Coronavirus: Testing and why it matters

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The UK government wants to do 100,000 coronavirus tests a day by the end of April, but has faced criticism for not increasing the number more quickly. By mid-April, 21,000 tests were being conducted a day, on 14,000 people.

So what are the tests and why has it been difficult to scale them up?

What coronavirus tests are there?

The tests currently being used in UK hospitals are to see if somebody currently has Covid-19.

They are being carried out in hospitals and at 29 drive-through testing centres across the country.

These are done by taking a swab of the nose or throat, which is sent off to a lab to look for signs of the virus’s genetic material.

The other type of test the government wants to use is an antibody test. These are done to see if someone has already had the virus.

They work by looking for signs of immunity, by using a drop of blood on a device, a bit like a pregnancy test.

The government bought three-and-a-half million antibody tests, but has not yet found one that is reliable enough to use.

Why isn’t the UK doing more tests?

The UK did not start with the resources to do mass testing, unlike some other countries.

Health Secretary Matt Hancock said: “We have the best scientific labs in the world but we did not have the scale. My German counterpart for instance could call upon 100 testing labs ready and waiting when the crisis struck.”

The UK government also took a different approach at the beginning of the crisis, using a smaller number of labs and keeping more control centrally.

There have been suggestions it did not act quickly enough, as countries like Germany and South Korea – which have been able to test far more widely than the UK has – rapidly stockpiled kits and made the test available to a larger number of labs.

At first, Public Health England was only using its own eight laboratories, later expanding to a further 40 NHS labs. It was only at the end of March that the government said it would work to recruit more laboratories from universities, research institutes and private companies.

As well as lab space and people to do the swabs, UK testing efforts have been held back by challenges in getting hold of swabs, testing kits and reagents.

A reagent is the substance used to extract the virus’s genetic material so it can be studied more easily. At the moment there is high global demand for reagents, which is why they are hard to obtain.

The government is trying to ease this shortage by involving pharmaceutical companies GlaxoSmithKline and Astrazeneca in producing reagents in the UK.

Why is testing important?

There are two main reasons for testing people – to diagnose them individually, and to work out how far the virus has spread.

Having this second piece of information could help the health service plan for extra demand, including on intensive care units.

Testing could also inform decisions around social distancing measures. For example, if large numbers of people were found to have already been infected, then a lockdown might become less necessary.

And not testing more widely means many people might be self-isolating for no reason, including NHS workers.

Can I get tested?

Testing is not yet available for most people.

At the moment, tests are reserved for seriously ill patients in hospital and for certain key workers.

Tests had previously been available for health and social care workers who have coronavirus symptoms, or who live in a household with someone who does.

The eligibility has now been expanded beyond health and care workers to include the police, the fire service, prison officers, judges and some local government staff. Workers responsible for administering benefits can also get tests.

This means that if even if you develop symptoms, but you don’t work in one of those roles, then you can’t currently find out if you have coronavirus.

If you do work in one of those roles and you develop symptoms, then the government’s advice is that you should “let your employer know you’re isolating” and they should “confirm if you’re eligible and help you get a test appointment”.

The Health Secretary Matt Hancock has said that there is currently extra “capacity” in the system, particularly at the drive-through testing centres, but that there hasn’t been “enough demand”.

But this has been challenged by some of the bodies representing key workers, who have said that a major issue is the accessibility of those centres.

Dame Donna Kinnair, from the Royal College of Nursing, said: “What I’m hearing from the frontline is nurses are sometimes driving two hours, feeling very unwell with possible symptoms of coronavirus and driving to a testing station.”

Matt Wrack, from the Fire Brigades Union, responded directly to the suggestion from Mr Hancock that the problem has been a lack of “demand” for tests, saying: “This is surely an issue of accessibility, rather than frontline staff not wanting to be tested. Many of the testing centres are far out of town and require extended trips in a car.”

How accurate are the tests?

The diagnostic tests used in hospitals are very reliable.

However, that doesn’t mean they will pick up every case of coronavirus. A patient at the very start of their infection or with relatively low levels of the virus may show up as a negative.

And a swab may come back negative if it has not picked up enough of the virus from the back of the throat.

So far, antibody tests have not proved to be as reliable.

Health Secretary Matt Hancock has said that 15 of the most promising antibody tests had been tested, but none was good enough.

Prof John Newton, who is overseeing testing, said tests bought from China had been able to identify antibodies in patients who had been seriously ill with coronavirus, but didn’t pick up the milder cases.

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