A clinic in Las Vegas was ordered to shut down after authorities discovered that more than 40,000 patients may have been exposed to deadly diseases such a hepatitis C and the HIV virus, through the reuse of syringes and vials.

The Endoscopy Center of Southern Nevada "was served with an emergency suspension of its business license," city authorities declared in a statement, according to Agence France-Presse.

40,000 people need to be tested for hepatitis B and C or HIV, because of the unsafe medical practices at the clinic. Unless the former patients are tested, they will not know whether they have been infected or not, as symptoms such as nausea or jaundice appear only in one out of five cases. Some of the former patients have already contacted lawyers for a potential suit against the clinic.

Health authorities began an investigation at the clinic after six former patients were diagnosed with hepatitis. Apparently, nurses at the clinic reused syringes and vials, at the recommendation of the managers, who wanted to save money. Even though the nurses changed the needle of the syringe, they used the same syringe to draw anesthetic from another vial and therefore, contaminated it.

The clinic is now shut and its business license suspended.

"The city now has the business license in hand. They don't have a license to do business in the city of Las Vegas. They might not ask for a hearing. We may just keep the license in our possession indefinitely," Las Vegas Mayor Oscar Goodman said, as reported by United Press International.