Covid-19 – Update on outbreaks in UK food manufacturing plants and possible risk factors

Over the last few weeks, you will have seen a number of reports regarding Covid-19 outbreaks in food manufacturing environments, particularly meat processing plants. [Note: According to PHE (see section 4.1 here) an outbreak may be defined as: An incident in which two or more people experiencing a similar illness are linked in time or place].

 

Two such declared outbreaks have been in Wales and are being managed in line with the Communicable Disease Outbreak Plan for Wales. In response to the outbreaks, Vaughan Gething MS, Minister for Health and Social Services in Wales issued a statement and reiterated that “whilst all necessary action is being taken to control and prevent the spread of the virus from person to person, I would like to emphasise that there is no evidence that coronavirus survives in food”.

Detail of the Welsh outbreaks (as reported on 24^th June):

2 Sisters plant – Llangefni, Anglesey

• More than 450 tests taken.
• 200 confirmed cases – majority staff members at the plant. Some are household contacts.
• 89 people still to be tested
• Factory closed by employer. Will only re-open once effective controls put in place.
• All contacts of cases being followed up and tested.
• All cases and contacts are self-isolating.

Rowan Foods – Wrexham

 

• Over 1,000 tests taken.
• 97 confirmed cases
• Factory remains operational up to
• All contacts of cases are being followed up and tested.
• All cases and contacts are self-isolating

 

Note regarding Kepak Food Group – Merthyr Tydfil

 

There is also an incident centred on the Kepak Food Group plant in Merthyr Tydfil which is currently being investigated but has not been declared an outbreak. 33 cases have potentially occurred in workers at the plant since April but only a small number of these have occurred since June. Investigations are continuing.

 

 

Emerging Findings 

 

Proving modes of transmission during an outbreak is difficult but the emerging view is that aerosol transmission of Coronavirus (SARS-CoV-2), whether through direct respiratory droplet transfer or contaminated surfaces or objects may be more important than first thought. Multiple recent studies are showing evidence of links between indirect contact and cases of infection.

 

Research by the London School of Hygiene and Tropical Medicine (LSHTM) has shown that after ships and workers’ dormitories, food processing factories have been responsible for the biggest localised outbreaks.

 

Also, according to a report carried out in April 2020 by the American Centers for Disease Control and Prevention (CDC) an estimated 5,000 people working in meat-processing plants in the US had tested positive for the coronavirus and one analysis estimated that half of the cases of the disease in the United States could be traced back to these production facilities.

 

According to investigations carried out by institutions such as CDC and LSHTM there are various factors, including some socio-economic, which may make meat-processing plants ideal breeding grounds for the virus:

 

• Direction of the airflow in air-conditioned ventilation systems may be a factor. Following an outbreak in January at a Chinese restaurant researchers conducted a limited study and concluded that droplet transmission was prompted by air-conditioned ventilation and the key factor for infection was the direction of air flow (you can read more here)
• Work practices in such environments may make it difficult for employees to maintain a physical distance, particularly if they work on production lines.
• Social distancing also difficult to maintain in break rooms
• The pace and physical demands of factory work make it hard for workers to wear face coverings – CDC observers noticed that workers tended to cover just their mouths, not their noses, and frequently readjusted their masks.
• The noise in factories means that workers have to either stand close to each other when talking or shout, which can increase the projection of viral particles.
• There have also been some reports that the virus can survive for longer periods at cold temperatures and one theory is that if a worker has a cold nose that could help the virus take hold.

Socio-economic factors:

• Workers on zero hours contracts may be unwilling to take sick leave and also may move from job to job across different food production sites.
• Workers travel to work together – either on buses or in car shares, enabling the virus to spread even further.
• Employees are more likely to live in crowded, multi-generational households, facilitating the spread of the disease to older, more at-risk individuals.
• The CDC noted that in one factory 40 different languages were spoken so communicating information about social distancing and safe working practices was difficult.

BFFF will keep the membership updated as and when further research is concluded.