Tests carried out at Birch Hill Hospital in Rochdale, Greater Manchester, after the woman developed the potentially fatal liver disease, traced the source back to the member of staff.
The patient involved has since made a full recovery. A spokesman for the Rochdale Healthcare Trust said that the chances that anyone else had been infected were less than one in one thousand.
"However, the only way to be absolutely sure is to perform a blood test," the spokesman said last night.
The trust has written to 114 patients and their GPs to arrange for testing and advice and counselling if it is required.
It was not known what job the member of staff involved held. But the trust spokesman said that he had since left the hospital.
"He no longer takes part in operations although he is completely safe to practise other forms of health care," he said.
He was employed in line with recommendations from a UK panel on healthcare workers with blood-borne viruses.
The operation was carried out last year, but the disease took some time to develop.
"It must be emphasised that the risks of infection are very small indeed and we expect to find no further cases," the spokesman said.Reuse content