But the good news was that no new cases of hepatitis surfaced Sunday, which is the first time the numbers have stalled since Nov. 3, when the health department began offering daily tallies of those who became sick after dining at Chi-Chi's Mexican restaurant at the Beaver Valley Mall.
In addition, health investigators say they have no evidence suggesting any other local restaurants are involved with spreading the disease. And they have not uncovered a secondary round of infection, which would include people who contracted the disease from those who had eaten at Chi-Chi's.
Health officials said the fact that the number of confirmed cases has leveled off does not necessarily mean the worst hepatitis A outbreak in U.S. history has reached its apex.
"We may see more. We may not see more," said health department spokesman Jay Pagni. "Tomorrow will tell."
Meanwhile on Monday, funerals were held for Dineen Wieczorek, 51, of Hopewell Township and John Spratt, 46, of Aliquippa - both victims of the hepatitis outbreak. The third fatality, Jeff Cook, 38, of Aliquippa, was buried last week.
"When you have a loss of life, there's very little that we can say to ease the pain of someone who lost a loved one," state Secretary of Health Dr. Calvin B. Johnson said, adding that the state was working "very hard" to stop the disease spread and pinpoint its cause.
One hepatitis patient remained in critical condition in UPMC Presbyterian on Monday and a second remained in fair condition. Officials at Children's Hospital and Allegheny General Hospital, both in Pittsburgh, said they had no new hepatitis patients.
Of the 510 confirmed cases, 346 are Beaver County residents, six more than previously reported. Pagni said the six people were previously listed as living in other areas.
The state continues to offer free inoculations - to people who may have been exposed to the disease - at its Vanport Township office. To date, 9,757 people have been screened for the disease and 8,992 have been inoculated.
Johnson, who briefed reporters on Monday in Pittsburgh - 35 miles from the heart of the outbreak - said state health officials are now working with the Centers for Disease Control and Prevention in Atlanta and investigators from the U.S. Food and Drug Administration to determine the source.
He also said investigators have not ruled out a single food handler as the source.
In addition, the investigators are continuing to interview people who have the disease and those who ate at Chi-Chi's, but were not infected.
Johnston, who fielded questions for about 20 minutes before he was hurried away, could not predict when and whether the source might be found.
"I wish I could tell the future for you," he said. "I don't think it is without a possibility of finding the source, but it is a challenging task."
The FDA has issued an advisory that recent hepatitis A outbreaks in Georgia, Tennessee and North Carolina have been linked to raw green onions and warned people to cook the onions thoroughly before eating them. Chi-Chi's and other national restaurant chains have removed green onions from their restaurants.
Pennsylvania investigators are conducting tests on blood samples from people who have tested positive for hepatitis here in an attempt to see whether they can find a genetic match to samples taken from people sickened in the southern states.
However, no links to the Southern outbreaks have been established.
Richard Quartarone, spokesman for the Georgia Division of Public Health, said about 250 people were sickened in September and October in the Georgia outbreak, which was linked to green onions served in at least a dozen restaurants in different sections of the state.
State health investigators traced the onions to a certain lot that came from California, he said.
"We really feel very strongly that it's green onions," Quartarone said.
"One of the things that's been challenging is we really didn't find a strong connection to the outbreak in Tennessee, but we did see some evidence that it could have been connected to North Carolina's outbreak."
In Asheville, N.C., however, where 16 people were infected, the source was linked to an oriental cabbage, according to Dr. Susan Mims, medical director at the Buncombe County Health Department.
She said studies suggested some link to green onions, but the Napa-variety cabbage was the main suspect.
Like Beaver County, the North Carolina outbreak was contained to one restaurant - Doc Chey's. More than 3,300 people were inoculated in September and October. Mims said the restaurant, which is privately owned by a family, closed for a short period for an intensive cleaning, but has since reopened and seems to operating with no difficulty.
Mims said the outbreak will not be declared over until Dec. 1, after the hepatitis incubation period from the last confirmed case has ended.
"We haven't seen any new cases, but we're holding our breath," she said.