Dentist With AIDS Was Likely Source of Infection in 3 Patients, Officials Say : Health: The case fans debate over whether medical personnel with the HIV virus should be allowed to do surgery and other invasive procedures.

WASHINGTON —  A federal investigation has found that three patients of a Florida dentist with AIDS were all infected with strains of the virus extremely similar to that of the dentist--but unlike other strains found in the community--indicating that they were infected in his office, The Times has learned.

The case, expected to be reported next week by the federal Centers for Disease Control, is significant because it has ignited a national controversy over whether health care professionals infected with the human immunodeficiency virus should be restricted in performing surgery and other invasive procedures.

The CDC is currently debating new guidelines to deal with the question of whether infected doctors pose a risk to their patients.

But the latest findings raise the possibility that contaminated equipment played a role in transmission. The findings probably will lead to a new look at the infection control procedures of all doctors, dentists and other health professionals who practice invasive procedures in non-hospital settings.

Molecular sequencing studies of the viral strains of all three patients showed them to be very close to that of Dr. David Acer, a Jensen Beach, Fla., dentist who since has died of AIDS, but different from those collected elsewhere in the community, sources said. Those two facts indicate that it is unlikely the three patients were infected elsewhere, the sources said.

What remains unclear, however, is exactly how transmission of the virus occurred.

Initially, only one infected patient had been identified--Kimberly Bergalis, now 22, who has since developed AIDS. At that time, health officials theorized that Acer somehow had injured himself when operating on Bergalis and that his blood had mixed with hers.

Since the discovery of two other infected patients, however, speculation has also focused on the possibility of contaminated equipment as a source of transmission.

None of the three patients had independent risk factors for HIV infection, again pointing to the dentist’s office as the place where transmission probably occurred, sources said.

“One of the patients was an older woman in a long-term marital relationship who had never had a blood transfusion and whose husband tested negative,” one source said.

A fourth infected patient of the dentist “who turned up in the course of the investigation” had a strain of virus unlike that of the dentist and of the other three, sources said. Moreover, “he had an independent risk unrelated to dental procedures,” sources said, meaning it is likely that he was infected elsewhere.

Dr. Harold Jaffe, the CDC epidemiologist in charge of the investigation, refused to comment Thursday.

But, in an interview last November, Jaffe acknowledged that there had always been “questions about how the transmission actually occurred.” He said then that the CDC was examining several possibilities, among them whether Acer had contaminated his equipment after working on his own teeth, or possibly after operating on one of his own sexual partners.

“If you buy the premise that the patient was infected in the dental office, the number of possibilities are small,” he said. “Either the dentist injured himself without knowing it, or contaminated instruments--that’s about it.”

He predicted, however, that “we’ll end up saying that more than one person was infected in the dentist’s office, but we don’t know how. That’s quite unsatisfying, but it may be the way it turns out.”

At the time of the interview last November, the CDC had identified three patients of Acer as having the AIDS virus but had not yet identified the strains. When asked at that time if all three patients had been seen on the same day, Jaffe refused to answer. He then volunteered the fact that Acer had destroyed his daily patient logs.

The case is likely to raise calls for new attention to infection control procedures outside of hospitals.

“If it turns out that contaminated equipment was the source, then we shouldn’t be focusing on infected dentists--we should be concerned about all dentists and whether they are following proper infection control procedures,” said Tom Stoddard, executive director of the Lambda Legal Defense and Education Fund.

“The CDC is myopically looking at only one issue--HIV-infected health care workers--while ignoring the much larger and more important question of how dentists and doctors conduct routine procedures,” said Stoddard. He served as a CDC consultant during the first round of deliberations over developing new guidelines for infected health care workers who perform invasive procedures, such as surgeons and dentists.

Philip Weintraub, a spokesman for the American Dental Assn., said in a recent interview that the ADA has “very specific” guidelines for infection control procedures. “But we’re not a regulatory agency,” he said.

The guidelines state that dentists should change gloves after each patient and should sterilize, disinfect or dispose of instruments and supplies after each patient.

“Do all the doctors do it? We’d like to think they’re doing it,” Weintraub said. “But we know that all of them are not, and that’s tragic. They are asking for a catastrophe.”