By her own admission, Kristen Diane Parker cruised for empty operating rooms at the Denver hospital where she worked.
The surgical technician would slip into the rooms and steal syringes of fentanyl, a powerful painkiller, replacing them with syringes she'd filled with saline, she later confessed to investigators.
Parker, who has hepatitis C, had allegedly used those decoy syringes -- the source of transmission, authorities believe, for at least 23 Coloradans now infected with the liver-damaging disease.
Parker's arrest this summer has reverberated through the state, prompting the testing of nearly 6,000 patients at a hospital and surgery center and focusing scrutiny on healthcare safety.
"The system is broken," said a 41-year-old Denver woman who contracted hepatitis C after a minor surgery at Rose Medical Center. She spoke on the condition of anonymity. "The system failed not only me, but Kristen. She has an addiction. It was too easy for her to get that drug." As Colorado wraps up its testing, with more than half of the exposed patients believed to be infection-free and results pending for about 2,100 people, two other states where Parker worked are probing the extent of damage she may have wrought.
Transmitted by blood, hepatitis C is treatable but incurable, and can cause lifelong health problems and death.
In Mount Kisco, N.Y., about 2,700 patients at Northern Westchester Hospital are being tested; the hospital has reported five cases, three of which it says are not linked to Parker. She worked there for about five months in 2007 and 2008. Further testing will determine whether the remaining two infections are linked to Parker, hospital spokesman Mark Vincent said.
In Nassau Bay, Texas, authorities are trying to determine when Parker contracted hepatitis before they order tests on patients at Christus St. John Hospital, where Parker worked from 2005 to 2006.
Though cases in which healthcare workers transmit their own diseases to patients are relatively rare, the effects are far-reaching. The Centers for Disease Control and Prevention have documented four such cases in which 70 patients were infected with hepatitis C between 1992 and 2003, the most recent years for which data were available.
Parker, 26, told police she believes she contracted hepatitis last year, when she became addicted to heroin and shared needles. Authorities say she learned of her illness in October, when she began work at Rose and a pre-employment test detected the disease.
However, Parker maintains that she didn't realize she had hepatitis, saying hospital staff told her only that her test results warranted follow-up, her attorney Gregory Graf said.
She didn't pursue it because she didn't have health insurance or a doctor, he said. "Obviously, she's upset she may have put other people at risk, something she never intended."
Parker aroused co-workers' suspicions in April when she was caught coming out of an operating room to which she wasn't assigned. A drug screen tested positive for fentanyl, and she was fired.
She moved on to the Audubon Ambulatory Surgery Center in Colorado Springs, where she had applied and been accepted shortly before her firing.
As police began investigating the hospital's report of a potential fentanyl theft, health officials were trying to track the source of two recent hepatitis C infections. By the time they identified Parker as the suspected source, she'd been at her new job for more than a month -- a fact that has sparked criticism of health officials for not linking the cases more rapidly. Colorado's chief medical officer, Dr. Ned Calonge, defends the department, citing the difficulty of tracing the cases to an employee seemingly unassociated with some of the patients.
Parker, who is in custody, is charged federally with tampering with a consumer product and obtaining a controlled substance by deceit. If convicted of all 42 counts against her, she faces life in prison.
Her alleged victims are devastated, said Jim Leventhal, a Denver attorney representing seven patients.
"How do you go to a hospital and then walk out of the hospital with hepatitis C from a dirty needle?" said Leventhal, who faults Rose for not having "a system in place to make it impossible for someone like Kristen Parker to accomplish what she accomplished."
Rose spokeswoman Cara Harshberger declined to discuss Parker's alleged methods of obtaining drugs, but said the hospital has tightened access to drugs. It is also reviewing its hiring practices, although she noted that a criminal background check raised no red flags.
At Audubon, spokeswoman Amy Triandiflou said the surgery center was awaiting investigation results before making any changes. Health officials have connected one of the 18 cases to Audubon, but the center disputes a link.
Parker's case has prompted a number of proposed and planned changes. State officials are considering licensing medical assistants, a move that potentially could have barred Parker from obtaining a new job after Rose reported its suspicions.
Health officials will begin cross-referencing drug diversion reports they receive against infection reports, Calonge said. In this case, different divisions at the department had received reports about thefts and infections, but did not link the two. Calonge said they also will probe health facilities for more detail about people suspected of drug thefts.
Other measures, such as making syringes that can't be reused, are needed to prevent future outbreaks, said Evelyn McKnight, president of Hepatitis Outbreaks National Organization for Reform. The group also advocates greater oversight of outpatient facilities.
"Nineteen cases are 19 too many," said McKnight, who contracted hepatitis at her doctor's clinic in Nebraska.
That sentiment was echoed by the Denver patient, who said every report of a new infection sickens her.
"Every day, the number grows, and there's more of us out there," she said. "If we don't learn from this tragedy, if we don't change the system, then this is going to continue."
Correll writes for The Times.