The Veterans Affairs Department is investigating whether one patient’s positive HIV test result is linked to unsterilized endoscopic equipment at VA clinics, which may have exposed thousands of veterans to infectious diseases, The Associated Press reports.

According to the article, this is the first HIV case that could potentially be linked to contaminated equipment used at VA clinics in Murfreesboro, Tennessee, and Miami. The equipment—which was not properly sterilized between treatments—was also used at an ear, nose and throat facility in Augusta, Georgia. The VA previously reported that at least five veterans treated at VA facilities have tested positive for hepatitis B and 11 for hepatitis C; however, it is not possible to determine whether those cases are directly linked to the VA clinics.

In a statement, the VA said it is investigating “the possibility of such a relationship.” The agency did not reveal where the HIV-positive veteran received treatment.

Roughly 10,000 veterans who had received colonoscopies during the past five years were notified earlier this year that they may have been exposed to other patients’ body fluids at the Tennessee and Miami clinics. Thus far, less than a third have received their test results, and the VA is attempting to locate veterans whose notification letters were returned. To date, no infections have been reported from Miami.