-- California health officials are investigating a bacterial outbreak after at least 93 people were sickened.
The restaurant was closed on Sunday and health department officials are asking anyone who has eaten at the restaurant and developed symptoms, including fever or sudden onset of diarrhea, to see a doctor immediately. No specific source of contamination has been identified, according to the health department.
Health department officials said many of those who had been in the intensive care unit had been discharged, but they were warning anyone with symptoms to stop working to curb the infection.
Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, said officials would be especially concerned about improper food handling or if the produce was contaminated with polluted water.
"If produce comes in from the developing world, on occasion fresh produce has been irrigated or freshened with polluted water," he explained.
"This is serious business. It is a highly infectious agent," Schaffner said. "It usually takes very little [bacteria] to make people sick. ... That may account in part for the large number of [patients in] the outbreak."
Every year, 500,000 Americans are sickened with shigella, according to the CDC.
Mariscos San Juan Restaurant did not immediately respond to ABC News' calls seeking comment.