Some patients might have been told they were HIV-negative when in fact they were positive — and vice versa — and the hospital failed to notify the patients of the problem, said Nelson J. Sabatini, secretary of the state Department of Health and Mental Hygiene.
"I think this is unconscionable behavior: people not being told about the status of their tests," Sabatini said.
Hepatitis C, for which some patients were tested, can cause a chronic liver infection that could eventually lead to liver failure and cancer.
Acting on a complaint apparently filed by a former hospital employee, state health officials discovered in January that the hospital's laboratory personnel overrode controls in the testing equipment that showed the results might be in error, then mailed them to patients anyway.
Maryland General President Timothy D. Miller said hospital executives knew nothing about the problem until they were notified by the state in late January. "We want to make this right," Miller said Wednesday.
The testing problem affected about 460 patients, most of whom were tested for HIV, according to Miller. He added that efforts were under way to notify the patients and urge them to return to the hospital for a free re-test.
A hot line was being set up for people to call beginning Thursday.
State inspectors found that over a 14-month period ending in August, 10 to 15 percent of the HIV tests performed might have been inaccurate.