Antigenic tests now make it possible to detect Covid-19 and influenza at the same time to facilitate diagnosis and improve care. What are these so-called “multiplex” tests? Are they effective? What prices?
Combined so-called “multiplex” antigen tests now make it possible to detect Covid-19 and influenza at the same time to facilitate diagnosis and improve management. “The clinical signs of winter respiratory infections, particularly influenza, and those of Covid-19 are similar; no symptoms are specific. It is therefore difficult to make a differential diagnosis of influenza/Covid-19 during the period of co-circulation. of these viruses without carrying out virological diagnostic tests” reminded the High Authority of Health (HAS) in 2020. The combined influenza/Covid test is “a real progress, this allows to prescribe less antibiotics and justify it to the patient. It’s a excellent therapeutic education tool” defended Jean-Paul Hamon, the honorary president of the Federation of Doctors of France, at the Sunday newspaper the 1st January 2023. The Union of Community Pharmacists’ Unions (USPO) also asks “insistently” at HAS that it positions itself on the performance and management of combined Flu/Covid/RSV tests (bronchiolitis) to respond to the emergency of the triple epidemic. We take stock of the multiplex test.
What is the Covid and flu test?
To diagnose the flu or the Covid, we can do unitary PCR tests targeting each of the different viruses. Currently, several types of tests diagnose Covid-19 by testing for RNA on nasopharyngeal, salivary, or oropharyngeal swabs, or by testing for SARS-CoV-2 antigen (antigenic test) on nasopharyngeal swabs. Diagnosis of influenza is most often clinical. the influenza virus antigen test (influenza virus type A and B) is already used in everyday practice and covered by health insurance, “but its sensitivity is low in adults, can be at less than 60% between 70 to 90% in children” specifies the HAS. It is now possible to perform an antigen test to detect Covid-19 and influenza in the same sample (same nasal swab), then analyzed with the PCR technique. The so-called multiplex combination test detects influenza A antigen (including the H1N1 subtype), influenza B and/or Sars-Cov-2. Unlike unit tests, the multiplex test makes it possible to detect multiple pathogens targets from the same sample. In 15-30 minutes, the patient gets the result. Various types of samples can be used to carry out these tests, the most common being the nasopharyngeal swab.
For who ?
To date, the HAS advocates the use of multiplex testing”in hospitalized adults or arriving at the emergency roomresidents in nursing homes and young children. In other people, the identification of the virus of winter viruses does not have any consequences on the management which is based on the treatment of the symptoms and the monitoring of the evolution of the disease, the use of these tests is useless. . Only a SARS-CoV-2 detection test is then indicated“. Practitioners are waiting for the green light from the Ministry of Health to generalize them.
This is not a self-test you can take home.
Where to buy the Covid and flu test?
The multiplex Covid and flu test is available over the counter in some pharmacies, not all offer it. This is a rapid screening test to be carried out by a health professional (pharmacist or doctor). This is not a self-test you can take home.
Can we do a Covid and flu test in a pharmacy?
Yes, the combined Flu and Covid tests are achievable in pharmacies that offer it (not all do) with or without a prescription. The result is given in 30 minutes maximum. They can also be performed directly by the doctor during the consultation.
Which laboratories market the Covid and flu test?
Several laboratories market multiplex tests: Biron, AAZ, Toda Pharma, Roche etc “The sample is the same, it is nasal mucus that we will recover, and that we will not only migrate on a strip that will detect Covid antigens, but also influenza antigens“said Fabien Larue, director of the AAZ laboratory at franceinfo January 2.
The test does not make it possible to know if the patient is contaminating.
How reliable is the Covid and flu test?
According to the French laboratory Toda Pharmatheir multiplex test presents an accuracy rate of 98.9% for Covid-19, 99.9% for influenza A and 99% for influenza B. “The multiplex test is a qualitative test, not making it possible to determine in which phase of the infection the patient is located, nor to decide whether the patient is contaminating. However, it allows detect the presence of pathogens even with a low viral load as is the case at the beginning or end of an infection but also the pathogens of an asymptomatic infection” specifies the HAS. “The main advantage of multiplex testing is to be able to search for several infectious agents at the same time with a single sample. One of the disadvantages could be the interpretation of positive results for several pathogens, especially among immunocompromised patients who have prolonged viral shedding that would be undetectable by viral culture, as well as in children, as respiratory viruses are often present asymptomatically“shades authority.
Do I need a prescription for the Covid and flu test?
“Combined flu/Covid tests are possible in pharmacies that offer them with or without prescription“ says Laura Fonteneau, pharmacist.
What is the cost of the Covid and flu test?
The price of the Covid and flu test depends on the pharmacies. “As flu screening tests are not reimbursed, combination tests may have varying purchase prices by pharmacists according to the brands, conditions of purchase etc and therefore variable prices for patients” emphasizes Laura Fonteneau. Some tests are sold around 5 euro.
Is the Covid and flu test reimbursed?
“Again, it all depends on the pharmacies, there are no fixed rules“says Laura Fonteaneau. Flu screening tests are not reimbursed.”In certain situations, covid tests being reimbursed, if the pharmacist performs a combined flu/Covid test, it can be covered but only on the basis of reimbursement of the Covid test” supports the pharmacist. “According to the pharmacies that offer them (free price), some will not charge the patient anything extra if the pharmacist finds it financially, or if the combined test is too expensive for the pharmacist to buy, there may be an additional charge for the patient“adds Laura Fonteneau.
Thanks to Laura Fonteneau, pharmacist.
Source: Distinguishing influenza from COVID-19: in which situations and with which tests? HAS, October 21, 2020