Background
SARS-CoV-2 is a new virus of the family of viruses called coronaviruses. They are called “corona” because of the crown-like appearance of the spikes that adorn the outer surface of the virus when viewed under an electron microscope.
Figure 1 - Image of SARS-CoV-2 courtesy CDC.
COVID-19, the disease caused by the SARS-CoV-2 was first reported in Wuhan, Hubei Province, China at the end of 2019. The disease spread rapidly and on the 11 March the World Health Organisation (WHO) declared COVID -19 a global pandemic.
How is it spread?
COVID-19 is predominantly spread from person to person, mainly through respiratory droplets when an infected person coughs, sneezes or talks. These droplets can land in the mouths, noses or eyes of people close or be inhaled into the lungs. The droplets can also land on objects (fomites) and be spread when a person touches the contaminated object and then touches their own mouth, nose or eyes. The droplets are relatively heavy, rapidly fall to the ground and do not travel far.
Small aerosol spread can occur, but it does not appear to be the main source of infection.
Figure 2 High-speed images of a sneeze. Images by Lydia Bourouiba, MIT(1)
Studies done in hospitals and other settings showed contamination on phones, computer mice, floors and trash cans. (2,3) Studies suggest that coronaviruses can survive from a few hours or up to several days on surfaces. This may vary under different conditions, e.g. type of surface, humidity and temperature.
Figure 3 Persistence of Coronaviruses on surfaces. Image from Medscape. (4)
It is important to remember the method of spread when instituting mitigation measures. SARS-CoV-2 is an enveloped virus with a fragile outer lipid layer that makes it susceptible to disinfectants.
Symptoms
The predominant symptoms are those of an acute upper respiratory infection with the most common symptoms being fever, dry cough and tiredness. The National Institute for Communicable Disease lists the symptoms as including ANY of the following: cough, sore throat, shortness of breath, anosmia (loss of a sense of smell) or dysgeusia (alteration of a sense of taste), with or without other symptoms (which may include fever, weakness, myalgia (body pains), or diarrhoea. (5)
Prognosis
The majority of people infected have a mild illness and are able to recover at home. Approximately 14% require hospitalisation with 4,7% needing intensive care. The fatality rate increases with age (6) and with the addition of certain chronic conditions (co-morbidities). The risk of having a severe infection increases with the number of co-morbidities. (7) At the height of the pandemic, a doubling rate of 4-5 days can be expected. (8)
Applicable legislation
Health and safety (H&S) legislation, specifically the Occupational Health and Safety Act (OHSA), and the Hazardous Biological Agents Regulations (HBA Regs), require employers to provide and maintain as far as reasonably practicable, a workplace that is safe and without risks to the health of employees.
In addition, various directives and guidelines have been issued by the Department of Employment and Labour and the Department of Health to address COVID-19 in the workplace.
These include:
• COVID-19 Occupational Health and Safety Measures in Workplaces Directive, 4 June 2020. (9)
• The Department of Employment and Labour: Workplace Preparedness: COVID-19(10)
• Specialised health risk assessment for workplaces (11)
• Notice on Compensation for occupationally acquired novel coronavirus disease (COVID-19)
· under Compensation for Occupational Injuries and Diseases Act. (12)
• Guidance for symptom monitoring and management of essential staff. (13)
• Guidance note for workplaces in the event of identification of a COVID-19 positive employee.
· (14)
• Guidance on vulnerable employees and workplace accommodation in relation to COVID-
· 19.(15)
• COVID-19 Disease: Infection Prevention and Control Guidelines (16)
These documents guide the employer and the employee on their various roles and responsibilities in the workplace. Employers are required to take steps to eliminate or mitigate any risk or potential risk through engineering and administrative controls before resorting to personal protective equipment. The essential role of the workplace COVID-19 health risk assessment is enshrined in the various directives and guidelines.
References
1. Bourouiba L. Turbulent Gas Clouds and Respiratory Pathogen Emissions: Potential Implications for Reducing Transmission of COVID-19. JAMA [Internet]. 2020;323(18):1837–8. Available from: https://jamanetwork.com/journals/jama/fullarticle/2763852
2. Guo Z-D, Wang Z-Y, Zhang S-F, Li X, Li L, Li C, et al. Early Release - Aerosol and Surface Distribution of Severe Acute Respiratory Syndrome Coronavirus 2 in Hospital Wards, Wuhan, China, 2020 - Volume 26, Number 7—July 2020 - Emerging Infectious Diseases journal - CDC. Emerging Infectious Diseases [Internet]. 2020;26(7). Available from: http://wwwnc.cdc.gov/eid/article/26/7/20-0885_article.htm
3. Santarpia JL, Rivera DN, Herrera V, Jane Morwitzer M, Creager H, Santarpia GW, et al. Transmission Potential of SARS-CoV-2 in Viral Shedding Observed at the University of Nebraska Medical Center. Available from: https://doi.org/10.1101/2020.03.23.20039446
4. Doremalen N van, Bushmaker T, Morris DH, Holbrook MG, Gamble A, Williamson BN, et al. Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. https://doi.org/101056/NEJMc2004973 [Internet]. 2020;382(16):1564–7. Available from: http://www.nejm.org/doi/10.1056/NEJMc2004973
5. National Health Laboratory Service. Coronavirus disease 2019 (COVID-19) Quick Reference for Clinical Health Care Workers [Internet]. 2020. Available from: www.nicd.ac.za
6. Verity R, Okell LC, Dorigatti I, Winskill P, Whittaker C, Imai N, et al. Estimates of the severity of coronavirus disease 2019: a model-based analysis. The Lancet Infectious Diseases. 2020 1 June;
7. Guan WJ, Liang WH, Zhao Y, Liang HR, Chen ZS, Li YM, et al. Co-morbidity and its impact on 1590 patients with Covid-19 in China: A Nationwide Analysis. The European respiratory journal. 2020 1 May;
8. African News Agency. Cape Town's Covid-19 spike occurred in malls in the last weeks of hard lockdown: Prof Karim. 2020;
9. Department of Employment and Labour. Consolidated Direction on Occupational Health and Safety Measures in Certain Workplaces. 4 June 2020 [Internet]. 2020. Available from: www.gpwonline.co.za
10. Department: Employment and Labour RSA. The Department of Employment and Labour: Workplace Preparedness: COVID-19 (SARS-CoV-19 virus). 2020.
11. Department: Health RSA, Department: Employment and Labour RSA. Specialised health risk assessment for workplaces (by employers and self-employed persons). 2020.
12. Compensation Commissioner, Department of Employment and Labour. Notice on Compensation for occupationally-acquired novel coronavirus disease (COVID-19). 2020;
13. Guidelines for symptom monitoring and management of essential workers for COVID-19 related infection [Internet]. Available from: https://www.cdc.gov/coronavirus/2019-ncov/healthcare-facilities/hcp-return-work.html
14. Guidance note for workplaces in the event of identification of a COVID-19 positive employee (V5: 14 May 2020) [Internet]. Available from: https://www.nicd.ac.za/wp-content/uploads/2020/03/NICD_DoH-
15. RSA DH. Guidance on vulnerable employees and workplace accommodation in relation to COVID-19 (V4: 25 May 2020). 2020.
16. Department: Health RSA. ipc-guidelines-covid-19-version-2-21-may-2020. 2020.
Dr Haidee Williams offers specialist occupational medicine services with an interest in developing evidenced based safety, health and environment policies and programmes. Expertise includes medical examinations, medical adjudication, toxicology, health based risk assessments, hazardous chemical substances, hazard communication and training and guidance on H,S&E legal compliance requirements.
Tel: 087 809 0054
Email: haidee@occupational-medicine.co.za
Twitter: @drhmwilliams