Southern Nevada Health District officials are recommending nearly 40,000 people be tested for all trains of hepatitis as well as HIV after six cases of hepatitis C were identified at the Endoscopy Center of Southern Nevada in Las Vegas.

The warnings come after six people who underwent procedures at the Endoscopy Center of Southern Nevada now were diagnosed with hepatitis C virus, the Southern Nevada Health District said in a statement, according to the Associated Press. Five of them were treated the same day in late September; the sixth is thought to have been infected in July, the district said.

An investigation team including the Nevada State Bureau of Licensure and Certification and officials from the Centers for Disease Control and Prevention determined that “unsafe injection practices related to the administration of anesthesia medication might have exposed patients to the blood of other patients,” the statement said.

Hepatitis C is a chronic, potentially fatal virus that can cause liver ailments, including cancer and lifer failure. The concern is higher than usual, as many patients who contract the blood-borne hepatitis C are asymptomatic for many years. Early symptoms include jaundice, nausea, and fatigue. The disease is most often transmitted by sharing unclean needles and syringes.

Chief Health Officer Lawrence Sands said anyone who received anesthesia at the Endoscopy Center of Southern Nevada should be tested for the virus, along with hepatitis B and HIV, the AP reported.

"We are recommending all patients during this time frame to get tested because we cannot determine which patients may have been exposed. Hepatitis C is a serious medical condition and infected patients may not have outward symptoms of the disease for many years. As a precaution, and in order to take appropriate steps to protect their health, it is important for these patients to get tested and for anyone with the illness to seek medical treatment,” Sands said.

Moreover, the Endoscopy Center of Southern Nevada officials issued a statement on their Website in which they recommend people get tested.

“We wish to emphasize that the actual risk of anyone being affected by this is extremely low, but as a precaution, anyone who has undergone procedures at the Endoscopy Center who required anesthesia should be tested,” the statement said.