Key questions as France aims for 700,000 Covid tests
The French government has said it is aiming for the country to do 700,000 Covid-19 tests per week from May 11, the start date for deconfinement. We answer key questions, including test length, cost, and reliability.
Mass testing of the population has long been one of the government’s aims to help contain the spread of Covid-19 before and after deconfinement.
On Tuesday (April 28), Prime Minister Edouard Philippe announced aims to provide “700,000 virological tests per week, from May 11”. In anticipation, French news source FranceInfo has answered some key questions on the tests.
We summarise and translate.
Who can get tested?
At the moment, only at-risk people, elderly care home residents, healthcare staff and pregnant women are considered a priority for a Covid-19 test, and only if they show symptoms.
But health minister Olivier Véran said yesterday (Wednesday April 29) that from May 11, “if you have symptoms and you wish to know if you are infected, you can - you must - get this virological test”.
You will need a medical prescription through your GP to get a test, so you must contact your GP first, preferably by phone or online consultation.
The tests will also be available for people who have “close contact” with an infected person, even if the other person has no symptoms. Each department will have a team that will trace contacts of an infected person, and make sure they are tested.
What happens during a test?
A very long “cotton bud-type” swab is inserted into the nostril, sometimes both; and sometimes also the throat. This is called a “collection of nasopharyngeal specimens”. (See the video below).
Bruno Pozzetto, head of virology at the Saint-Etienne CHU hospital, said: “You have to push the swab into the back of the throat [through the nose], beyond the eye-line. This risks making the patient cry [or making their eyes water], and it can hurt a bit, but that is almost a sign [that it has been done properly].”
In longer cases, where the patient has been ill for more than seven days, the test may also include testing the lower respiratory system, through saliva, a direct throat swab, or inspection of the bronchial tubes.
The laboratory performing the test can then check for DNA material of the virus in the sample.
Where can we get tested?
Health minister Mr Véran has said the aim will be to make the test available “everywhere possible where it makes sense”.
Not all the tests will be done in a clinical or hospital setting.
This is likely to include local testing centres, as well as local town laboratories and hospitals, as well as veterinary clinics, research labs, and even some police and gendarmerie stations.
Local authorities may also set up temporary testing sites such as large tents or areas of public buildings, as is the case currently in the 5th arrondissement in Paris.
There are also plans to operate more “drive-through” testing centres, with people being tested without having to leave their car. There are already several centres of this kind throughout France.
Who will do the test?
The tests must be carried out “obligatorily by a trained staff member with the correct equipment, who has laboratory expertise”, said prestigious research centre l’Institut Pasteur.
Mr Véran said it must be “people who are trained to do the swabbing, and who can then take those swabs back to the various labs”.
How long does it take to get the results?
Results are generally available within three to five hours of the test, which is long enough to confirm the presence (or not) of virus DNA, l'Institut Pasteur said.
Patients must be contacted with their results within a maximum of 24 hours after the test, as specified by a governmental decree from March 7. This can be done on the telephone, by your lab or your GP.
Are the tests reliable?
The tests are “98% reliable when correctly performed”, said François Blanchecotte, national president of the Union of Biologists. “When DNA is detected, if there is any, that is definitely the virus.”
Nicolas Lévêque, head of virology at the Poitiers CHU hospital, said: “The [test] is a technical procedure, so if it is poorly done, that can explain a good part of what we can call ‘false negatives’.”
The reliability of the test can also depend on when it is done. If it is taken too early in the development of the illness in the patient, the virus may not yet show up.
At the other end of the scale, if the test is taken too late - on the seventh or eight day of the illness - the virus may no longer be showing up much in the nose, meaning that a nasal swab may not find it there.
Dr. Blanchecotte said: “Out of every 100 patients you test, there may be around 30 who are missed [in terms of a false negative].”
Will I need to pay?
Mr Philippe said: “We will pass 100% of the cost of these tests to l’Assurance Maladie [from May 11].”
Until now, a PCR (polymerase chain reaction; the nasal swab) done in a town lab or in a hospital has cost €54, of which 60% is reimbursed by la Sécurité Sociale, and the remaining 40% is covered by health insurers (mutuelles).
What is the difference between these tests and blood tests?
The nasal swab test looks for virus DNA.
A blood test - which takes blood in the same way as any other blood test - does not look for the presence of the virus itself.
Instead, it looks for antibodies against the virus in the blood, which indicate that the patient has been infected by the virus at some point recently.
Currently, it is not known whether the presence of antibodies necessarily means that the person is immune, and/or protected from a second infection, and how long any possible immunity could last in any case.
The reliability of these blood tests is also not certain, but it is hoped that in future, they will become a more reliable means of evaluating the spread and impact of the epidemic among the population.
Is it really possible for the country to do 700,000 tests per week from the start of deconfinement?
Dr. Blanchecotte has said that this is an “achievable” objective, but to do so will mean “involving everyone, including health professionals such as biologists, and nurses - but also doctors - to be able to take enough samples and screen en masse", he said.
There are also practical considerations.
Dr. Blanchecotte explained that to reach this goal would require having enough tests and machines available. He said that the country had set up a central “ordering unit”, and that the ordered materials “should come through fairly quickly”.
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