viernes, 26 de agosto de 2016

Engineered nanomaterials: toward effective safety management in research laboratories

Background: It is still unknown which types of nanomaterials and associated doses represent an actual danger to humans and environment. Meanwhile, there is consensus on applying the precautionary principle to these novel materials until more information is available. To deal with the rapid evolution of research, including the fast turnover of collaborators, a user-friendly and easy-to-apply risk assessment tool offering adequate preventive and protective measures has to be provided.
Results: Based on new information concerning the hazards of engineered nanomaterials, we improved a previously developed risk assessment tool by following a simple scheme to gain in efficiency. In the first step, using a logical decision tree, one of the three hazard levels, from H1 to H3, is assigned to the nanomaterial. Using a combination of decision trees and matrices, the second step links the hazard with the emission and exposure potential to assign one of the three nanorisk levels (Nano 3 highest risk; Nano 1 lowest risk) to the activity. These operations are repeated at each process step, leading to the laboratory classification. The third step provides detailed preventive and protective measures for the determined level of nanorisk.
Conclusions: We developed an adapted simple and intuitive method for nanomaterial risk management in research laboratories. It allows classifying the nanoactivities into three levels, additionally proposing concrete preventive and protective measures and associated actions. This method is a valuable tool for all the participants in nanomaterial safety. The users experience an essential learning opportunity and increase their safety awareness. Laboratory managers have a reliable tool to obtain an overview of the operations involving nanomaterials in their laboratories; this is essential, as they are responsible for the employee safety, but are sometimes unaware of the works performed. Bringing this risk to a three-band scale (like other types of risks such as biological, radiation, chemical, etc.) facilitates the management for occupational health and safety specialists. Institutes and school managers can obtain the necessary information to implement an adequate safety management system. Having an easy-to-use tool enables a dialog between all these partners, whose semantic and priorities in terms of safety are often different.

Groso, Amela et al. “Engineered Nanomaterials: Toward Effective Safety Management in Research Laboratories.” Journal of Nanobiotechnology 14 (2016): 21. PMC. Web. 18 Aug. 2016.

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miércoles, 24 de agosto de 2016

#UANL: 2º Taller "Control de Riesgos Biológicos en Laboratorios de Investigación"

2º Taller "Control de Riesgos Biológicos en Laboratorios de Investigación"
12 de Septiembre de 2016
Facultad de Ciencias Biológicas, UANL.
Ciudad Universitaria, San Nicolás de los Garza, Nuevo León.

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lunes, 22 de agosto de 2016

Use of Protective Gloves in Nail Salons in Manhattan, New York City

Objectives: Nail salon owners in New York City (NYC) are required to provide their workers with gloves and it is their responsibility to maintain healthy, safe working spaces for their employees. The purpose of this study was to determine the frequency with which nail salon workers wear protective gloves.
Methods: A Freedom of Information Law request was submitted to New York Department of State’s Division of Licensing Services for a full list of nail salons in Manhattan, NYC. A sample population of 800 nail salons was identified and a simple random sample (without replacement) of 30% (n=240) was selected using a random number generator. Researchers visited each nail salon from October to December of 2015, posing as a potential customer to determine if nail salon workers were wearing gloves.
Results: Among the 169 salons in which one or more workers was observed providing services, a total of 562 workers were observed. For 149 salons, in which one or more worker was observed providing services, none of the workers were wearing gloves. In contrast, in six of the salons observed, in which one or more workers was providing services, all of the workers (1 in 2 sites, 2 in 1 site, 3 in 2 sites, and 4 in 1 site) were wearing gloves. Almost three-quarters of the total number of workers observed (n=415, 73.8%) were not wearing gloves.
Conclusions: The findings of this study indicate that, despite recent media attention and legislation, the majority of nail salon workers we observed were not wearing protective gloves when providing services.

Basch, Corey et al. “Use of Protective Gloves in Nail Salons in Manhattan, New York City.” Journal of Preventive Medicine and Public Health 49.4 (2016): 249–251. PMC. Web. 18 Aug. 2016.

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jueves, 18 de agosto de 2016

Performance analysis of exam gloves used for aseptic rodent surgery

Aseptic technique includes the use of sterile surgical gloves for survival surgeries in rodents to minimize the incidence of infections. Exam gloves are much less expensive than are surgical gloves and may represent a cost-effective, readily available option for use in rodent surgery. This study examined the effectiveness of surface disinfection of exam gloves with 70% isopropyl alcohol or a solution of hydrogen peroxide and peracetic acid (HP-PA) in reducing bacterial contamination. Performance levels for asepsis were met when gloves were negative for bacterial contamination after surface disinfection and sham 'exertion' activity. According to these criteria, 94% of HP-PA-disinfected gloves passed, compared with 47% of alcohol-disinfected gloves. In addition, the effect of autoclaving on the integrity of exam gloves was examined, given that autoclaving is another readily available option for aseptic preparation. Performance criteria for glove integrity after autoclaving consisted of: the ability to don the gloves followed by successful simulation of wound closure and completion of stretch tests without tearing or observable defects. Using this criteria, 98% of autoclaved nitrile exam gloves and 76% of autoclaved latex exam gloves met performance expectations compared with the performance of standard surgical gloves (88% nitrile, 100% latex). The results of this study support the use of HP-PA-disinfected latex and nitrile exam gloves or autoclaved nitrile exam gloves as viable cost-effective alternatives to sterile surgical gloves for rodent surgeries.

LeMoine DM, et al. Performance analysis of exam gloves used for aseptic rodent surgery. J Am Assoc Lab Anim Sci. 2015 May;54(3):311-6.
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lunes, 15 de agosto de 2016

Gain-of-Function Research: Ethical Analysis

Gain-of-function (GOF) research involves experimentation that aims or is expected to (and/or, perhaps, actually does) increase the transmissibility and/or virulence of pathogens. Such research, when conducted by responsible scientists, usually aims to improve understanding of disease causing agents, their interaction with human hosts, and/or their potential to cause pandemics. The ultimate objective of such research is to better inform public health and preparedness efforts and/or development of medical countermeasures. Despite these important potential benefits, GOF research (GOFR) can pose risks regarding biosecurity and biosafety. In 2014 the administration of US President Barack Obama called for a "pause" on funding (and relevant research with existing US Government funding) of GOF experiments involving influenza, SARS, and MERS viruses in particular. With announcement of this pause, the US Government launched a "deliberative process" regarding risks and benefits of GOFR to inform future funding decisions-and the US National Science Advisory Board for Biosecurity (NSABB) was tasked with making recommendations to the US Government on this matter. As part of this deliberative process the National Institutes of Health commissioned this Ethical Analysis White Paper, requesting that it provide (1) review and summary of ethical literature on GOFR, (2) identification and analysis of existing ethical and decision-making frameworks relevant to (i) the evaluation of risks and benefits of GOFR, (ii) decision-making about the conduct of GOF studies, and (iii) the development of US policy regarding GOFR (especially with respect to funding of GOFR), and (3) development of an ethical and decision-making framework that may be considered by NSABB when analyzing information provided by GOFR risk-benefit assessment, and when crafting its final recommendations (especially regarding policy decisions about funding of GOFR in particular). The ethical and decision-making framework ultimately developed is based on the idea that there are numerous ethically relevant dimensions upon which any given case of GOFR can fare better or worse (as opposed to there being necessary conditions that are either satisfied or not satisfied, where all must be satisfied in order for a given case of GOFR to be considered ethically acceptable): research imperative, proportionality, minimization of risks, manageability of risks, justice, good governance (i.e., democracy), evidence, and international outlook and engagement. Rather than drawing a sharp bright line between GOFR studies that are ethically acceptable and those that are ethically unacceptable, this framework is designed to indicate where any given study would fall on an ethical spectrum-where imaginable cases of GOFR might range from those that are most ethically acceptable (perhaps even ethically praiseworthy or ethically obligatory), at one end of the spectrum, to those that are most ethically problematic or unacceptable (and thus should not be funded, or conducted), at the other. The aim should be that any GOFR pursued (and/or funded) should be as far as possible towards the former end of the spectrum.

Selgelid MJ. Gain-of-Function Research: Ethical Analysis. Sci Eng Ethics. 2016 Aug 8. doi:10.1007/s11948-016-9810-1

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viernes, 12 de agosto de 2016

Soliciting Stakeholder Input for a Revision of Biosafety in Microbiological and Biomedical Laboratories (BMBL): Proceedings of a Workshop.

Since its publication by the National Institutes of Health (NIH) and the Centers for Disease Control and Prevention (CDC) in 1984, Biosafety in Microbiological and Biomedical Laboratories (BMBL) has become the cornerstone of the practice of biosafety in the United States and in many countries around the world. The BMBL has been revised periodically over the past three decades to refine the guidance it provides based on new knowledge and experiences—allowing it to remain a relevant, valuable, and authoritative reference for the microbiological and biomedical community. Seven years after the release of the BMBL 5th Edition, NIH and CDC are considering a revision based on the comments of a broader set of stakeholders. At the request of NIH, the National Academies of Sciences, Engineering and Medicine conducted a virtual town hall meeting from 4 April to 20 May 2016 to allow BMBL users to share their thoughts on the BMBL in general and its individual sections and appendices. Specifically, users were asked to indicate what information they think should be added, revised, or deleted. Major themes from the virtual town hall meeting were further discussed in a workshop held on 12 May 2016 in Washington, DC. This document encapsulates the discussion of the major comments on the BMBL that were posted on the virtual town hall prior to 12 May 2016 and the various BMBL comments and issues related to biosafety that were raised during the workshop by participants who attended the meeting in Washington DC and those who listened to the live webcast.

Board on Agriculture and Natural Resources; Division on Earth and Life Studies; National Academies of Sciences, Engineering, and Medicine. Soliciting Stakeholder Input for a Revision of Biosafety in Microbiological and Biomedical Laboratories (BMBL): Proceedings of a Workshop. WASHINGTON (DC): National Academies Press (US); 2016 Jul.
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viernes, 29 de julio de 2016

Interim Guidance for Health Care Providers Caring for Pregnant Women with Possible #Zika Virus Exposure

CDC has updated its interim guidance for U.S. health care providers caring for pregnant women with possible Zika virus exposure, to include the emerging data indicating that Zika virus RNA can be detected for prolonged periods in some pregnant women. To increase the proportion of pregnant women with Zika virus infection who receive a definitive diagnosis, CDC recommends expanding real-time reverse transcription–polymerase chain reaction (rRT-PCR) testing. Possible exposures to Zika virus include travel to or residence in an area with active Zika virus transmission, or sex* with a partner who has traveled to or resides in an area with active Zika virus transmission without using condoms or other barrier methods to prevent infection.† Testing recommendations for pregnant women with possible Zika virus exposure who report clinical illness consistent with Zika virus disease§ (symptomatic pregnant women) are the same, regardless of their level of exposure (i.e., women with ongoing risk for possible exposure, including residence in or frequent travel to an area with active Zika virus transmission, as well as women living in areas without Zika virus transmission who travel to an area with active Zika virus transmission, or have unprotected sex with a partner who traveled to or resides in an area with active Zika virus transmission). Symptomatic pregnant women who are evaluated <2 weeks after symptom onset should receive serum and urine Zika virus rRT-PCR testing. Symptomatic pregnant women who are evaluated 2–12 weeks after symptom onset should first receive a Zika virus immunoglobulin (IgM) antibody test; if the IgM antibody test result is positive or equivocal, serum and urine rRT-PCR testing should be performed. Testing recommendations for pregnant women with possible Zika virus exposure who do not report clinical illness consistent with Zika virus disease (asymptomatic pregnant women) differ based on the circumstances of possible exposure. For asymptomatic pregnant women who live in areas without active Zika virus transmission and who are evaluated <2 weeks after last possible exposure, rRT-PCR testing should be performed. If the rRT-PCR result is negative, a Zika virus IgM antibody test should be performed 2–12 weeks after the exposure. Asymptomatic pregnant women who do not live in an area with active Zika virus transmission, who are first evaluated 2–12 weeks after their last possible exposure should first receive a Zika virus IgM antibody test; if the IgM antibody test result is positive or equivocal, serum and urine rRT-PCR should be performed. Asymptomatic pregnant women with ongoing risk for exposure to Zika virus should receive Zika virus IgM antibody testing as part of routine obstetric care during the first and second trimesters; immediate rRT-PCR testing should be performed when IgM antibody test results are positive or equivocal. This guidance also provides updated recommendations for the clinical management of pregnant women with confirmed or possible Zika virus infection. These recommendations will be updated when additional data become available.

Oduyebo T, et al. Update: Interim Guidance for Health Care Providers Caring for Pregnant Women with Possible Zika Virus Exposure — United States, July 2016. MMWR Morb Mortal Wkly Rep 2016;65:739–744. DOI:

Brooks JT, et al. Update: Interim Guidance for Prevention of Sexual Transmission of Zika Virus — United States, July 2016. MMWR Morb Mortal Wkly Rep 2016;65:745–747. DOI:
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jueves, 28 de julio de 2016

HISTORY 1951: Yellow fever and Max Theiler: the only Nobel Prize for a virus vaccine

Max Theiler receives the Nobel Prize in Physiology or
Medicine from the hands of  His Majesty the King Gustaf
Adolf VI on December 10, 1951. Photo provided by the
Karolinska Institutet.

In 1951, Max Theiler of the Rockefeller Foundation received the Nobel Prize in Physiology or Medicine for his discovery of an effective vaccine against yellow fever—a discovery first reported in the JEM 70 years ago. This was the first, and so far the only, Nobel Prize given for the development of a virus vaccine. Recently released Nobel archives now reveal how the advances in the yellow fever vaccine field were evaluated more than 50 years ago, and how this led to a prize for Max Theiler.

Norrby, Erling. “Yellow Fever and Max Theiler: The Only Nobel Prize for a Virus Vaccine.” The Journal of Experimental Medicine 204.12 (2007): 2779–2784. PMC. Web. 27 July 2016.
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miércoles, 20 de julio de 2016

Hipoclorito de sodio como agente desinfectante

Este artículo es sobre soluciones desinfectantes, siga el link para ver la >> desinfección de agua potable <<. 
Publicado originalmente el 19 de Julio de 2008.
El hipoclorito de sodio (NaOCl) es un compuesto oxidante de rápida acción utilizado a gran escala para la desinfección de superficies, desinfección de ropa hospitalaria y desechos, descontaminar salpicaduras de sangre, desinfección de equipos y mesas de trabajo resistentes a la oxidación, eliminación de olores y desinfección del agua. Los equipos o muebles metálicos tratados con cloro, tienden a oxidarse rápidamente en presencia de hipoclorito de sodio.
El hipoclorito de sodio es vendido en una solución clara de ligero color verde-amarillento y un olor característico. Como agente blanqueante de uso domestico normalmente contiene 5-6.5% de hipoclorito de sodio (con un pH de alrededor de 11, es irritante y corrosivo a los metales). Cuando el hipoclorito se conserva en su contenedor a temperatura ambiente y sin abrirlo, puede conservarse durante 1 mes, pero cuando se ha utilizado para preparar soluciones, se recomienda
 su cambio diario. Entre sus muchas propiedades incluyen su amplia y rápida actividad antimicrobiana, relativa estabilidad, fácil uso y bajo costo.
El hipoclorito es letal para varios microorganismos, virus y bacterias vegetativas, pero es menos efectivo contra esporas bacterianas, hongos y protozoarios. La actividad del hipoclorito se ve reducida en presencia de iones metálicos, biocapas, materiales orgánicos, bajo pH o luz UV. Las soluciones de trabajo deben ser preparadas diariamente. El cloro comercial que contiene 5-6%, que será utilizado para la desinfección de superficies, debe ser diluído 1:10 para obtener una concentración final de aproximadamente 0.5% de hipoclorito. Cuando se quiere desinfectar líquidos que pueden contener material orgánico, debe tenerse una concentración final de 1% de hipoclorito.
Gracias a su alta disponibilidad continua siendo de alto uso en hospitales. Pueden encontrar otras características y hojas de seguridad del hipoclorito de sodio. 

Antes de someter materiales o superficies a procesos de desinfección, es recomendable realizar un lavado con agua y jabón, para eliminar los materiales orgánicos presentes, que pueden interferir en la efectividad del hipoclorito de sodio. Antes de elegir un agente desinfectante, por favor revisa su efectividad para el microorganismo que te interesa.
Concentraciones recomendadas:
  • Venta al público: (Blanqueador casero, presentación comercial): 5-6 % (50-60 g/l, 50,000 ppm) de cloro libre
  • Para limpieza general, desinfección de manos, desinfección de ropa: 0.05% (500 mg/L; 500 ppm) *
  • Para desinfección general de áreas sin materia orgánica:  0.5% (5g/L;  5,000 ppm)
  • Para desinfección con material orgánico o derrames:  1 % (10 g/l, 10,000 ppm)
Cualquier concentración puede ser utilizada para obtener una solución de hipoclorito diluída utilizando la siguiente fórmula:  =>

Por ejemplo para preparar una solución 0.5% a partir de una 4.5% de hipoclorito de sodio se utilizarán 8 partes de agua con 1 parte de agua. 
Donde "parte" puede ser utilizado para cualquier unidad de medida (litro, mililitro, galones, etc), o utilizando cualquier medidor (taza, frasco, garrafón, etc). En paises de habla francesa, la cantidad de hipoclorito se expresa como "grados de cloro". Un grado de cloro = 0.3% de cloro activo. (Ref. 8)

Otra fórmula para calcular el volumen necesario para preparar el hipoclorito de sodio 0.5% a partir de una solución concentrada:

Toda la ropa de cama que ha estado en contacto con pacientes puede estar contaminado con líquidos o fluidos corporales (orina, sangre, vómito). Cuando se manejan este tipo de ropa, debe utilizarse equipo de protección adecuado, pero debe incluirse, guantes, mascarillas, lentes de protección, batas y botas. Los excesos de excremento deberán retirarse y colocarse en bolsas para desechos. Antes de desinfectar, deberá realizarse un lavado en lavadora con agua y jabón. Enjuagar para eliminar el exceso de jabón. Finalmente, colocar las sábanas en una solución de hipoclorito de sodio al 0.05%, durante por lo menos 30 minutos ó una hora. Puede realizarse un segundo enjuague para eliminar el exceso de hipoclorito, y continuar con los procesos normales de secado. 
El lavado a mano debe evitarse en la medida de lo posible. Cuando por las condiciones, no puede utilizarse lavadoras automáticas, las sábanas deberán colocarse en un gran contenedor con agua caliente y jabón, y agitar en círculos con un palo o varilla. Eliminar el agua, y colocar una solución al 0.1% de hipoclorito de sodio por 15 minutos, sumergiendo completamente las sábanas. Enjuagar nuevamente y dejar secar, evitando sacudir en la medida de lo posible (Ver Ref. 8).


Para la desinfección de líquidos que puedan contener microorganismos, debe prepararse una solución al 2% de hipoclorito de sodio. Posteriormente, mezclar en proporción 1:1 (1 volumen de desinfectante, 1 volumen de líquido). De esta forma, al final tendrá una concentración de 1%. Dejar reposar durante 30 minutos. Por ejemplo: 200 ml de orina + 200 ml de solución de hipoclorito de sodio al 2%.

Para desinfectar superficies o materiales de laboratorio (que no sean metálicos), que no contengan material orgánico, deberá usarse una solución de hipoclorito de sodio al 0.5%. Por ejemplo, para desinfectar gradillas de laboratorio de plástico, sumérjalas en la solución al 0.5% por al menos 30 minutos.

Sobre la inestabilidad del cloro:
Una vez preparadas, las soluciones guardadas a 25ºC, en recipientes cerrados, contenedores opacos, pierden 50% de su contenido de cloro libre en un periodo de 30 días. Una solución al 1%, tendrá solo 0.5% de cloro 30 días después de preparado. Las soluciones al 5% se degradan más lentamente si se almacenan en contenedores obscuros. A mayor temperatura y con mayor cantidad de luz que reciban, el proceso de degradación se acelera. 
Referencia: Guideline for disinfection and Sterlization in healthcares facilities, 2008.

Sobre la toxicidad del cloro:
El hipoclorito de sodio ocasiona:
  • Irritación ocular, orofaríngea, esofagial y quemaduras gástricas.
  • Corrosión a los metales 
  • Reacciona de forma tóxica con el amoniaco y ácidos (presente en los productos desinfectantes comunes), por lo que no deben hacerse mezclas de desinfectantes.
  • Producción de carcinógeno bis (clorometil) eter cuando se mezcla con formaldehído.
  • Producción de carcinógeno trihalometano cuando el agua es hiperclorinada (exceso de cloro).

Por favor visite esta página para ver las características y tratamiento de la intoxicación por cloro:

  1. Rutala WA and Weber DJ. Uses of Inorganic Hypochlorite (Bleach) in Health-Care Facilities. Clinical Microbiological Reviews 1997; 10(4):597-610. PDF. 
  2. Enviromental Health and Safety. University of Kentucky. PDF.
  3. Uso de desinfectantes. Guías para la prevención, control y vigilancia epidemiológica de infecciones intrahospitalarias. Secretaría Distrital de Salud de Bogotá. PDF.
  4. Githui WA, Matu SW, Tunge N, Juma E. Biocidal effect of bleach on Mycobacterium tuberculosis: a safety measure. Int J Tuberc Lung Dis 2007. 11(7):798–802. PDF.
  5. Hojas de seguridad de microorganismos, con las recomendaciones de agentes desinfectantes.
  6. Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008. CDC.
  7. Intoxicación con hipoclorito de sodio
  8. How to make chlorine solutions for environmental disinfection (Annex 6 from Interim Infection Prevention and Control Guidance for Care of Patients with Suspected or Confirmed Filovirus Haemorrhagic Fever  in Health-Care Settings, with Focus on Ebola 2014)
  9. OSHA: Cleaning and Decontamination of #Ebola on Surfaces. Guidance for Workers and Employers in Non-Healthcare/Non-Laboratory Settings
  10. For General Healthcare Settings in West Africa: How to Prepare and Use Chlorine Solutions

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