A hepatitis C exposure registry developed two weeks ago by the Southern Nevada Health District now has 3,200 people on the list.
It was developed to help identify patients who had procedures at two gastroenterological clinics principally owned by Dr. Dipak Desai.
"We sent out 53,000 letters and already have 3,200 responses from patients at both the Shadow Lane and Burnham Avenue Clinics," said Brian Labus, senior epidemiologist for the health district. "We consider that a very good response."
Forty thousand letters were sent to former patients of the Endoscopy Center of Southern Nevada on Shadow Lane, and 13,000 additional letters were sent to patients of the Desert Shadow Endoscopy Center on Burnham Avenue.
The registry enrollment forms are four pages long and ask former patients to reveal procedure dates, testing results and possible risk factors for disease. They are available online at www.southernnevadahealthdistrict.org.
"We know that we don't have contact information for everybody or that the contact information we have may be wrong," Labus said. "We're hoping that publicity about the registry will also get more people to contact us."
Seven cases of hepatitis C have been linked to the Endoscopy Center of Southern Nevada on Shadow Lane as a result of the reuse of syringes and single dose vials of anesthesia. Initially, health officials sent letters to 40,000 former patients urging them to be tested for blood borne diseases.
"We don't know how many of them actually got tested," said Labus, adding that a number of letters were returned because former patients had moved. "We need all the information we can get to help with the investigation and to understand the effects of exposure or disease."
One case of hepatitis transmission has been linked to the Burnham Avenue facility.
Officials now think as many as 50,000 patients visited the Shadow Lane facility between March 2004 and Jan. 11, the time frame that officials believe unsafe injection practices took place.
Along with the seven hepatitis C cases linked to that clinic, an additional 77 people who have chronic hepatitis C might have contracted the disease there. About 400 people who underwent procedures at the clinic have tested positive for hepatitis C.
Calling patients based on positive lab results has not proved successful, Labus said.
Often, he said, individuals had common names and clinic records did not help public health officials sort out who to call. Labus said telephone numbers often had changed.
At present, Labus said the registry has no cutoff date.
"We have to remember that some people can't even be tested until July," Labus said.
Even if someone has contracted hepatitis, it can take six months before signs of the disease will show up in a test.