|Mexico and Florida are the biggest suppliers of tomatoes at the time of the outbreak|
According to the U.S. Centers for Disease Control and Prevention, 383 people in 30 states have been infected with Salmonella Saintpaul, a rare strain of the bacteria.
The most recent report of onset is June 5 and at least 48 people have been hospitalized, CDC said.
The rise in cases is due to increased monitoring by states and the completion of a significant amount of lab work, CDC said.
"We do not think the outbreak is over," Robert Tauxe, deputy director of CDC's division of foodborne, bacterial and mycotic diseases.
Food safety experts have linked the outbreak to tainted raw round, plum and Roma tomatoes and have not yet identified the source of contamination.
David Acheson, director of food safety for the U.S. Food and Drug Administration, said investigators continue to study a cluster of cases involving nine people in a single geographic location who ate at two outlets in the same restaurant chain.
The Chicago Department of Public Health told the Chicago Tribune on Wednesday that it reported a cluster of nine salmonella cases at Adobo Grill restaurants in two parts of the city
The restaurant operators told the Tribune in a statement there is no way to know whether the produce it buys harbors Salmonella bacteria.
When asked about the Chicago Health Department's comments, FDA's Acheson cited confidentiality requirements and declined to give the name or the location of the restaurant chain.
Health experts have repeatedly said the outbreak has not been linked to a single restaurant, grocery or retail chain.
Most produce in the
"We may not ultimately know the farm where these came from," Acheson said.
Meanwhile, investigators are focusing on
"There is certainly a high likelihood that they came from