Breath research in times of a global pandemic and beyond: the game changer

The research community has always recognized that universal precautions must be taken when dealing with human subjects and when collecting biological specimens such as tissue, blood, urine and breath due to the risk of infectious transmissions. That said, exhaled breath is fundamentally different from liquid or solid specimens. Each human adult emits about 16 m³ of 'gas' per day into their immediate surroundings without a second thought; the same cannot be said for blood, urine or tissue. Until recently, collection and analysis of breath was considered relatively risk-free, but the present global COVID-19 pandemic has changed the game for breath research.

Currently, public health professionals have cautioned that there are significant risks associated with exposure to exhaled aerosols in the environment as they represent a major source of COVID-19 disease transmission via the SARS-Cov-2 virus. In addition to extensive hand washing/disinfection and social distancing, it is generally accepted that improvised facial coverings and medical masks are important factors to reduce exposure to infectious agents, leading to widespread recommendations and/or regulations to wear facial masks as a way to limit the spread of COVID-19 (Pleil et al 2020). Essentially, breath can no longer be considered a relatively safe biological medium.

So, on the one hand we must handle breath more cautiously than in the past, yet on the other hand the COVID-19 pandemic has prompted the research and medical communities to work towards developing breath-based diagnostic tests to identify the infection in patients. Researchers within our community are working with live viruses or are studying case-control samples to discover potential biomarkers for the SARS-Cov-2 virus. To minimize risk of infection, hospitals, treatment centers and research facilities actively involved in COVID-19 studies have adopted individual safety protocols to protect individuals (staff, study participants and patients) from inadvertent SARS-Cov-2 virus exposure (Makoto commentary—accepted for publication, Gould et al 2020, Chandrapalan et al 2020). But risk of infection is not limited to studies that focus on this virus: current research has shown that it is possible for pre-symptomatic and asymptomatic carriers to spread COVID-19. Therefore, it can no longer just be assumed that any individual or patient without diagnosed illness is 'safe'.

As Journal of Breath Research is a primary resource for breath-related research, we (the editors) are presently developing safety guidance applicable to all breath research , not just for those projects that involve known COVID-19 infected subjects. We are starting this process by implementing requirements on reporting safety precautions in research papers and notes. This editorial serves to announce that authors of all new submissions to JBR henceforth must state clearly the procedures undertaken for assuring laboratory and clinical safety, much like the existing requirements for disclosing Ethics Committee or Institutional Review Board protocols for studies on human subjects. In the following, we additionally make some recommendations based on best practices drawn from our experience and input from the JBR Editorial Board.

Working with breath is fundamentally different from blood or urine media in that breath is invisible; it pervades the environment as a gas and adsorbs to sampling gear and analytical instrument surfaces as aerosols. The standard universal precautions as prescribed by Centers for Disease Control for blood and other potentially infectious human samples may no longer be fully protective (Siegel et al 2007).

It is reasonable now to follow what has been described as universal pandemic precautions (UPP) against respiratory pathogens when performing breath related research (sampling, analysis, etc) as recommended by the Society of Healthcare Epidemiology of America (SHEA) (Weber et al 2020). To protect clinicians, researchers, and research participants from acquisition of COVID-19 and other respiratory pathogens, we propose a paradigm shift; implementation of UPPs as recommended by SHEA: Use of a mask and eye protection for all direct patient contacts or at a minimum, use of a mask and eye protection for direct patient contact.

There are additional precautions to consider during the collection of exhaled breath samples (volatiles, condensate and/or aerosols) where breath researchers, patients or study participants could be exposed to potential infectious agents. It should be assumed that any breath sampling equipment, sampling media, breath analysis instrumentation, and rooms where breath samples are collected or analyzed could contain infectious agents.

This is particularly important for the sampling interfaces of medical respirators, pulmonary testing instrumentation, or other breath monitoring/sampling devices that come into contact with breath gas donors. Just because disposable filters or sampling assemblies (tubing, mouthpieces, non-rebreathing valves, etc) are 'one use only' between patients does not guarantee that the downstream components have not been coated with breakthrough aerosols and have become contaminated. Care must be taken that any reverse flows by active or inadvertent inhalation by the study participant cannot pose an infection risk.

Previous research has shown that the surfaces of all types of facial coverings can collect exhaled aerosols. In fact, researchers have exploited disposable hospital masks, firefighter self-contained breathing apparatus masks, jetfighter pilot oxygen masks, laboratory face-shields, etc as convenient sampling media for assessing exposures, inflammation, and health state based on extraction of deposited aerosols (Wallace et al 2019). After use, however, such gear is often treated somewhat casually rather than the potential source of infection it represents in the post-COVID era. Face-shields, tubing, tools, glassware, etc may not be fully disinfected; masks and laboratory coats, may be re-used throughout the day, and PPE disposal containers may be left open, or repeatedly disturbed. We recommend that any PPE and other related items from occupational, laboratory, or medical use be treated with the same care as biological samples with respect to post-use disposal or disinfection and storage.

Safety is paramount for the editorial board and publishing staff of Journal of Breath Research. We hereby require that submitted research paper and note article manuscripts include a separate section, 'Safety Procedures' that describes all safety procedures adopted for the subject matter study. Specifically, this section must include risk-reduction in terms of personal protective measures, safety of breath sampling equipment, safety procedures for the transport and analysis of collected samples, and finally disposal of all potentially contaminated samples and materials.

Breath research may play an important role in the tackling the global COVID-19 outbreak, and researchers in our community who are developing diagnostics and health monitoring technology are already acutely aware of the risks involved. However, we expressly assert here the need to recognize that all breath research is affected by this current pandemic, and indeed beyond it. Every single patient/research participant must be treated as if they were an asymptomatic spreader of this and potentially other infectious disease. This awareness is not just for the actual samples or laboratory ware, but extends to all surfaces that exhaled aerosol may have been exposed to during sample collection, including PPE, respirators, laboratory equipment, breathing interfaces (sampling inlets), and even the interior surfaces of analytical instruments. Certainly, the UPPs should be followed, but additional scrutiny should be extended to ambient air and surfaces in the clinic and laboratory.

In short, the outbreak of the COVID-19 pandemic in Spring 2020 has changed the breath research landscape and our community must be ever more vigilant to adhere to good laboratory practices and due diligence aimed at preventing the spread of infectious agents to any personnel.