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[Usefulness of warning flags in the handling of biological samples in an emergency room].

The present study evaluates the utility of biohazard precautions labels for identifying biological samples of patients with probable severe transmissible infectious diseases. The study was performed in a total of 633 patients in the emergency department of a General Hospital. In an anonymous way we determine the presence or absence of serological markers of HIV and hepatitis B infection (HBsAg) and we evaluated the labeling of the sample. Our results demonstrate the very low usefulness of this common procedure: a total of 54.5% of HIV positive patients and 87.5% of those positive to HBsAg were not marked correctly. We discuss the necessity of using universal precautions instead of labeling samples in the current way.

Blood Specimen Collection↗

[Development of slide-method to distinguish alive and dead mycobacteria by fluorescent staining--a trial for solving the biohazard problem in TB laboratories].

An acid-fast staining can detect mycobacteria in clinical specimens rapidly and specifically. It equally stains living and dead bacteria. It would be of more clinical use if the viability of mycobacteria in a sample was determined by the staining. In the present paper, the problems of FDA/EB staining, which detects live or dead bacteria, were solved by establishing a new technique, a slide-method. An air-dried smear of Mycobacterium bovis BCG (Tokyo 172) on a glass slide was covered by a filter paper fully soaked in the staining solution (500 micrograms FDA and 40 micrograms EB per ml PBS). This was kept in an incubator at 37 degrees C for 20 min. The filter paper was removed after incubation and the slide was examined using a fluorescent microscope with a blue filter. Live bacteria were stained greenish yellow taking the FDA stain in while dead bacteria were stained red with EB. This new slide technique eliminated the problems associated with FDA/EB staining. Moreover, stained smears appeared to be more stable compared with the conventional tube method. To overcome the biohazard problems in smear examination of tubercle bacilli, heating of the slides on a heat block at 100 degrees C for 20 min or passing air dried smears in a flame 5 to 30 times was tried to kill the bacteria. The heat-treated slides were stained with FDA/EB and the number of green and red bacteria were counted. Samples of the smeared bacteria were taken after heating and cultured on a solid medium to determine the presence of any colony-forming unit. It was found that no CFU was observed after heating and the morphology of the stained sample was the same to that before heating. These facts suggest that the above mentioned method is a simple, safe yet inexpensive diagnostic tool for mycobacterial clinical specimens.

Bacteriological Techniques↗

A nose-only apparatus for airborne delivery of Mycobacterium tuberculosis to mice: calibration of biological parameters.

Mycobacterium tuberculosis is the main cause of tuberculosis and is still a public health concern worldwide. This mycobacterium is transmitted through aerosols from human beings suffering from pulmonary tuberculosis to susceptible persons. To study this natural route of infection, we designed a new nose-only aerosol apparatus--system of aerosolisation of microorganisms (SAM)--in a carefully designed biohazard facility. For safety reasons, Mycobacterium smegmatis was first used to calibrate several parameters, such as inoculum density, atmospheric conditions (i.e. hygrometry) and particle size distribution. We present evidence that our apparatus is totally adapted to airborne delivery; the particle size of generated aerosol ranges from 1 to 7 microm, which is ideal for an infection by inhalation. We found that 99% of generated particles (<7 microm) could be retained by the respiratory tract, and among these particles, 62-79% (<3.3 microm) were able to reach pulmonary compartments. The next step was to simultaneously challenge 48 mice with M. tuberculosis in a highly reproducible way. We showed that a moderate dose (4 log10 colony-forming units (CFU) per mice) of M. tuberculosis was capable of causing progressive lung pathology and death in mice 30 days post-aerosolisation. Therefore, our apparatus, once calibrated, is easy to handle, safe, and can be used with any pathogen, which is spread by aerosol.

Aerosols↗

Assessment of Diesse Ves-matic automated system for measuring erythrocyte sedimentation rate.

Measurement of the erythrocyte sedimentation rate (ESR) using a closed tube system reduces the biohazard risk to laboratory staff. The Diesse Ves-matic system offers manual or vacuum collection of blood into plastic tubes, automated mixing of the sample, and automated reading of the end point after 20 minutes of sedimentation. This system was compared with the 1977 Westergren ESR method of the International Council for Standardization in Haematology (ICSH) and with the 1988 ICSH undiluted ESR method. Manually collected Ves-matic samples showed good agreement with ICSH values, although there was a tendency to false low results at low ESR values which may represent dilution of plasma protein with excess citrate. Vacuum collected Ves-matic samples also showed good agreement with ICSH values, although there was a tendency to false high results which may reflect a change in the blood: citrate ratio caused by loss of anticoagulant diluent or vacuum from plastic tubes during storage. The Diesse Ves-matic system incorporates several improvements over previous technology and offers a safer, quicker, and more standardised ESR.

Acute-Phase Reaction↗

[Biohazard in clinical laboratories in Japan].

This survey of occupationally acquired infections in clinical laboratory workers was made by questionnaires to 306 hospitals in which 698 doctors and 8654 technicians worked. There were 177 probable infections during the previous decade (1979-88). In both doctors and technicians annual incidence rate of infection was 0.2% on an average. These included 77 cases of tuberculosis, 59 cases of HBV hepatitis, 24 cases of non-A, non-B hepatitis, 6 cases of rubella, 5 cases of HAV hepatitis, 2 cases of mycoplasmal pneumonia, one case of campylobacter enteritis, one case of paratyphus, one case of salmonellosis and one case of chicken pox. There were no fatal cases. In the recent two years the occurrence of HBV hepatitis among the clinical laboratory workers apparently has decreased, but tuberculosis and non-A, non-B hepatitis occurred unchangedly. Tuberculosis occurred frequently among the staff of the pathology laboratory (40 cases) and in bacteriology (25 cases), but rarely in biochemistry (3 cases) and in hematology (one case). On the other hand, HBV hepatitis occurred frequently among the staff of the biochemistry laboratory (33 cases) and in hematology (11 cases), but rarely in bacteriology (one case). These differences showed the existence of occupational exposure, but only 20% of these cases were due to recognized accidents. According to these results infection control practices for diminishing laboratory-associated infection must be performed.

Containment of Biohazards↗

Genetically-engineered microorganisms: I. Identification, classification, and strain history.

We have argued that accurate identification of the microorganism will form a cornerstone of the assessment of potential hazard. Appropriate methodology for identification exists, and is continually under development and refinement. Organizations such as the American Type Culture Collection will perform certified identifications for relatively low cost. Thus there appears to be little reason that an organism should not be identified insofar as current microbiology allows prior to submission for PMN review. We suggest that a complete microbiological characterization be considered an essential element of an acceptable PMN. To accomplish this, however, current institutional arrangements for the protection of trade secret information needed in the process of identification may need to be improved. An accurate identification of the strain will often provide access to important information with which to evaluate its ecology, pathogenicity, biochemistry, and genetics. Specialized texts, the scientific literature, and professional consultation are ready sources of such information. However, a major effort should be made to establish a data base that can specifically address the needs of biohazard evaluation. This could be done, in part, by collecting information about the construction, and about the behavior in the environment of genetically-engineered microorganisms that are now under development and will soon be tested or used. Identification information may also eventually be useful for the formulation of hypotheses about possible modes of harm or about relative safety, based on phylogenetic relationships. This is a very difficult undertaking at present, however. Microbial taxonomy is currently in a process of radical reevaluation as new macromolecular sequence information reveals previously unsuspected phylogenetic relationships, and disturbs categorizations based on older types of traits such as morphology, etc. This means that both inferences about relative safety and about possible modes of harm from taxonomic relationships must be highly tentative based on current information. Regulatory authorities may wish to consider requesting confirmatory DNA hybridization data or other macromolecular sequence comparisons in cases where strong arguments related to safety must be made from taxonomic information in relatively poorly studied groups of organisms. Detailed strain histories would provide valuable information for safety evaluations.(ABSTRACT TRUNCATED AT 400 WORDS)

Bacteria↗

Laboratory safety aspects of SARS at Biosafety Level 2.

The severe acute respiratory syndrome (SARS)-associated coronavirus causes severe disease, is transmissible to the community and there is no effective prophylaxis or treatment--perhaps fulfilling the criteria for biohazard group 3 or 4. The recommendation to use Biosafety Level (BSL)3 practices within a BSL2 environment appears to have been a practical decision based on available resources; most diagnostic laboratories operate at BSL2. Safety is achieved with controls in administration, engineering and personal protective equipment/behaviour. At the heart of every safety policy is a risk assessment based on the exact manipulations employed. Excessive administrative and engineering controls are less important than the training and personal attitudes, abilities and understanding of the staff. The SARS outbreak focused our attention on the safety aspects of common mundane tasks, such as decapping blood tubes. Laboratories often claim they follow certain practices but casual observation does not always support these claims. Guidelines differed and created uncertainty. This was stressful for laboratory staff held accountable for their implementation. Attempts to categorise risks and their management into neatly wrapped parcels are attractive, but closer inspection reveals a subjective element that allows doubt to creep in with varying interpretations of the literature. Staff most at risk were those handling respiratory samples. Staff receiving samples via pneumatic tubes had least control over their exposure and were potentially exposed to aerosols from leaking samples. Risk assessment remains a balance between cost and benefit.

Clinical Laboratory Techniques↗

Advantages of combined touch screen technology and text hyperlink for the pathology grossing manual: a simple approach to access instructive information in biohazardous environments.

Gross examination, encompassing description, dissection, and sampling, is a complex task and an essential component of surgical pathology. Because of the complexity of the task, standardized protocols to guide the gross examination often become a bulky manual that is difficult to use. This problem is further compounded by the high specimen volume and biohazardous nature of the task. As a result, such a manual is often underused, leading to errors that are potentially harmful and time consuming to correct-a common chronic problem affecting many pathology laboratories. To combat this problem, we have developed a simple method that incorporates complex text and graphic information of a typical procedure manual and yet allows easy access to any intended instructive information in the manual. The method uses the Object-Linking-and-Embedding function of Microsoft Word (Microsoft, Redmond, WA) to establish hyperlinks among different contents, and then it uses the touch screen technology to facilitate navigation through the manual on a computer screen installed at the cutting bench with no need for a physical keyboard or a mouse. It takes less than 4 seconds to reach any intended information in the manual by 3 to 4 touches on the screen. A 3-year follow-up study shows that this method has increased use of the manual and has improved the quality of gross examination. The method is simple and can be easily tailored to different formats of instructive information, allowing flexible organization, easy access, and quick navigation. Increased compliance to instructive information reduces errors at the grossing bench and improves work efficiency.

Containment of Biohazards↗

The Cooperative Human Tissue Network. An update.

BACKGROUND: During the past decade, the National Cancer Institute became aware of a lack of availability of human tissues for research, especially in the fields of molecular biology, genetics, and immunology. METHODS: In 1987, the National Cancer Institute (NCI) established the Cooperative Human Tissue Network (CHTN) by funding three institutions that had extensive experience in the procurement and distribution of tissues for research. RESULTS: Since its inception, the CHTN has been expanded to five member institutions, with the addition of the Columbus Children's Hospital (the Pediatric Division for the procurement of pediatric tissues) and Case Western Reserve University. Each of the five divisions have established regional networks of institutions that supply tissues to the major divisions. From 1987 through 1991, the CHTN has distributed more than 29,000 human tissue samples and supplied approximately 500 researchers throughout the country. CONCLUSIONS: This report describes the development and current status of the CHTN, a valuable resource to the research community.

Containment of Biohazards↗

Urinary sediment analyzed by flow cytometry.

A flow cytometer for the automated analysis of urinary sediment was designed, and its performance was examined by the evaluation of 821 specimens. Auramine O, a dye for DNA and RNA, was used for the staining of the sediment. Urine (5 ml or more) was processed by the instrument for sediment analysis. Conventional microscopic analysis was done for comparison. The RBC count, the WBC count, and the number of bacterial cells, epithelial cells, and casts found by the flow cytometer and by microscopy were compared. Correlation was high for all these results. The overall sensitivity, specificity, and efficiency (accuracy) in the items analyzed were 84.7%, 57.8%, and 67.2%, respectively. One hundred specimens could be analyzed by the instrument per hour. The instrument seemed useful for screening for urinary tract disorders to identify specimens that should be analyzed microscopically in routine laboratories.

Adolescent↗

Measuring containment of viable infectious cell sorting in high-velocity cell sorters.

BACKGROUND: With the advent of high-speed sorters, aerosols are a considerable safety concern when sorting viable infectious materials. We describe a four-part safety procedure for validating the containment. METHODS: This procedure includes aerosol containment, physical barriers, environmental controls, and personal protection. The Aerosol Management System (AMS) produces a negative pressure within the sort chamber, where aerosols are forced through a HEPA filter. Physical barriers include the manufacturer's standard plastic shield and panels. The flow cytometer was contained within a BSL-3 laboratory for maximum environmental control, and the operator was protected by a respiratory system. Containment was measured by using highly fluorescent Glo-Germ particles under the same conditions as the cell sort. RESULTS: Escaping aerosols were vacuumed for 10 min onto a glass slide and examined. With the AMS active and the cytometer producing the maximum aerosols possible, Glo-Germ particles remained within the sort chamber. Measurements taken directly outside the door averaged fewer than one particle per slide, and those taken at 2 ft away and on top of the sorter were completely negative. CONCLUSIONS: With this monitoring system in place, aerosols can be efficiently measured, thus reducing the risk to the operator while sorting viable infectious cells.

Aerosols↗

Containment system for the preparation of vitrified-hydrated virus specimens.

A guillotine-type quick freezing device and a bio-hazard containment box have been designed, constructed, and used to prepare vitrified-hydrated specimens of viruses in their native environment. Special design considerations include the preservation of the specimen in its natural state in vitrified ice, prevention of virus aerosols escape, and control of the potentially explosive air-coolant vapor mixtures.

Containment of Biohazards↗

Toxicity of three oil spill remediation techniques to the Australian bass Macquaria novemaculeata.

Australian bass, Macquaria novemaculeata, were exposed to the water accommodated fraction (WAF) of Bass Strait crude oil, dispersed crude oil, burnt crude oil, and 4-chlorophenol. The WAF of dispersed crude oil was the most toxic treatment with 96-h LC(50) values of 7. 15% (7.94% upper and 6.42% lower 95% CI) and 7.45% (8.26% upper and 6.71% lower 95% CI). The WAF of crude oil was less toxic, with 96-h LC(50) values of 43.72% (49.21% upper and 38.87% lower 95% CI) and 45.87% (51.51% upper and 40.97% lower 95% CI). The WAF of burnt crude oil was the least toxic treatment with 96-h LC(50) values of 49.81% (63.33% upper and 39.44% lower 95% CI) and 47.28% (59.72% upper and 37.62% lower 95% CI). Sublethal toxicity of the crude oil WAF and burnt crude oil WAF was observed at dilutions seven to eight times less than in the dispersed crude oil WAF.

Animals↗