Guernsey Press

'Border restrictions still best defence against another lockdown' - Brink

PUBLIC HEALTH has sought to explain to islanders the methodology and reasons behind how prevalence rates influence border restrictions.

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Chair of the Civil Contingencies Authority Deputy Peter Ferbrache and Director of Public Health Dr Nicola Brink. (29551719)

From today, anyone who falls into a Category 2 zone where there is a prevalence rate of 30 per 100,000 population or less, once a negative Covid test is received, can go about their business with very limited restrictions.

'Many people have looked at the UK data and border measures in Jersey and the Isle of Man, we are not in the same place as those other jurisdictions,' Chairman of the Civil Contingencies Authority Deputy Peter Ferbrache said.

'We have no on-island restrictions, not a single one.'

That, he said, was the freedom authorities in Guernsey - and many islanders - hoped to maintain.

'We are not being unduly cautious. For us [with no internal restrictions], our protection comes entirely from our border restrictions and vaccinations.'

The CCA, in light of the questions from Bailiwick residents, reviewed the categorisations and decided not to reduce the prevalence threshold.

No guarantees were given that borders will open fully on 1 July, although that is the date still being worked towards.

Deputy Ferbrache described claims that Public Health and the CCA were making up evidence as 'absolute rubbish'.

'We all expected, from a broadcast a couple of weeks ago, that more regions in the UK would have dropped into Category 2 by now. Prevalence then was coming down quickly,' he said.

'It's slowed down [and] in some regions it's even begun to creep up again.'

However, the CCA wants people to be able to travel, which is why Portsmouth, Poole and Southampton ports do not count towards categories.

Graphic by States of Guernsey. (29551724)

He expected more UK regions would come into Category 2 soon, but asked that people who wished to see the back of travel restrictions remained patient.

Director of Public Health Dr Nicola Brink said moving forward, another lockdown and unnecessary internal restrictions wanted to be prevented.

'We also want to prevent loss of life and breaching hospital capacity,' she said.

Almost 56,000 doses of the vaccine have been administered in the Bailiwick now, with 72% of over-18s having at least one dose.

36% of over-18s are fully vaccinated.

Graphic by States of Guernsey. (29551650)

Explaining the 14-day prevalence rate, Dr Brink said it was a tool to measure recent instant cases in a particular area.

A risk assessment can then be done.

'The 14-day rate is calculated by taking the total number of new cases in a country or region over the last 14 days, then you divide it by the population of the area involved and multiply by 100,000.

'That same 14-day rate is used by Jersey, the Isle of Man and by the European Centre for Disease Prevention and Control.'

Public Health England uses a seven-day rate, which allows them to compare regions within the UK and monitor trends there.

Graphic by States of Guernsey. (29551672)

'It doesn't really matter what methodology you use, the important thing to define is what risk you think your population can accept if you're using a prevalence rate to define border restrictions,' Dr Brink said.

'The 14-day rate is a rolling rate over a 14-day period, but what we also want to do is have a stable analysis of our trends. When a country or region is in a category, we have a period of seven consecutive days for that region to change categories.'

This, she said, helps because if the prevalence pops above the particular threshold, it is not immediately moved to the higher category, and vice-verca. This is because Public Health does not want regions bouncing in and out of categories frequently.

If, for seven consecutive days, a region is consistently above or below the prevalence rate of the category it is in, it will then be moved into the most appropriate category.

The 14-day rate is not comparable to the seven-day rate, she confirmed.

'Both are tools to assess a prevalence rate, but what you then have to consider with that tool is what does that mean,' she said.

More to follow