Thousands of patients at a New York hospital are at risk for possibly being exposed to hepatitis and HIV. South Nassau Communities Hospital in Long Island reported that over 4,000 that were admitted from March 2011 to January 2014 people could have been exposed.

According to newschannel3 patients at the hospital could have been treated with an insulin pen that had been used on other patients possibly exposing them to diseases.

The recommendation to get tested occurred after it was evident that a nurse had been giving multiple patients insulin shots using the same pen. According to the New York Daily News hospital spokesman Damian Beckner said, “The warning came after a nurse was heard saying it was acceptable to use multidose insulin pens on different patients.”

Everyone that received insulin shots at the hospital received a letter and although the hospital believes they are at low risk for being infected it is recommended that they are tested for HIV, hepatitis B and hepatitis C.