Scientists have proposed lifting lockdown completely for a “medium-sized city” to see if coronavirus can be controlled through weekly testing of residents.
A paper published in the Royal Society Open Science journal argues that a demonstration study is needed to see if such regular testing, strict household quarantine, contact tracing and mobile phone apps could end the Covid-19 epidemic.
Researchers suggest large-scale testing of city residents could be done through examining saliva samples – a technique called RT-LAMP testing, which they said is cheaper and more viable than nasal or throat swab tests.
The paper, authored by Julian Peto, professor of epidemiology at the London School of Hygiene & Tropical Medicine and 10 other experts, said 10 million tests per day are needed for weekly testing of the UK population.
“This is feasible with single-step RT-LAMP on saliva samples, which requires minimal equipment and training,” they said.
“A facility with about 100 staff could probably do 50,000 tests per day. If so, a city of 350,000 people could be served by a single laboratory.”
The hypothesis that the combination of weekly testing with an earlier test if symptoms appear, strict household quarantine, contact tracing and mobile phone apps would end the epidemic is thus plausible
Researchers said no government has considered this option as it was assumed it would not be technically possible, but they argued that the technology could be implemented “even in low resource rural settings”.
A trial of a coronavirus saliva test is due to be launched in Southampton this week – with more than 14,000 people recruited for the first phase.
The new test only requires an individual to spit into a sample pot to be tested for current Covid-19 infection.
The project is being jointly led by Southampton City Council, the University of Southampton and the NHS.
Researchers of the new paper said: “About one-third of transmissions are within households.
“This large contribution to epidemic growth would be almost eliminated by strict household quarantine.
“Self-quarantine as soon as Covid-19 symptoms are noticed will further reduce transmissions.
“Contact tracing and mobile phone apps can have a large additional effect and would be even more effective within a population whose weekly test results are already available online.
“Whether the combined effect would control the epidemic can only be determined by a demonstration study in which a whole city is tested weekly and ends lockdown.”
They argued that requiring evidence of a recent negative test to access restaurants, bars and other public venues would encourage participation in testing.
Making quarantine “safe and tolerable” for households would also support compliance, as well as other measures such as hotel accommodation for infected people, helplines, social support, furlough arrangements and personal protective equipment for households.
Whether the economy can be rescued and tens or hundreds of thousands of unnecessary deaths in the UK and millions worldwide can be prevented may depend on the outcome
The scientists said: “The hypothesis that the combination of weekly testing with an earlier test if symptoms appear, strict household quarantine, contact tracing and mobile phone apps would end the epidemic is thus plausible.”
Their paper added: “Testing should be voluntary, and if those who agree to be tested are deemed to have consented to household quarantine, if a household member tests positive individual informed consent would not be needed.
“Within a few weeks, the epidemic may be reduced to occasional outbreaks, but if prevalence falls more slowly testing may have to continue for three or more months.”
Researchers said the aim of the experiment would be to see whether the R number – which represents the average number of secondary infections produced by one infected person – remains below 1.
“Whether the economy can be rescued and tens or hundreds of thousands of unnecessary deaths in the UK and millions worldwide can be prevented may depend on the outcome,” they concluded.