The Health Information and Quality Authority has recommended that antigen tests be used once or twice a week in meat plants as an alternative to a monthly PCR test.

HIQA's Chief Scientist, Dr Conor Teljeur, said meat processing plants have been identified as setting where workers have a higher risk of infection and transmission.

Speaking on RTÉ's News at One, he said rapid antigen tests are not as accurate as PCR tests and are designed for use in symptomatic individuals.

Dr Teljeur said serial testing is used for asymptomatic people and rapid antigen testing is not as sensitive in those individuals.

He said: "But you can overcome that issue by using frequent testing. So the person may detect negative today but test positive tomorrow or the next days.

"So by more frequent use, you can make up, to some extent, for the lack of accuracy of the test."

Dr Teljeur said there has been "quite a high incidence of cases and outbreaks" in meat processing plants, with some 3,000 cases in workers since the start of the pandemic.

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Having a fast turnaround test would be beneficial, he said, but they have to bear in mind that there are logistical challenges to doing rapid antigen testing.

He said they would be looking at a process where plant workers are self-swabbing while supervised by a trained operator.

Dr Teljeur said quite a high proportion of those who work in meat processing plants live in shared accommodation and are also predominantly in the age group that has the highest incidence of Covid-19 in the country - a lot of people in their 20s and 30s.

He added: "Areas within meat processing plants are also conducive to transmission.

"They have low working temperature, they're very wet, the workers are in close proximity, and sometimes there are quite low rates of air change per hour.

"That's to meet requirements for food safety, but it also makes the setting very conducive to transmission."