Livestock and Risk Group 4 Pathogens: Researching Zoonotic Threats to Public Health and Agriculture in Maximum Containment

Maximum-containment laboratories are a unique and essential component of the bioeconomy of the United States. These facilities play a critical role in the national infrastructure, supporting research on a select set of especially dangerous pathogens, as well as novel, emerging diseases. Understanding the ecology, biology, and pathology at the human-animal interface of zoonotic spillover events is fundamental to efficient control and elimination of disease. The use of animals as human surrogate models or as target-host models in research is an integral part of unraveling the interrelated components involved in these dynamic systems. These models can prove vitally important in determining both viral- and host-factors associated with virus transmission, providing invaluable information that can be developed into better risk mitigation strategies. In this article, we focus on the use of livestock in maximum-containment, biosafety level-4 agriculture (BSL-4Ag) research involving zoonotic, risk group 4 pathogens and we provide an overview of historical associated research and contributions. Livestock are most commonly used as target-host models in high-consequence, maximum-containment research and are routinely used to establish data to assist in risk assessments. This article highlights the importance of animal use, insights gained, and how this type of research is essential for protecting animal health, food security, and the agriculture economy, as well as human public health in the face of emerging zoonotic pathogens. The utilization of animal models in high-consequence pathogen research and continued expansion to include available species of agricultural importance is essential to deciphering the ecology of emerging and re-emerging infectious diseases, as well as for emergency response and mitigation preparedness.

[Development of a positive pressure protective suit for BSL-4 laboratory]

Biosafety Level 4 (BSL-4) laboratories are required for research on microorganisms that are highly pathogenic to humans and for which there are no prevention or treatment methods. Currently, the majority of BSL-4 laboratories in more than 60 around the world are suit-type laboratories using positive pressure protective suits. In 2021, the first suit-type BSL-4 laboratory in Japan was constructed at Nagasaki University. Positive pressure protective suits are important as primary barriers to protect workers from pathogens, but the selection process has been largely unexplored. Here, I describe the selection process for the positive pressure protective suits to be used at the BSL-4 laboratory of Nagasaki University, and introduce a novel positive pressure protective suit (PS-790BSL4-AL), which was originally designed and produced in Japan.

Peracetic acid-based disinfectant is the most appropriate solution for a biological decontamination procedure of responders and healthcare workers in the field environment

AIMS

An effective decontamination procedure of personnel wearing personal protective equipment is required by CBRN responders and healthcare workers when dealing with biological warfare agents or natural outbreaks caused by highly contagious pathogens. This study aimed to identify critical factors affecting the efficacy of peracetic acid (PAA)-based disinfectants and products containing either hydrogen peroxide or sodium hypochlorite under the same conditions.

METHODS AND RESULTS

The influence of concentration, application (contact) time, erroneous human behaviour, interfering substance, technical assets and weather conditions on disinfection efficacy against Bacillus subtilis spores were assessed in 14 experimental groups. Residual contamination of protective suits was measured to provide responders with readily understandable information (up to 100 colony forming units classified a suit as disinfected). Weather conditions, short application time and erroneous human behaviour substantially affected the effectiveness of PAAs (P < 0·05). Non-PAA-based disinfectants (either liquid or foam) did not reach comparable efficacy (P < 0·001).

CONCLUSIONS

Peracetic acid was effective at a concentration of 6400-8200 ppm and an application time of 4 min.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study provides operationally relevant data for the use of PAA-based disinfectants in preparedness planning and management of biological incidents and natural outbreaks.