In violation of the published recommendations of federal health officials and major medical organizations, one in four U.S. hospitals does not require the consent of patients before testing for infection with the AIDS virus and does not require patients to be notified if their tests are positive.

The numbers, which shocked AIDS experts interviewed on the findings, are contained in a survey conducted last year and published in today's issue of the Journal of the American Medical Association.

"This is very distressing," said June Osborne, chairman of the National Commission on AIDS. "Some hospitals are clearly walking away from the best judgments of all of the people that have looked at this issue."

"There is an awful lot more testing going on in hospitals than people are aware of," said University of California at Los Angeles researcher Charles E. Lewis, a co-author of the study. "If there is any lesson to this, it is that if you don't want to be tested, say so. And if you want to know the result, say so."

Since the mid-1980s, when a blood test for infection with the human immunodeficiency virus (HIV) first came into widespread use, the Centers for Disease Control and national medical organizations such as the American Hospital Association and American Medical Association have issued recommendations for how and when HIV tests should be used.

In general, all these organizations agree that medical providers should take general precautions to prevent transmission of diseases via blood or body fluids, rather than testing all patients, because of the possibility that a patient who tested positive would receive substandard health care.

In cases where testing is necessary, the recommendations are unanimous that it should be done only with the patient's consent and that the results of all tests should be shared with the patient.

According to the UCLA survey of hospitals' policies on HIV testing, 22 percent of the 561 U.S. hospitals sampled did not require that patients be informed before being tested, and 25 percent did not require that patients be told if they tested positive. Seventeen percent had no written policy on HIV testing, and one-third of all hospitals surveyed had no provision requiring that patients receive counseling before undergoing an HIV test.

Only 15 percent of hospitals reported that they test some or all patients for infection at the time of admission. The study did not specify the circumstances under which other surveyed hospitals performed such testing.

In some cases, Lewis said, the lack of an HIV testing policy reflected the lack of experience of some rural hospitals with AIDS patients. But he said that in more cases, hospitals test patients without telling them because staff members want to know whether patients are infected without having to go through the process of informing patients and obtaining their consent, with the possibility that they might refuse.

"On the one hand, institutions want to protect a patient's privacy and avoid litigation," he said. "On the other hand, those who work in institutions want to know which patients are infected and whose blood is infected. . . . Universal precautions ought to be enough to protect people, but this has become what most of AIDS has become, a non-rational set of issues driven by fear and gut-level responses."

"We're clearly disturbed by this data," said Carissa Cunningham, a spokesman for the Gay Men's Health Crisis in New York. "The point is not patient's rights but disease prevention. If people aren't giving consent then they're not getting counseling. People aren't getting information about how to prevent transmission to others right at the point where they are most susceptible to that information."