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This study conducted human factors risk analyses of a doffing protocol for Ebola-level personal protective equipment to identify and quantify the risk of errors made by healthcare workers, marked with surrogate viruses, while doffing and to predict rates of self-contamination.

Standard precautions to minimize the risk of SARS-CoV-2 transmission implies that infected cell cultures and clinical specimens may undergo some sort of inactivation to reduce or abolish infectivity. We evaluated three heat inactivation protocols (56 °C-30 min, 60 °C-60 min and 92 °C-15 min) on SARS-CoV-2 using (i) infected cell culture supernatant, (ii) virus-spiked human sera (iii) and nasopharyngeal samples according to the recommendations of the European norm NF EN 14476-A2. Regardless of the protocol and the type of samples, a 4 Log10 TCID50 reduction was observed. However, samples containing viral loads > 6 Log10 TCID50 were still infectious after 56 °C-30 min and 60 °C-60 min, although infectivity was < 10 TCID50. The protocols 56 °C-30 min and 60 °C-60 min had little influence on the RNA copies detection, whereas 92 °C-15 min drastically reduced the limit of detection, which suggests that this protocol should be avoided for inactivation ahead of molecular diagnostics. Lastly, 56 °C-30 min treatment of serum specimens had a negligible influence on the results of IgG detection using a commercial ELISA test, whereas a drastic decrease in neutralizing titers was observed.

Synthetic biology has expanded the availability of engineered bacterial systems for diverse applications and is now developing safeguards for their effective and secure use. The report of two synthetic gene circuit ‘kill switches’ provides new biocontainment mechanisms for engineered Escherichia coli . Biocontainment systems that couple environmental sensing with circuit-based control of cell viability could be used to prevent escape of genetically modified microbes into the environment. Here we present two engineered safeguard systems known as the 'Deadman' and 'Passcode' kill switches. The Deadman kill switch uses unbalanced reciprocal transcriptional repression to couple a specific input signal with cell survival. The Passcode kill switch uses a similar two-layered transcription design and incorporates hybrid LacI-GalR family transcription factors to provide diverse and complex environmental inputs to control circuit function. These synthetic gene circuits efficiently kill Escherichia coli and can be readily reprogrammed to change their environmental inputs, regulatory architecture and killing mechanism.

A biosecurity panel met, expecting to approve recommendations, but myriad concerns complicated the proceedings. A biosecurity panel met, expecting to approve recommendations, but myriad concerns complicated the proceedings. Credit: Patrick Semansky/AP/Shutterstock A sign on the door of a Biosafety Level 4 laboratory at the U.S. Army Medical Research Institute of Infectious Diseases.

The ongoing Ebola outbreak poses an alarming risk to the countries of West Africa and beyond. To assess the effectiveness of containment strategies, we developed a stochastic model of Ebola transmission between and within the general community, hospitals, and funerals, calibrated to incidence data from Liberia. We find that a combined approach of case isolation, contact-tracing with quarantine, and sanitary funeral practices must be implemented with utmost urgency in order to reverse the growth of the outbreak. As of 19 September, under status quo, our model predicts that the epidemic will continue to spread, generating a predicted 224 (134 to 358) daily cases by 1 December, 280 (184 to 441) by 15 December, and 348 (249 to 545) by 30 December.

In the Ebola Virus Disease (EVD) outbreak in Liberia, two major emergency disease-control measures were cremation of bodies and enforcement of quarantine for asymptomatic individuals suspected of being in contact with a positive case. Enforced by State-related actors, these were promoted as the only method to curtail transmissions as soon as possible. However, as with other harsh measures witnessed by Liberian citizens, in many cases those measures elicited uncontrolled negative reactions within the communities (stigma; fear) that produced, in some cases, the opposite effect of that intended. The research has been conducted in two phases, for a total of 8 weeks. Ethnography of local practices was carried out in 7 neighbourhoods in Monrovia and 5 villages in Grand Cape Mount County in Liberia. 45 Focus Group Discussions (432 participants) and 30 semi-structured interviews sustained the observing participation. Randomly selected people from different social layers were targeted. The principal investigator worked with the help of two local assistants. Perceptions and practices were both analysed. Participants stressed how cremation perpetuated the social breakdown that started with the isolation for the sickness. Socio-economical divides were created by inequitable management of the dead: those who could bribe the burial teams obtained a burial in a private cemetery or the use of Funeral Homes. Conversely, those in economic disadvantage were forced to send their dead for cremation. State-enforced quarantine, with a mandatory prohibition of movement, raised condemnation, strengthened stigmatization and created serious socio-economic distress. Food was distributed intermittently and some houses shared latrines with non-quarantined neighbours. Escapes were also recorded. Study participants narrated how they adopted local measures of containment, through local task forces and socially-rooted control of outsiders. They also stressed how information that was not spread built up rumours and suspicion. Populations experiencing an epidemic feel a high degree of social insecurity, in addition to the health hazards. Vertical and coercive measures increase mistrust and fear, producing a counter-productive effect in the containment of the epidemic. On the other hand, local communities show a will to be engaged and a high degree of flexibility in participating to the epidemic response. Efforts in the direction of awareness and community involvement could prove to be better strategy to control the epidemic and root the response on social participation.

In simulations of Ebola-level personal protective equipment doffing with experienced healthcare workers, hands, inner gloves, and scrubs are contaminated with nonenveloped viruses and, infrequently, with enveloped viruses.

The fast‐paced field of synthetic biology is fundamentally changing the global biosecurity framework. Current biosecurity regulations and strategies are based on previous governance paradigms for pathogen‐oriented security, recombinant DNA research, and broader concerns related to genetically modified organisms (GMOs). Many scholarly discussions and biosecurity practitioners are therefore concerned that synthetic biology outpaces established biosafety and biosecurity measures to prevent deliberate and malicious or inadvertent and accidental misuse of synthetic biology's processes or products. This commentary proposes three strategies to improve biosecurity: Security must be treated as an investment in the future applicability of the technology; social scientists and policy makers should be engaged early in technology development and forecasting; and coordination among global stakeholders is necessary to ensure acceptable levels of risk. Graphical Abstract Biosecurity policies and practices must be updated to accommodate the novel challenges associated with synthetic biology and to maximize technological benefits while minimizing its dual‐use potential. This Commentary proposes three strategies to improve biosecurity.

Clinical samples collected in coronavirus disease 19 (COVID-19), patients are commonly manipulated in biosafety level 2 laboratories for molecular diagnostic purposes. Here, we tested French norm NF-EN-14476+A2 derived from European standard EN-14885 to assess the risk of manipulating infectious viruses prior to RNA extraction. SARS-CoV-2 cell-culture supernatant and nasopharyngeal samples (virus-spiked samples and clinical samples collected in COVID-19 patients) were used to measure the reduction of infectivity after 10 min contact with lysis buffer containing various detergents and chaotropic agents. A total of thirteen protocols were evaluated. Two commercially available formulations showed the ability to reduce infectivity by at least 6 log 10, whereas others proved less effective.

Genetically modified organisms (GMOs) are increasingly deployed at large scales and in open environments. Genetic biocontainment strategies are needed to prevent unintended proliferation of GMOs in natural ecosystems. Existing biocontainment methods are insufficient because they impose evolutionary pressure on the organism to eject the safeguard by spontaneous mutagenesis or horizontal gene transfer, or because they can be circumvented by environmentally available compounds. Here we computationally redesign essential enzymes in the first organism possessing an altered genetic code ( Escherichia coli strain C321.ΔA) to confer metabolic dependence on non-standard amino acids for survival. The resulting GMOs cannot metabolically bypass their biocontainment mechanisms using known environmental compounds, and they exhibit unprecedented resistance to evolutionary escape through mutagenesis and horizontal gene transfer. This work provides a foundation for safer GMOs that are isolated from natural ecosystems by a reliance on synthetic metabolites. Essential enzymes in genetically modified organisms are computationally redesigned to functionally depend on non-standard amino acids, thereby achieving biocontainment with unprecedented resistance to escape by evolution or by supplementation with environmental metabolites. Two routes to safer GMOs Two manuscripts published in this issue of Nature describe independent approaches towards generating an organism dependent on unnatural amino acids, a development which could find applications for biocontainment and exploration of previously unsampled fitness landscapes. George Church and colleagues redesigned essential enzymes in an organism ( Escherichia coli ) with an altered genetic code to make it metabolically dependent on non-standard amino acids for survival. The resulting genetically modified organisms (GMOs) cannot metabolically circumvent their biocontainment mechanisms and show unprecedented resistance to evolutionary escape. The few escapees are rapidly outcompeted by unmodified organisms. Using multiplex automated genome engineering, Farren Isaacs and colleagues construct a series of genomically recoded organisms whose growth is restricted by the expression of essential genes that depend on exogenously supplied synthetic amino acids. They constructed synthetic auxotrophs with advanced orthogonal barriers between engineered organisms and the environment, thereby creating safer GMOs.