Thousands of patients who might have been exposed to blood-borne diseases during medical procedures at a Las Vegas clinic have yet to be warned they're at risk, health officials said Thursday.
Some 10,000 patients of the Endoscopy Center of Southern Nevada have not been notified because clinic staff failed to provide their names to investigators of a hepatitis outbreak.
"The clinic told us that they had given us a complete list. Obviously, that wasn't true,'' said Brian Labus, senior epidemiologist for the Southern Nevada Health District.
"Why? I can't answer that,'' he said.
The latest estimate came after information from insurance claims was analyzed and health officials found some names were not on the list of 40,000 patients provided to investigators by the clinic at 700 Shadow Lane.
The original list of 40,000 people and the additional patients underwent procedures at the facility between March 2004 and Jan. 11. Health officials believe unsafe injection practices took place during that time frame, putting patients at risk of hepatitis strains B or C or HIV, the virus that causes AIDS.
"That brings us to about 50,000 people who were possibly exposed,'' Labus said. "We're not surprised. Looking at the volume of patients that clinic had, it should really be closer to 50,000 patients. But without clean data from the endoscopy center we had no way of identifying how many or who these patients were.''
Because the data received by the health district do not contain patient addresses or phone numbers, the agency now must try to locate them and urge testing, Labus said. He said officials are unsure how that will be done.
"We would redo what we did with the other patients if we had (the information) available to us,'' he said.
Jennifer Sizemore, a health district spokeswoman, said some insurance companies notified their clients and told them to get tested even though they never received a notice from the health district.
Thursday's development adds to the district's struggle to determine how seven people contracted hepatitis C at the Shadow Lane facility and how many of the clinic's patients actually were exposed to the disease.
The health district, with help from volunteers from the federal Medical Reserve Corps, is calling patients whose test results have come back positive.
Labus told the health district board Thursday that some patients are unwilling to speak with district staff about their positive results, which is slowing the investigation. Additionally, some patients don't remember their procedure dates. In some cases, the health district can't definitively match patients who are testing positive to the endoscopy center's list because they have common names that are on the list multiple times.
The endoscopy center's list did not include birth dates.
"We're not dealing with things on a small level," Labus said. "Our major challenge is that there are so many people involved and we have received very bad information.''
In the past month, the agency has received upwards of 150 positive results a day from laboratories such as LabCorp and Quest Diagnostics, although that number recently has declined. When called, individuals are being asked six questions, including whether they had any blood transfusions or organ transplants prior to 1992 and whether they have been on long-term hemodialysis.
Individuals also are asked whether they have had sexual contact with a hepatitis C carrier.
Based on their answers, patients are put into one of four categories: clinic associated, possible clinic associated, clearly unrelated or indeterminate.
"We are finding quite a few people with one or more of those risk factors,'' Labus told the Legislative Committee on Health Care earlier this week.
Some patients of the Shadow Lane facility who might have been exposed in January would be getting sick about this time. The incubation period for these patients would end in July. For that reason, Labus said, other test results probably will come in during the next few months.
The health district also is receiving reports of acute hepatitis C cases that were never initially reported to the agency.
Under state law, physicians and other health care providers are required to report certain diseases and conditions to the health district. Hepatitis C is one of these diseases, but the health district has linked one acute case to the Shadow Lane facility that never was reported. That person became ill about nine weeks after his procedure in June 2005, health officials said.
Another unreported acute case has been linked to Desert Shadow Endoscopy Center, 4275 Burnham Ave. That patient tested positive several weeks after a procedure on June 14, 2006.
Both of the facilities are part of a group of centers owned by Dr. Dipak Desai, a Las Vegas gastroenterologist who has voluntarily agreed to stop practicing medicine as the state's Board of Medical Examiners, and health district and law enforcement officials investigate the outbreak.
In all, the health district has linked seven acute cases to the Shadow Lane facility. Five of those cases were linked to patients who underwent procedures on Sept. 21. Another was traced to a July 25 procedure.
Health officials believe hepatitis C was transmitted when nurse anesthetists reused syringes on infected patients, contaminating vials of medication that were shared by multiple patients.
Hepatitis C is a blood-borne disease that infects the liver. The infection can cause liver inflammation that is often asymptomatic.
It is spread by blood-to-blood contact with an infected person's blood.
Genetic tests for four patients on Sept. 21 show the disease came from the same source. Health officials are awaiting word about the fifth case on that day.
Roughly 117 patients were seen at the facility on those days. Those patients are being interviewed.
Labus said the health district is still awaiting access to medical records at the Burnham facility to determine whether patients treated there need to be notified. Patient records are in the possession of the Metropolitan Police Department.
The department has finalized a contract with a medical records company to organize the files.
"Law enforcement is not dragging their feet or anything. It is just a challenge to get through 2,000 boxes of files,'' Labus said.
Contact reporter Annette Wells at awells @reviewjournal.com or 702-383-0283.