It's a letter no one wants to get but it's one some 42 hundred patients of South Nassau Communities Hospital have received.
It says that they should get tested for Hepatits B, C and HIV if they recently received an insulin pen injection at the hospital.
Michael Byrd came to check on his elderly mother who is diabetic and is being treated there.
"I spoke with her this morning and she says that she didn't take the needle and the doctor told her don't take it." said Byrd.
"She doesn't know everything that they're bringing her. Yes the awareness is very high right now. "I'm really concerned about what is going on," said Hempsted resident Gloria Thompson.
Hospital officials say they are issuing the warning out of an abundance of caution after a nurse was overheard saying that it's ok to put a clean needle on an insulin pen and reuse it on a different patient.
Dr. Daniel Lorber is the chief of endicronology at New York Hospital Queens and the president of the Long Island chapter of the American Diabetes Association.
He showed us why reusing an insulin pen, even with a new needle head, isn't safe.
"If it was all one way flow that would be great, but we know from studies some of the earlier pens on the market that there's two way flow and there's a certain amount of flow and red blood cells into this reservoir that holds the insulin," said Lorber.
Hospital officials confirm that they've already heard from several hundred people inquiring about the free blood test the hospital is now offering.
The hospital says they are now no longer using the insulin pens and have switched to single patient use syringes and vials.