair good level. CONCLUSIONS: despite the discordance in some sections, the JEM proved to be useful to identify the risk of exposure in this type of small business.

[Medical justification of the eight-hour shift work]. / Justificaciones médicas de la journada laboral máxima de ocho horas.

The 8-hour shift work is one of the main achievements of the organized workers. International solidarity with United States miners, who were massacred in Chicago in 1886, and the aftermath of World War I promoted the establishment of 8-hour shift work in many countries. In Mexico, the 1917 Social Rights Declaration adhered to this position under the idea that the excessive workload above the 8-hour limit had negative effects on the health of workers; nevertheless, this statement seems to be sustained only by testimonies, anecdotal opinions and/or by the logic and common sense that then prevailed. For this reason, a literature review was carried out in search for the evidence supporting this apparently immovable length of the shift work. The globalization of the economy and the tendency towards flexibility and deregulation of current contractual relationships, are the new challenges that the 8-hour shift work is facing.

[Reflecting about 40 years of occupational medicine in Mexico]. / Reflexiones en torno a los 40 años de la medicina del trabajo en México.

Thirty-eight years ago, occupational medicine was recognized as medical specialty in Mexico. Its achievements have been discreet and its evolution has been marked by situations that have questioned its credibility, relevance and viability, despite its significant value for the Mexican health care institutions, for the public and for the private sector. This paper addresses the importance of the field of occupational medicine, showing its social relevance and makes some remarks about the essential quality of the specialists that this discipline requires.

Occupational health in Mexico.

This article describes the current situation of occupational health (OH) in Mexico, including socioeconomic context, legislation, health system, and educative and investigative resources, as well as the practice of OH. Workplace accidents per 100 workers decreased from 7.23 to 2.3 workers in 20 years; deaths decreased from 1.68 to 0.9 per 10,000 workers, while the occupational disease rate increased from 0.6 to 1 per 10,000 workers. This can be interpreted as an improvement in preventive measures as well as problems of recognition and registry. In Mexico OH faces challenges that range from needs for professional training and performance to needs for development of legal measures, coordination, information, and research.

[Brainstem auditory evoked potentials latencies, by age and sex, among Mexican adult population]. / Latencias de los potenciales evocados auditivos del tallo cerebral, por edad y sexo, en población adulta mexicana.

BACKGROUND: Brainstem auditory evoked potentials (BAEP) evaluate the auditory pathway, and are a complementary test for tone audiometry in evaluating auditory diseases. The aim of the study was to determine BAEP mean latencies of waves and intervals, among healthy adults. METHODS: Cross-sectional study, comprising 196 subjects, aged 16 to 65 years, without auditory diseases, to whom family and personal history were asked, physical examination and laboratory studies were made, as well as tonal audiometry, impedanciometry and BAEP. RESULTS: A total of 107 men and 89 women were studied. The mean latency periods of waves I, III and V, and intervals I-III, III-V and I-V from both ears were similar. An increase in the latency periods for each age category was observed. Latency periods were significantly shorter in women compared to men. The predictors that increased the latency periods in the multiple linear regression models for waves and intervals were male gender and age ≥45 years. CONCLUSIONS: Age and sex were the variables that showed more statistical power to explain the latencies' differences.

Introducción: los potenciales evocados auditivos del tallo cerebral (PEATC) evalúan la vía auditiva central y son una herramienta complementaria de la audiometría tonal para analizar enfermedades auditivas. El objetivo de este estudio fue determinar el tiempo promedio de las latencias de las ondas y los intervalos de los potenciales evocados auditivos en adultos sanos. Métodos: estudio transversal que contó con 196 participantes, de 16 a 65 años de edad normo-oyentes, a quienes se investigaron antecedentes familiares y personales patológicos, se realizó exploración física y se obtuvieron estudios de laboratorio, audiometría tonal e impedanciometría normales, y potenciales evocados auditivos. Resultados: Se estudiaron 107 hombres y 89 mujeres. El promedio de las latencias de las ondas I, III y V e intervalos I-III, III-V y I-V de ambos oídos fueron similares. Los predictores que incrementaron el tiempo de latencia en los modelos de regresión lineal múltiple de las ondas e intervalos fueron el sexo masculino y la edad ≥ 45 años. Conclusiones: la edad y el sexo fueron las variables que mostraron mayor poder estadístico para explicar las diferencias de las latencias en este grupo de personas.

Blood lead determinants and the prevalence of neuropsychiatric symptoms in firearm users in Mexico.

OBJECTIVES: To identify blood lead predictors and the prevalence of neuropsychiatric symptoms in firearm users of public security in Mexico. MATERIAL AND METHODS: A cross-sectional study was performed on 65 males. We obtained socio-occupational data and determined venous blood lead (blood (B), lead (Pb) - BPb), as well as neuropsychiatric symptoms using the Q-16 questionnaire. A multiple linear regression model was constructed to assess determinants of BPb. RESULTS: The mean age in the study group was 34.8 years (standard deviation (SD) = 6.9, range: 21-60); the mean number of years spent in the company amounted to 14 years (SD = 8.5, range: 1-48). Twenty percent of the respondents (N = 13) used leaded glazed clay pottery (lead (Pb), glazed (G), and clay pottery (C) - PbGC) in the kitchen. During practice they fired a mean of 72 shots (SD = 60, range: 20-250), and during their whole duration of employment 5483 shots (SD = 8322.5, range: 200-50 000). The mean BPb was 7.6 µg/dl (SD = 6.8, range: 2.7-51.7). Two caretakers from the firing range had 29.6 µg/dl and 51.7 µg/dl BPb. The subjects who had shooting practice sessions ≥ 12 times a year reported a greater percentage of miscarriages in their partners (24% vs. 0%). Twelve percent of the respondents showed an increase in neuropsychiatric symptoms. The BPb multiple linear regression model explained R2 = 44.15%, as follows: those who had ≥ 12 practice sessions per year - ß = 0.5339 and those who used PbGC - ß = 0.3651. CONCLUSIONS: Using firearms and PbGC contributes to the increased BPb in the studied personnel. The determinants of BPb were: shooting practices >12 times a year and using PbGC. Blood lead concentrations reported in the study, despite being low, are a health risk, as evidenced by the prevalence of neuropsychiatric symptoms.

[Update on epidemiology, pathophysiology, diagnosis and treatment of malignant pleural mesothelioma]. / Actualización sobre la epidemiología, fisiopatología, diagnóstico y tratamiento del mesotelioma maligno pleural.

Malignant pleural mesothelioma is an occupational tumor caused by asbestos exposure. In Mexico, as asbestos usage is not prohibited, an increase in the number of cases is expected. Asbestos exposure is ubiquitous due to the great amount of products in which it is present. Its carcinogenicity is caused as the inhaled asbestos fibers cannot be eliminated by macrophages and, thus, they travel to the pleura through lymphatic pathways, producing a persistent inflammatory response. Diagnosis approach includes occupational history, along with clinical signs and symptoms, and paraclinical studies, such as pleural fluid cytology, chest x-rays, computed tomography, magnetic resonance imaging, and biopsy with immunohistochemistry. The main differential diagnosis is lung adenocarcinoma. Regarding the treatment of this tumor, it mainly comprises palliative care, even though chemotherapy, radiotherapy, and, in selected cases, surgical treatments have been used. There is an urgent need for general physicians and specialists to identify asbestos exposure, in order to make a timely diagnosis. Research is necessary to develop screening and prompt diagnostic tools, along with an epidemiological surveillance program for the workers and the general population exposed to asbestos.

El mesotelioma maligno pleural es un tumor ocupacional ocasionado por la exposición a cualquier tipo de fibra de asbesto. Y dado que en México el uso del asbesto no está prohibido, se espera que la incidencia de este tumor siga aumentando. La exposición al asbesto es ubicua, debido a la gran diversidad de productos en los que se encuentra. Su carcinogenicidad está dada porque las fibras de asbesto inhaladas no pueden ser eliminadas por los macrófagos y viajan hacia la pleura por vía linfática, donde producen una reacción inflamatoria persistente. Para su diagnóstico se precisa de una historia clínica laboral, además de que hay que orientarse con base en el cuadro clínico y los estudios paraclínicos, como la citología de líquido pleural, radiografía de tórax, tomografía axial computarizada, resonancia magnética y biopsia con inmunohistoquímica. El principal diagnóstico diferencial es el adenocarcinoma de pulmón. El tratamiento es principalmente paliativo, aunque se ha utilizado quimioterapia, radioterapia y, en seleccionados casos, cirugía. Para lograr un diagnóstico oportuno y certero es de vital importancia identificar las exposiciones al asbesto. Por otra parte, es necesaria la investigación para desarrollar pruebas de diagnóstico temprano y tamizaje, además de un programa de vigilancia epidemiológica para los trabajadores y la población general expuesta al asbesto.

Burnout syndrome among Mexican hospital nursery staff.

OBJECTIVE: To identify frequency and related factors to burnout syndrome in the nursing staff at a specialty hospital in the Mexican state of Guanajuato. MATERIALS AND METHODS: A prolective, analytical cross-sectional study was carried out. In 236 randomly selected nurses, a 35-item questionnaire proposed by Cyberia Shink was applied in a blind survey. Seniority, workplace, shift and kind of service, work category, age and marital status were investigated for a link with burnout syndrome. RESULTS: Mean age of nursing personnel was 33+/-11.93 years with 13+/-7.2 years of seniority; 95 (40%) workers showed emotional exhaustion, 78 (32%) felt dehumanized, 148 (63%) had lost interest in their work, and 120 (50%) reported general exhaustion. From the studied nursing personnel, 92 (39%) showed burnout syndrome-compatible data. There were statistical differences with nurses without burnout syndrome age >33 years (p=0.001), seniority (p=0.05), and workplace (p=0.05), but not with kind of medical service (p=0.36), shift (p=0.86), and work category (p=0.96). Questionnaire validity in agreement with alpha Cronbach test was 0.7496. Relation between professional attrition and work environment was r=0.738. CONCLUSIONS: The instrument can be relied upon to identify burnout syndrome and is considered as acceptable. Age, seniority, and workplace are factors linked to nursing staff with burnout syndrome-compatible data. Employers, managers, and supervisors of health care services must promote preventive actions for burnout syndrome to synchronize present work conditions in nursing staff with their biologic characteristics.

[Historical and social perspective from the 64-65 Mexican medical movement]. / Perspectiva histórica y social del Movimiento Médico de 1964-1965 en México.

The Mexican Medical Movement from 1964-1965 constitutes an important event from the rising urban middle-class, besides it was the first time medical doctors claimed for fair working conditions. The background of this movement is the so-called Crisis of 1958, which included the Movements from the educators union, oil workers union, telegraph workers union and the railroad workers union. The conflict began because interns and residents from the "Hospital 20 de Noviembre" would not get a payment at the end of the year, so on November 26th, 1964, the movement started. The Asociación Mexicana de Médicos Residentes e Internos (AMMRI) was created and their demands were the following: 1) Full working site restitution without retaliations, 2) Legal examination of the scholarship-contract terms, in order to get annual, renewable and progressive contracts, and a fixed salary with the usual working-hours and characteristics of each institution, 3) To have preference to get an adscription at the hospital where the resident studied, 4) Active participation from the resident in the elaboration of the academic plans, and 5) Resolution of each hospital's problems. This movement had social impact for Mexico's contemporary life, nevertheless some of the demands are still unchanged among medical residents.

El movimiento médico mexicano de 1964-1965 constituyó parte del primer despertar de la clase media urbana, además de haber sido la primera vez que los médicos reclamaron condiciones de trabajo justas. Como antecedente se tiene la llamada crisis de 1958, la cual incluyó los movimientos: revolucionario del Magisterio, del Sindicato de Trabajadores Petroleros, de la Alianza de Telegrafistas, y del Sindicato de Trabajadores Ferrocarrileros de la República Mexicana. El comienzo del conflicto médico se debió a que los residentes e internos del Hospital 20 de Noviembre del hoy Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado (ISSSTE) no recibieron su aguinaldo, por lo que el 26 de noviembre de 1964 inició el paro, a partir del cual se formó la Asociación Mexicana de Médicos Residentes e Internos (AMMRI), cuyas demandas fueron: 1) Restitución total en sus puestos, sin represalias, 2) Revisión legal y cambio de los términos del contrato-beca, en el sentido de lograr contratos de trabajo anuales, renovables y progresivos, con el horario y características acostumbrados en cada institución además de determinación de sueldos base, 3) Preferencia para ocupar plaza de médico adscrito a los residentes egresados de las propias instituciones, 4) Participación activa del residente en la elaboración de los planes de enseñanza, y 5) Resolución de los problemas de cada hospital. Este movimiento, aunque tuvo repercusiones sociales para la vida contemporánea en México, a 50 años de su inicio, algunas de las demandas siguen sin ser resueltas para los médicos residentes.

[Overview of sharps injuries among health-care workers]. / Panorama de heridas por objetos punzocortantes en trabajadores intrahospitalarios.

Sharps injuries are one of the most frequent health-care related accidents. It is estimated globally that 35 million workers are at risk; in Mexico there is no data available for this type of injuries. They are associated with lack of training, instrument and procedure risk, fatigue and stress. The occupational distribution is nurses 45 %, technicians 20 %, doctors 20 % and maintenance workers 5 %. The most commonly associated procedures are injection, venipuncture, suture, and insertion and manipulation of IV catheters. Hepatitis B is the most commonly transmitted agent. Emotional distress is huge as well as the cost of prophylaxis and follow-up. More than half of the injuries are not notified. The most common reasons for not reporting are: the belief that the exposure has low risk of infection, the lack of knowledge of reporting systems and the assumption that it is difficult to notify. Many strategies have been created to reduce the incidence of sharps injuries, such as: identifying the risk of blood exposure, the creation of politics to minimize the risk, the education and training to create a safe workplace, the enhancing of the reporting system, the use of double-gloving and using safety-engineered sharps devices. In many countries these politics have reduced the incidence of sharps injuries as well as the economic burden.

Las heridas por objetos punzocortantes son uno de los accidentes intrahospitalarios más frecuentes. A nivel mundial se estima que 35 millones de trabajadores de la salud se encuentran en riesgo; en México no se tienen datos actualizados para estas heridas. Los accidentes están relacionados con falta de entrenamiento, características de los instrumentos y procedimientos, y fatiga y estrés de quien los practica. La distribución por ocupación es: enfermeras 45 %, técnicos 20 %, médicos 20 % y mantenimiento 5 %. Los procedimientos asociados son: inyección, venopunción, sutura, manipulación e inserción de catéter intravenoso. La infección más comúnmente transmitida es la hepatitis B. La afectación emocional por ansiedad es grande al igual que los costos por profilaxis y seguimiento. Más de la mitad de las heridas por punzocortantes no son notificadas. Las razones más comunes para no reportar son: la suposición de que hay bajo riesgo de infección, la falta de conocimientos sobre métodos de reporte y la creencia de que es difícil notificar. Numerosas estrategias han sido creadas para reducir la incidencia, por ejemplo: la identificación del riesgo de exposición a sangre, la creación de procesos y políticas, la educación y el entrenamiento para laborar en un ambiente seguro, asícomo alentar el reporte de accidentes, el uso de doble enguantado y la utilización de dispositivos de seguridad. En varios países, estas políticas han logrado disminuir la incidencia de heridas por punzocortantes a la vez que se ha generado un ahorro para los sistemas de salud.

Increased Cardiovascular Risk Using Atherogenic Index Measurement Among Healthcare Workers.

BACKGROUND AND AIMS: Cardiovascular diseases are one of the leading causes of death worldwide. This burden of disease is particularly high among healthcare workers. The aim of the study was to identify determinants that increase atherogenic index among healthcare workers. METHODS: In 1,678 healthcare workers, cardiovascular risk factors were analyzed: body mass index, waist-to-hip ratio, systolic and diastolic blood pressure, glucose, total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides. Atherogenic index was calculated and determinants were identified. RESULTS: Mean (SD) age was 41.2 (8.4) years; body mass index 28.4 (4.8); waist-hip-ratio 0.88 (0.07); glucose 96.6 (22.2) µg/dL; TC 195.3 (50.3) mg/dL; HDL 49.0 (16.3) mg/dL; LDL 112.7 (35.0) mg/dL; triglycerides 171.7 (121.2) mg/dL; and atherogenic index 3.3 (1.5). Overweight and obesity prevalence was 77.2%. In the multiple linear regression model, the coefficients for AI were being a physician ß = 0.381, male gender = 0.443, BMI ß = 0.35, waist-to-hip ratio ß = 2.15, age = 0.014, and triglycerides ß = 0.915. CONCLUSIONS: The main contributors to atherogenic index increase were male sex, increased age, waist-to-hip ratio increase, overweight and obesity, high triglyceride levels and working as a physician. Although waist-to-hip ratio was the most powerful determinant, the physician occupational category added risk factors such as stress and adverse psychosocial working conditions, which may potentiate cardiovascular diseases.

Malignant Pleural Mesothelioma: Accuracy of CT Against Immunohistochemical Test Among the Mexican Population.

BACKGROUND AND AIMS: Malignant pleural mesothelioma (MPM) is associated with occupational and environmental exposure to asbestos. The incidence is expected to increase as the use of asbestos is not prohibited in many countries, such as in Mexico. We undertook this study to determine sensitivity, specificity, predictive values and likelihood ratios of computed tomography (CT) in a sample from Mexican population with suspected MPM and other pleuropulmonary diseases. METHODS: CT films of 38 patients suspected of having MPM were analyzed. A single observer was blinded to MPM diagnoses. The frequencies of ten CT findings were identified. A cut-off point of ≥5 CT findings was established to determine high MPM probability. Sensitivity, specificity, predictive values and likelihood ratio of the CT against biopsy using immunohistochemical testing (IHC) for MPM were calculated. RESULTS: Of the 38 patients, 31 had MPM and seven had lung adenocarcinoma. The five key findings were mediastinal pleural thickening 96.7% (n = 30), nodular pleural thickening 93.3% (n = 29), pleural mass 83.9% (n = 26), diminished lung 70.9% (n = 22) and contracted hemithorax 70.9% (n = 22). Sensitivity 96.8% (83.2-99.4), specificity 85.7% (42.2-97.6), positive likelihood ratio 6.7 (1.1-41.6), and negative likelihood ratio of 0.04 (0.01-0.2) were reported. CONCLUSIONS: Sensitivity and specificity in this study was greater than previously reported, 96.8% and 85.7 vs. 93.2 and 65.6%, respectively. CT is an easily accessible and useful tool that should be incorporated into the medical education of general physicians to improve MPM diagnosis of suspected cases.

Seroprevalence of Pandemic A(H1N1) pmd09 Virus Antibodies in Mexican Health Care Workers Before and After Vaccination.

BACKGROUND AND AIMS: In April 2009, a new strain of influenza A(H1N1) was identified in Mexico and in the U.S. In June 2009, WHO declared this a pandemic. Health care workers constituted a risk group for their close contact with infected individuals. The aim was to estimate seropositivity for A(H1N1)pdm09 in health staff at the Instituto Mexicano del Seguro Social. METHODS: A two-stage cross-sectional study, before and after vaccination in the same workers, was performed on a random sample of health-care workers. A socio-occupational questionnaire was applied and serum antibodies against influenza A(H1N1)pdm09 were determined through neutralization of retroviral pseudotypes; two logistic regression models for both were constructed. RESULTS: The average (median/mean) age of 1378 participants from 13 work centers was 41.7 years and 68.7% (947) were women. Seroprevalence for the first stage was 26.5% (365) (7.4-43%) vs. 20.8% (11) in a control group from the blood bank; for the second stage, the vaccinated group was 33% (215) (18.2-47%) and 27% (196) (11.6-50%) for the unvaccinated group. In regression models, seropositivity was associated with occupational exposure to suspected influenza infected patients, being physicians, and being vaccinated. CONCLUSIONS: Seropositivity against pandemic virus is similar to what was reported, both for vaccinated (2.8-40.9%) and unvaccinated (18.8-64.7%). Low seroprevalence in the vaccinated group indicates that between 67% and 73% were susceptible to infection. Given the relatively low vaccine-induced seropositivity, it is imperative to increase, hygiene and safety for health staff and at-risk populations, and strengthen epidemiological surveillance.

[Risk factors associated with work-related accidents in the construction industry in the Valley of Mexico]. / Factores de riesgo asociados a los accidentes de trabajo en la industria de la construcción del Valle de México.

OBJECTIVE: Our aim was to describe construction-industry, work-related accident prevalence in, associated factors in, and potential impact on affiliated workers of the Mexican Institute of Social Security (Instituto Mexicano del Seguro Social, IMSS) in the Valley of Mexico. MATERIALS AND METHODS: Prevalent cases in a retrospective case-control design. CASES: These include 385 construction-industry workers who were found to have construction work-related accidents in 2001. Controls comprised 385 active construction-industry workers without work-related accident background paired by gender, workplace, and worksite. RESULTS: Work-related accident prevalence in construction workers was 5.5%; most important risk factors and etiology fraction (Ef) included the following: age 16-20 years odds ratio, OR = 1.58, 95% confidence interval (95% CI) 1.40-10.7, p = 0.001, Ef 0.36; eventual insurance, OR = 3.7, 95% CI, 2.16-26.45, p = 0.001), Ef, 0.72, and no training for job, OR = 5.3, 95% CI, 4.9-69.2, p = 0.01), Ef: 0.81. Variables not showing significance were included salary, work shift, and workday. CONCLUSIONS: Work-related accident prevalence maintains its preponderance in the Valley of Mexico construction industry; identified risk factors are potentially modifiable, among which job training acquires unquestionable relevance.