What is general medical guidance for plant managers for protecting employees against COVID-19 (car manufacturers, slaughterhouses, etc.)?
Measures that likely reduce transmission of COVID-19 in the workplace include social distancing, encouraging hand hygiene practices, use of face masks, screening of employees before entry into the workplace, cleaning of frequently touched surfaces, clear return to work policies and paid sick leave for illness and quarantine timeframes. These measures have been investigated with regard to other respiratory viruses, such as influenza. They have not been tested for efficacy with SARS-CoV-2. Workers should stay home if they feel sick, regardless of the symptoms.
- The Centers for Disease Control and Prevention (CDC) defines social distancing as “keeping space between yourself and other people outside of your home.” Specifically, they mention avoidance of close contact by staying at least 6 feet (2 meters) from other people and not gathering in groups. They define close contact as being with 6 feet (2 meters) for a prolonged period of time (which has been interpreted to be 15-30 minutes). The recommendation for 6 feet stems from the approximate distance that potentially infectious droplets can travel from an infected patient, e.g., with coughing. Social distancing can reduce virus transmission by increasing physical distance or reducing frequency of congregation in workplace settings. Social distancing should be practiced at all times, including meals and breaks. A systematic review evaluated three epidemiologic studies and twelve modeling studies of the impact of workplace social distancing in reducing influenza transmission. The epidemiologic studies suggested a benefit of social distancing measures including working from home for those who can do so. The authors stated: “The modeling studies estimated that workplace social distancing measures alone produced a median reduction of 23% in the cumulative influenza attack rate in the general population.”
- Hand washing or use of alcohol-based hand sanitizers reduces the number of pathogens that contaminate the hands. A meta-analysis of studies assessing hand hygiene as an intervention found a statistically significant 16% reduction in the number of participants with acute respiratory illnesses. Another meta-analysis of case-control studies found that frequent handwashing, at least 11 times per day, reduced the occurrence of cases of SARS in the 2003 pandemic (odds ratio 0.54, 95% CI 0.44 to 0.67).
- Use of surgical masks has been shown to be effective at reducing transmission of other respiratory viruses. They may particularly provide protection when work tasks require close contact of employees (less than 6 feet). Surgical mask supplies are currently limited and therefore are reserved for healthcare workers. Face masks, including homemade masks do not provide as much protection, but are recommended.
- Intuitively, screening of employees for symptoms suggestive of infection or for close contact with infected individuals makes sense, though it has not been demonstrated to be effective. Such screening could be as simple as self-screening, including temperature checks, at home before entry into the workplace. In other settings, e.g., airports, temperature screening prior to entry has not been shown to be effective. The limitations of screening may be especially pronounced with COVID-19 since people are highly infectious in the 2-3 days before they have symptoms and many people may be infected without experiencing symptoms. While temperature screening at the worksite is not recommended, it has been mandated in several jurisdictions. If it is used, it is important to maintain social distancing during the process.
- Paid sick leave has been shown to reduce attendance at work when sick with influenza or influenza-like illness (ILI). At least 14 days of paid sick leave is recommended for COVID-19. Employees who are household contacts of COVID-19 confirmed cases may not be able to follow CDC guidance on separation in shared spaces. Employers should consider their workforce and, in some cases, require employees to stay at home for 7 days after isolation has been discontinued for the ill household member.
- If an employee is confirmed to have COVID-19, identification of close contacts and having them self-quarantine away from work for 14 days would be important. Cleaning of commonly touched surfaces, such as stair handrails, is recommended by CDC.
CDC, Social Distancing, Quarantine, and Isolation, https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/social-distancing.html
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Al-Ansary L, Bawazeer G, Beller E et al., Physical interventions to interrupt or reduce the spread of respiratory viruses. Part 2 - Hand hygiene and other hygiene measures: systematic review and meta-analysis. medRxiv 2020.04.14
Jefferson T, Del Mar CB, Dooley L, et al. Physical interventions to interrupt or reduce the spread of respiratory viruses. Cochrane Database Syst Rev. 2011; 2011(7):CD006207.
CDC, Recommendation Regarding the Use of Cloth Face Coverings, Especially in Areas of Significant Community-Based Transmission, https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover.html
Piper K, Youk A, James A E, Kumar S. (2017). Paid sick days and stay-at-home behavior for influenza. PloS one, 12(2), e0170698. https://doi.org/10.1371/journal.pone.0170698