Almost half the people found to have had coronavirus following tests on their blood at the Sanquin blood bank were not aware they had been infected, a new report has shown.

The blood bank sent out questionnaires to plasma donors about their health and coronavirus in May and 3,676 people took part in the survey.

Sanquin labs identified coronavirus antibodies in the blood of 239 of these donors but 48% of them were not aware they had ever had the virus. One in 10 reported having no symptoms, while many others had dismissed their complaints as hay fever or a cold.

At the same time, just 20% of the people who told Sanquin they thought they had caught the virus were actually found to have antibodies in their blood.

The results of the survey, Sanquin said, shows that people are bad at deciding whether or not they have the virus and more should get a test, even if they only have mild symptoms.