ABOARD THE SILVER METEOR, MIAMI TO WASHINGTON -- The long journey of Kimberly Bergalis begins on the platform of the Okeechobee Amtrak station, 100 miles north of Miami amid the cane fields of her native Florida. Too weak to stand, she waits for the train slumped in the arms of her parents, her body shrunken, her face expressionless.

Four years ago Bergalis, then 19, contracted the AIDS virus during a visit to her dentist. On Tuesday she boarded the train for Washington to testify before Congress for what has become the obsession of her last dying months, that all health-care workers be tested regularly for HIV so that no one else should have to suffer as she has.

As the train pulls in, a crowd of photographers and reporters -- sensing the drama of the moment -- surges around her. Kimberly's father reaches down and sweeps her up into his arms. Her mother turns to her.

"Give them the V sign, honey, give them the victory sign," she says. When Kimberly cannot lift her arm, her mother raises it for her, spreading her daughter's index and middle fingers, holding the matchstick limb aloft long enough for the cameras to record the image.

Kimberly Bergalis's march on Washington has begun.

It is a march fueled by anger. The AIDS of Kimberly's dentist, Jeffrey Acer, had already been diagnosed when he treated her. She is angry at Acer, who died last year, because she thinks he should have told her about his condition. She is angry that public officials did not stop him from practicing.

"Whom do I blame? Do I blame myself? I sure don't," she wrote in an open letter to Florida health officials in June. "I never used IV drugs, never slept with anyone, never had a blood transfusion. I blame Dr. Acer and every one of you bastards. ... You are all as guilty as he was."

On the train, that anger is turned against Washington. Kimberly was supposed to testify before Congress two weeks ago. But because of scheduling problems, the hearing was postponed. The Bergalises thought that Democrats in Congress, under the influence of AIDS activists opposed to mandatory testing, were trying to silence their daughter.

"They don't want Kimberly in Washington," says her mother, Anna Bergalis, a nurse. She is alone with Kimberly. Her husband, George, is flying to Washington to join them. "They want her to go to her back yard and die quietly and not tell anyone how she got AIDS."

Around her a dozen cameras click ceaselessly, a constant media vigil that will record the Bergalises' every move during most of the 20-hour train journey. Pictures from Kimberly's college days are produced -- happy, smiling pictures of a beautiful young girl. "The daughter I had two years ago is not the daughter I have now," Anna Bergalis says.

A deadline of 10 more minutes for photos and questions is extended. Five more minutes. And then again. Kimberly is tired, but her mother reminds her, "This is what you wanted." She and her daughter know that their best argument is Kimberly's wasted image, repeated over and over.

"We are going to show them Kimberly," Anna Bergalis says of the upcoming hearing. "We're going to say this is the final product of your policy coming home."

The message and the passion of the Bergalises have thrust them into the center of the current debate over what to do about health-care workers who carry the AIDS virus. When Rep. William Dannemeyer (R-Calif.) introduced mandatory testing legislation last summer, he called it the Kimberly Bergalis Act. She was on Oprah Winfrey's show yesterday. Her father was scheduled to do "Today" and "Good Morning America" today. After the hearing today she will tour the White House.

"Everywhere I go, whether on network television, to the Centers for Disease Control, or to Congress, her name arises in ways that defy logic," said Larry Gostin, professor of health law at Harvard University, in a phone interview. "When I make a point on Ted Koppel saying the risks are very low and have to be placed in perspective, the comeback is what about Kimberly Bergalis. She is all that matters now. The whole health policy debate has been personalized to this one case."

But her message, while powerful, has made many uncomfortable. By turning on a fellow HIV patient -- her dentist -- and by pushing for measures that activists believe will harm the livelihood of others carrying the virus, she has broken the bond of solidarity in the AIDS community.

"The thing Kimberly and I have in common is that we are both furious," said New York AIDS activist David Barr. "But I don't hear her talk about the inability of HIV-infected people to get good health care. ... Her message is you {messed} up, I'm dying guys, goodbye. None of us ever said I'm dying guys goodbye. Kimberly's empowerment has never been about fighting her disease, and that's what makes her different."

No mainstream gay rights or AIDS activist group has been in touch with the Bergalises to express its sympathy. Her appearance today before Congress is widely predicted by activists to be a public relations disaster for their movement. She is the one AIDS patient the AIDS community will not embrace, a frightening and hostile new public symbol of an epidemic the AIDS community thought it had tamed.

"Ryan White was a young boy who could harm no one and yet was still being excluded and stigmatized," said Gostin, referring to the teenage hemophiliac who came to symbolize the disease in the late 1980s. "That touched America and brought AIDS into the mainstream. What Kimberly Bergalis symbolizes is exactly the opposite, that AIDS is to be feared and that it can be contracted easily in health-care settings. She has created fear."

"This is a country that does not deal well with abstractions," said Tom Stoddard, executive director of the Lambda Legal Defense Fund in New York. "Our presidential campaigns rarely talk about reforming the criminal justice system. Instead we have Willie Horton. This is the HIV version of Willie Horton."

The Fatal Link Bergalis, 23, began to develop the first of a series of puzzling symptoms in March 1989, while a business major at the University of Florida. First came persistent sore throats and ulcerated tonsils, then oral thrush -- a fungal infection of the mouth -- and weight loss.

At the time, HIV seemed the least likely diagnosis. Bergalis is a strict Catholic. She had had boyfriends but never, she says, sex. She had no history of drug use or blood transfusions. But after tests for hepatitis, diabetes and leukemia turned up nothing, her doctors ran out of possibilities. In January 1990, she was given an HIV test. She had AIDS.

From that point, it was only a matter of months before Bergalis's condition was linked to Acer, a 40-year-old dentist with a large practice in the resort community of Jensen Beach. Acer had removed two of Bergalis's molars in December 1987.DNA tests conducted by government health officials showed that Acer's and Bergalis's viruses were almost identical. Somehow, while pulling her teeth four years ago, Acer infected Bergalis.

There, according to many medical experts, the matter should have rested. Even after federal investigators identified four other patients of Acer's who had been infected with HIV at his office, the episode remained a freak accident in the opinion of many experts. No other case of doctor-to-patient transmission has been recorded. Indeed, no one is sure how Acer managed to transmit the virus.

"The Florida case is too bizarre to be helpful in making public policy," former surgeon general C. Everett Koop said in congressional testimony last week.

Consider, for example, if Acer cut himself while operating on Bergalis, letting his own infected blood drip into an open wound in her mouth. Based on extensive experience with needle-stick injuries, scientists estimate that the risk of actually passing on the virus in that situation is remote, between 0.3 and 3 in 1,000. Add that to the fact that doctors and dentists rarely cut themselves and that HIV-infected health-care workers are few in number, and the actual risk of accidentally contracting HIV has been calculated to be about the same as a person's risk of dying in a car accident on the way to the hospital.

A rigorous program of identifying and excluding HIV-infected health-care workers could well have spared Bergalis. But the cost of a mandatory testing program has been estimated to run as high as $500 million a year, which many feel is a questionable use of scarce health-care dollars considering how low the risk is.

"We can't make this a risk-free world, but people are afraid to say that in the case of Kimberly Bergalis because they are afraid to be called insensitive," said Michael Osterholm, epidemiologist for the Minnesota Department of Health. "Her case is a tragedy, but in the real world tragedies happen every day. All we can do is to make sure the fewest number of tragedies happen to the fewest number of people."

A Mission Kimberly Bergalis is lying down in her sleeping compartment, a cubbyhole scarcely big enough for another person to sit beside her. She speaks in a halting, barely audible voice. Questions get one-word answers. She tires easily. Asked if she is at peace, she says no, she is "frustrated." Asked what she wants her legacy to be, she answers "mandatory testing." She does not go on.

Later, her mother will explain that Kimberly sees the trip as her final act. Her daughter had a dream recently, she says, in which she saw her late grandmother beckoning to her.

"I scolded her," Kimberly told her mother. "I told her I wasn't ready."

"Most of her soul is gone," says Anna Bergalis. "Once the little part of it that is left fulfills her mission, she will go too."

During the past few months, her crusade has slowly gathered momentum. Bergalis has become what one AIDS expert calls the "accidental heroine of the AIDS epidemic."

"The Kimberly Bergalis story is to not let happen to others what happened to her," said Sanford Kuvin, a Palm Beach, Fla., infectious disease specialist who has served as the family's medical consultant for the past year. "For most Americans who do not use intravenous drugs or who are not homosexuals, their only risk is in the health-care setting. The numbers are small. But they are definite. ... Kimberly has pointed out that health-care workers are a risk group capable of transmitting the virus, that they are potentially lethal weapons, potentially loaded guns."

Letters have come by the bagful. Lee Blessing, author of "A Walk in the Woods," has been asked to write a play. William Roper, the director of the Centers for Disease Control, has come to pay his respects. Florida Gov. Lawton Chiles came by as well, saying as he left that he felt he had been "in the presence of a saint." Her attorney, Palm Beach liability lawyer Robert Montgomery, said that the "aura" surrounding Kimberly "is almost like divine providence."

"This whole tragedy was preconceived to happen," said her father, who like most Bergalis intimates sees Kimberly as an instrument of divine will. "There was something dangerously wrong in this country for many years and something had to be done. To do that you needed a special cast of characters and someone chose Kimberly to play the lead role. We gave up a long time ago asking why."

At 7 yesterday morning, Kimberly arrives in Washington. Her mother descends first, greeting the assembled mob of television crews and cameras. Kimberly comes afterward, supported by a railway attendant, her eyes vacant and glassy.

They climb into a waiting luggage cart. "She's had a restful trip," her mother says. "She's ready for Washington, right Kim?"

She puts her arm around herdaughter. Kimberly slumps against her mother's shoulder. She is silent.