Rules and recommendations
If you have been infected with COVID-19, tell your employer immediately so they can take the necessary steps. e.g. disinfect work surfaces, inform other employees in case you had a risky encounter with them or other preventive measures.
If you find out that your colleague is infected, evaluate whether you had a risky encounter with him. If so, please behave considerately and do quarantine yourself voluntarily. By doing so you will prevent the further spread of the virus, should you indeed get infected.
Inform your GP about your risky encounter. He/she will then assess your health state and if needed, issue a request for a COVID-19 PCR test for you.