Ed Bernstein said he has at least 20 clients who tested positive for one of the blood-borne diseases, and Richard Harris said his firm represents about 25 such clients. Most of the positive tests were for hepatitis C.

The attorneys expect to see more positives in coming weeks as blood test results come back for the thousands of patients who had procedures at the clinic at 700 Shadow Lane, where, health officials say, at least six people contracted hepatitis C because of unsafe medical practices.

Late Thursday, a source in the state Health and Human Services Division said it will be announced today that another clinic, the Centennial Spine and Pain Center, 4454 N. Decatur Blvd., was found to be reusing single-dose vials of medication on multiple patients. Syringes were not reused, the source said.

Health officials have urged 40,000 patients of the Shadow Lane clinic to get blood tests for HIV and hepatitis strains B and C. They could have been exposed to the diseases when nurse anesthetists reused syringes on infected patients and contaminated single-use vials of medicine. The infection spread when the vials were shared between multiple patients, health officials said.

At the Southern Nevada Health District, confirmed cases of hepatitis C have been coming in, but the number of cases is only slightly greater than those reported before the clinic scandal broke two weeks ago, senior epidemiologist Brian Labus said.

Under normal circumstances, the office receives 20 to 30 reports of hepatitis C a day, he said. Those chronic cases are different from the Shadow Lane facility's cluster of six, which are acute.

Chronic cases are not symptomatic, and the health district would not undertake an investigation.

However, the cluster of six were symptomatic, and the district noticed the spike in the number of such cases.

Overall, Labus said, "the number of cases we've received in recent weeks have been on the high end of our normal range but not at a level that we would consider abnormal."

The numbers have been expected because roughly 2 percent of the U.S. population carries hepatitis C. Labus said there might yet be an increase in cases as it takes time for test results to come back.

Health investigators estimate 4 percent of the Endoscopy Center of Southern Nevada's patients will end up testing positive for hepatitis C. But that number would not reflect the number of patients who contracted the disease there. The estimate is based on the clinic's older clientele.

The elderly have a higher rate of hepatitis C because they were more likely to have been infected during blood transfusions conducted before regular screening for the disease began in 1992.

Hepatitis C is inflammation of the liver because of the hepatitis C virus, which is usually spread by blood transfusions, blood dialysis and needle sticks. The damage it causes can lead to cirrhosis and liver cancer.

As part of the ongoing investigation, the health district is checking the files of known acute hepatitis C cases from two to three years ago to determine whether those patients visited the endoscopy center.

The health district has indeed linked some of those names to the known days when infection probably was spread at the facility: Sept. 21 and July 25. They are being contacted for additional testing and interviews, Labus said. Investigators linked the six confirmed hepatitis C cases to those dates.

At this point, it's believed 117 patients underwent procedures on those two days at the Shadow Lane clinic, Labus said. But health district officials believe that number could change because the agency never received a complete patient list from the clinic.

Investigators had asked management for a complete patient list covering March 2004 to Jan. 11 of this year. They asked for the addresses, birth dates, procedure dates and insurance company names of each of those patients, but the district only received addresses and billing dates.

"We were never given the dates of procedures, which adds another layer of questioning,'' Labus said. "We now have to go back and ask people, 'When did you have your procedure?' Some of the patients had multiple procedures on multiple dates."

Labus said once investigators have matched a positive test to a name on their list of 40,000 people who received notifications, that patient will receive a phone call and a questionnaire to help disease investigators determine the source of infection.

Meanwhile, the city of Las Vegas is set to start the process of potentially revoking the Shadow Lane clinic's business license.

The city suspended the license two days after the center's practices were disclosed. The center unsuccessfully appealed the suspension.

Next week's City Council agenda includes a complaint alleging that the business is "a public or private nuisance" because business "is being conducted in an unlawful, illegal and impermissible manner."

Also Thursday, the Bureau of Licensure and Certification announced that 35 of the state's 50 ambulatory surgery centers have been inspected. The remaining 15, all in Southern Nevada, will be completed by March 21.

Review-Journal writers Sean Whaley and Alan Choate contributed to this report. Contact reporter Annette Wells at awells@reviewjournal.com or (702) 383-0283. Contact reporter Brian Haynes at bhaynes@reviewjournal.com or (702) 383-0281.