More than 8,000 patients across the UK who may have been treated by a former healthcare worker who tested positive for hepatitis C are being advised to arrange a blood test, NHS Lanarkshire have said.
The worker did not return to clinical practice after testing positive in 2008 but NHS Lanarkshire is working with other health boards across the UK to notify patients who may have had a surgical procedure carried out by the individual between 1982 and 2008.
The individual worked in hospitals across Lanarkshire during the period, based primarily at Wishaw General Hospital and the former Law Hospital.
They also worked at the William Harvey Hospital in East Kent for three months between January and April 2006.
More than 8,300 patients across the UK are to receive letters informing them of the situation and urging them to arrange a blood test.
NHS Lanarkshire said the majority of those contacted will be in Lanarkshire, with about 1,000 across Scotland and the rest of the UK.
In England, 336 people are to be contacted with a further 11 in Wales and five in Northern Ireland.
Expert advice is that the risk of the hepatitis C virus having been transmitted to a patient during surgery involving the healthcare worker is low, the health board said.
In previous similar exercises either no patients or only a small number have been found to be infected, according to NHS Lanarkshire.
Dr Iain Wallace, medical director at NHS Lanarkshire, said: "We would like to reassure people that the likelihood of patients acquiring the virus from a surgical procedure carried out by the healthcare worker is low.
"We know that some people receiving the letter may be anxious about what this means for them. We have apologised to patients for any concern that may be caused by this situation.
"We are committed to supporting patients and are ensuring they have every opportunity to get information about hepatitis C, the testing process and the situation in general.
"We are also putting on additional clinics locally to make it as straightforward and convenient as possible for people to get tested."
After the worker tested positive in 2008, the UK Advisory Panel (UKAP) advised a patient notification exercise was not required based on the evidence available at the time.
NHS Lanarkshire decided to contact patients now after its health protection team was made aware of a patient recently referred for treatment for hepatitis C last year who had previously had a surgical procedure carried out by the healthcare worker.
Further investigations found it was "probable" the patient was infected with the virus during a surgical procedure carried out by the healthcare worker.
The health board added: "Subsequent investigations identified another patient in Lanarkshire with hepatitis C for whom it is also probable that they were infected during a procedure carried out by the healthcare worker.
"After detailed investigations, including extensive testing of viruses, NHS Lanarkshire submitted a report to UKAP. UKAP endorsed NHS Lanarkshire's proposal to carry out a patient notification exercise.
"Patients are receiving a detailed question-and-answer sheet with their letter which includes information about hepatitis C and how to arrange to be tested."
The virus infects the liver and can cause serious and potentially life-threatening damage. Around 215,000 people in the UK have hepatitis C, according to the NHS.
It is usually spread through blood-to-blood contact and can be passed by sharing unsterilised needles, razors or toothbrushes.
The NHS said it does not have any noticeable symptoms until the liver has been significantly damaged, meaning people can have the infection without realising it.
When symptoms do occur, they can be flu-like symptoms, tiredness and loss of appetite.
Professor David Goldberg, consultant clinical epidemiologist at Health Protection Scotland, said: "Although the risk of infection is low, we are recommending that people take up the offer of a blood test to ensure anyone who does have the virus can receive the right treatment.
"Treatment for hepatitis C is highly effective."