OCEANSIDE, New York (PIX11) – South Nassau Counties Hospital is warning thousands of patients of possible blood contamination, including serious diseases such as HIV and hepatitis.

In a letter to patients, hospital officials say that a single-use insulin pen may have been reused with multiple patients.

“The risk of infection from this is extremely low, nonetheless, out of an abundance of caution, the hospital is recommending that patients receiving the notification be tested for hepatitis B, hepatitis C and HIV,” officials said. “While the testing is voluntary, it is recommended.”

According to the hospital, the component of the insulin pen that was reused was the reservoir, not the needles. Because of the backflow of blood mixed with insulin, however, there could still be a risk of contamination.

“South Nassau has already implemented a hospital-wide policy that bans the use of insulin pens and permits only the use of single-patient-use vials to administer prescribed insulin treatments to patients,” according to an official.

The hospital is recommending anyone who believes they could be at risk get tested. To arrange a free and confidential test, patients are encouraged to call (516) 208-0029.