Because of improper medical procedures, an outpatient clinic has exposed thousands of patients to Hepatitis C and HIV/AIDS over the past four years. Medical officials admitted that thousands who underwent a procedure at the Endoscopy Center of Southern Nevada may have been exposed to the viruses after six patients with acute Hepatitis C used needles that were never changed.

An investigation revealed that the virus spread because the clinicians used the same syringes on different patients receiving multiple shots of medications.

Nevada health officials have sent warnings to 40,000 patients who were injected with anesthesia from March 2004 to January 11, 2008. Chief Health Office Lawrence Sands said that they should be tested for Hepatitis A, B and HIV/AIDS.

"We are recommending all patients during this time frame to get tested because we cannot determine which patients may have been exposed," Sands said,

Hepatitis C is a blood-borne infectious disease that inflames the liver and is often asymptomatic but ensuing chronic hepatitis can result later in cirrhosis and even liver cancer.