TESTS on women treated with unsterilised equipment at a Darwen surgery have come back with results showing some to be positive for hepatitis B.

But health chiefs say it is because the patients will have had the infection in the past and got over it, often without even knowing.

Those testing positive have been written to and offered counselling by an expert and health chiefs say they have no danger of passing it on.

Around 450 women had to be recalled after it was discovered the practice nurse at Perry Street surgery had been carrying out smear tests dating back to 1991 with cleaned but unsterilised equipment. The vast majority of women have been offered blood and urine tests because there was a risk they could have caught hepatitis B or C, chlamydia or human papilloma virus.

Dr Jim Paris, director of public health at the Blackburn with Darwen Primary Care Trust said: "The PCT has identified a number of patients who have had hepatitis B in the past and are now immune.

"Such a result would be expected from blood tests conducted on a large number of people.

"All have been written to, reassured and offered the opportunity to discuss this result with a consultant in infectious disease control.

"In the meantime, we would like to reassure such patients that they are at no risk from having had and resolved hepatitis B.

"This is the most usual result of catching hepatitis B and results in complete cure. Nor are is there any risk to their families or friends."

Hepatitis B is easily transmitted by contact with blood and other body fluids. Many patients have no symptoms and most people -- about 90 per cent -- will conquer the virus, giving them immunity. Public health officials expect to have informed all 450 women of their results in around three weeks.

Until then they are refusing to say how many women have tested positive for infections or whether they are receiving treatment to avoid causing anxiety through speculation.

The Perry Street problem was picked up in April by an infection control nurse who was invited to the surgery by GP Dr Ibrahim Derar.

It was his wife Sabria who had been carrying out the tests without properly sterilising the specula -- the instruments used in smear tests. She has been referred to the Nursing and Midwifery Council for possible disciplinary proceedings.