A new study from Germany shows that COVID-19 can be transmitted over distances of at least 8m in confined spaces where there is low air exchange rates and high rates of recirculated unfiltered air, like those in meat factories.
The research, which focused on a "superspreader" COVID-19 outbreak in one of Germany’s largest meat processing plants, found that environmental conditions promoted viral transmission from a single worker to more than 60% of co-workers within a distance of 8m.
“Our findings indicate that a physical distance of 2m does not suffice to prevent transmission in environmental conditions such as those studied here,” the report authors noted.
“Additional measures, such as improved ventilation and airflow, installation of filtering devices or use of high-quality face masks, are required to reduce the infection risk in these environments,” they added.
A physical distance of 2m does not suffice to prevent transmission
The study was carried out in the largest meat processing plant in Germany, located in RhedaWiedenbrück, where cattle and pigs are slaughtered and processed.
It also assessed a second processing plant 30km away in Dissen, which specialises in sow deboning.
The research looked at the position of workers in the plant, what shift they worked on, who they travelled to work with and who they shared living accommodation with.
While some workers did live and travel together and these crossovers analysed, the report found that it was more likely that they contracted the virus from working close together in the boning region of the factory, rather than outside the factory.
There was a high infection rate among workers who worked in close proximity of the original COVID-19-positive worker and a positive correlation between the infection rate of workers in a unit and the percentage of unit members working in the 8m area.
“While some secondary infections may have occurred within apartments, bedrooms or carpools, our collective data strongly suggest that the majority of transmissions occurred within the beef processing facility, with case B1 being at the root of the cluster,” the report noted.
Meat plants as hotspots
The report noted that meat processing plants have emerged as hotspots of SARS-CoV-2 around the world.
This is attributed to operational practices, such as close proximity of workers in the production line, combined with physically demanding work that promotes heavy breathing, but also from sharing of housing and transportation that may facilitate viral transmission.
The requirement to operate at low temperature in an environment with low air exchange rates is another factor that may promote spread of the virus among workers.
Superspreading
The German “superspreading event” in the RhedaWiedenbrück beef processing plant originated from a single employee.
“Our findings suggest that the facilities’ environmental conditions, including low temperature, low air exchange rates and constant air re-circularisation, together with relatively close distance between workers and demanding physical work, created an unfavourable mix of factors promoting efficient aerosol transmission of SARS-CoV-2 particlesm,” the researchers said.
“It is very likely that these or similar factors are also responsible for current worldwide ongoing outbreaks in other meat or fish processing facilities.”
Screening of employees
They suggest that employees in meat or fish processing facilities need to be frequently and systematically screened to prevent future coronavirus outbreaks.
They warned that “immediate action needs to be taken to quarantine all workers in a radius around an infected individual that may significantly extend beyond 2m”.
The researchers also said more studies are required to determine the most important parameters which may be altered to lower infection risk, for example via optimisation of airflow or ventilation conditions.
“In contrast to work-related exposure, shared apartments, bedrooms or carpools appear not to have played a major role in the initial outbreak described in this study,” they noted.
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A new study from Germany shows that COVID-19 can be transmitted over distances of at least 8m in confined spaces where there is low air exchange rates and high rates of recirculated unfiltered air, like those in meat factories.
The research, which focused on a "superspreader" COVID-19 outbreak in one of Germany’s largest meat processing plants, found that environmental conditions promoted viral transmission from a single worker to more than 60% of co-workers within a distance of 8m.
“Our findings indicate that a physical distance of 2m does not suffice to prevent transmission in environmental conditions such as those studied here,” the report authors noted.
“Additional measures, such as improved ventilation and airflow, installation of filtering devices or use of high-quality face masks, are required to reduce the infection risk in these environments,” they added.
A physical distance of 2m does not suffice to prevent transmission
The study was carried out in the largest meat processing plant in Germany, located in RhedaWiedenbrück, where cattle and pigs are slaughtered and processed.
It also assessed a second processing plant 30km away in Dissen, which specialises in sow deboning.
The research looked at the position of workers in the plant, what shift they worked on, who they travelled to work with and who they shared living accommodation with.
While some workers did live and travel together and these crossovers analysed, the report found that it was more likely that they contracted the virus from working close together in the boning region of the factory, rather than outside the factory.
There was a high infection rate among workers who worked in close proximity of the original COVID-19-positive worker and a positive correlation between the infection rate of workers in a unit and the percentage of unit members working in the 8m area.
“While some secondary infections may have occurred within apartments, bedrooms or carpools, our collective data strongly suggest that the majority of transmissions occurred within the beef processing facility, with case B1 being at the root of the cluster,” the report noted.
Meat plants as hotspots
The report noted that meat processing plants have emerged as hotspots of SARS-CoV-2 around the world.
This is attributed to operational practices, such as close proximity of workers in the production line, combined with physically demanding work that promotes heavy breathing, but also from sharing of housing and transportation that may facilitate viral transmission.
The requirement to operate at low temperature in an environment with low air exchange rates is another factor that may promote spread of the virus among workers.
Superspreading
The German “superspreading event” in the RhedaWiedenbrück beef processing plant originated from a single employee.
“Our findings suggest that the facilities’ environmental conditions, including low temperature, low air exchange rates and constant air re-circularisation, together with relatively close distance between workers and demanding physical work, created an unfavourable mix of factors promoting efficient aerosol transmission of SARS-CoV-2 particlesm,” the researchers said.
“It is very likely that these or similar factors are also responsible for current worldwide ongoing outbreaks in other meat or fish processing facilities.”
Screening of employees
They suggest that employees in meat or fish processing facilities need to be frequently and systematically screened to prevent future coronavirus outbreaks.
They warned that “immediate action needs to be taken to quarantine all workers in a radius around an infected individual that may significantly extend beyond 2m”.
The researchers also said more studies are required to determine the most important parameters which may be altered to lower infection risk, for example via optimisation of airflow or ventilation conditions.
“In contrast to work-related exposure, shared apartments, bedrooms or carpools appear not to have played a major role in the initial outbreak described in this study,” they noted.
Read more
‘Attempt by MII to link COVID testing and prices is inflammatory' - IFA
80% of workers not covered by sick pay - Meat Industry Ireland
Care needed to prevent COVID-19 going underground
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