Biosafety level 3 laboratory for autopsies of patients with severe acute respiratory syndrome: principles, practices, and prospects

Management of post-mortem examination in SARS-CoV-19 infections

A brief overview on the management of autopsies during the SARS-CoV-19 epidemic is proposed. In particular, the point is made of the Italian laws on the subject, the characteristics required for the autopsy room and the sampling suggested for the histological examination.

Risk of occupational infection in forensic workers: a review

The occupational risk of infection in forensic workers is a cause for concern, furthermore in the current context of the coronavirus disease-19 (COVID-19) pandemic. In order to characterize this risk, we performed an extended review of the literature on occupational infections occurring in forensic workers. Seventeen articles were included. Direct contamination by aerosolization was the main mode of transmission reported, with 17 cases of tuberculosis. Indirect contamination was described as the mode of transmission in 10 cases (five cases of blastomycosis, two cases of tuberculosis, two Streptococcus pyogenes, and one case of human immunodeficiency virus). In all the other included cases, the mode of transmission was unknown. For two of them, the information provided was sufficient to link them to occupational exposure (one case of toxoplasmosis, one case of tuberculosis). For the remaining 10 cases, the link was uncertain (six cases of tuberculosis, three of hepatitis B, and one of COVID-19). Even if there is probably significant under-declaration, the number of infections linked to an occupational risk in forensic workers is not alarming, thanks to effective preventive measures.

Rate of shed of SARS COV-2 viral RNA from COVID-19 cadavers

BACKGROUND

At what rate does the RNA of SARS CoV-2 shed from cadavers? Although, there have been numerous studies which have demonstrated the persistence of the virus on dead bodies, there is a lack of conclusive evidence regarding the variation of viral RNA content in cadavers. This has led to a knowledge gap regarding the safe handling/management of COVID-19 decedents, posing a barrier in forensic investigations.

METHODS

In this study, we report the presence of RNA of SARS CoV-2 by real time RT-PCR, in nasopharyngeal swabs collected after death from two groups of bodies - one who died due to COVID-19 and the other who died due to other diagnoses. A prospective study on 199 corpses, who had tested positive for COVID-19 ante-mortem, was conducted at a tertiary care center. RNA testing was conducted at different time intervals (T1-T5).

RESULTS

112(56.3%) died primarily due to COVID-19 and 87(43.7%) died due to other diagnoses. 144(72.4%) were male and 55(27.6%) were female. A total of 115 (57.8%) tested positive for COVID-19 after death at different time points. The mean age was 50.7 ± 18.9 years and the length of hospitalization ranged from 1 to 50 days with a mean of 9.2 ± 7.6 days. Realtime RT-PCR positivity of SARS CoV-2 RNA decreases with time.

CONCLUSION

We observed that real time RT-PCR positivity, indicating viral RNA detection, decreases with time. Therefore, it is advisable to follow appropriate COVID-19 precautions to carry out scientific studies, medico-legal investigations and mortuary services on suspected/confirmed COVID-19 corpses.

Coronavirus disease (COVID-19) transmission through aerosols in restorative and endodontic practice: Strategies for prevention

Rapid spread of coronavirus disease 2019 (COVID-19) in several countries of the world has created a state of public health emergency. COVID-19 is principally a respiratory disease, and the virus is present in respiratory secretions. Oral health-care professionals are susceptible to being infected with the disease since they work in close proximity to patient's face and oral cavity for long period of time. Restorative dentists and endodontists play a significant role in delivering "urgent" or "emergency" dental care to patients. Occupational Safety and Health Administration has categorized dentists performing aerosol-generating treatment procedures at "very high exposure risk" whereas the dentists not performing aerosol-generating procedures at "high exposure risk." Most of the restorative and endodontic treatment procedures involve generation of aerosols. Owing to the possibility of transmission of virus through aerosols, these procedures may transmit the disease to clinician or other patients. A comprehensive search of literature was conducted with the help of PubMed/MEDLINE and Scopus databases using a combination of terms, "COVID-19," "severe acute respiratory syndrome coronavirus 2," "aerosols," "restorative dentistry," and "endodontics." Along with universal precautions, some additional precautions need to be taken to prevent such transmission and cross-infection. This article reviews the research evidence about the role of aerosols in the transmission of COVID-19 and various measures which should be implemented during restorative and endodontic practice for the prevention of such transmission.

An overview of the anti-SARS-CoV-2 properties of Artemisia annua, its antiviral action, protein-associated mechanisms, and repurposing for COVID-19 treatment

Artemisia annua and its phytocompounds have a rich history in the research and treatment of malaria, rheumatoid arthritis, systemic lupus erythematosus, and other diseases. Currently, the World Health Organization recommends artemisinin-based combination therapy as the first-line treatment for multi-drug-resistant malaria. Due to the various research articles on the use of antimalarial drugs to treat coronaviruses, a question is raised: would A. annua and its compounds provide anti-severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) properties? PubMed/MEDLINE, Scopus, and Google Scholar were searched for peer-reviewed articles that investigated the antiviral effects and mechanisms of A. annua and its phytochemicals against SARS-CoVs. Particularly, articles that evidenced the herb’s role in inhibiting the coronavirus-host proteins were favored. Nineteen studies were retrieved. From these, fourteen in silico molecular docking studies demonstrated potential inhibitory properties of artemisinins against coronavirus-host proteins including 3CL^PRO, S protein, N protein, E protein, cathepsin-L, helicase protein, nonstructural protein 3 (nsp3), nsp10, nsp14, nsp15, and glucose-regulated protein 78 receptor. Collectively, A. annua constituents may impede the SARS-CoV-2 attachment, membrane fusion, internalization into the host cells, and hinder the viral replication and transcription process. This is the first comprehensive overview of the application of compounds from A. annua against SARS-CoV-2/coronavirus disease 2019 (COVID-19) describing all target proteins. A. annua’s biological properties, the signaling pathways implicated in the COVID-19, and the advantages and disadvantages for repurposing A. annua compounds are discussed. The combination of A. annua’s biological properties, action on different signaling pathways and target proteins, and a multi-drug combined-therapy approach may synergistically inhibit SARS-CoV-2 and assist in the COVID-19 treatment. Also, A. annua may modulate the host immune response to better fight the infection.

Design and Construction of a Biosafety Level 3 Autopsy Laboratory

CONTEXT.—

Autopsy pathologists, including medical examiners, provide valuable public health support for infectious disease deaths through surveillance for deaths of public health concern including emerging infections, identifying causative organisms for unexplained deaths, and providing insights into the pathology and pathogenesis of novel or unusual infections. However, autopsy poses biosafety risks to workers within and outside the laboratory. The highest rates of laboratory-acquired infections occur in autopsy workers.

OBJECTIVE.—

To design and construct an appropriately biosafe autopsy laboratory.

DESIGN.—

We conducted a biosafety risk assessment for autopsy workers using the process developed by the US Centers for Disease Control and Prevention and National Institutes of Health and applied these findings as the basis of laboratory design and construction.

RESULTS.—

Autopsy workers are unpredictably exposed to a variety of infectious organisms, including hepatitis C virus, HIV, and Mycobacterium tuberculosis. Hazardous autopsy procedures include using and encountering sharp objects and the generation of aerosols from dissection, fluid aspiration, rinsing tissues, and dividing bone with an oscillating saw.

CONCLUSIONS.—

Exposure to blood-borne and airborne pathogens from procedures that can cause cutaneous inoculation and inhalation of aerosols indicates that human autopsies should be performed at biosafety level 3. We designed a large, entirely biosafety level 3 medical examiner autopsy laboratory using design principles and characteristics that can be scaled to accommodate smaller academic or other hospital-based autopsy spaces. Containment was achieved through a concentric ring design, with access control at interface zones. As new autopsy laboratories are planned, we strongly recommend that they be designed to function uniformly at biosafety level 3.

Autopsies in pandemics - a perspective on barriers and benefits. Is it time for a revival?

Influenza virus and coronavirus pandemics regularly sweep the globe, at great cost of health and economy. Our aim was to conduct a PubMed search for autopsy studies on influenza and coronavirus to investigate the contribution of autopsies during pandemics, focussing on autopsy methods and procedures and the role of autopsy findings in pandemics. The retrieved autopsy studies generally relied on microscopy, polymerase chain reaction (PCR), immunostaining and electron microscopy. Most were small and reported on lung effects, including diffuse alveolar damage (DAD), pneumonia and tracheobronchitis. Antibiotic therapy has diminished a role for bacterial pneumonia, whereas obesity is an emerging risk factor. Autopsy studies have provided new insights into coronavirus disease 2019 (COVID‐19) treatments like anti‐coagulative therapy. Unfortunately, autopsies during pandemics are hampered by lack of guidelines, facilities and expertise for handling potentially infectious corpses and by widely varying recommendations for personal protective equipment and procedures. The Department of Forensic Pathology, at the Forensic Institute, at the University of Copenhagen in Denmark has, in collaboration with the Department of Pathology, Rigshospitalet, Copenhagen, initiated a prospective observational study on COVID‐19‐related deaths encompassing postmortem imaging, standardized autopsy procedures/reporting and extensive tissue sampling for histological, chemical, microbiological and genetic analysis. The study involves a diverse array of research groups at the University of Copenhagen, and the clinical field.

[Management of samples in pathology laboratories and biobanks during the Covid-19 pandemic]

La pandémie liée à la Covid-19 a brutalement bouleversé le fonctionnement des hôpitaux, en particulier les activités des services cliniques et des laboratoires de biologie, notamment de virologie. Cette pandémie a eu aussi une répercussion soudaine sur la prise en charge des échantillons tissulaires et cellulaires par les laboratoires de pathologie. Les conséquences ont été l’optimisation de mesures sanitaires au sein de ces laboratoires, mais aussi selon les institutions, une forte diminution dans différents secteurs d’activité de la pathologie clinique et moléculaire. Ainsi, les pathologistes ont dû s’adapter très rapidement à de nouvelles contraintes sanitaires, et organiser les laboratoires selon des recommandations internationales, afin de maintenir l’offre de soins aux patients hospitalisés, en particulier ceux atteints d’un cancer. Cette revue aborde les principales conséquences de la pandémie liée à la Covid-19 au niveau des laboratoires de pathologie et les mesures prises par ces laboratoires pour assurer leur fonctionnement durant cette période.

Postmortem Swabs in the Severe Acute Respiratory Syndrome Coronavirus 2 Pandemic: Report on 12 Complete Clinical Autopsy Cases

CONTEXT.—

Clinical autopsies have historically provided a fundamental contribution in the definition of the clinicopathologic basis of infectious diseases. Even though we are witnessing the decline of the clinical autopsy, its importance remains unchanged as it is the most exhaustive way to investigate diseases. The identification of the virus in postmortem tissues is a fundamental step in the definition of its clinical features.

OBJECTIVE.—

To investigate the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in postmortem examination with swabs.

DESIGN.—

We performed postmortem swabs in 12 autopsy cases of patients with a clinical diagnosis of SARS-CoV-2-related pneumonia. Our protocol consisted of a rhinopharyngeal and a tracheal swab in order to search for the virus in the upper airways, and of 2 swabs on the parenchyma of each lung. We also performed a fifth swab on the parenchyma of both lungs in order to search for other viruses that could evolve in a clinical picture of interstitial pneumonia.

RESULTS.—

Overall, we found 9 of 12 cases had at least 1 postmortem swab positive for SARS-CoV-2. Moreover, we evaluated the time between the antemortem and postmortem swabs, the time between death and the postmortem swabs, and the time between the postmortem swabs and acceptance to the microbiology laboratory. Of note, we did not find a relationship between the results of the swabs and either the time elapsed from their collection or the time elapsed before their acceptance in the microbiology laboratory.

CONCLUSIONS.—

A thorough knowledge of the eventual persistence of pathogens in deaths related to infectious diseases is fundamental for the safety of the operators during the autopsy practice, especially when referring to emergent pathogens, such as SARS-CoV-2. Our study highlights the importance in performing multiple swabs in the postmortem examination, because SARS-CoV-2 swab positivity can be limited to only a single swab.

Pathology Trainee Redeployment and Education During the COVID-19 Pandemic: An Institutional Experience

Pathology training programs throughout the United States have endured unprecedented challenges dealing with the ongoing coronavirus disease 2019 pandemic. At Houston Methodist Hospital, the Department of Pathology and Genomic Medicine planned and executed a trainee-oriented, stepwise emergency response. The focus was on optimizing workflows among areas of both clinical and anatomic pathology, maintaining an excellent educational experience, and minimizing trainee exposure to coronavirus disease 2019. During the first phase of the response, trainees were divided into 2 groups: one working on-site and the other working remotely. With the progression of the pandemic, all trainees were called back on-site and further redeployed within our department to meet the significantly increased workload demands of our clinical laboratory services. Adjustments to trainee educational activities included, among others, the organization of a daily coronavirus disease 2019 virtual seminar series. This series served to facilitate communication between faculty, laboratory managers, and trainees. Moreover, it became a forum for trainees to provide updates on individual service workflows and volumes, ongoing projects and research, as well as literature reviews on coronavirus disease 2019–related topics. From our program’s experience, redeploying pathology trainees within our department during the coronavirus disease 2019 pandemic resulted in optimization of patient care while ensuring trainee safety, and importantly, helped to maintain continuous high-quality education through active involvement in unique learning opportunities.

No-Touch Automated Room Disinfection after Autopsies of Exhumed Corpses

Autopsies of exhumed bodies pose a risk of infections with environmental bacteria or fungi, which may be life-threatening. Thus, it is important to use effective methods of disinfection in forensic pathology facilities. In this study, we investigated the effectiveness of no-touch automated disinfection (NTD) system after autopsies of exhumed bodies. Directly after 11 autopsies of exhumed bodies, we used an NTD system based on a peroxone vapor to disinfect the air and surfaces. We measured microbial burden in the air and on surfaces before and after NTD. The NTD system reduced the mean bacterial burden in the air from 171 colony forming units (CFU)/m³ to 3CFU/m³. The mean fungal burden in the air decreased from 221 CFU/m³ to 9CFU/m³. The mean all-surface microbial burden was 79 CFU/100 cm² after all autopsies, and it decreased to 2 CFU/100 cm² after NTD. In conclusion, the peroxone-based NTD system was effective for decontamination of the air and surfaces in a dissecting room after autopsies of exhumed bodies.

Challenges and issues surrounding the use for translational research of human samples obtained during the COVID-19 pandemic from lung cancer patients

In only a few weeks after the eruption of the pandemic caused by syndrome coronavirus 2 (SARS-CoV-2), the number of associated research projects worldwide increased dramatically. The continual and almost daily improvement in the information associated with this viral infection has been spectacular, notably in the areas of epidemiology, pathophysiology and therapy. This knowledge but also the many uncertainties concerning coronavirus disease 2019 (COVID-19), in particular with respect to the level of contagiousness of different samples sent to pathology and biology laboratories, rapidly effected the collection for translational research projects, notably of samples from patients with thoracic cancers. However, it is still difficult to evaluate the current and the near impact of the COVID-19 pandemic on this domain. It is essential in this context to be reminded of good practice for the management of biological samples for research, notably concerning the biosafety and security procedures. Moreover, new recommendations concerning the traceability and use of human lung cancer samples from tissue and different biofluids may rapidly be issued in the near future. This review aims to discuss the new challenges and constraints encountered by pathologists, biobankers and researchers within the framework of collection and the use of samples from patients with lung cancer for research while taking into account the COVID-19 pandemic.

Construction of SARS-CoV-2 Virus-Like Particles by Mammalian Expression System

Virus-like particle (VLP) is a self-assembled nanostructure incorporating key viral structural proteins. VLP resembles molecular and morphological features of authentic viruses but is non-infectious and non-replicating due to lack of genetic materials. Successful applications of VLP has been shown in vaccinological and virological research. As an accessibly safe and relevant substitute of naturally pathogenic viruses, the construction of SARS-CoV-2 VLPs is much in demand in the ongoing fight against 2019 Coronavirus disease (COVID-19) pandemics. In the current study, using mammalian expression system, which is advantageous in maintaining correct protein glycosylation patterns, we efficiently constructed SARS-CoV-2 VLPs. We showed that among four SARS-CoV-2 structural proteins, expression of membrane protein (M) and small envelope protein (E) are essential for efficient formation and release of SARS-CoV-2 VLPs. Moreover, the corona-like structure presented in SARS-CoV-2 VLPs from Vero E6 cells is more stable and unified, as compared to those from HEK-293T cells. Our data demonstrate that SARS-CoV-2 VLPs possess molecular and morphological properties of native virion particles, which endow such VLPs with a promising vaccine candidate and a powerful tool for the research of SARS-CoV-2.

The autopsy at the time of SARS-CoV-2: Protocol and lessons

A new viral disease named COVID-19 has recently turned into a pandemic. Compared to a common viral pneumonia it may evolve in an atypical way, causing the rapid death of the patient. For over two centuries, autopsy has been recognized as a fundamental diagnostic technique, particularly for new or little-known diseases. To date, it is often considered obsolete giving the inadequacy to provide samples of a quality appropriate to the sophisticated diagnostic techniques available today. This is probably one of the reasons why during this pandemic autopsies were often requested only in few cases, late and discouraged, if not prohibited, by more than one nation. This is in contrast with our firm conviction: to understand the unknown we must look at it directly and with our own eyes. This has led us to implement an autopsy procedure that allows the beginning of the autopsy shortly after death (within 1–2 h) and its rapid execution, also including sampling for ultrastructural and molecular investigations. In our experience, the tissue sample collected for diagnosis and research were of quality similar to biopsy or surgical resections. This procedure was performed ensuring staff and environmental safety. We want to propose our experience, our main qualitative results and a few general considerations, hoping that they can be an incentive to use autopsy with a new procedure adjusted to match the diagnostic challenges of the third millennium.

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Early performed autopsy (within 1-2 hour from death) provides tissue samples for diagnosis and research of quality similar to biopsy or surgical resections.

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Early samples collection reduces post-mortem artifacts, thus preventing the wrong interpretation of the morphological pictures observed.

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Precise autopsy planning prevents risks for the staff.

Precautions in postmortem examinations in Covid-19 - Related deaths: Recommendations from Germany

The Covid-19 pandemic is also a considerable risk for forensic workers, among other healthcare providers. The risk of contamination is serious in post-mortem procedures. SARS-CoV2 is a microorganism classified as Hazard Group 3. However, the lack of adequate scientific work on Covid-19 should prompt us to be even more cautious when handling potentially infected persons or materials. Before starting the post-mortem investigation a risk assessment should be carried out and the suitability of facilities, personnel and equipment should be evaluated. An autopsy room conforming to BSL 3 standards would be ideal but is not mandatory. For suspicious or approved cases however a number of procedural changes must be made concerning the body's removal, storage and inspection procedures. Facilities, equipment and training issues need to be revised against existing and potential risks of infection. In addition to proper ventilation and insulation, personal protective equipment, aerosol reduction measures and disinfection applications are required. As of yet it is still unclear how long this public health issue, which has grown to become a pandemic, will last. This article highlights preventive measures to be taken into consideration in post-mortem processes when a Covid-19 infection is suspected or confirmed. It should be noted that there is no standard guide yet in this regard. A guide should be created according to international standards and revised according to changing conditions.

Safe management of bodies of deceased persons with suspected or confirmed COVID-19: a rapid systematic review

INTRODUCTION

Proper strategies to minimise the risk of infection in individuals handling the bodies of deceased persons infected with 2019 novel coronavirus (2019-nCoV) are urgently needed. The objective of this study was to systematically review the literature to scope and assess the effects of specific strategies for the management of the bodies.

METHODS

We searched five general, three Chinese and four coronavirus disease (COVID-19)-specific electronic databases. We searched registries of clinical trials, websites of governmental and other relevant organisations, reference lists of the included papers and relevant systematic reviews, and Epistemonikos for relevant systematic reviews. We included guidance documents providing practical advice on the handling of bodies of deceased persons with suspected or confirmed COVID-19. Then, we sought primary evidence of any study design reporting on the efficacy and safety of the identified strategies in coronaviruses. We included evidence relevant to contextual factors (ie, acceptability). A single reviewer extracted data using a pilot-tested form and graded the certainty of the evidence using the GRADE approach. A second reviewer verified the data and assessments.

RESULTS

We identified one study proposing an uncommon strategy for autopsies for patients with severe acute respiratory syndrome. The study provided very low-certainty evidence that it reduced the risk of transmission. We identified 23 guidance documents providing practical advice on the steps of handling the bodies: preparation, packing, and others and advice related to both the handling of the dead bodies and the use of personal protective equipment by individuals handling them. We did not identify COVID-19 evidence relevant to any of these steps.

CONCLUSION

While a substantive number of guidance documents propose specific strategies, we identified no study providing direct evidence for the effects of any of those strategies. While this review highlights major research gaps, it allows interested entities to build their own guidance.

Limiting factors for wearing personal protective equipment (PPE) in a health care environment evaluated in a randomised study

Pandemics and re-emerging diseases put pressure on the health care system to prepare for patient care and sample logistics requiring enhanced personnel protective equipment (PPE) for health care workers. We generated quantifiable data on ergonomics of PPE applicable in a health care setting by defining error rates and physically limiting factors due to PPE-induced restrictions. Nineteen study volunteers tested randomly allocated head- or full body-ventilated PPE suits equipped with powered-air-purifying-respirators and performed four different tasks (two laboratory tutorials, a timed test of selective attention and a test investigating reaction time, mobility, speed and physical exercise) during 6 working hours at 22°C on one day and 4 working hours at 28°C on another day. Error rates and physical parameters (fluid loss, body temperature, heart rate) were determined and ergonomic-related parameters were assessed hourly using assessment sheets. Depending on the PPE system the most restrictive factors, which however had no negative impact on performance (speed and error rate), were: reduced dexterity due to multiple glove layers, impaired visibility by flexible face shields and back pain related to the respirator of the fully ventilated suit. Heat stress and liquid loss were perceived as restrictive at a working temperature of 28°C but not 22°C.

U.S. Medical Examiner/Coroner capability to handle highly infectious decedents

In the United States of America, Medical Examiners and Coroners (ME/Cs) investigate approximately 20% of all deaths. Unexpected deaths, such as those occurring due to a deceased person under investigation for a highly infectious disease, are likely to fall under ME/C jurisdiction, thereby placing the ME/C and other morgue personnel at increased risk of contracting an occupationally acquired infection. This survey of U.S. ME/Cs' capabilities to address highly infectious decedents aimed to determine opportunities for improvement at ME/C facilities serving a state or metropolitan area. Data for this study was gathered via an electronic survey. Of the 177 electronic surveys that were distributed, the overall response rate was N = 108 (61%), with 99 of those 108 respondents completing all the questions within the survey. At least one ME/C responded from 47 of 50 states, and the District of Columbia. Select results were: less than half of respondents (44%) stated that their office had been involved in handling a suspected or confirmed highly infectious remains case and responses indicated medical examiners. Additionally, ME/C altered their personal protective equipment based on suspected versus confirmed highly infectious remains rather than taking an all-hazards approach. Standard operating procedures or guidelines should be updated to take an all-hazards approach, best-practices on handling highly infectious remains could be integrated into a standardized education, and evidence-based information on appropriate personal protective equipment selection could be incorporated into a widely disseminated learning module for addressing suspected or confirmed highly infectious remains, as those areas were revealed to be currently lacking.

A 2009 cross-sectional survey of procedures for post-mortem management of highly infectious disease patients in 48 isolation facilities in 16 countries: data from EuroNHID

Purpose

The handling of human remains may pose a risk for transmission of highly infectious agents. The use of appropriate biosafety measures is very important in case of management of patients deceased from highly infectious diseases (HIDs), such as Ebola virus disease. This paper presents the capabilities and resources in this field in 16 European countries, and suggests indications for the safe post-mortem management of HID patients.

Methods

The European Network for Highly Infectious Diseases conducted in 2009 a survey in 48 isolation facilities in 16 European countries. A set of standardized checklists, filled during on-site visits, have been used for data collection.

Results

Thirty-nine facilities (81.2 %) reported to have written procedures for the management of human remains, and 27 (56.2 %) for the performance of autopsies in HID patients. A Biosafety Level 3 autopsy room was available in eight (16.6 %) facilities, other technical devices for safe autopsies were available in nine (18.7 %). Overall, four facilities (8.3 %) reported to have all features explored for the safe management of human remains. Conversely, in five (10.4 %) none of these features were available.

Conclusions

The level of preparedness of surveyed isolation facilities in the field of post-mortem management in case of HIDs was not satisfactory, and improvements are needed.

Assessment of the risk of infectious aerosols leaking to the environment from BSL-3 laboratory HEPA air filtration systems using model bacterial aerosols

To assess the risk of infectious bacterial aerosols leaking to the environment, the filtration efficiency of a biosafety level 3 (BSL-3) laboratory high-efficiency particulate (HEPA) filter was investigated using the aerosolized bacteria Serratia marcescens. The aerosol size was measured using an Andersen sampler. Eight first stage HEPA filters (numbered 1-8) were distributed in contaminated labs and exhausts from each of the first stage HEPA filters were aggregated and filtered through one second stage HEPA filter before being released to the environment. In total, 8 first-stage and 1 second-stage HEPA filters from the BSL-3 air purification system were analyzed. No S. marcescens was detected in first stage filters 1, 2, 4, 5, 7 and 8 and the second stage HEPA filter. The filtration efficiencies against aerosolized S. marcescens were >99.9999%. First stage filter numbers 3 and 6 had filtration efficiencies of 99.9825% and 99.9906%, respectively. When filter number 3 was replaced by a new filter and the bracket for filter number 6 was sealed, no aerosolized S. marcescens was detected in the filtered air. Our work suggests that the BSL-3 laboratory HEPA filter air purification system is effective against bacterial aerosols, with little to no bacterial leakage into the environment.

A systematic molecular pathology study of a laboratory confirmed H5N1 human case

Autopsy studies have shown that human highly pathogenic avian influenza virus (H5N1) can infect multiple human organs other than just the lungs, and that possible causes of organ damage are either viral replication and/or dysregulation of cytokines and chemokines. Uncertainty still exists, partly because of the limited number of cases analysed. In this study, a full autopsy including 5 organ systems was conducted on a confirmed H5N1 human fatal case (male, 42 years old) within 18 hours of death. In addition to the respiratory system (lungs, bronchus and trachea), virus was isolated from cerebral cortex, cerebral medullary substance, cerebellum, brain stem, hippocampus ileum, colon, rectum, ureter, aortopulmonary vessel and lymph-node. Real time RT-PCR evidence showed that matrix and hemagglutinin genes were positive in liver and spleen in addition to positive tissues with virus isolation. Immunohistochemistry and in-situ hybridization stains showed accordant evidence of viral infection with real time RT-PCR except bronchus. Quantitative RT-PCR suggested that a high viral load was associated with increased host responses, though the viral load was significantly different in various organs. Cells of the immunologic system could also be a target for virus infection. Overall, the pathogenesis of HPAI H5N1 virus was associated both with virus replication and with immunopathologic lesions. In addition, immune cells cannot be excluded from playing a role in dissemination of the virus in vivo.

Severe acute respiratory syndrome (SARS)

This article reviews the virology, history, pathology, epidemiology, clinical presentations, complications, radiology, laboratory testing, diagnosis, treatment, and prevention of severe respiratory distress syndrome, with reference to documented outbreaks of the disease.

Infection control in the management of highly pathogenic infectious diseases: consensus of the European Network of Infectious Disease

The European Network for Infectious Diseases (EUNID) is a network of clinicians, public health epidemiologists, microbiologists, infection control, and critical-care doctors from the European member states, who are experienced in the management of patients with highly infectious diseases. We aim to develop a consensus recommendation for infection control during clinical management and invasive procedures in such patients. After an extensive literature review, draft recommendations were amended jointly by 27 partners from 15 European countries. Recommendations include repetitive training of staff to ascertain infection control, systematic use of cough and respiratory etiquette at admission to the emergency department, fluid sampling in the isolation room, and analyses in biosafety level 3/4 laboratories, and preference for point-of-care bedside laboratory tests. Children should be cared for by paediatricians and intensive-care patients should be cared for by critical-care doctors in high-level isolation units (HLIU). Invasive procedures should be avoided if unnecessary or done in the HLIU, as should chest radiography, ultrasonography, and renal dialysis. Procedures that require transport of patients out of the HLIU should be done during designated sessions or hours in secure transport. Picture archiving and communication systems should be used. Post-mortem examination should be avoided; biopsy or blood collection is preferred.

Evidence-based biosafety: a review of the principles and effectiveness of microbiological containment measures

We examined the available evidence on the effectiveness of measures aimed at protecting humans and the environment against the risks of working with genetically modified microorganisms (GMOs) and with non-GMO pathogenic microorganisms. A few principles and methods underlie the current biosafety practice: risk assessment, biological containment, concentration and enclosure, exposure minimization, physical containment, and hazard minimization. Many of the current practices are based on experience and expert judgment. The effectiveness of biosafety measures may be evaluated at the level of single containment equipment items and procedures, at the level of the laboratory as a whole, or at the clinical-epidemiological level. Data on the containment effectiveness of equipment and laboratories are scarce and fragmented. Laboratory-acquired infections (LAIs) are therefore important for evaluating the effectiveness of biosafety. For the majority of LAIs there appears to be no direct cause, suggesting that failures of biosafety were not noticed or that containment may have been insufficient. The number of reported laboratory accidents associated with GMOs is substantially lower than that of those associated with non-GMOs. It is unknown to what extent specific measures contribute to the overall level of biosafety. We therefore recommend that the evidence base of biosafety practice be strengthened.

H5N1 infection of the respiratory tract and beyond: a molecular pathology study

BACKGROUND

Human infection with avian influenza H5N1 is an emerging infectious disease characterised by respiratory symptoms and a high fatality rate. Previous studies have shown that the human infection with avian influenza H5N1 could also target organs apart from the lungs.

METHODS

We studied post-mortem tissues of two adults (one man and one pregnant woman) infected with H5N1 influenza virus, and a fetus carried by the woman. In-situ hybridisation (with sense and antisense probes to haemagglutinin and nucleoprotein) and immunohistochemistry (with monoclonal antibodies to haemagglutinin and nucleoprotein) were done on selected tissues. Reverse-transcriptase (RT) PCR, real-time RT-PCR, strand-specific RT-PCR, and nucleic acid sequence-based amplification (NASBA) detection assays were also undertaken to detect viral RNA in organ tissue samples.

FINDINGS

We detected viral genomic sequences and antigens in type II epithelial cells of the lungs, ciliated and non-ciliated epithelial cells of the trachea, T cells of the lymph node, neurons of the brain, and Hofbauer cells and cytotrophoblasts of the placenta. Viral genomic sequences (but no viral antigens) were detected in the intestinal mucosa. In the fetus, we found viral sequences and antigens in the lungs, circulating mononuclear cells, and macrophages of the liver. The presence of viral sequences in the organs and the fetus was also confirmed by RT-PCR, strand-specific RT-PCR, real-time RT-PCR, and NASBA.

INTERPRETATION

In addition to the lungs, H5N1 influenza virus infects the trachea and disseminates to other organs including the brain. The virus could also be transmitted from mother to fetus across the placenta.