More than ten per cent of people with positive coronavirus tests in Northamptonshire have snubbed local test and trace teams' plea to pass information on to their direct contacts.
Northamptonshire's team — which includes 20 customer service centre staff and a group of trainee dentists — is helping to get information from four out of every five calls.
But figures revealed by Public Health Northamptonshire showed 63 out of 603 people contacted "point blank refused" to give any information to help stop the spread of Covid-19.
Director of Public Health Lucy Wightman admitted: "About eight per cent point-blank refuse to engage with the process — that's 63 people who would not provide any details of who they have been in contact with despite the fact they had a confirmed positive test.
"We still provide them with a letter to state reasons why a follow up is so important and try to enforce and educate where we can. But this is one of the most important approaches to stopping the spread and clearly we still have some challenges."
National headlines yesterday revealed NHS Test and Trace is only making contact with around 60 per cent of cases within the first 24 hours of a positive test being notified.
Those they miss are passed to the local team in an effort to obtain details of any recent visits to public places and close contacts to give warnings of the risk of having passed on the virus to others.
Around 750 cases have come the county's way since the local team went live in August. The success rate in Northamptonshire is now 79 per cent, up from 69 per cent in the week before the local team went live.
And Mrs Wightman says the local system is "improving" despite the number of referrals being dealt with multiplying from 15 a week in August to 147 in mid-October as cases have spiked.
She added: "We see approximately 30 per cent of cases confirmed in Northamptonshire transferred which would otherwise have been typically lost to follow ups.
"Of 603 telephone contacts which have successfully been made since 'go live,' 455 provided full contact details while 71 were duplicates which had already been reached.
"Another 20 per cent were not reached by phone or through door-knocking. Sometimes that is down to not having the correct details but perhaps the most worrying outcome would be that they are a case and not at home.
"We are still exploring other ways of trying to follow up but, overall, it is an improving picture."
FOLLOW Friday's weekly media briefing on the Covid-19 situation in Northamptonshire LIVE from 3pm via the Chronicle & Echo and Northants Telegraph websites