Some 400 patients are being recalled for blood tests after being treated by a doctor with HIV.
The recall affects patients who were under the care of the locum doctor, who has not been named, at three hospitals between June 2010 and February 2015.
Chesterfield Royal Hospital NHS Foundation Trust has recalled 120 patients, Nottingham University Hospitals NHS Trust has recalled 223 and Royal Cornwall Hospitals NHS Trust has recalled 57.
The hospitals said patients who had undergone "invasive procedures where there is a potential risk of infection" had been identified and had been invited back for a precautionary blood test.
NHS England said concerns about the doctor first emerged in December 2015 at the Heart of England NHS Foundation Trust (HEFT) in Birmingham.
It has tried to contact one of its patients thought to be at risk but has been unable to do so.
The doctor also worked at other trusts but a review found no patients were put at risk, NHS England said.
It said the doctor no longer works for the NHS and conditions have been placed on their registration by the General Medical Council (GMC).
The doctor was also given an interim suspension order earlier this year "because they failed to comply with the conditions placed upon them".
NHS England said it will review the incident to learn lessons for the future.
Nottingham's medical director, Dr Stephen Fowlie, said the doctor had treated patients and then subsequently been diagnosed with HIV.
He said: "The risk that any patient has been infected by transmission of the virus from this doctor is extremely low.
"However, because the doctor's diagnosis was unknown during their employment with us (2013 to 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.
"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.
"We are arranging clinic appointments, test results within 24 hours, and appropriate support and advice from our specialists for these 223 patients and their families."
The Royal Cornwall said the doctor worked there for a six-month period in orthopaedics between 2011 and 2012.
Its medical director, Dr Malcolm Stewart said: "We understand this will be concerning to patients, however, it should be stressed that the risk of the virus having been passed on to any of the individuals we are writing to is extremely low.
"There has not been any instance of cross-infection following similar look-back exercises in the UK in the past.
"We are writing to 57 patients offering the opportunity, as a precaution, to return to the hospital for a blood test.
"There is no need for individuals to take any special precautions in advance of receiving our letter."
Dr David Levy, regional medical director for NHS England Midlands and East, said: "We understand that this will be a worrying time for patients who are being invited for precautionary testing and their families.
"However, clinical evidence shows that the risk of infection is extremely low and it is highly unlikely that any of the patients being contacted will have been infected with HIV.
"Advice and counselling is available for those affected by this recall, and we would encourage them to access this support."
Dr Gail Collins, medical director at Chesterfield Royal, said: "This is news that these patients will not be expecting and I offer apologies for the understandable anxiety and distress it is likely to cause them, or members of their family.
"I assure patients and people in North Derbyshire that Chesterfield Royal Hospital is committed to making sure their care and treatment is safe.
"As worrying as this issue sounds, it is extremely unlikely the virus transferred to anyone during their treatment."