In-vitro diagnostic tests for detecting the coronavirus is an essential tool in slowing the progression of the pandemic.
To enter the European Market, these tests (devices) must comply with the European Directive 98/70/EC on in-vitro diagnostic medical devices (IVD). The coronavirus diagnostic tests are grouped according to1:
- Scientific rationale
- Type of technology used
- Intended user
This determines the specific conformity assessment route to obtain a CE-mark and access to the market in the European Union.
According to the scientific rationale, there are two categories of tests; those that detect the virus itself, SARS-CoV-2 virus RNA, and those that detect exposure to it. The tests that detect the virus are called polymerase chain reaction (PCR) tests, take at least 4 hours to do, and require proper laboratory equipment and reagents, and skilled professionals to perform. These tests have the highest sensitivity and specificity, and the World Health Organization (WHO) recommends this kind of testing method2. The tests that detect exposure to the virus, so-called serological tests, check for antibodies against SARS-CoV-2 virus in the blood. The usefulness of serological tests is limited because antibodies only appear in the blood several days after the infection, and the presence of antibodies does not mean that you are currently infected.
Coronavirus diagnostic tests are grouped in terms of the type of technology used; tests developed for use on automated analyzer machines, and rapid tests that involve nonautomated procedures on qualitative or semi-quantitative devices and used in small series to give a fast result.
There is an urgent need to develop rapid tests that provide results in 10-30 minutes to allow for the detection of the virus in the population. Rapid tests include:
- Antigen tests
- Antibody tests.
Rapid antigen tests are rare; in fact, reports from 18 European countries’ competent authorities indicate that there are only three such devices with CE marking3. Rapid antibody tests are more readily available; more than 60 such tests are currently CE marked. These tests, however, are of limited use because they do not show if the subject is infected, only if the patient has suffered COVID-19.
Finally, diagnostic tests are classified according to the intended user; health care professionals at hospitals, or lay users utilizing self-tests.
For COVID-19 tests intended for use by health care professionals, the device manufacturer ensures that the device is safe and performs well, provides a declaration of conformity with the requirements of the Directive 98/70/EC, and affix the CE-mark to the product. Devices intended for self-testing require the involvement of a third-party reviewer, a so-called notified body, which must carry out additional verification of the technical documentation before CE-mark may be affixed to the product.
Some of the rapid tests, sold as self-tests on the European market, do not meet the Directive requirements and have not undergone a correct CE mark conformity assessment process, because fraudulent or incomplete documentation has been identified3. Various Member States very quickly prohibited the use of these self-tests1.
The validation of rapid test performance must be carried out with gold standard tests and in a large population before being introduced on the market. The European Commission and the European Member States are therefore funding a clinical validation study to support the development of rapid diagnostic tests. The European Centre for Disease Prevention and Control (ECDC), the European Commission, Member State authorities, FIND (Foundation for Innovative New Diagnostics)4, and WHO are working together to validate these rapid tests to be able to provide guidance on which tests that provide accurate and reliable results. When such rapid tests are available, they should be used in people at risk of severe disease, patients with acute respiratory disease, symptomatic health workers, and symptomatic individuals in closed places, such as prisons or hospitals. These tests serve as a complement to the PCR tests and will greatly help in overcoming the burden and challenges that COVID-19 places on our society.
1- Communication from the Commission: Guidelines on COVID-19 in vitro diagnostic tests and their performance. C(2020) 2391, 15.4.2020. Available here: https://ec.europa.eu/info/sites/info/files/testing_kits_communication.pdf
2- World Health Organization. Laboratory testing strategy recommendations for COVID-19. 19.03.2020. Available here: https://www.who.int/publications-detail/laboratory-testing-for-2019-novel-coronavirus-in-suspected-human-cases-20200117
3- European Centre for Disease Prevention and Control. An overview of the rapid test situation for COVID-19 diagnosis in the EU/EEA. 01.04.2020. Available here: https://www.ecdc.europa.eu/sites/default/files/documents/Overview-rapid-test-situation-for-COVID-19-diagnosis-EU-EEA.pdf
4 – FIND is the Foundation for Innovative New Diagnostics. A global non-profit organization driving innovation in the development and delivery of diagnostics to combat major diseases affecting the world’s poorest populations. https://www.finddx.org/at-a-glance/