Officials with Inova Loudoun Hospital have contacted 144 patients who underwent endoscopic exams last month and urged them to get tested for HIV and hepatitis, citing the hospital's failure to properly disinfect its equipment.

The problem was discovered July 14 during the review of a new piece of equipment used to clean scopes in the hospital's Endoscopy Suite, officials said. Although the scopes were manually scrubbed, rinsed with alcohol and dried, the hospital said that staff found that the cleaning equipment was improperly programmed to immerse the scopes in disinfectant for one minute instead of the manufacturer's recommended five minutes.

An endoscope, a long tube with a video camera attached to the end, is used to examine a patient's internal organs.

Although hospital officials characterized the risk to patients who were treated during a 10-day period beginning July 5 as "remote," they have offered free blood tests to determine whether anyone was harmed.

"Experts were brought in to review the scopes, and it was determined that the cleaning was still sufficient to have killed any bacteria and likely to have killed any viruses," said Inova Health System spokeswoman Beth Visioli. "But in the interest of safety, we've contacted the patients individually to get a blood test."

The blood tests, which will screen for HIV and hepatitis B and C, are being provided at the hospital and at patients' homes. Patients will be asked to take a follow-up blood test in six months.

Hospital officials said they began contacting patients Aug. 10, about 30 days after the problem was discovered. Officials said they used that time to determine the risk and identify the affected patients. They said they have increased monitoring of disinfectant equipment settings to prevent a recurrence. The problem was initially reported in the Leesburg Today newspaper.

In recent years, other hospitals have reported similar mishaps. State health officials in California reported that almost 6,000 patients were potentially exposed to blood-borne pathogens from improperly disinfected colonoscopes, gastroscopes, endoscopes and cystoscopes during a two-year period.

Douglas Nelson, a physician spokesman for the American Society for Gastrointestinal Endoscopy, said that about 34 million upper and lower endoscopic procedures are done annually in the United States. Nelson's research found that in the past 10 years, there have been 35 cases of infection worldwide as a result of poorly cleaned instruments, mostly in Europe. Nelson said there has never been a case of HIV transmission from endoscopy.

"I don't want to defend Inova, because they goofed," Nelson said. "They made an error. But despite the error, the risk of infection is remote. People should not defer getting a potentially life-saving endoscopic procedure because of an incident like this."

But one Fairfax man who asked not to be identified said yesterday that Inova Loudoun's error has caused him to rethink his first colonoscopy. "I have some serious questions about [the procedure] now," said the man, who is 60. "Cancer doesn't run in my family, but the doctors keep pushing this on me. In light of what's come up, I keep thinking maybe I don't need this. If I don't have cancer now and I'm introduced to hepatitis or HIV? That's rather disconcerting."

Staff writer January Payne contributed to this report.