Disinfection of corona virus in histopathology laboratories

Severe acute respiratory syndrome (SARS CoV-2/COVID-19) is a highly contagious and deadly disease caused by a virus belonging to the coronaviridae family. Researchers working in histopathology laboratories, dealing with morbid samples, are particularly vulnerable to infection unless they have very strong immunity. Hence, a proper precautionary protocol is required for the safety of the laboratory staff. The current review highlights the biological and physical agents that can be used to inactivate the virus and disinfect the surrounding environment in the laboratory.     

Working with male rodents may increase risk of allergy to laboratory animals

BACKGROUND: Our aim was to study the risk of laboratory animal allergy (LAA) among research staff working in laboratories separate from the animal confinement area. The roles of atopy and exposure intensity in LAA were studied with special regard to exposure to male rodents, who excrete higher levels of urinary allergens than female rodents. METHODS: Eighty rodent-exposed subjects gave blood samples for the analysis of total IgE, Phadiatop, and specific IgE against rat (RUA) and mouse urinary allergens (MUA), and answered questionnaires. Air samples were collected for RUA and MUA aeroallergen measurement in both laboratories and animal confinement facilities. RESULTS: Twenty percent of the subjects had IgE >0.35 kU/l to RUA and/or MUA, and 32% had experienced animal work-related symptoms, although 90% of aeroallergen samples from the research department laboratories were below the detection limit (<0.26 ng RUA per m(3) and <0.8 ng MUA per m(3)). Atopy (positive Phadiatop), total IgE >100 kU/l, other allergies (especially to other animals), or more than 4 years of exposure significantly increased laboratory animal sensitization and symptoms. Working with mainly male rodents gave odds ratios (95% CI) of 3.8 (0.97-15) for sensitization and 4.4 (1.4-14) for symptoms. Subjects with both exposure to mainly male rodents and atopy or elevated total IgE had a 10-fold higher frequency of sensitization than exposed subjects with neither risk factor. CONCLUSION: A majority of subjects with a combination of exposure to mainly male rodents and atopy or elevated total IgE developed sensitization to and symptoms from laboratory animals. Current low exposure seems to maintain the presence of specific IgE. Further measures must be undertaken to provide a safe workplace for laboratory animal workers.     

BSL-2实验室开展SARS-CoV-2核酸检测过程中的生物安全管理

目的:总结生物安全二级(bio-safety level 2,BSL-2)实验室开展新型冠状病毒(severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)核酸检测过程中的生物安全管理经验与效果。方法:检测样本来源于2020年2月21日到2020年11月5日送达中国疾控中心病毒病预防控制所病毒资源中心科室的人体咽拭子、鼻拭子、痰液、尿液、便液等。在遵循常规生物安全管理要求的基础上,在检测过程中积极进行人员、岗位、标本、过程、安全巡视等生物安全管理。结果:共开展了27692人次样本的SARS-CoV-2核酸检测,平均每天检测(2.32±0.11)批样本,每批平均检测(87.22±6.83)件样本,BSL-2实验室平均每天工作时间(3.43±0.23)h。在检测过程中未出现任何生物安全问题。结论:BSL-2实验室在长时间的SARS-CoV-2核酸检测过程中,要积极从多方面加强生物安全管理,从而保障检测工作安全有序进行。     

Coronavirus disinfection in histopathology

ABSTRACT

The 2019 Coronavirus epidemic, provisionally called 2019-nCoV, was first identified in Wuhan, China, in persons exposed to a seafood or wet market. There is an international push to contain the virus and prevent its spread. It is feasible that potentially infectious samples may be received in histopathology laboratories for diagnosis. This technical note presents disinfection procedures and histotechnology processes that should alleviate the risk of infection to laboratory staff. Using data obtained from similar coronaviruses, e.g. severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), experts are confident that 70% ethanol and 0.1% sodium hypochlorite should inactivate the virus. Formalin fixation and heating samples to 56oC, as used in routine tissue processing, were found to inactivate several coronaviruses and it is believed that 2019-nCoV would be similarly affected.     

Brucella abortus RB51 Strain Sent in a Proficiency Testing Panel to Clinical and Public Health Laboratories

In early 2017, a laboratory proficiency testing panel, designed to assess laboratory competency for culture and identification of bacterial organisms, was distributed to clinical and public health microbiology laboratories. The panel included a Brucella abortus RB51 isolate. Although B. abortus RB51 is an attenuated Brucella species strain, it still poses some risk to laboratory personnel, particularly if safety precautions and personal protective equipment are not adequately deployed. The PT event highlighted the challenges that clinical and public health microbiology laboratories face when handling samples that can contain highly transmissible organisms that can lead to laboratory-acquired infections. This review describes the B. abortus RB51 PT event, its associated exposures, and subsequent medical interventions. General considerations for handling Brucella species, including RB51, in the clinical microbiology laboratory are also discussed. Finally, we describe lessons learned from this event, including improving a “culture of safety” in the clinical laboratory.     

Detection of the gene rearrangement in chronic myelogenous leukemia with biotinylated gene probes

The breakpoint cluster region gene rearrangement associated with chronic myelogenous leukemia is becoming important in the diagnosis and management of the disease. At this time, the ability to demonstrate the gene rearrangement is limited to a few research laboratories. The problem results partially from unfamiliarity of medical laboratory personnel with DNA technology, but more because of the restricted use of radiolabeled phosphorus in hospital laboratories. With the introduction of biotinylated deoxynucleotides, nucleic acid hybridization procedures can now be performed without the use of radioisotopically labeled gene probes. This article describes the use of biotin-labeled gene probes to detect the gene rearrangement of the breakpoint cluster region of chromosome 22 in chronic myelogenous leukemia. The techniques are reproducible, sensitive, and safe. With the procedures described in this article, the assay can become more available to medical laboratories interested in offering this diagnostic and decision-making tool.     

Emergent viruses: SARS-associate coronavirus and H5N1 influenza virus

Two viral agents with RNA genome are responsible for emerging illnesses: influenza virus A/H5N1 and Severe Acute Respiratory Syndrome virus (SARS). For the diagnosis of SARS virus infection, an epidemiological investigation is necessary to know whether the patient has been exposed to a risk in a country where the SARS virus is circulating or whether the patient had worked in a laboratory handling SARS virus. The detection of SARS virus is possible in various clinical samples (including urine) by viral culture or RT-PCR. The handling of those samples and RNA extraction must be performed in a BSL3 laboratory. The SARS virus RT-PCR is poorly sensitive, therefore the test should be performed on samples collected consecutively for several days. In front of a suspicion of A/H5N1, similar procedures are recommended. An epidemiologic investigation is necessary to specify whether the patient stayed in a country where A/H5N1 virus was circulating. Clinical samples needed for a specific diagnosis are: nasopharyngeal, throat-swab or fecal samples, cerebrospinal fluid and blood. The presence of A/H5N1 virus is confirmed by viral isolation or RNA detection by RT-PCR. RNA extraction must be performed in a BSL3 laboratory. For diagnosis of A/H5N1 virus infection, RT-PCR test amplifies specifically a fragment of H5 gene (Hemagglutinin). In french laboratories of medical virology, procedures are ready to diagnose the first case of A/H5N1 virus infection and cases of reemerging SARS virus infection.     

U.S. hospital mycobacteriology laboratories: status and comparison with state public health department laboratories.

In response to the resurgence of tuberculosis, the Centers for Disease Control and Prevention recommended the use of certain mycobacteriology laboratory methods to improve the accuracy of diagnosis and/or minimize times to complete specimen processing. A study to determine the extent to which these recommended methods were being used in hospital laboratories was needed. In 1992, a survey was mailed to infection control and laboratory personnel at 1,076 hospitals with > or = 100 beds to determine the mycobacterial laboratory services being performed, the methods being used, the number of specimens being processed, and the times to completion during 1991. In 1995, a 20% sample of hospital laboratories that responded to the initial questionnaire was resurveyed. Responses to the 1992 survey were received from personnel at 756 (70%) hospitals representing 750 laboratories. Among laboratories performing the services, the use of recommended methods was as follows: fluorochrome stain for acid-fast bacillus microscopy (47%); radiometric methods for primary culture (29%); rapid (radiometric methods, use of nucleic acid probes, high-performance liquid chromatography, or gas-liquid chromatography) methods for identification of Mycobacterium tuberculosis (59%); and radiometric methods for drug susceptibility testing (55%). Reported times to complete specimen processing were shortest for laboratories that used recommended methods and longest for hospitals that referred specimens to outside laboratories. Only 46% of surveyed laboratories performed at least the minimal number of mycobacterial cultures (20/week) deemed necessary to maintain competence. Among 145 laboratories that performed the services and were resurveyed in 1995, use of recommended techniques increased from 44 to 73% for acid-fast bacillus microscopy, from 27 to 37% for primary culture, from 59 to 88% for M. tuberculosis identification, and from 55 to 75% for drug susceptibility testing. These changes were associated with reductions in reported specimen turnaround times. Use of the methods recommended by the Centers for Disease Control and Prevention increased at the resurveyed hospital mycobacteriology laboratories between 1991 and 1995. However, continued efforts are needed to increase the use of recommended methods at moderate- and high-volume laboratories, encourage referral of specimens from low-volume laboratories, and transmit results rapidly from all laboratories.     

International Federation of Clinical Chemistry. The expanding role of robotics in the clinical laboratory.

Increasing numbers of robots are going to be employed industrial chemical laboratories. Most of these will be used to reduce the monotonous tasks of sample preparation, to minimize human exposure to dangerous environments or to carry out huge numbers of repetitive experimental procedures. For example, looking for the most effective condition or combination in chemical synthesis or the best microorganism in a large number of cultures. In the clinical laboratory the situation is slightly different and robotics is not so widely applied in clinical laboratories, but there is a definite trend to employ robots or robotic systems both to reduce labor volume and exposure of employees to possible biohazards and to help get more precise and correct results. These needs will be hard to fulfill via the usual automated devices and especially when adequate devices are not available. Specially designed machines will have to be produced to satisfy these demands and robotics will play a part. Finally we need to evaluate the effectivity of introduction of robotics in terms of economy, strategy, biosafety and other aspects. Typical examples of implementation of robotics in the clinical laboratory are transportation of specimens, front-end automation of sample preparation, separation and aliquotting as well as selected processes in a large scale automation systems. As described previously, robots that are commercially available now, are not intelligent enough to be easily handled by personnel who are not trained for robotics. There is a need for personnel dedicated to robotics who join the project from the very beginning of the plan and who can maintain the system properly.(ABSTRACT TRUNCATED AT 250 WORDS)     

Interlaboratory evaluation of indirect enzyme-linked immunosorbent assay, antibody capture enzyme-linked immunosorbent assay, and immunoblotting for detection of immunoglobulin M antibodies to Toxoplasma gondii.

One hundred and fifteen serum samples from healthy laboratory personnel and 50 consecutive samples from 19 patients with anamnestic clinical signs of toxoplasmosis were assayed by four laboratories for the presence of immunoglobulin M antibodies to Toxoplasma gondii by an indirect enzyme-linked immunosorbent assay (ELISA), an antibody capture assay with peroxidase-labeled toxoplasma antigen, and an immunoblotting assay. In addition, a commercially available antibody capture ELISA was used. Highly significant correlation coefficients were obtained between the four laboratories and the commercial test. The indirect ELISA and antibody capture ELISA showed equal sensitivity in detection of immunoglobulin M antibodies to toxoplasma in early-stage serum samples. However, in this study, the antibody capture assay discriminated better between serum samples obtained at early or late stages of toxoplasma infection.     

Microbial stabilization of antibiotic-containing urine samples by using the FLORA-STAT urine transport system.

The FLORA-STAT Urine Transport System (Wadley Biosciences Corp./Lymphokine Partners Ltd., Dallas, Tex.) was evaluated for its efficacy in maintaining organism count and in effectively blocking the bactericidal action of therapeutic antimicrobial agents in urine samples when the urine samples were held at room temperature. Reconstructions with 53 organism-antimicrobial combinations were performed at 0, 4, 8, and 24 h in which the FLORA-STAT system was compared with two boric acid-based systems (Urine C&S Transport Kit [Becton Dickinson VACUTAINER Systems, Rutherford, N.J.]; Sage Urine Collection Kit for Culture [Sage Products, Inc., Cary, Ill.]) and untreated urine. At 24 h, less than 1-log-unit changes in organism counts were found in 100, 92, and 10% of the urine samples without antimicrobial agents and in 97, 65, and 16% of the urine samples with antimicrobial agents for FLORA-STAT-treated, boric acid-treated, and untreated urine samples, respectively. The FLORA-STAT system was further evaluated by sending split samples prepared from laboratory-inoculated patient urine samples (57 without and 50 with antimicrobial agents) to four commercial laboratories by using their respective transport devices and procedures. Samples were also sent to a local reference laboratory which provided prompt processing. Each laboratory received independently labeled transport devices containing untreated, FLORA-STAT-treated, and preservative-treated (if provided by the commercial laboratory) samples prepared from the same urine specimen of a patient. Average estimated transport times ranged from 13 to 24 h for the commercial laboratories; the transport time was less than 4 h for the local reference laboratory.(ABSTRACT TRUNCATED AT 250 WORDS)     

Laboratory diagnosis and biosafety issues of biological warfare agents

Bioterrorism events have been rare until recently. Many clinical laboratories may not be familiar with handling specimens from a possible bioterrorism attack. Therefore, they should be aware of their own responsibilities and limitations in the handling and treatment of such specimens, and what to do if they are requested to process clinical samples. The Centers for Disease Control and Prevention has developed the Laboratory Response Network to provide an organized response system for the detection and diagnosis of biological warfare agents based on laboratory testing abilities and facilities. There are potentially many biological warfare agents, but probably a limited number of agents would be encountered in case of an attack, and their identification and laboratory safety will be discussed.     

Evolving concepts of the role of pathology and their respective dilemmas

Remarkable changes are affecting the discipline of pathology. Variety and volume of testing, new instrumentation, personnel matters, economics, and government are effecting these changes. Laboratory costs and charges have been confused and in hospitals, laboratories are changing from revenue centers to cost centers. Twelve principles upon which physician payment emphasize productivity, quality, efficiency, and variety. Seven competency characteristics of a clinical laboratory director stress administration, strategic planning, laboratory test use, communication, education, and research and development. Relationships with physicians' office laboratories, the likelihood of overproduction of laboratory personnel, fundamental problems of competition, and the rationing of human life pose additional dilemmas.     

The effect of changes in laboratory practices on the rate of false-positive cultures for Mycobacterium tuberculosis

CONTEXT: False-positive cultures for Mycobacterium tuberculosis have been found in nearly all DNA fingerprinting studies, but the effectiveness of interventions to reduce cross-contamination has not been evaluated. OBJECTIVE: To evaluate whether changes in laboratory policies and procedures reduced the rate of false-positive cultures. DESIGN: Retrospective study of isolates with matching DNA fingerprints. SETTING: A mycobacteriology laboratory serving an urban tuberculosis control program and public hospital system. PATIENTS: All M tuberculosis isolates processed from July 1994 to December 1999. METHODS: Isolates were fingerprinted using IS6110; pTBN12 was used to fingerprint isolates having fewer than 6 copies of IS6110. We further evaluated all patients having only one positive culture whose DNA fingerprint matched that of another isolate processed in the laboratory within 42 days. INTERVENTIONS: We changed laboratory policy to reduce the number of smear-positive specimens processed and changed laboratory procedures to minimize the risk of cross-contamination during batch processing. MAIN OUTCOME MEASURE: The rate of false-positive cultures. RESULTS: Of 13 940 specimens processed during the study period, 630 (4.5%) from 184 patients and 48 laboratory proficiency specimens grew M tuberculosis. There were no cases (0/184) of probable or definite cross-contamination, compared with the 4% rate (8/199) identified in our previous study (P =.008). We also fingerprinted a convenience sample of isolates from other laboratories in Denver; 13.6% (3/22) of these were false-positive, a rate similar to the 11.9% rate (5/42) identified for other laboratories in our previous study (P =.84). CONCLUSIONS: Laboratory cross-contamination decreased significantly after relatively simple, inexpensive changes in laboratory policies and practices. Cross-contamination continued to occur in other laboratories in Denver.     

DNA probe technology in parentage testing

Paternity tests involve laboratory procedures on blood samples obtained from the alleged father, mother, and child to determine if the alleged father is the true father. Conclusions are based on the principle that the child inherits half of the characteristics (markers) in his/her blood from each true parent. DNA probe analysis has emerged from the research laboratory and is currently being utilized by laboratories engaged in parentage testing to improve their efficiency in discriminating between fathers and nonfathers. This new technique provides a very powerful tool.     

Shared Perspectives from Cytology and Microbiology

Cytology, also known as cytopathology, and microbiology laboratories reside in hospitals, clinics, or free-standing laboratories, in which scientists are employed to diagnose many medical conditions, including infection, inflammation, or cancer. There is overlap in the types of clinical samples shared by cytology and microbiology laboratories. Specimens include swabs, sputum, and fine-needle biopsy specimens or aspirates. When laboratories share clinical samples, there can be similarities and differences in the proper transport media and preservatives used. When specimens or functions are shared, there is an opportunity for each laboratory to learn from each other. Increased awareness of the roles and processes in cytology and microbiology can decrease the number of lost or improperly preserved specimens. Improved communication and collaboration between laboratory sections can increase diagnostic accuracy and reduce patient harm. This review summarizes laboratory career choices, sample collection devices, shared specimens, and preservatives associated with shared specimens. Cytology and microbiology laboratories can work together to improve pre-analytic processes and diagnostic accuracy.     

2008年揭阳市艾滋病筛查实验室质量评价

目的通过室间质量考评,规范揭阳市艾滋病检测筛查实验室的建设和管理,确保检测质量。方法分析2008年揭阳市医疗卫生机构的13个艾滋病检测筛查实验室的质量考评情况。结果考评综合成绩,13个艾滋病检测筛查实验室全部合格,取得良好以上成绩的实验室占69．23％。医疗、妇幼机构考评成绩较差,主要问题在于弱阳性样品的检测出现错检、漏检情况。总体分析,本次考评出现问题的主要环节是室内质控、定量仪器的校准及检定、生物安全防护。结论全市艾滋病检测筛查实验室总体上检测质量较好,基本符合艾滋病筛查实验室的要求,弱阳性样品检测能力、质量控制和生物安全是薄弱环节。     

Negative impact of laws regarding biosecurity and bioterrorism on real diseases

Research on highly pathogenic microorganisms in biosafety level 3 and 4 laboratories is very important for human public health, as it provides opportunities for the development of vaccines and novel therapeutics as well as diagnostic methods to prevent epidemics. However, in recent years, after the anthrax and World Trade Center attacks in 2001 in the USA, the threat of bioterrorism has grown for both the public and the authorities. As a result, technical and physical containment measures and biosafety and biosecurity practices have been implemented in laboratories handling these dangerous pathogens. Working with selected biological agents and toxins is now highly regulated, owing to their potential to pose a threat to public health and safety, despite the fact that the anthrax attack was found to be the result of a lack of security at a US Army laboratory. Thus, these added regulations have been associated with a large amount of fruitless investment. Herein, we describe the limitations of research in these facilities, and the multiple consequences of the increased regulations. These limitations have seriously negatively impacted on the number of collaborations, the size of research projects, and, more generally, scientific research on microbial pathogens. Clearly, the actual number of known victims and fatalities caused by the intentional use of microorganisms has been negligible as compared with those caused by naturally acquired human infections.     

The Howie code: is the price of safety too high?

The code of practice for the prevention of infection in clinical laboratories and postmortem rooms (the "Howie code") was produced in order to standardise laboratory safety procedures at a level which would minimise risks to laboratory workers. The costs of implementing this code, which were not given proper consideration when the code was drawn up, are seen to be very high. This paper questions whether the benefits of risk reduction resulting from the code can justify the high cost of its implementation. Beginning with an examination of the incidence in recent years of laboratory-acquired infections, the paper looks at the perceptions of risk by laboratory workers and the feasibility of low cost alternatives to those of the Howie code. The potential benefits of the code are then viewed against the cost of upgrading the laboratories of two Scottish hospitals to Howie standards. The fact of high costs relative to benefits reinforces the paper's call for the proper consideration of economic issues to be given at the development rather than the implementation stage of any regulatory codes.