Measuring Infection Transmission in a Stochastic SIV Model with Infection Reintroduction and Imperfect Vaccine.

An additional compartment of vaccinated individuals is considered in a SIS stochastic epidemic model with infection reintroduction. The quantification of the spread of the disease is modeled by a continuous time Markov chain. A well-known measure of the initial transmission potential is the basic reproduction number [Formula: see text], which determines the herd immunity threshold or the critical proportion of immune individuals required to stop the spread of a disease when a vaccine offers a complete protection. Due to repeated contacts between the typical infective and previously infected individuals, [Formula: see text] overestimates the average number of secondary infections and leads to, perhaps unnecessary, high immunization coverage. Assuming that the vaccine is imperfect, alternative measures to [Formula: see text] are defined in order to study the influence of the initial coverage and vaccine efficacy on the transmission of the epidemic.

Valoración de limitaciones en reumatología. Herramientas más utilizadas en la práctica / Assessment of limitations in rheumatology. Tools most used in practice

Resumen Introducción: Las enfermedades reumáticas son patologías de alta prevalencia, impacto y repercusión, caracterizadas por dolor y limitación funcional. Para valorar la limitación, la historia clínica es el punto de partida, junto con las pruebas específicas necesarias, según el tipo de padecimiento. De forma complementaria, se recomienda el uso de herramientas clinimétricas. Objetivo: Comparar algunas herramientas o cuestionarios usados en las enfermedades reumáticas más prevalentes, revisando la bibliografía para destacar sus aportes y su utilidad en la labor del médico con finalidad clínica o pericial. Método: Se revisan las características básicas de los cuestionarios y herramientas más usadas en: osteoartritis, artritis reumatoide y artritis psoriásica, espondilitis anquilosante y lupus eritematoso sistémico. Se revisa en Medline la experiencia de los autores con algunos cuestionarios en función de la patología y de sus diversos usos. Resultados: Los cuestionarios se utilizan en su mayoría para la valoración de la calidad de vida, la discapacidad y la evolución clínico-terapéutica de los pacientes. No hay acuerdo entre los autores sobre si existe prioridad en el uso de algún cuestionario concreto por patología y se tiende a combinar varios. Los cuestionarios genéricos más utilizados son SF-36, NHP y EQ-5D. Por enfermedades: en artritis reumatoide, HAQy DAS28; en osteoartritis, WOMAC y Knoos; en Lupus, SLEDAI y BICLA, y en espondilitis, BASDAI y ASDAS. Conclusiones: En reumatología los cuestionarios son de uso habitual y resultan de utilidad de forma complementaria a la historia clínica y a las pruebas específicas. La elección por el profesional médico se basa en su experiencia y en la adecuación al objetivo buscado.

Abstract Introduction: Rheumatic diseases are high prevalence, high impact and repercussion pathologies characterised by pain and functional limitation. To assess the limitation, the starting point is the clinical history, together with the specific tests required according to the type of condition. The use of complimentary clinometric tools is recommended. Objective: To compare some tools or questionnaires used in the most prevalent rheumatic diseases, and a review of the literature to highlight their contributions and usefulness in medical practice by the clinician or expert. Method: A review is made of the basic characteristics of the questionnaires and the most used tools in osteoarthritis, rheumatoid arthritis and psoriatic arthritis, ankylosing spondylitis and systemic lupus erythematosus. The experience of the authors is reviewed in Medline, with some questionnaires depending on the pathology and its various uses. Results: The questionnaires are used mainly to assess the quality of life, disability, and clinical-therapeutic evolution of patients. There is no agreement among the authors on whether there is a priority in the use of a specific questionnaire by pathology, and there is a tendency to combine several. The most commonly used generic questionnaires are SF-36, NHP and EQ-5D. For diseases: in rheumatoid arthritis, the HAQ and DAS28; in osteoarthritis, WOMAC and Knoos; in lupus, SLEDAI and BICLA; and in spondylitis, BASDAI and ASDAS. Conclusions: In rheumatology, questionnaires are commonly used, and are useful as a complement to the clinical history and specific tests. The choice by the medical professional is based on their experience and on the adaptation to the objective sought.

Diabetes mellitus and work. Assessment and questionnaires revision. / Diabetes mellitus y trabajo. Valoración y revisión de cuestionarios.

Diabetes mellitus presents high prevalence, severe complications, clinical repercussions, costs and occupational implications. Their assessment requires the use of the medical history and support questionnaires. A literature review was conducted on the topic of clinical and occupational evaluation aspects of diabetes; the database searched was Medline. The search showed numerous papers about diabetes clinical and therapeutic aspects as well as social or public health aspects but the results lacked occupational aspects. To assess the disease, the use of questionnaires is generalized and each author selects those which fit best to their purpose. It is concluded that to carry out a clinical and occupational evaluation related to diabetes, an inter-specialities cooperation, based on a complete medical history including occupational risk factors, is recommended. The questionnaires are useful, adapted to the objective, recommending those valued in Spanish as in Fear of hypoglycemia questionnaire (EsHFS) and Diabetes-related quality of life questionnaire (EsDQOL).

High pressure processing effect on different Listeria spp. in a commercial starter-free fresh cheese.

In this study, both microbial inactivation and growth of Listeria spp. inoculated in commercial free-starter fresh cheese was evaluated after high-pressure processing (HPP). HPP conditions (300, 400, 500 and 600 MPa at 6 °C for 5 min) and inoculum level (3-4 or 6-7 log CFU/g of cheese), as well as differences among strains inoculated (Listeria innocua, L. monocytogenes CECT 4031 and L. monocytogenes Scott A) were investigated. Inactivation and generation of sublethal injury were determined after HPP using ALOA (Agar Listeria according to Ottaviani and Agosti) and TAL (Thin Agar Layer) plating methods, respectively. Listeria inactivation increased with the pressure applied, presenting some statistical differences between the employed strains, inoculum level and sublethal injury. The highest lethality values were obtained at 600 MPa for the three strains tested, although the 500 MPa treatment presented high lethality for L. innocua and L. monocytogenes CECT 4031. After treatment, L. innocua and L. monocytogenes CECT 4031 counts in fresh cheese increased gradually during cold storage. By contrast, counts in cheeses inoculated with L. monocytogenes Scott A did not change significantly (p ≥ 0.05), being this strain the most pressure resistant and with the slowest growth rate. The manuscript present information supporting that, strains with high-level resistance should be employed during inactivation studies, instead of surrogate microorganisms. Application of HPP treatments of 500 MPa and especially 600 MPa on fresh cheeses would be effective to eliminate the most resistant microorganism to a level that should not present a public health risk under normal conditions of distribution and storage.

Diseño de una herramienta para la valoración y clasificación de la limitación en fibromyalgia / Design of a tool for the assessment and classification of fibromialgia limitation

Resumen Introducción: El síndrome fibromiálgico se caracteriza por dolor crónico asociado a sintomatología somática no específica y con las limitaciones asociadas a su impacto personal, social, laboral y económico. Su valoración se realiza de forma independiente, analizando sus aspectos clínicos, de severidad, los tratamientos y su efectividad, la repercusión en las actividades de la vida diaria y la repercusión o afectación laboral. La herramienta FM-Check es una escala subjetiva que puede ser de ayuda para valorar de forma conjunta todos estos aspectos y servir de apoyo al profesional en el seguimiento del paciente y facilitar la colaboración conjunta interprofesional. Método: Para elaborar la FM-Check se parte de la historia clínica en la que se definen las variables que se van a utilizar agrupándolas en 4 bloques a los que se asignan porcentajes de limitación para cada variable y cada bloque, para llegar a un porcentaje global de limitación en los roles de las personas. Resultados: La distribución de porcentajes por cada bloque es en máximos: 10% para aspectos personales, 55% para clínico-terapéuticos, 24% para laborales y 10% para repercusión en la vida diaria. En función del porcentaje global obtenido tras la valoración del paciente se asignan grados de limitación: grado 1 hasta un porcentaje global < 20%, grado 2 del 20-40%, grado 3 entre el 41-70% y grado 4 > 70%. Conclusión: FM-Check pretende facilitar la labor médica en la evolución del paciente y la toma de decisiones clínico-terapéuticas tras una valoración global de la limitación del paciente con fibromialgia, siguiendo una metodología unificada que permita comparar resultados evolutivos individuales y la realización de estudios epidemiológicos colectivos.

Abstract Introduction: Fibromialgia syndrome is characterised by chronic pain associated with nonspecific somatic symptoms, and has a personal, social, occupational, and economic impact. The assessment is performed independently, by analysing the clinical aspects, severity, therapies, and their effectiveness, as well as the impact on daily life activities and its effect on employment. The FM-Check tool is a subjective scale that can be helpful in jointly assessing all these aspects, and provide professional support in monitoring the patient, as well as contribute to a multidisciplinary approach. Method: To develop FM-Check is developed by starting with the clinical history in which the variables that are going to be used are defined, and grouped into 4 blocks to which a percentage limitation rate is assigned for each variable and each block. An overall percentage limitation is then calculated for the activities in each person. Results: The distribution of assigned percentages was: a maximum of 10% for personal appearance, 55% for clinical-therapeutic aspects, 24% for work aspects, and 10% for impact on everyday life. The limitation levels were classified according to the overall percentage obtained after assessing the patient; grade 1: an overall percentage < 20%, grade 2: 20-40%, grade 3: 41-70%, and grade 4: > 70%. Conclusion: FM-Check aims to make it easier for the clinician to monitor the patient and making medical-therapeutic decisions after an overall assessment of the limitation of the fibromialgia patient. This achieved by following a unified methodology that can compare individual developmental outcomes, as well as for conducting joint epidemiological studies.

[Occupational disability in epilepsy. The assessment criteria]. / La incapacidad laboral en epilepsia. Criterios de valoración.

Epilepsy is a chronic disease cursing with recurrent and paroxysmal crises due to anomalies in the electrical activity of brain, and is controllable in most of the patients by using antiepileptic drugs, in single or combination therapy. Probably one of the most complex aspects of epilepsy is the assessment of disability for work of the affected person. For this purpose, multiple factors need to be taken into account for homogeneous decision-making, and according to criteria of approval and within the principle of equity inherent in the granting of Social Security disability benefits. This requires the cooperation of all professionals involved in the different specialties, with reports using common criteria and taking into account the disease itself, as well as the effects of the prescribed treatments, the effects of which can contribute to the limitations in the performance of certain professions of risk.

[Dry eye syndrome. Occupational risk factors, valuation and prevention]. / Síndrome del ojo seco. Factores de riesgo laboral, valoración y prevención.

Dry eye syndrome in the workplace is associated with new ways of working, with increasing use of screens and electronic devices and environmental conditions encountered in modern office designs and other environments. Also affect occupational exposure to ionizing radiation, chemicals or atmospheric dust with increased ocular dryness. The study of pathophysiological aspects and laboral causality of the dry eye, must be to develop joint task in Occupational Health, Public Health in coordination with and responsible for the national health system, which would involve primary and secondary preventive measures more effective and proper diagnosis, control and monitoring of the disease, A better knowledge of occupational hazards and actions agreed and coordinated between occupational physicians, preventers, primary care physicians and specialist physicians, such as ophthalmology, will get results much more effective when earlier and optimize available resources.

[Costs of temporary disability in Spain related to diabetes mellitus and its complications]. / Costes por incapacidad temporal en España derivados de la diabetes mellitus y sus complicaciones.

INTRODUCTION AND OBJECTIVES: To ascertain the socioeconomic impact of diabetes, it is essential to estimate overall costs, including both direct and indirect costs (premature retirements, working hours lost, or sick leaves). This study analyzed indirect costs for temporary disability (TD) due to diabetes and its complications in Spain in 2011 by assessing the related ICD-9 MC codes. MATERIAL AND METHOD: For this purpose, the number of TD processes and their mean duration were recorded. The indirect costs associated to loss of working days were also estimated. RESULTS: In 2011, diabetes and its complications were related to 2.567 TD processes, which resulted in the loss of 154.214 days. In terms of costs, this disease represented for Spanish public health administrations an expense of 3,297.095.3 €, with an estimated cost per patient and year of 141 €. CONCLUSIONS: These data suggest an urgent need to devise plans for prevention and early diagnosis of diabetes and its complications, as well as programs to optimize the available health care resources by creating multidisciplinary teams where occupational medical services assume an important role. A decrease in absenteeism would result in benefits for diabetic patients, society overall, and companies or public institutions.

[Colorectal cancer in Spain: Temporary disability and preventive occupational strategies]. / El cáncer colorrectal en España. Costes por incapacidad temporal y opciones preventivas desde las empresas.

BACKGROUND: Colorectal cancer is one of the most frequent cancers in both sexes and the most frequent in the developed countries, if men and women are considered together as a group. It has an important associated morbidity and mortality in all countries and constitutes a public health problem with a high direct and indirect economic cost. The number of workdays lost due to temporary disability (TD) is one of the quantifiable references of these indirect costs. AIMS: To determine the indirect cost associated with TD due to colorectal cancer in Spain during the year 2011, a cost that aids in the prevention cost/benefit estimation. METHODS: The number of TD processes, the number of workdays lost due to TD, and the mean duration of those processes, based on the CIE 9-MC codes related to this pathology, as well as the calculated cost, using the Spanish minimum wage as a reference, during the period of January to December 2011, were all reviewed. RESULTS: Colorectal cancer in Spain during 2011 represented 1,046 TD processes, 202,784 workdays lost, and a mean process duration of 194 days/year. The resulting cost of the pathology due to TD was 4,335,521.92 euros. CONCLUSIONS: These results are beneficial for evaluating the usefulness of implementing public health support strategies for a greater reduction in colorectal cancer prevalence and mortality, and an improvement in quality of life of the affected individuals and their families, together with an economic savings resulting from a reduction in TD as a consequence of this disease.

On the exact measure of disease spread in stochastic epidemic models.

The basic reproduction number, R0, is probably the most important quantity in epidemiology. It is used to measure the transmission potential during the initial phase of an epidemic. In this paper, we are specifically concerned with the quantification of the spread of a disease modeled by a Markov chain. Due to the occurrence of repeated contacts taking place between a typical infective individual and other individuals already infected before, R0 overestimates the average number of secondary infections. We present two alternative measures, namely, the exact reproduction number, Re0, and the population transmission number, Rp, that overcome this difficulty and provide valuable insight. The applicability of Re0 and Rp to control of disease spread is also examined.

Stochastic epidemic models with random environment: quasi-stationarity, extinction and final size.

We investigate stochastic [Formula: see text] and [Formula: see text] epidemic models, when there is a random environment that influences the spread of the infectious disease. The inclusion of an external environment into the epidemic model is done by replacing the constant transmission rates with dynamic rates governed by an environmental Markov chain. We put emphasis on the algorithmic evaluation of the influence of the environmental factors on the performance behavior of the epidemic model.

The SIS and SIR stochastic epidemic models: a maximum entropy approach.

We analyze the dynamics of infectious disease spread by formulating the maximum entropy (ME) solutions of the susceptible-infected-susceptible (SIS) and the susceptible-infected-removed (SIR) stochastic models. Several scenarios providing helpful insight into the use of the ME formalism for epidemic modeling are identified. The ME results are illustrated with respect to several descriptors, including the number of recovered individuals and the time to extinction. An application to infectious data from outbreaks of extended spectrum beta lactamase (ESBL) in a hospital is also considered.

On the number of recovered individuals in the SIS and SIR stochastic epidemic models.

The basic models of infectious disease dynamics (the SIS and SIR models) are considered. Particular attention is paid to the number of infected individuals that recovered and its relationship with the final epidemic size. We investigate this descriptor both until the extinction of the epidemic and in transient regime. Simple and efficient methods to obtain the distribution of the number of recovered individuals and its moments are proposed and discussed with respect to the previous work. The methodology could also be extended to other stochastic epidemic models. The theory is illustrated by numerical experiments, which demonstrate that the proposed computational methods can be applied efficiently. In particular, we use the distribution of the number of individuals removed in the SIR model in conjunction with data of outbreaks of ESBL observed in the intensive care unit of a Spanish hospital.

Quasi-stationary and ratio of expectations distributions: a comparative study.

Many stochastic systems, including biological applications, use Markov chains in which there is a set of absorbing states. It is then needed to consider analogs of the stationary distribution of an irreducible chain. In this context, quasi-stationary distributions play a fundamental role to describe the long-term behavior of the system. The rationale for using quasi-stationary distribution is well established in the abundant existing literature. The aim of this study is to reformulate the ratio of means approach (Darroch and Seneta, 1965, 1967) which provides a simple alternative. We have a two-fold objective. The first objective is viewing quasi-stationarity and ratio of expectations as two different approaches for understanding the dynamics of the system before absorption. At this point, we remark that the quasi-stationary distribution and a ratio of means distribution may give or not give similar information. In this way, we arrive to the second objective; namely, to investigate the possibility of using the ratio of expectations distribution as an approximation to the quasi-stationary distribution. This second objective is explored by comparing both distributions in some selected scenarios, which are mainly inspired in stochastic epidemic models. Previously, the rate of convergence to the quasi-stationary regime is taking into account in order to make meaningful the comparison.

Smart investments in sustainable food production: revisiting mixed crop-livestock systems.

Farmers in mixed crop-livestock systems produce about half of the world's food. In small holdings around the world, livestock are reared mostly on grass, browse, and nonfood biomass from maize, millet, rice, and sorghum crops and in their turn supply manure and traction for future crops. Animals act as insurance against hard times and supply farmers with a source of regular income from sales of milk, eggs, and other products. Thus, faced with population growth and climate change, small-holder farmers should be the first target for policies to intensify production by carefully managed inputs of fertilizer, water, and feed to minimize waste and environmental impact, supported by improved access to markets, new varieties, and technologies.

[Clinical evaluation of the Amplified Mycobacterium Tuberculosis Direct 2 test]. / Valoración clínica de la prueba Amplified Mycobacterium tuberculosis Direct 2 (AMTD-2, GenProbe) en el diagnóstico rápido de la tuberculosis.

OBJECTIVE: To evaluate the performance of the Amplified Mycobacterium tuberculosis Direct Test 2- Gen Probe (AMTD- 2) for direct detection of Mycobacterium tuberculosis in smear-negative samples. PATIENTS AND METHODS: From January to December 1999, 683 specimens, 333 respiratory and 350 non-respiratory ones collected from 457 patients, were included in the study. All the samples of HIV-positive patients, the respiratory samples from patients suspected of having pulmonary tuberculosis (at least two by patient) and all non-respiratory samples were included. As diagnosis method of reference, the culture isolation was considered. Clinical data were analyzed in case of discrepant results and clinical diagnosis was considered the reference criteria. The technique was performed once a week. RESULTS: The sensitivity, specificity, and positive and negative predictive values of this assay were 58.9%, 93.9%, 37.1% and 97.4% respectively related to the standard culture. When referred to clinical diagnosis of active tuberculosis, these values improved to 70.4%, 97.7%, 73.1% and 96.8% respectively (in respiratory samples were 67.6%, 98.6%, 86.2% and 95.9% and in nonrespiratory ones 76.5%, 96.9%, 56.5% and 98.7% respectively). The mean time of diagnosis by culture and by AMTD-2 were 20.3 days (range 10-63) and 5.7 days (range 2-20) respectively. DISCUSSION: It is concluded that AMTD-2 is a rapid diagnosis method when clinical data are sugestive with active tuberculosis. However, due to the low positive predictive value, it would be convenient to obtain successive samples to confirm the result in patients without clinical evidence of tuberculosis.

Analysis of the effect of nitric oxide synthase inhibition on mouse sperm employing a modified staining method for assessment of the acrosome reaction.

A commercially available staining kit (Spermac) was combined with swelling in a hypoosmotic medium (HOS) for simultaneous assessment of viability and acrosome reaction in mouse spermatozoa. We compared the results obtained with the combined technique (HOS-Spermac) with those obtained with currently used techniques: the chlortetracycline fluorescence assay and eosin exclusion. The results obtained with HOS-Spermac were the same as those obtained with the chlortetracycline fluorescence assay. Viability assessment with HOS-Spermac showed a good correlation with the percentage of spermatozoa showing eosin dye exclusion. Using this novel technique, we studied the effect of a nitric oxide synthase inhibitor (NG-nitro-L-arginine methyl ester, L-NAME) on the acrosome reaction. L-NAME produced a dose-dependent inhibition of spontaneous acrosome reaction and its inhibitory effect was specifically counteracted by L-arginine. We conclude that HOS-Spermac provides a simple and reliable tool for assessment of the acrosome reaction and that nitric oxide synthase participates in this important function of the spermatozoon.

[Practical training in primary care for nursing students: evaluation assessment by nurses' satisfaction]. / Formación práctica de los alumnos de enfermería en atención primaria: evaluación a través de una encuesta de satisfacción.

OBJECTIVE: To show that nursing skills and activities are acquired by third-year nursing students while they are doing their Primary Care practicals in the Health Centres and to discover the level of satisfaction of the students after these practicals. DESIGN: A descriptive study, using a questionnaire on the level of satisfaction. SETTING: Huerta del Rey Health Centre, Valladolid. PARTICIPANTS: Twenty-four third-year nursing students doing Primary Care practicals during the teaching year 1991-2. MEASUREMENTS AND MAIN RESULTS: Before their practical studies in the Health Centre, 50% or more of the students defined as unknown or little-known the following nursing skills: taking out ear-plugs, extraction of blood, respiratory physiotherapy and stitching. After the nurses had finished the practicals, the items which reflected general satisfaction obtained positive percentages above 72.2%. CONCLUSIONS: Nursing skills and activities which are specific to Primary Care are unknown to most nursing students before their period of practical work in a Health Centre. The same occurs with certain basic nursing skills and activities. Students were highly satisfied.

Audit of ranitidine administration in parenteral nutrient solutions.

An audit of the use of ranitidine administered in parenteral nutrient (PN) solutions is reported. Pharmacists at a 747-bed teaching institution developed criteria addressing justification of the use of ranitidine in PN solutions, process indicators for monitoring, and outcome measures. All patients who received ranitidine in their PN solutions between October 29 and November 22, 1989, were included in the study. Data were collected on a standardized form. A total of 23 evaluable patients received ranitidine in PN solutions during the study period. No inappropriate uses of ranitidine were identified. Patients with renal impairment tended to be underdosed. There were no duplicate administrations of ranitidine by the i.v. minibag and PN solution routes. However, on four occasions the PN solution was interrupted for more than six hours; additional ranitidine by i.v. minibag was ordered for only one of these patients. Testing of nasogastric aspirates for pH was not performed in 17 of the 22 patients who needed this test. Gastrointestinal bleeding was observed in two patients, both of whom were not monitored for gastric pH and were underdosed. A program is being developed to promote the safe and effective use of ranitidine administered in PN solutions. An audit of the administration of ranitidine in PN solutions showed that the drug is usually used appropriately at the institution and that most of the patients had positive clinical outcomes.