LAS VEGAS - Health officials are reporting a threefold increase in positive tests for the potentially fatal hepatitis C virus, but say they don't know yet how many cases can be traced to treatment at a Southern Nevada medical clinic.
The Southern Nevada Health District typically fields 20 to 40 positive hepatitis C reports a day, but has been getting up to 150, officials said in a report released Thursday.
Telephone calls will be needed to identify patients who may have contracted hepatitis C from the Endoscopy Center of Southern Nevada or the affiliated Desert Shadow Endoscopy Center in Las Vegas.
"This is a marathon, not a sprint," said Brian Labus, senior epidemiologist for the health district. Health officials last month began notifying 40,000 patients treated since 2004 at the Endoscopy Center to get tested for hepatitis strains C, B and HIV, the virus that causes AIDS.
"It is really going to take some time," Labus said.
The investigation was triggered by the discovery that six patients contracted hepatitis C on two dates last year because of unsafe practices at the Endoscopy Center.
A seventh person with the virus has been linked to the Desert Shadow Endoscopy Center in Las Vegas. Both clinics are among six headed by Dr. Dipak Desai.
Authorities still need to pinpoint when patients who've tested positive contracted the virus, and Labus said calls will seek information about patients' medical history and risk factors, including whether they use intravenous drugs.
The earliest the district could have complete results is July, he said, although some preliminary findings should be available earlier.
The federal Medical Reserve Corps, a group of about 200 local volunteer health care professionals, will assist in asking the questions, said Paula Martel, program coordinator. She said the organization assists local health authorities during medical emergencies.
The questionnaire will be used to verify a patient's name, place and date of procedure and whether they were given Propofol, an injectable form of anesthesia.
"Obviously, if the person didn't have a procedure at the clinic, that is pretty much the end of the interview," Labus said.
Health officials believe the six known hepatitis C cases occurred when nurse anesthetists reused syringes on infected patients, contaminating vials of medication that were shared by multiple patients.
The health district has linked 117 patients to days when infection probably was spread at the facility. They are being contacted and are currently undergoing interviews and blood testing, Labus said.
The health district is awaiting access to medical records currently held by Las Vegas police to determine if patients of the Desert Shadow Endoscopy Center should be advised to be tested, Labus said.