The Occupational Medicine Forum is a JOEM Forum reviewed opinion piece and does not necessarily represent an official ACOEM position. The Forum is intended for health professionals and is not intended to provide medical or legal advice, including illness prevention, diagnosis or treatment, or regulatory compliance. Such advice should be obtained directly from a physician and/or attorney.
Answered by Catherine Kelaher, MBBS (Hons), FAFOEM, FRACGP, Principal Medical Adviser, Australian Government Department of Health, Australia; Gwendolyn L. Gilbert AO, MD, FRACP, FRCPA, M. Bioethics, Marie Bashir Institute for Infectious Diseases and Biosecurity, Westmead Clinical School, The Westmead Institute for Medical Research, The University of Sydney, Sydney, Australia; Allen Cheng, MB BS, FRACP, MPH, PhD, Department of Epidemiology and Preventive Monash University, Melbourne, Australia; and Michael Kidd AM, MD, FAHMS, Principal Medical Advisor & Deputy Chief Medical Officer, Australian Government Department of Health, Australia; Professor of Primary Care Reform, Australian National University, Canberra, Australia; Adjunct Professor, Department of Family & Community Medicine, University of Toronto, Canada; Emeritus Director, WorldHealth Organization Collaborating Centre on Family Medicine and Primary Care; Professorial Fellow, Murdoch Children's Research Institute, The Royal Children's Hospital Melbourne, Australia; Honorary Professor of Global Primary Care, Southgate Institute for Health, Society and Equity, Flinders University, Australia.
HOW WILL INDUSTRY AND BUSINESS FIND A “NEW NORMAL” AFTER THE COVID-19 SHUT DOWNS?
The novel coronavirus disease (COVID-19) pandemic has caused countries to shut down in an attempt to slow transmission, avoid health systems being overwhelmed, and prevent unnecessary deaths. As countries have achieved suppressed transmission, industries and workplaces are preparing to return to work. Risk management, in a world in which COVID-19 continues to spread, in the absence of effective vaccines or treatments, requires a whole-of-business risk assessment, analysis and management plan which considers the virus, how it is transmitted and the symptoms it causes. Mitigation measures need to be targeted to prevent its entry into and transmission in the workplace.
In December 2019, a cluster of cases of viral pneumonia of unknown etiology was reported in Wuhan City in the Hubei Province of China. It was caused by a novel beta-coronavirus, now called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).1 COVID-19, the disease caused by SARS-CoV-2 was characterized as a pandemic on March 11, 20202 and many countries experienced an exponential growth in the rate of infections. By May 1, 2020 there were 3,214,256 cases and 232,570 deaths worldwide.3 In the absence of an effective treatment or vaccine, countries implemented varying degrees of non-pharmaceutical interventions (NPI) including active detection and isolation of cases and tracing and quarantine of their contacts, as well as “stay-at-home except for essential activities” policies and other physical distancing measures such as the cancellation of mass gatherings and closure of workplaces, schools, and public spaces. These measures have been effective in minimizing transmission in many countries but are disruptive and have adverse economic, social, and health impacts. So, as COVID-19 case numbers diminish, countries are beginning to navigate a reversal of these NPI3 and industry and workplaces are preparing to recommence operations. This is difficult, because, until there is an effective vaccine or a change in disease epidemiology, a return to normal is unlikely. There have already been multiple case clusters in workplaces, in offices,4 call centers,5 meat processing plants,6 aged care facilities, schools, and health care settings.7 Cases or clusters of COVID-19 in workplaces cause adverse health impacts, employee absences, business closures, process disruption, loss of consumer confidence, potential brand damage, and financial loss.
Businesses and workplaces should consider an extensive risk assessment and develop a management plan. Mitigations should model a defence-in-depth-strategy and use a hierarchy of controls to minimize the risk of COVID-19 to the health of employees, the community, and operations.8
The occupational risk management process for COVID-19 requires an understanding of the virus and its transmission, the disease symptomatology, local epidemiology, and the specific work environment. COVID-19 is the illness caused by infection with SARS-CoV-2. Managing the related risks requires a knowledge of possible presentations so as to: identify unwell people and prevent their entry into the workplace; manage people who become unwell in the workplace to minimize risk of transmission; and identify and shield those who may be at increased risk of severe COVID-19 illness should they become infected.
The most common symptoms of COVID-19 are fever/chills (49%), dry or productive cough (24%), sore throat (12%), general weakness (8%), muscle pain (7%), runny nose (4%), and diarrhea (2%).9 Other reported symptoms include headache and loss of taste and smell. Workers and workplace managers should be aware that infectivity appears to peak when people become symptomatic, but that people may be infectious before symptoms develop and a small proportion of people may be infectious but never develop symptoms.9
Workplace managers should also be aware of, identify and apply appropriate measures to protect groups of people who appear to be at higher risk of severe illness should they become infected with COVID-19. These include those who are older (aged over 70 years), or have chronic conditions including cardiac disease, hypertension, diabetes, obesity, chronic respiratory disease, and cancer.9
Many workplaces have considered screening as a way of preventing people with COVID-19 from entering the workplace, but there is little evidence to support this.10 Temperature screening has been the main modality but modeling shows that it is only likely to detect 38% of cases.11 Its poor detection rate (sensitivity) relates to a combination of fever being present in only about half COVID-19 cases and, when it is present, a possible delay before an infected person becomes febrile. Fever is also nonspecific and therefore not a reliable indicator of COVID-19.12 Questionnaires have also been used and can screen for both symptoms and risk of exposure, but modeling suggests this may miss up to 50% of cases because people are asymptomatic, presymptomatic, or unaware of an exposure risk.12 While data supporting efficacy is limited, screening may raise awareness, change behavior and detect, at least, a proportion of cases. A layered approach using a combination of methods (ie, temperature screening and targeted questionnaire) could be used in specific settings such as remote or vulnerable work setting (eg, health or aged care or in prisons).13 Other forms of testing are sometimes considered for highly sensitive settings such as remote communities or work sites. At this stage, the only reliable and widely available test for COVID-19 (polymerase chain reaction) detects active infection.
Others, including point-of-care serological tests, detect antibodies that develop in response to acute infection. Until they are properly evaluated, their capacity to reliably detect past infection or protective immunity is uncertain. If used, the limitations of screening tests must be understood; sensitivities and specificities vary, and outputs represent a point in time. People who screen negative may be asymptomatically infected and screening may give a false sense of security.14
Immunity passports have also been proposed. At this stage, they cannot be used to infer immunity because the degree and duration of protection following COVID-19 infection are not yet known. Some mitigations, which can be used to manage the risk of introducing COVID-19 into the workplace and managing cases, if they occur, are at Table 1.
Because people may be asymptomatic or presymptomatic it is not always possible to prevent someone who is infected from entering the workplace.14,15 Therefore, it is also important to consider ways to prevent transmission. This requires an understanding of how the virus spreads, which is important in developing and applying appropriate controls. For example, we know proximity is important. In a COVID-19 outbreak in a call center in South Korea it was found that, of 1143 persons in the building who were tested, only 97 were positive; of these, 94 worked on the same floor in close proximity to each other.5 Proximity was also found to be a factor in a review of a series of clusters in meat processing plants in the United States.6 A cluster in a restaurant in Guangzhou in China, found that in addition to proximity, airflow in an area may also play a role in spread.16 This is because of characteristics of the virus and the way that SARS-CoV-2 is transmitted.
Understanding transmission of SAR-CoV-2 to inform mitigation measures SARS-CoV-2 can be spread, potentially, in four ways: by contact (directly or via a contaminated surface); by respiratory droplets, produced when an infected individual coughs or sneezes, which settle on a susceptible individual or surface in close proximity; through aerosols (generated by medical procedures); and, theoretically, by the faecal-oral route.17 The epidemiology of disease, which predominantly reflects prolonged contact between adults in crowded indoor settings, strongly suggests that contact and droplet spread are predominant.
Once on a surface, viable virus can persist for variable periods, from hours to possibly days. Studies of virus viability are complicated by the lack of knowledge on the infecting dose, and other factors, such as surface material and prevailing environmental conditions.18,19
Coronaviruses survive relatively well on smooth surfaces and in cool conditions (4 °C), they are inactivated as temperatures increase (more rapid inactivation at 40 °C than 20 °C), survival may also be affected by relative humidity.20,21 SAR-CoV-2 is likely to survive for a period indoors, and may survive longer in cool areas with hard surfaces such as bathrooms and toilets.22 However, as enveloped viruses, they are quite easily inactivated and appropriate cleaning can eliminate viral contamination.18
These characteristics of SARS-CoV-2 highlight the importance of physical distancing, reducing social interactions, and hand, respiratory and environmental hygiene to reduce the risk of contact and droplet spread, directly or indirectly, from contaminated surfaces. Risk management plans should include ways to increase distancing and decrease social interaction in all aspects of the business operation. Measures should be based on a specific risk assessment and management plan and may include, but are not limited to, the mitigations detailed at Table 2, which should be combined with those in Table 1.
The information around COVID-19 is rapidly evolving but it is clear that, in the absence of effective treatments or a vaccine, a return to “business as usual” will be unlikely in the near future. As industry and workplaces plan to recommence operations they will need to find a “new normal.” Resumption of business will require a review of all aspects of operations and the development of comprehensive risk management strategies to protect the health of employees, the community, and the business, from COVID-19. Risk management needs to consider the hierarchy of controls, the specific characteristics of the virus, its transmission and persistence in the environment, likely symptomatology in infected people and the risk factors that predispose to severe illness. Mitigations should include preventing entry of affected people into the workplace and development of an effective management plan to manage a case should it occur and prevent the spread of infection and the broader disruption related to a workplace cluster. Specifically, this will involve preventing transmission by physical distancing, limiting social interactions and ensuring appropriate hand, respiratory and environmental hygiene measures. Industry sectors should also consider the development of best practice guidelines based on expert advice from specialist occupational medicine physicians.
The authors wish to acknowledge the work of all the members of the Australian Government Department of Health Primary Care COVID-19 Implementation Group.
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