Published on 15th April 2020
Companies all over the world face huge challenges in managing their way through the advancing COVID-19 pandemic. They are faced with crucial decisions balancing their need to maintain or restore normal operations to ensure their economic survival, whilst upholding their principal duty of care protecting the health and well-being of their employees. Doing battle with an invisible and silent & killer, they need to look for critical ammunition to wage war and defeat the COVID-19 enemy, to protect a fearful workforce whose productivity is being destroyed amid the enduring threat.
To make matters even worse, the Health & Safety Executive recently published revisions to The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations1 (RIDDOR), specific to Covid-19. The new requirements issued on 07 April 2020 mandate companies to file a formal RIDDOR report in the following circumstances:
Preventing COVID-19 transmission into the workplace is now amongst the highest priorities for all company executives and it’s widely accepted that antibody testing is now key to the global exit strategy from the disease e.g. the prominent USA COVID-19 roadmap from former US FDA Director Scott Gottlieb, MD, includes widespread antibody testing as a critical step toward reopening society.
Currently, there are two principal types of commercially viable test for occupational screening of employees – antigen (PCR) testing and antibody testing. Both kinds of tests help employers make decisions about measures to contain the outbreak and inform employees’ return to work decisions.
Antigen tests which are often referred to as PCR tests, directly detect the virus itself using swabs from the nose and throat and have a high accuracy rate. The swab is then sent to an accredited laboratory for testing with results typically available within 1-3 days.
Antibody tests reveal if you have been exposed to the virus, and your body has developed antibodies. They involve an affordable finger prick blood test and a small cassette onto which a drop of blood is placed, buffer solution added and results read in 10-15 minutes. Such tests detect the presence of immunoglobulins which are produced by white blood cells as an immune response to viruses. Immunoglobulin M (IgM) is the first antibody to be made by the body to fight a new infection. IgM rises within the first week of infection AFTER the incubation period and is detectable after 3-5 days. At this time the subject has the disease and is highly infectious but they may have no symptoms. The IgG immunoglobulin, which is more abundant appears later.
COVID-19 is new for humanity and people will not have antibodies against it if they have not been infected. We don’t know yet if our antibodies are able to protect against re-infection, and we don’t know how long they will last in the blood. It is likely, however, that if employees have recovered, they should be able to return to work. Some countries like Germany are investigating using antibody test results as an “immunity passport” to advise those that have recovered to return to work. Dr. Deborah Birx, the response coordinator for the White House coronavirus task force, has called antibody tests “critical” in the response to the pandemic.
The best test protocol for an early infection is combining the antibody test AND the PCR test which is reported to achieve a 98.6% detection rate within the first 5.5 days of infection2
With respect to Covid-19 employees can be categorised as follows:
The below figure explains the antibody immune response in the body to help explain the important role antibody screening tests can play in preventing and containing Covid-19 outbreaks in the workplace.
With respect to each category of employees who present themselves for work, here’s a summary of the role each of the two test types can play in assisting employers with their decision making:
Category 1 (free from any infection and never previously infected) – both antibody & antigen tests will be negative for employees in this group.
Category 2 (free from any infection and recovered from previous infection) – PCR antigen tests will likely be negative whilst antibody tests will likely be positive for those in this group. Antibody tests are useful to detect this group, as it’s generally recognised that these people will have developed some form of immunity. Major caution is required though as according to a study9 in the American Journal of Respiratory and Critical Care Medicine, patients may continue to shed the virus for up to eight days after symptoms resolved. “Cases have been reported where a patient could infect their close contacts even after ‘apparent recovery’ from the infection,” the authors wrote.
Guidelines from the World Health Organisation3 recommended that a clinically recovered COVID-19 patient should test negative for the virus twice, with tests conducted at least 24 hours apart. Antigen PCR tests are the critical test for this ‘return to work’ scenario.
Category 3 (infected without symptoms and within the 5 day incubation period) – PCR tests are critical to identify employees in this group.
It’s therefore important for employers to anticipate the potential for category 3 subjects and define a screening strategy to mitigate any risks – see later.
Category 4 (infected, past the incubation period and with symptoms) – both types of test will identify these employees, however, it’s unlikely (but possible) that employees will report for work with symptoms, given the plethora of advice and guidance issued.
Category 5 (infected, past the incubation period & without symptoms) is the most significant risk – those employees who are infected (i.e. have the disease) and are highly contagious, but without symptoms. Such employees left undiagnosed (i.e. without pre-screening) would potentially spread the infection throughout the workplace, whilst being totally oblivious. Antibody tests are the most effective and appropriate to diagnose this category of subject with 97% clinical specificity.
As we learn more about this disease there’s an increasing knowledge bank that shows a high proportion of infected people who are highly contagious, show no symptoms:
According to McKinsey7, studies in China & Singapore report that asymptomatic transmission may account for ~50% of cases. In China, as they begin to return to work and daily life, they still experience small outbreaks and new cases. It’s widely accepted that the asymptomatic carriers are those who contribute largely to the ongoing spread – often referred to as the “super spreaders”. This is why testing is being widely introduced as the best practice to adopt, to prevent spread. South Korea did so well at controlling the COVID-19 outbreak because they immediate began testing hundreds of thousands of asymptomatic people.
Therefore without extensive screening, it’s impossible to know whether asymptomatic employees are bringing Covid-19 into the workplace and causing a potential major outbreak.
Research by McKinsey & Company (Covid-19: Briefing materials 3rd April 20207) concludes that “Antibody tests are currently the best method for detecting asymptomatic cases”
Prof Ashley Woodcock2, Associate Dean for Clinical Affairs and Professor of Respiratory Medicine, University of Manchester, and Clinical Director for Respiratory Medicine, University Hospital of South Manchester commented8:
“Currently the ‘stick’ [antibody] test will be invaluable as POC diagnosis. If positive, then the patient can immediately be triaged. False positives are rare. There may be 5% false negatives (IgM may not have yet gone up), but this can be checked in patients with the syndrome by re-testing”
For category 6 (employees who are symptomatic but not Covid-19 infected) as in category 4, it’s unlikely they’ll report for work with symptoms.
For category 7 (relapsed/reactivated cases) on-going periodic testing using either test would be the only way diagnose their re-activation from category 2.
The Health & Safety Executive (HSE) published new requirements1 issued on 07 April 2020 mandating companies to file a formal RIDDOR report in the following scenarios:
1 Dangerous Occurrences
An unintended incident at work has led to someone’s possible or actual exposure to coronavirus. This must be reported as a dangerous occurrence. According to RIDDOR regulation 7, Schedule 2 section 10,
“Biological agents – Any accident or incident which results or could have resulted in the release or escape of a biological agent likely to cause severe human infection or illness”
If something happens at work which results in (or could result in) the release or escape of coronavirus employers must report this as a dangerous occurrence.
2 Cases Of Disease: Exposure To A Biological Agent
If there is reasonable evidence that someone diagnosed with COVID-19 was likely exposed because of their work, employers must report this as an exposure to a biological agent using the case of disease report. According to RIDDOR regulation 9:
“Where, in relation to a person at work, the responsible person receives a diagnosis of—
(b) any disease attributed to an occupational exposure to a biological agent, the responsible person must follow the reporting procedure, subject to regulations 14 and 15”
3 Work Related Fatalities
If someone dies as a result of a work-related exposure to coronavirus and this is confirmed as the likely cause of death by a registered medical practitioner, then employers must report this as a death due to exposure to a biological agent using the ‘case of disease’ report form. Employers must report workplace fatalities to HSE by the quickest practicable means without delay and send a report of that fatality within 10 days of the incident.
According to RIDDOR regulation 6 (2):
“(2) Where any person dies as a result of occupational exposure to a biological agent, the responsible person must follow the reporting procedure.
(3) Where an employee has suffered an injury reportable under regulation 4 which is a cause of his death within one year of the date of the accident, the employer must notify the relevant enforcing authority of the death in an approved manner without delay, whether or not the injury has been reported under regulation 4.
(4) This regulation is subject to regulations 14 and 15, and does not apply to a self-employed person who suffers a fatal accident or fatal exposure on premises controlled by that self-employed person.”
It can be seen that employers face a huge obligation under RIDDOR for preventing and managing exposure to COVID-19 for their employees and occupational testing a critical in upholding their duty of care to employees.
Notwithstanding the HSE directives, the Society of Occupational Medicine8 (SOM) is calling for robust and increasing access to occupational health (OH). It is encouraging workplaces to design-in exposure prevention measures as advised by the Health and Safety Executive – helping employees take the opportunity to better understand the risks and demonstrate good practice in their work. Testing can play a key role in meeting this requirement.
CONCLUSION
The overwhelming conclusion from the scientific and medical community is that antigen and antibody tests are critical to the global exit and recovery strategy from the disease. Eminent medical opinion concludes combining the antibody test AND the PCR swab taken from the patient gives a 98.6% detection rate within the first 5.5 days of infection2
The individual tests can play different roles in different scenarios and should be considered complimentary. Coupling a positive antibody test with a negative PCR result could reduce the chance that people who are still contagious reenter society. Asymptomatic transmission poses perhaps the biggest threat to a COVID-19 workplace outbreak and the antibody test is very effective in screening for these cases.
By implementing an enduring regime of testing, employees’ fears will be mitigated and increased productivity and engagement can result. Driving improved business outcomes. The case of occupational health screening for COVID-19 is compelling for companies to maintain (or return to) normal operations to ensure their economic survival, whilst maintaining their principal duty of care protecting the health and well-being of their employees.
Major Corporations & health practitioners worldwide are rushing to adopt these tests to help control the spread of this deadly virus, with demand rising rapidly as the crisis deepens.
To assist employers, Martek Lifecare can offer PCR and antibody testing.
CoronaSafeTM+ PCR testing is delivered via our UKAS accredited laboratory with a 24-hour SLA
Antibody testing using the CoronaSafeTM finger prick antibody screening test. CoronaSafeTM has been proven in extensive clinical trials of 570 patients during the recent outbreak to deliver >95% accurate diagnosis of COVID-19.
The test is approved and certified by the European Union as meeting the safety, quality & performance requirements of European Standard IVDD 98/79/EC the highest standard applicable for these devices. It’s also in wide-scale use by authorities/corporations in Japan, China, Germany, Poland, Indonesia and is formally certified by CFDA, Philippines FDA Singapore Health Sciences Authority with US FDA pending.
REFERENCES
The CoronasafeTM antibody tests are further certified to the following additional International Standards: