Ensuring people who are in regular contact with high-risk individuals are not infected with coronavirus could be a way of controlling outbreaks, research suggests.
Hospital staff and care home staff are routinely screened in order to protect patients and residents, but a broader protection strategy would extend the same logic to everyone who is considered to be at high risk.
The suggestions are made in a paper presented to the Government’s Scientific Advisory Group for Emergencies (Sage).
Experts Mark Woolhouse, Bram van Bunnik and Aziz Sheikh, from the University of Edinburgh, say there is evidence that by partially decoupling hospital admissions or deaths from community spread, large-scale segmentation and protection could allow lighter interventions in the general population.
This would also still limit the public health burden of Covid-19, they write.
The strategy could allow for more targeted interventions to protect at-risk groups rather than further generalised lockdowns, they said.
The researchers say segmentation and protection is a natural extension of current ideas about managing transmission networks.
The intention is to target links in potential transmission chains that lead to high-risk individuals.
Shielders are people who are in contact with high-risk individuals, such as members of the same household, care-in-the-home workers and informal carers, and if infected would pose a high risk to them.
The most practical way of identifying them may be asking them to self-identify, and they may need to protect themselves in order to protect their high risk contacts, the researchers suggest.
In the August 4 document, they say there should be no contact with a high-risk individual by any person who has symptoms and should be self-isolating.
There should also be no contact with anyone who should be quarantining, or anyone who has been in contact with anyone with symptoms, anyone who should be self-isolating or anyone who should be quarantining.
Shielders therefore need to pay close attention to their own contacts and particularly should not have contact with persons in any of the above categories, they said.
The document says: “Segmentation and protection raises ethical questions as some measures are targeted at subsets of the population.
“However, lockdown also raises ethical questions as the benefits are felt mainly by those same subsets of the population.
“Clear guidance needs to be provided on how that protection is delivered. Though reducing contacts will play a key role, just as much emphasis is needed on making contacts safer.”
The experts say contacts could be made safer by regular testing of shielders, but this would require very large testing volumes.
They add that segmentation and protection can be used in conjunction with other Covid-19 control strategies, and mass social distancing measures can be targeted at activities/locations where high-risk individuals are over-represented.