Social distancing, self-isolation, super-spreader, shielding. These are all words that, prior to March this year, we never really uttered. Now, they’re part of our daily vocabulary.
The next Covid phrase that could be making its way onto that list is ‘chain of trust’, after a professor of medicine said that forming one may be “the only effective means” to reduce deaths during the coming winter without imposing a full lockdown.
Paul Hunter, Professor of Medicine at the University of East Anglia, was referring to a document shared with the Scientific Advisory Group for Emergencies (SAGE) which suggested vulnerable people could form a ‘chain of trust’ with a select number of people to protect themselves against Covid-19.
So, what is a chain of trust? It refers to a strategy of infection control where people in regular contact with at-risk individuals – or ‘shielders’ – tweak their lifestyles to reduce the risk of spreading Covid-19 to them.
People on the shielded patient list would surround themselves with a few of these trusted individuals.
The onus would be on those who are vulnerable to choose who is in their chain of trust, but also those in the chain of trust to adopt measures in their lives to reduce their own risk of transmission.
Those considered a transmission risk – and therefore who shouldn’t be included in a chain of trust – include: people who have Covid-19 symptoms and should be self-isolating, people who should be self-quarantining (for example, because they’ve come back to the UK from a country where cases are high), or people who have been in contact with anyone with symptoms, anyone who should be self-isolating or anyone who should be self-quarantining.
“Any individual who has had high risk contacts or been in a high risk setting within the past two weeks should suspend contact with high risk individuals,” reads the document, authored by Professor Mark Woolhouse, Bram van Bunnik and Professor Aziz Sheikh from the University of Edinburgh.
Possible examples of high risk scenarios include if the person in the chain has attended hospital, has been to a large indoor social gathering, or has travelled to a high incidence area.
The concept of a chain of trust isn’t new – people who work in hospitals and care homes are routinely screened, and adopt special measures, to protect the vulnerable. “A broader protection strategy extends the same logic to all high risk individuals,” the document suggests.
More detail is needed on the nitty gritty of how a chain of trust could work, and some of the challenges it poses – for example, what happens if you live with people who wouldn’t be deemed suitable for a chain of trust? The paper also recognises how ‘shielding’ has become a negative term associated with extreme self-isolation – and recommends the term “protecting” instead.
Prof Paul Hunter said the paper on so-called chains of trust – published in August – “is a very thoughtful discussion of what is a really important topic”.
“If, as it now seems, the UK will be unable to prevent a large number of infections this winter the only other option if we are to reduce the death toll will be to protect our most vulnerable citizens, the groups of people that had previously been asked to shield,” he says.
“Whilst the document does not give a clear picture how [chains of trust] could work in practice, in my view this is something that does need to be looked at in much more detail.
“Such an approach, if it could be implemented, may be the only effective means to reduce deaths during the coming winter without imposing a full lockdown.”