Health Minister David Ashford insists testing at the border will not add anything to the island’s Covid defences.

Guernsey last month introduced border testing and has attributed this to identifying three new cases of coronavirus over the weekend of October 31/November 1.

All three were ’tested on day one and picked up by our new border testing regime’, the States of Guernsey posted on Facebook.

Three out of four new positive cases of Covid identified on November 5 were incoming travellers who were tested at the border.

But Mr Ashford said while border testing would always pick up the odd case its accuracy rate is just 7%.

’If you use it on its own as a measure without isolation you would be releasing a large number of positive cases into the community,’ he said.

’If people have to isolate anyway it doesn’t add anything. If someone comes back positive we isolate them for 14 days, if someone comes back negative we isolate them for 14 days.

’Either way they still have to isolate as the test on the border can’t be relied upon.’

Guernsey has spent £4m on border testing. Anyone travelling to the Bailiwick needs to register their journey on a Travel Tracker app and take a self throat and nose swab on arrival.

Mr Ashford said the Isle of Man uses PCR testing which is the most accurate test available as it looks for the RNA of the virus which if present it will find.

He said Covid-19 is unique as a virus in having an incubation period of up to 14 days and in the early days of infection, despite someone being contagious, the level of virus in the system and viral shedding can be undetectable.

This means someone who is in the first three days of infection could be expected to potentially pass a test despite being infected.

By day five of infection it would be expected that 88% of cases would be identified by PCR test, 94% at day seven and 98% at day 10.

’Border testing would be expected to pick up as a result only 7% of infected travellers due to many being in the early days of incubation,’ said the Minister.

Some island-based companies have asked staff to work from home if their children have returned home from university and are self-isolating.

Asked whether the policy on whole household isolating is to be reviewed, Mr Ashford said: ’Self isolation means you must not come into contact with other family members.

’You must remain in a separate space and any communal facilities such as bathrooms must be cleaned after each use. If you can’t separate from other family members within the home then the whole household should isolate.

’That is still currently the position. All decisions in relation to the Covid-19 response are reviewed fortnightly by the Council of Ministers.’