89 patients are to be offered blood tests over fears they may have contracted HIV.

Nearly 100 patients are to be contacted after being treated by a healthcare worker who may have been infected with HIV, NHS bosses have said.

A total of 89 patients will be contacted by the Mid Yorkshire Hospitals NHS Trust and Kettering General Hospital NHS Trust in Northants and offered a blood test to establish whether they have picked up the illness.

Letters will be posted out by the Mid Yorkshire Trust to 46 patients who were treated by the healthcare worker at Pontefract General Infirmary between 1999 and 2001, while Kettering will send letters to 43 people who were seen by the worker at Kettering General Hospital between February 1997 and February 1999.

Dr Rob Lane, associate director at The Mid Yorkshire Hospitals NHS Trust, said it was unclear if the medical professional was HIV positive and reassured patients the chance of infection was slim.

He said: "We recognise that patients may be anxious about this news but they can be reassured that the risk of infection is extremely low.

"They are being offered a blood test as a precaution and to provide reassurance."

Kettering General Hospital's medical director, Dr Brendan O'Malley, also said it was unclear if the healthcare worker had the illness and the offer of an HIV test was simply to offer peace of mind.

He added: "The Department of Health has stated that between 1988 and 2003 in the UK there were 28 patient notification exercises similar to the one about to be carried out - this resulted in 7,000 patients being tested for HIV. No patient tested positive."

Both Trusts said that once the healthcare worker was found to have the virus it was reported to and subsequently investigated by the UK Advisory Panel.

A list of patients has been "carefully" established where the worker had been involved in certain types of procedures and operations, with arrangements being put in place for blood testing clinics and counselling.