My father has incurable cancer, he is in the shielded group. None of his household have left the house for 8 weeks. They have received deliveries of medicines and food outside and I have been there once a week as a carer to do tasks they cannot do independently. He's had a call today to say he will be visited tomorrow for a Coronavirus test to be done. He's had no symptoms, none of them have. Has anyone heard about this? If he is symptom free and shielded why is he being tested?