The Texas Department of State Health Services (DSHS) has advised residents of Tyler, Texas, who received tattoos at an unlicensed, illegal apartment-based tattoo facility to get tested for HIV and other infectious diseases, reports local ABC affiliate KRTE 9 News.

DSHS issued a cease and desist letter to the illegal tattoo operation after a disease control investigation discovered someone with an infectious disease might have been tattooed at the location.

At least 20 people—including minors—received tattoos at the apartment and are being tested. DSHS is also providing HIV, hepatitis B and hepatitis C testing for anyone else who received a tattoo there.

Unlicensed and home-based tattoo facilities do not necessarily adhere to industry standards that reduce the risk of transmitting communicable diseases, such as sterilizing tattoo instruments and changing tattooing needles for each client.