There are several tests for coronavirus: virological tests by PCR (in the nose), serological tests for antibodies in the blood and soon salivary. Where to get tested? When? Do you need a prescription? How much does it cost ? Is it reimbursed?
[Mise à jour le mardi 9 juin à 16h22] The Sars-CoV-2 coronavirus still circulates in France. To control the epidemic, screening is possible for each French person who presents symptoms suggestive of Covid-19. This screening is carried out by PCR test (in the nose). Serological tests for antibodies to the virus in the blood and which may signify immunization are also proposed. During June, “rapid” saliva tests should also arrive on the French market for the same purpose as serological tests. How to get tested? Where to find a screening center near you? At what price ? Do you still need a prescription? Guide.
The coronavirus screening strategy in France has evolved. “The first tests were distributed in late January-early February to hospitals” reminded Professor Arnaud Fontanet, member of the Covid-19 Scientific Committee on April 20, 2020. At the very beginning, it was decided to test people who presented symptoms of respiratory disorders (cough, fever, shortness of breath, acute respiratory distress syndrome ) and if there had been contact with China or with a person returning from China. But faced with the increase in cases and in the midst of an influenza epidemic, testing all the people presenting such symptoms became impossible due to lack of testing capacities. This lack of tests would have cost France a greater epidemic outbreak than in Germany according to Pr Jean-François Delfraissy, president of the Scientific Council Covid-19: “TheGermany used diagnostic tests widely before us and from the month of January, from the beginning of February, Germany used, roughly, around 60,000 tests per day, whereas in early March, when we arrived, there was a use of 3,000 tests per day [en France]”, he explained on France Inter on June 5. Jean-François Delfraissy. On March 14 when France went to stage 3 of the epidemic, only people at risk were tested (caregivers …). Screening was prioritized and extended to residents of nursing homes and the personnel accompanying them on April 6. From May 11, all French people with symptoms suggestive of Covid-19 could be tested.
Why not have tested everyone during deconfinement? “It is not possible and above all it has no use. We should retest everyone 8 days later and retest another 15 days later “, replied Professor Delfraissy on April 30.
If you have difficulty getting in touch with a doctor to be tested, contact on-call doctors on 0 800 130 000.
All coronavirus screening tests validated by the National Reference Center (CNR) in France are indicated on the website of the Ministry of Health. Among them, the list of 30 “rapid” serological tests validated in France has been available since May 25. These 30 tests are reimbursed by Social Security and can only be performed to date in the laboratory. One of these tests is produced in France by AAZ company, located in Ile-de-France. She developed the COVID-PRESTO Rapid Serological Test. This test has been evaluated and validated on capillary blood obtained by pricking at the fingertip by the Doctor Thierry Prazuck, Head of Department of Infectious Diseases at the CHRU of Orléans: “These tests made it possible to prove that 100% of patients presenting with symptoms suggestive of COVID-19 and tested positive with the molecular PCR test, were immunized from 16 days after the onset of symptoms. The results fell quickly, since it only takes 10 minutes per patient to demonstrate an immunization “he explains in a press release from the company on May 25. The COVID-PRESTO test® differentiates two kinds of antibodies which are, at the beginning of the disease, Immunoglobulins M then at the stage of cure, Immunoglobulins G. The test thus makes it possible to distinguish the immunized patients and therefore, a priori, immune to a new infection. On the website of the Ministry of Health also appear the 38 RT-PCR tests validated by the CNR in France.
In the current context of public health emergency, laboratories and research institutes are developing diagnostic solutions to detect the SARS-Cov-2 virus, responsible for the Covid-19 epidemic. Among the proposed solutions:
Virological test or PCR: in the nose
It is the screening test used in France since the beginning of the epidemic. The diagnostic test says “virological” or “PCR” (“polymerase chain reaction“) consists of nasopharyngeal swab (throat, nose, nasopharynx) which is done using a small swab (brush) inserted in the nose. This is an easy test to perform, non invasive but unpleasant for the patient because a little painful. It must be carried out by a doctor or nurse. The result is available after 3 to 4 hours The sample is then analyzed by a specialized laboratory in order to search for the presence of the genetic material of the coronavirus and thus confirm the diagnosis of the infection. A Chinese study published on April 19 on the site Clinical Infectious Diseases and reported by Inserm on 56 Covid-19 patients hospitalized with mild to moderate symptoms shows that “virus shedding can last up to 6 weeks after symptoms appear. PCR tests were positive in the majority of patients during the first 3 weeks, and from the fourth week on, the number of negative tests gradually increased. Finally, the median duration between the onset of symptoms and the end of viral excretion was evaluated at 24 days. However, it is not known whether patients can transmit the virus throughout the period of viral shedding. The study suggests that an extended observation period may be necessary for older patients. ”
Serological test for antibodies
Automated type serological tests ELISA (enzyme linked immunosorbent assay) and unit serological tests look for antibodies to the coronavirus in the blood that determine if someone has already been infected with the coronavirus. Carrying out a serological diagnosis allows the detection of the humoral post-infectious immune response (detection of antibodies IgM, IgG and possibly IgA). As of June 9, 12 automated Elisa-type tests have been validated by the National Reference Center (CNR) in France (one of which is produced by a French laboratory, the BioMérieux laboratory) as well as 30 rapid serological tests.
“A positive serological test should not change your behavior, you can still infect someone.”
What do they say ? “They say: you have been in contact with the virus but today we are not able to say if this contact with the virus is accompanied by protection so if you can consider yourself protected from reinfection. We don’t know if the antibodies you have are protective. The other problem is that with the available tests, they still have a high level of 5% false positives when we know that the proportion of French people infected on the territory is also around 5% so we cannot trust it today ” explains Professor Arnaud Fontanet of the Institut Pasteur. What Olivier Véran confirms on May 28: “A positive serological test should not change your behavior, you can still infect a person, social distancing applies to everyone, whether the serological test is positive or negative. Lserology does not replace the PCR test “.
What is serology? The serology is a biological method using serum to make medical diagnoses. Serum is a constituent of blood plasma. During a blood test, the biologist will analyze the serum. Serology makes it possible to make a diagnosis of infectious diseases, autoimmune diseases, to determine blood groups, to follow the evolution of certain diseases, to verify vaccinations.
Quick test
Rapid and ultra-rapid molecular tests (45 and 15 minutes respectively) have been under evaluation by the National Reference Center for respiratory infection viruses for several weeks. As of June 9, 30 rapid serological tests known as RDTs have been validated, indicates the Ministry of Health on its site. We also speak of “rapid diagnostic orientation tests” or “TRODs“They are presented in a unit format, detecting antibodies from a single drop of blood in minutes.
Saliva test
EasyCov, the quick-reading salivary test for Covid-19 (in 30 minutes), with simplified reading, developed by the Sys2Diag laboratory (CNRS-Alcediag and SkillCell) indicates that it has obtained “very good performance” in the preliminary phase of its clinical field studies. The tests carried out on 180 people: patients tested positive for the virus and on the medical staff assumed to be negative at the Montpellier University Hospital demonstrated that they are “easily achievable, without laboratory. Simply take saliva – one of the main vectors of the virus – and place it with the reagents at 65 ° C for 30 minutes. The nursing staff can then read the result with the naked eye ” indicates the laboratory on April 27. “At the same time, the development, production and distribution chain is being organized for rapid and massive deployment of test to health personnel from May “ specifies the laboratory. This new test has already been tested and validated with viral RNA isolated in the Sys2Diag laboratory, and with active virus at the Center for Infectious Diseases and Anti-Infectious Pharmacology Studies (CNRS / University of Montpellier). The researchers now aim to develop a consumer version of Easycov.
Detecting the coronavirus makes it possible to follow the evolution of the epidemic in the country and the circulation of the virus, particularly since the deconfinement. Several types of coronavirus are capable of causing respiratory infections whose manifestations range from a simple cold to respiratory distress. “In the most severe cases, a biological sample will identify the responsible pathogen. In addition, performing a CT or chest x-ray assesses the extent of lung damage and determines the person’s care“said the specialist. On May 28, the Minister of Health indicated that the positivity rate of the Covid-19 tests was one of the four epidemic indicators followed by health authorities to determine the green and orange zones in France.
While waiting for the result, the doctor will ask you to stay at home so as not to take any risks for you and those around you.
Since May 11: “If you have suggestive symptoms, fever, cough, respiratory discomfort, loss of taste or smell, you must act, do not wait for it to pass, said Minister of Health Olivier Véran on May 7. Contact your doctor or a doctor on call or 15. The doctor will order a screening test (PCR) if he considers it necessary. While waiting for the result, the doctor will ask you to stay at home so as not to take any risks for you and those around you. If the test is positive, the doctor will follow you and alert Health Insurance to carry out an investigation to call the case contacts. “
Second case: you are identified as a “contact case” of an infected person (whether or not they have symptoms). You will be contacted by the Health Insurance services who will ask you to stay in “preventive fortnight” and will tell you when to perform your test (in a 24 hour delay, if you live in the same household as the infected person, or by observing a period of 7 days after your last contact with this person, if you do not live with them). You will then have to make an appointment at a medical examination place. No medical prescription will be requested.
For serological tests, HAS recommends that it be done for:
- Initial diagnosis of symptomatic patients without signs of seriousness followed in town, and of symptomatic patients hospitalized, in case of discrepancy between the clinical picture and the result of the virological test (by RT-PCR);
- Catch-up diagnosis of symptomatic patients – serious and hospitalized or without sign of seriousness and followed in town – who could not have been the subject of a virological test within the period of seven days during which he is sensitive;
- Distant etiological diagnosis in symptomatic patients without sign of severity clinically diagnosed but not subjected to a virological test;
- Antibody detection in non-symptomatic healthcare professionals and staff in collective accommodation (nursing homes, prisons, etc.), during screening and detection of contact persons by gene amplification according to the recommendations in force after a negative virological test and only on an individual basis .
Coronavirus screening is done after consulting a doctor when symptoms are suggestive.
In no case should you go directly to the biological laboratories, but call them beforehand.
- For patients diagnosed in hospital or hospitalized with signs of severity, these tests are performed in hospitals.
- For patients with symptoms of Covid-19 and a medical prescription, it is possible to be tested in laboratories in town. It is also possible to be tested at home by medical teams who will travel if the doctor deems it necessary. Screening drives are also set up by the laboratories.
- Without prescription, to people identified as having been in contact, with a high risk of transmission, with a person tested positively. You will then be contacted by the Health Insurance services who will ask you to stay in “preventive fortnight” and tell you when to perform your test (immediately if you live in the same home as the infected person, or by observing a period of 7 days after your last contact with this person, if you do not not live with it). You will then have to make an appointment at a medical examination place. No medical prescription will be requested.
- To certain audiences as part of specific screening campaigns: vulnerable people, residents of collective accommodation structures and staff working in these structures in the event of a first confirmed case within the structure.
Once the screening location is identified (closest to the patient’s home), they must be contacted to make an appointment. If the laboratory performs the test on site, come with shas identity card, Carte Vitale and prescription. Without forgetting to wear a mask. When you return home, you must remain confined while awaiting the results which will be communicated within 24 hours.
→ Find a screening center on Sante.fr or on the website of the Ministry of Health.
Do you need a prescription?
PCR tests can be performed with or without a prescription according to two scenarios:
- you have symptoms: you need a prescription for a coronavirus test.
- you are identified as having been in contact, with a high risk of transmission, with a person tested positive: in this case, you do not need a prescription to be screened.
The time to get a PCR test result is between three and five hours in the laboratory. The result of this examination is returned to the patient within 24 hours, and to the prescribing doctor, with information to the intervention unit of Public Health France in the region, to the Regional Health Agency and to the crisis center of the General Directorate of Health.
Since May 11, “once the person has tested positive, all contact cases are tested and asked to isolate themselves” said Olivier Véran on May 7. The objective is to isolate carriers as quickly as possible to break the chain of transmission of the virus. “If the test is positive, the doctor will follow you and alert the Health Insurance to carry out an investigation and call the contact cases” continued the Minister of Health. Home isolation will be implemented for a period of 8 to 10 days. If symptoms worsen, do not wait, call the doctor or 15.
If you test positive for coronavirus, you must isolate yourself. “If you share your accommodation, stay in a specific room avoiding contact with other people in the home, detailed the Minister of Health, do not touch objects touched by other people, ventilate your home, wear a mask at all times, visits are not recommended, you will be able get masks from pharmacies without a prescription. ” The doctor may suggest that you perform isolation outside the home if necessary, for example in hotels provided for this case.
Depending on the symptoms presented, a patient may be suspected of having the Sars-Cov-2 virus, possibly infected or confirmed.
- Possible case: Anyone with clinical signs of acute respiratory infection with fever or feeling fever, AND Having traveled or stayed in a hazardous exposure zone within 14 days of the start date of clinical signs.
OR Any person, even without the notion of travel / stay in a risk exposure zone or close contact with a confirmed case of COVID-19, presenting with pneumonia for which another etiology has been excluded beforehand on the basis of clinical criteria , radiological and / or virological and the clinical state of which requires hospitalization OR signs of acute respiratory distress up to ARDS (Acute Respiratory Distress Syndrome) in a context possibly viral and without any other etiology obvious from the start.
- Probable case: Anyone with clinical signs of acute respiratory infection within 14 days of close contact with a confirmed case of COVID-19.
- Confirmed case: patients, symptomatic or not, with a biological sample confirming the presence of SARS-CoV-2.
- Contact case: person having been in contact with a “confirmed case” with different levels of risk: negligible, low and moderate / high. Close contact is a person who, from the 24 hours preceding the onset of symptoms of a confirmed case, has shared the same place of life (family, same room) or had direct contact with him, face to face , less than 1 meter from the case and / or for more than 15 minutes, during a discussion; flirt; close friends; class or office neighbors; neighbors of the case in a prolonged means of transport; person providing care to a confirmed case or laboratory personnel handling biological samples from a confirmed case, in the absence of adequate means of protection.
→ If you are case contact “more often than not you will be contacted by Health Insurance or the ARS. You should avoid contact with those around you, take your temperature twice a day, said Olivier Véran. If you can telecommute, fine, otherwise a work stoppage will be sent to you. Seven days after the last contact with the sick person you will be tested by PCR. If the test comes back negative, the doctor will be able to alleviate your isolation but it will have to persist for 7 more days. “
Even if the test result is negative, the patient must have no contact with fragile people for a week people aged 65 and over, carrying a chronic disease, with significant obesity or pregnant women in the 3rd trimester of pregnancy. He leaves the home systematically wearing a mask. He does not return to work except in telework and does not take public transport. Health Insurance may, if necessary, send him a work stoppage to cover the period when he must remain isolated.
The cost of the coronavirus PCR test is 54 euros. It is covered 100% by Health Insurance. The vast majority of laboratories dispense advance fees. If in doubt, contact the testing center, or plan ahead.
For the serological and rapid tests, the High Authority for Health decided in favor of their reimbursement on May 20. This HAS opinion only concerns reliability tests validated after evaluation by the National Reference Center (CNR)
Sources:
Opinion of the Scientific Council COVID-19 April 2, 2020 Inventory of containment and exit criteria.
Publication of the Institut Pasteur, results of serological tests, April 23, 2020.
Government information, Tests and screening, May 10, 2020.
Thanks to Marie-Françoise Gros, Director of Medical Affairs at bioMérieux, French specialist in medical diagnosis.
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