Thirteen residents at a nursing home in Hove have been tested for coronavirus after displaying symptoms.
Oaklands Nursing Home's manager Beti Koder said 13 of its 20 residents have had high temperatures, a cough, or both.
They were tested on Saturday but were told they will have to wait up to six days for results, Ms Koder said.
Seven members of staff have also shown symptoms, but have been told they will not be tested, she added.
Public Health England said it would not comment on individual cases.
Ms Koder said: "A nursing home is very different from a hospital in terms of contact and it’s extremely difficult to isolate someone."
She added she was worried about the fact none of her staff had been tested and one employee has been off work ill for "more than a week".