Since June it has been necessary for travellers returning to or visiting the UK to quarantine for 14 days. A series of travel corridors between the UK and other countries was introduced in July, but has since shrunk, with travellers returning from Spain, France and Croatia, among many others, now asked to self-isolate for two weeks on arrival in the UK. Some countries have instead adopted a test-on-arrival system which exempts travellers from quarantining if they return a negative test. Many have questioned why the UK government hasn’t adopted a similar system. Why isn’t the UK testing travellers on arrival? The UK has been studying the benefits of testing at airports since international travel reopened, but have no plans to introduce these measures at the moment. As well as being a logistical nightmare they also suggest that some cases could slip through the net as testing isn’t 100% reliable. Instead by keeping travellers under a 14-day quarantine, the government can reduce the risk to public health. Oliver Dowden explained the approach when he claimed testing was “not a silver bullet”. Refusing to rule out a future adoption, the Culture Secretary said: “It’s not the case that you can simply test somebody and be sure that they don’t have the disease. “It can incubate over a period of time so there’s not a silver bullet of just testing immediately at the border ... We are not at the point where there is a viable alternative to the 14-day quarantine." What does the science say? Nose and throat swab tests are currently used to detect if someone has Covid-19. Though these tests are safe and accurate, they are capable of delivering a false negative, meaning someone with the virus could return a negative test and go on to infect others. False negatives occur when people have only just been infected with coronavirus and don’t have a sufficient amount of the virus in their body for the test to pick it up. It can take days for the virus to be detectable. Could testing be used to reduce the length of quarantine? Not for profit organisation Institute For Global Change have suggested testing travellers five days into their quarantine. It is hoped that this would reduce the self-isolation period and reduce the risk of conducting a false negative. A study by the London School of Hygiene and Tropical Medicine suggested that testing travellers later could be effective in reducing the spread of the infectious virus. “Testing immediately on arrival is likely to prevent about only 50% of infectious persons entering the community,” says study author Dr Sam Clifford. “By seven days, a majority of people who will ever show symptoms will have noticed their symptoms and will self-isolate or seek medical attention. “Also by that time, PCR testing should detect most of those infections with a long incubation period or … asymptomatic infections.” What would testing at airports look like? Private companies have floated the idea of travellers booking a test which would be conducted at the airport on arrival. This would be conducted by a trained nurse and processed in the next 24 hours. Travellers who receive a negative result would then be able to forego quarantine and would only be required to self-isolate if they developed symptoms.
