3. What type of test and for what situation?
The recommended kind of test , be it PCR or a rapid test, depends on the degree of vulnerability of the person concerned by the test and his or her risk of exposure to the virus.
As a general rule :
The PCR test, recognised as the most reliable, is always recommended primarily for symptomatic individuals who are vulnerable and/or who are caregivers in direct contact with patients and/or who have had symptoms for more than 4 days. They are also recommended for children exposed to COVID-19, as rapid antigen tests are not as accurate in this population group.
For other indications, however, the use of rapid antigen tests is recommended. They have the advantage of being easier to access as they do not require laboratory analysis and, above all, they give an immediate result (15-20 minutes). Sometimes a positive rapid test will still need to be corroborated by a PCR test.
Professionals who perform the tests will advise you on which kind of test is recommended for your situation. The chart hereunder (in French) provides indications on the testing strategy.
PCR tests are the most reliable but only give a result within 24 hours as they require laboratory analysis. The sample is taken by a professional using a nasopharyngeal swab (cotton swab in the nose), an oropharyngeal swab (cotton swab in the throat) or a saliva swab (saliva sample). The saliva sample can be taken by the patient and then sent for analysis.
Antigenic or rapid tests have the benefit of providing a result within 15-20 minutes but are less accurate. They are recommended for broad screening in low-risk settings because they are easily accessible and do not require laboratory analysis. Sampling is carried out by a professional by means of a nasopharyngeal swab (cotton swab at the back of the nose) or an oropharyngeal swab (cotton swab in the throat). Antigenic tests with nasal sampling (cotton swab in the nostrils) will soon be available.
To simplify targeted and repetitive testing in a professional setting, the FOPH also recommends "pooled" PCR tests - i.e. tests carried out on the basis of personalised samples (nasopharyngeal, oropharyngeal or salivary) but analysed by grouping several samples. If one of the tested groups is positive, the samples from each member of the group are then analysed individually to identify the positive person or persons. This technique allows for regular testing of a large population group while reducing constraints and costs.
Intended to limit the transmission of the coronavirus in the environment of the person who uses it, the self-test is done at home. It is recommended for people without symptoms, and who have not had contact with COVID-19 cases, who want to visit a relative who isn't a vulnerable person or to take part in an event involving several people not living in the same household.
The self-test isn't recommended if:
- you have coronavirus symptoms
- you have had contact with someone who was tested positive
- you are in quarantine
- you intend to visit vulnerable people
- you are entering Switzerland and need a negative result for this.
Self-tests are available free of charge in Geneva drugstores when you present your insurance card. The maximum number of self-tests per person is 5 over a period of 30 days.
More information on the FOPH website