Liverpool is the first English city to have regular coronavirus testing for all residents, whether they have symptoms or not, as part of a pilot.
Testing is considered a key way to control the epidemic, but government’s system has experienced setbacks.
Should I get tested?
Testing people and then tracing the contacts of those infected is vital to stop the disease from spreading.
You should seek a test if you show one of these three key symptoms:
- a fever
- a new continuous cough
- a loss of smell or taste
The idea of testing is to find people with the virus and keep them isolated to avoid it being spread through the wider community.
Until you can get a test it’s important you and your household self-isolate.
How to get tested
Is the testing system coping with demand?
The testing system experienced plenty of well-publicised problems early on, with people struggling to book.
There were also multiple cases where some people could only book tests many miles from their homes.
But the system is running much better now and coping with demand.
How many tests are being carried out?
Roughly 300,000 tests a day on average were processed in the week to 1 November. The government says capacity is more than 500,000, although that number of tests has never actually been carried out in a day.
It has pledged to bring in mass coronavirus testing by the end of the year, even among people with no symptoms.
The prime minister has spoken of his desire for 10 million Covid-19 tests a day by early 2021, but experts have expressed doubt that this is possible.
However, Health Secretary Matt Hancock says the two new testing mega labs – which open in early 2021 – will add 600,000 tests to the UK’s daily capacity.
What kind of tests are available?
The first kind tests to see if you are currently infected.
In most cases a nose and throat swab is taken and then sent to be processed at a lab.
There are also rapid turnaround versions of these tests which are mostly available in hospitals.
One of the types available uses a technology similar to that of the slower lab tests, but scaled down so it can be processed using a portable machine.
Another, so-called “lateral flow” tests – which are being used in the Liverpool pilot – involve a handheld kit that gives a result a bit like a pregnancy test.
Because these miss out the step of amplifying the virus’s genetic information, they are less sensitive and will therefore will miss more cases of the virus – especially in people with relatively mild infections.
These lateral flow kits are extremely valuable in areas without big labs, which currently have very little access to any testing at all. But up until recently they haven’t been seen as a key part of the UK’s testing strategy.
Tests on saliva are also being trialled.
The second kind of test involves blood samples and looks for antibodies which indicate past, rather than current, infection.
At the moment, these are mainly being used by scientists to estimate what percentage of the population has had Covid, rather than to diagnose individuals.
What about private testing?
Private tests can be obtained from clinics and health centres, with some offering a result within three days.
Prices vary but are often around £100-£200 for a swab test – which shows if you are currently infected – and £50-£100 for an antibody test, which can indicate a past infection. However antibody tests do not work for everyone – and even some people who have had coronavirus do not have antibodies.
Tests must have a ”CE mark” to show they meet all legal criteria.
If you test positive, the test supplier must let your local health authority know so it can trace outbreaks.
How reliable are tests?
With the most common type of diagnostic test, scientists at the University of Bristol believe 20% of positive cases could falsely appear as negative – wrongly telling someone they are not infected.
This can be because the swab sample wasn’t good enough, there were problems in the lab, or because of the stage of infection the patient was at when tested.
How does the UK compare with other countries?
Each country records testing slightly differently, so like-for-like comparisons won’t be 100% accurate.
However, analysis from Our World In Data, a research team at the University of Oxford, suggests the UK is now performing more tests than many other countries.
For example, on 1 November, the UK carried out 417 tests per 100,000 people. This compares favourably to similar European countries: in France the number was 433 per 100,000 while in Germany it was 232 and in Spain 247 per 100,000 people.
This just tells us the raw numbers, though, and not how many tests were being carried out in proportion to the size of a country’s outbreak, or how well the tests were targeted.
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