The Health Information and Quality Authority (HIQA) has today (Friday, April 30) published its advice to the HSE on the potential impact of different serial testing scenarios using rapid antigen detection tests (RADTs) to detect Covid-19 in meat processing plant workers.

In Ireland and across the globe, meat processing plants have experienced a considerable number of Covid-19 outbreaks.

A recent analysis completed by the HIQA noted that outbreaks in meat processing plants in Ireland have been associated with approximately 3,000 cases of Covid-19.

The results of the analysis showed that those working in meat processing plants are at a higher risk of Covid-19 than the general population – “a crude relative risk for infection of 3.22 compared to the general population”, the report notes.

To address this risk, a suite of measures have been introduced, including serial testing of workers using monthly RT-PCR testing. The HIQA examined the impact of also using RADTs to further mitigate transmission risk in these settings.

Antigen testing once weekly preferred strategy

HIQA found that the preferred testing strategy used RADT-based serial testing once weekly with positive antigen tests confirmed by RT-PCR.

This scenario increased the detection of cases, reduced the number of days of infectious individuals being in a plant and reduced the overall cost relative to the current practice of monthly RT-PCR testing. Twice weekly RADT-based serial testing could also be considered.

Dr. Conor Teljeur, HIQA’s chief scientist, said: “We have advised the HSE on the benefits of introducing RADTs for serial testing in meat processing plants at a frequency of once a week.

“However, before discontinuing monthly RT-PCR-based serial testing, further evaluation will need to be carried out to ensure this strategy is both acceptable to relevant stakeholders and is implementable within the individual plants.

“We would favour a stepwise transition to frequent RADT-based serial testing, with the switch from monthly RT-PCR conditional on successful deployment of RADT-based testing within a plant.

“The higher risk associated with transmission in meat processing plants is multifactorial.

“As with other high-risk settings, contributing environmental issues can include the reduced ability to social distance, cold air, limited ventilation and loud work spaces.

“In addition, a number of non-environmental risk factors exist for the sector, such as shared accommodation, low wages and access to support payments.”