GLENVIEW, Ill. (AP) _ Officials began dismantling a Kraft Inc. plant in Virginia on Monday as they sought the source of bacteria in ice cream bars that may have sickened people in eight states, while Florida officials reported the first case of the disease linked to the bacteria.

More than 170 people reported flu-like symptoms after eating Polar B'ar ice cream bars, but until the disclosure in Florida, none of those afflicted had tested positive for listeriosis.

Listeriosis is the flu-like illness caused by the Listeria monocytogenes bacteria that was found in bars produced at the Richmond, Va., plant.

The elderly Jacksonville woman, who said she ate ice cream bars from the contaminated batch, contracted listeriosis, said Walt Lamies, environmental health supervisor for the northeast Florida city.

The illness can be life-threatening, but the Florida woman's physician, Dr. Jay Edelberg, said he had prescribed antibiotics and expected her to feel better within 72 hours. He said he was not sure the confection sickened the woman, Frances Weldon, who was said to be in her 70s.

Meanwhile, in this suburb of Chicago, company officials said they hope to reopen the Richmond plant in 30 to 60 days.

''We're going to keep at it until we find the source,'' Kraft spokesman Paul Johnson said from company headquarters.

Johnson said there had not been any conclusive evidence that the people reporting flu-like symptoms after eating Polar B'ars actually had ingested the bacteria.

People reported symptoms in Kentucky, Pennsylvania, Alabama, South Carolina, North Carolina, Virinia and Georgia. In Florida, Lamie said two women in addition to the ill woman had reported symptoms, but it had not been confirmed whether they had listeriosis.

The plant was closed Thursday after the Listeria bacteria were found in Checkerberry flavor Polar B'ars, which had left the factory nearly a month earlier. That day, Kraft - working with the federal Food and Drug Administration - recalled all Polar B'ars that had been made at the plant as a precaution.

Polar B'ars made at Kraft plants in Framingham, Mass., and Huntington, Ind., are not affected by the recall.

Thomas Hooker, regional FDA director, said from his Baltimore office that a federal inspector has been at the Richmond plant throughout the day, mainly gathering samples of ice cream bars.

Kraft officials said the recalled bars, coded 51-6426, were distributed east of the Mississippi River, to some 15,000 to 18,000 stores in several states.

Company officials believe the recall has been successful and consumers are encouraged to return any Polar B'ars they fear might be contaminated for a refund, Johnson said.

There is generally a five- to 12-day incubation period, so if people report feeling ill the day after eating one of the suspected ice cream bars, ''we can conclusively say they are not tied together,'' he said.

Listeriosis can be dangerous to pregnant women and their fetuses, as well as to small children, frail elderly people or others with weakened immune systems. In healthy adults, it may cause short-lived, flu-like symptoms, depending on the amount of bacteria present.

The bacteria do not multiply when frozen, but the dormant bacteria are activated when eaten, Greene said.

The five-ounce bars, sold in packages of six, were distributed primarily in the eastern United States, Johnson said.

People with significant symptoms of nausea, vomiting, headaches or fever who have eaten the Kraft product from the suspect lot should see their doctors, said Dr. Lorne Garretson, director of the Central Virginia Poison Center at Virginia Commonwealth University in Richmond.

At least 68 people in Kentucky, 29 in Pennsylvania, 16 in Alabama and 53 in South Carolina had reported flu-like symptoms after eating ice cream bars from the Virginia factory, poison control officials said Sunday. Earlier, four people in North Carolina reported flu-like symptoms after eating Polar B'ars, as did four people in one family in Augusta, Ga.

Lorne Garrettson of the Medical College of Virginia Poison Control Center said the center had received about 100 telephone calls about the bars. He said some callers had symptoms that could be related to the bacteria, but he was not aware of any confirmed cases.

On Monday, Nancy Matyunas, director of the Kentucky Regional Poison Center, said 73 people had called to report symptoms, but said several of those were from neighboring states.