Hundreds of patients who were treated by a doctor later diagnosed with HIV have been encouraged to take a test for the virus.
The locum doctor was employed by three NHS hospital trusts in Nottingham, Chesterfield and Cornwall between June 2010 and February 2015.
While doctors said the risk of HIV transmission through day-to-day contact was "extremely low", an appeal has been issued to 400 patients offering a test.
Nottingham University Hospitals NHS Trust has recalled 223 patients, while Royal Cornwall Hospitals NHS trust has recalled 57.
Chesterfield Royal Hospital NHS Foundation Trust said it had recalled 120 patients.
Stephen Fowlie, medical director of the Nottingham trust, said the doctor's diagnoses was unknown during their employment at the trust between 2013 and 2015.
"We are contacting patients who had had at-risk operations involving this doctor to advise they return to hospital for a blood test as a precautionary measure," said Dr Fowlie.
"The risk that any patient has been infected by transmission of the virus from this doctor is extremely low," he added.
“Transmission of the virus between an infected healthcare worker and a patient with an open wound can only occur if health workers themselves have an injury with bleeding when they are delivering patient care.
"There is no evidence this happened to this doctor in any patient contact."
HIV-positive staff are permitted to work in the NHS under strict conditions, after England's chief medical officer Professor Dame Sally Davies scrapped "outdated rules" prohibiting them from performing surgery and dentistry.
The doctor has not been named but the NHS confirmed they were no longer working for the health service.
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