Mass saliva testing proposed as a way to take cities out of lockdown
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Scientists are proposing that a “medium-sized” UK city be used as a testing ground to lift Covid-19 lockdown restrictions and impose a rigorous testing regime based on saliva samples.
Published in the Royal Society Open Science journal, the scientists said that normal life could be restored “quite quickly” through the use of cheap RT-LAMP testing, which can identify the virus using saliva instead of nasal or throat swabs.
Julian Peto, the paper’s author, said that a facility with about 100 staff “could probably do 50,000 tests per day”.
Peto continued: “If so, a city of 350,000 people could be served by a single laboratory”.
The study also proposes that isolated outbreaks could be contained by contact tracing, supplemented if necessary by temporary local reintroduction of population testing or lockdown.
With around 10 million tests needed every day to ensure everyone in the UK gets tested once a week, a broad rollout of such a proposal would be a big undertaking.
Nevertheless, the researchers believe that the RT-LAMP tests are “low resource” enough that the UK could manage to fund such a programme.
A large number of RT-LAMP tests can be done in under an hour in a pan of warm water using a thermometer to maintain the temperature at about 63°C. The colour change showing a positive result can easily be determined by the human eye.
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 researchers suggested that access to restaurants, bars and other public venues could be conditional on customers being able to produce a verified test demonstrating that they are free of the virus.
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.”
A recent trial in Scotland has seen scientists testing sewage for traces of Covid-19 in a bid to monitor the spread of the virus across the country.
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