Hundreds of students at the University of Derby are to be tested for HIV and hepatitis because a health worker reused syringe barrels for eight years.
More than 600 past and present students received blood tests or vaccinations from the health worker between 2005 and 2013.
Letters have been sent to the students inviting them to visit their GP or a hospital for a screening.
Doctors said the risk was “extremely low” but they were taking precautions.
NHS England and Public Health England spent six months examining the university’s health records.
Their investigation revealed that the worker involved failed to change the syringe barrels which needles are attached to between each patient.
Dr Doug Black, medical director for NHS England, said: “We are extremely sorry for the undoubted worry and concern people we are contacting may feel on receiving this news.
“I would, however, like to stress the risk is extremely low and would encourage all those we contact, who may not already have been screened after their time at the university, to present themselves for blood testing.”
Professor John Coyne, vice-chancellor of the university, said: “It’s unacceptable these students are in this position. We want to get everyone to see their GP as quickly as possible.
“I don’t think anyone can comprehend the degree of anxiety this could cause our students and that’s why we want to get everyone to see their GP as quickly as possible.”
A helpline has been sent up to provide further help and support. Call 03330 142 470.