Three people died and five others were sickened over the weekend after a Thanksgiving dinner at the American Legion Hall in Antioch, according to Contra Costa County health officials.
Eight people were treated at a hospital between Friday and Saturday, county officials said. It is not yet known if it is an outbreak of a food-borne illness. All the victims reportedly live together, officials said.
Sutter Delta Medical Center in Antioch confirmed they received eight patients with probable food-borne symptoms. Three patients died, four patients were treated and released and one patient remains hospitalized, officials said.
During a news conference Monday evening, county health officials said while the investigation is still in the early stages, they are not treating the incident as a food-related outbreak because they have no evidence anyone outside the family got sick.
A total of 835 people ate the meal.
Officials also said they have no reason to be concerned about the American Legion facility.
Veteran Esidor Alviar was among hundreds of people at the dinner Thursday and said he too experienced some symptoms later in the evening.
"It was a nice dinner, turkey, stuffing, cranberries and coffee," Alviar said. "About one o'clock in the morning, I had cramps and a terrible stomachache. I was sick. I thought about going to the hospital, but I hate hospitals."
"We are extremely, extremely upset that anyone lost their lives," said Autrey James, commander at American Legion Post 161. "We were not ourselves involved in the cooking of the meal."
The dinner, a standard Thanksgiving meal of turkey and stuffing, was hosted by Golden Hills Community Church in Brentwood, officials said. County officials did not know who was responsible for preparing the food, but they did say some of the food was brought in from other facilities and some was prepared at the hall. They said a permit was not required. On the church's website, a statement said that "the source of illness is not known and could have come from any of a number of sources. Our dinner in Antioch is only one of a number of possibilities that county health is investigating." The church added that its members are "praying fervently for the families who lost loved ones and for others who are sick."
Some causes have been ruled out, such as Norovirus, a bacteria that takes longer to incubate, health officials said.
Contra Costa County Public Health Department is investigating the cause of the deaths and illnesses and does not believe there is any risk to the general public.
NBC Bay Area's Terry McSweeney and Bay City News contributed to this report.