Short Report
COVID-19 absenteeism in a meat processing abattoir during sustained community transmission in Central Queensland, Australia
https://doi.org/10.21203/rs.3.rs-1951390/v1
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Here we present the evaluation of the effect of the new COVID-19 national policy for the management of cases and close contacts and school re-opening on staff absenteeism in a meat processing/abattoir in Central Queensland, Australia during sustained community transmission.
The new definition of a close contact and 7-day isolation period appeared to be minimizing the burden on absenteeism and the critical essential workforce model to helping this further.
Throughout Australia and the world, Coronavirus disease 2019 (COVID-19) has been a major threat to organizations directly and indirectly. Virtually all industries have had considerable impacts to their productivity through absenteeism. Here we evaluate the effect of an Australian national COVID-19 policy for the management of cases and close contacts on staff COVID-19-related absenteeism in a meat processing/abattoir in Central Queensland, Australia during sustained community transmission. (1)
Australian COVID-19 policy guidance requires a confirmed case to have seven days isolation from date of positive test result, and seven days quarantine for a close contact of a confirmed case from date of last contact with a case. (1, 2) To be deemed a close contact, a person must live in the same household, or spend 4 hours in a household like environment with a case. A new national policy was introduced on the 13th of January 2022 in attempt to minimise the burden of workplace COVID-19-related absenteeism by shortening isolation and quarantine from 14 days to 7 days. Note that the national policy allows the return of close contacts to work as critical essential workers (CEW) if they meet the appropriate criteria. (3)
According to the CDNA guidelines a confirmed case of SARS-CoV-2 requires laboratory definitive evidence such as the detection of SARS-CoV-2 by polymerase chain reaction (PCR) whilst a probable case of SARS-CoV-2 requires detection of SARS-CoV-2 by rapid antigen testing (RAT). (2) Since 16 February 2022, most cases were detected on RAT due to changes in legislation and limited PCR availability.
The meatworks in Central Queensland region, Australia has a total of 509 employees (81.0% fully vaccinated against SARS-CoV-2), with a total of 351 persons entering the facility each day. Between January 17, 2022, and March 11, 2022, a total of 196 employees (38.5%) had confirmed COVID-19 infection either by PCR or RAT. Our Public Health unit supported the organization in their management of staff and close contacts.
Figure 1 demonstrates the effect of sustained community transmission on absenteeism. At the peak, 17.7% staff were absent. We observed an attack rate of 65.2% (15/23) in close contacts. Overall, there was 11 employees that were CEW close contacts who trialled a return to work with daily RAT tests and symptom checks. (3) In this group, 5 returned a positive result during their return-to-work program, which suggests that 45.5% of CEW on a return-to-work program may work while infectious.
None required hospitalization or Intensive Care Unit (ICU) admissions, and there were no deaths. Public Health team visited this abattoir prior to the outbreak and found that due to the baseline stringent food and safety measures (e.g., strict hand washing with routine microbial audits, plentiful ventilation, full overalls, and cloth masking) plus the added SARS-COV-2 precautions (e.g., social distancing, addition of surgical masks and other personal protective equipment) it is highly unlikely that much, if any, transmission occurred on-site.
This review of the COVID-19 related absenteeism in a local meatworks facility found that a 7-day isolation for cases and a 7-day quarantine period for close contacts led to a peak of 17.7% absenteeism during Central Queensland’s first wave of COVID-19. The opening of schools may have increased transmission in younger children which leads to increased absenteeism in working families.
In November 2020 a UK study using Covasim stochastic individual-based model for transmission of SARS-CoV-2 calibrated to the UK pandemic, predicted a large second wave of infection following schools reopening and gradual relaxing of the lockdown measures unless high level of testing and contact tracing measures are implemented. (4) Regardless of full-time or part-time school reopening, predicted R was above 1 which could result in second wave of infections 2.0-2.3 times the size of the original COVID-19 wave. (4) Israel reported COVID-19 case numbers resurge following school reopening in March to July 2020 with higher rate ratios of sample positivity rates 21–27 days following school reopening relative to positivity rates prior to openings for the age groups of 40–59 (RR 4.72) and 20–39 (RR 3.37) years but not for children ages 0–9 (RR 1.46) and 10–19 (RR 0.93) years.(5) Case series study on the role of schools in the spread of COVID-19 in Europe in December 2020 argues that school closures and openings contribute to decreased and increased epidemic growth rates respectively, with school closures reducing epidemic growth rates ranging from 49–82% in different states in Germany.(6) Contrary to these views, a prospective cohort study of SARS-CoV-2 transmission in Australian education settings in January 2020 to April 2020 (low SARS-CoV-2 prevalence) in NSW showed no significant contribution to COVID-19 transmission via attendance in educational settings with the overall child to child transmission rate of 0.3% and the attack rate for child to staff member of 1.0%. (7). Policy changes around school closures and openings may help alleviate workplace absenteeism.
It is difficult to link changes in school attendances to changes in case incidence, however, national policy at the time of school reopening may significantly affect workplace COVID-19-related absenteeism. Our absenteeism rates (% of 351 employees per day) in the facility (Fig. 1), demonstrates two waves. The first wave emerged after meatworks reopening following Christmas break with school closures to a peak of 17.7% staff absent at the time. The second wave could be observed following schools` reopening on the 7th of February with the rate of absenteeism reaching its peak of 14.8%. If we accept that schools re-opening was the driver of the second wave of transmission and thus absenteeism, changes to the National policy on the management of COVID-19 cases and close contacts (2) would likely lead to changes in absenteeism rates in the setting of future school openings.
The intervention seemed to be appropriate for the “Suppression” phase of “Transition of the test-trace-isolate-quarantine (TTIQ) response”. Together, within three weeks the organization saw 38.5% of their staff infected with SARS-CoV-2. Compared to the previous 14-day isolation and quarantine periods, the 7-day isolation period appears to be minimizing the burden on absenteeism and the CEW model helps this further but noting that it is possible that with a pre-symptomatic infective period of 48 hrs, approximately 45.5% of these workers may work while infectious prior to a positive RAT test. However, in a highly vaccinated healthy adult population the risk of severe disease is lower than the adverse consequences of staff absenteeism on running a critical service and our finding should inform other essential areas like maritime and resources industries.
These data are limited in their applicability to other countries due to varying national policies. However, these data demonstrate the potential for significant supply chain disruption from policies used to minimize the spread of COVID-19. All cases occurred in a manual labour workforce. Therefore, the policy effects would have been reduced in a workplace that could effectively work from home (e.g., banking, Information technology). Additionally, the workers had pre-existing personal protective equipment (PPE) requirements which made worksite transmission unlikely. Therefore, the burden of absenteeism could have been worse in workplaces where PPE usage was less, and workplace transmission occurred frequently.
COVID-19
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Ethics approval and consent to participate: The project has been considered at the Townsville Hospital and Health Service Human Research Ethics Committee (HREC) chairperson on 07/01/2022. The project has been endorsed to be undertaken. The Townsville Hospital and Health Service Human Research Ethics Committee (Ref no: HREC/82361) approved this surveillance as exempt from review and waived the requirement for written informed consent. All methods were performed in accordance with the relevant guidelines and regulations.
Consent for publication: Ethical review for exemption to publish was obtained from Townsville Hospital and Health Service Human Research Ethics Committee (Ref no: HREC/82361). Publishing the results will produce evidence on epidemiological trends in a regional Australian context.
Availability of data and materials: This is an evaluation project using routinely collected public health surveillance data. Data is requested to be “the disclosure is to an employee of the department, or a person approved by the chief health executive who is contracted by the department to analyse, monitor or evaluate public health” under s82 of the Public Health Act. The data is stored at Central Queensland Public Health Unit in spreadsheets on password encrypted hard drives and the Queensland Health network drive which is password protected. Electronically stored data is only available to the researched working on the project. Data will be kept for 5 years from the date of last publication in accordance with the Australian Code for Responsible Conduct of Research and then treated as confidential waste in-line with the internal policy. Materials used for the project belong to CQPHU.
Competing interests: There is no competing interest to be declared.
Funding: No funding sources have been involved.
Authors' contributions: Svetlana Krasnova (http://orcid.org/0000-0002-5475-8541) [email protected], Nicolas Smoll (http://orchid.org/0000-0002-6923-9701) [email protected], Gulam Khandaker (http://orchid.org/0000-0002-0661-4113) [email protected]. contributed equally to this article and share first authorship.
No competing interests reported.
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