Two more people have come forward to report they were sickened after eating the Thanksgiving dinner prepared by the Golden Hills Community Church in Antioch, according to Contra Costa Health Services.
The two new cases bring the total number of people who fell ill after the meal to 21, three of whom died.
All of the people developed symptoms within 24 hours of eating the food, which was provided by the church and served at Antioch's American Legion Hall.
The three people who died were identified by the county coroner's office Wednesday as Christopher Cappetti, 43, Chooi Keng Cheah, 59, and Jane Evans, 69.
All had similar "intestinal abnormalities," according to the coroner's office.
The cause of the deaths and illnesses, which surfaced after 835 people ate the meal, is still under investigation, but county health officials said it's likely a food-borne illness.
Biological samples have been sent to the Centers for Disease Control and Prevention for additional testing, a process which county health officials said could take months to complete.
People should practice food safety at all times, said county health spokeswoman Victoria Balladares.
People should take care to wash their hands thoroughly, keep raw and cooked food separated and properly store ingredients and prepared food, Balladares said.
More food safety tips are posted at the Health Services website.