Officials now say they've counted 383 salmonella cases, up from the 228 reported on Monday. The outbreak now extends to 30 states and the District of Columbia.

"We do not think this outbreak is over," Robert Tauxe, MD, deputy director of the Division of Foodborne, Bacterial and Mycotic Diseases at the CDC, told reporters Wednesday. "CDC is continuing to receive reports of ill people."

Tauxe said the latest person to be sickened by contaminated tomatoes fell ill on June 5 with the saintpaul salmonella strain.

Tauxe said his agency does not believe the rate of infections has accelerated. Officials said case numbers jumped because states have stepped up their salmonella surveillance and because previously obtained lab samples have begun to come back.

The outbreak has been blamed on contaminated raw Roma, plum, and red round tomato varieties grown in certain states. Officials said seven new states have seen infections. At least 48 people have been hospitalized.

FDA officials said they had not yet found the source of the outbreak. Investigators are focusing on farms in South Florida and in Mexico as possible sources but have not given more specific information.

"I'm not able to tell you definitively yet where these contaminated tomatoes come from," said David Acheson, MD, the FDA's associate commissioner for foods.

Salmonella infection can cause diarrhea, vomiting, and fever, but it is usually not fatal. It can be dangerous in infants, the elderly, and in people with compromised immune systems because of HIV/AIDS, chemotherapy, or other conditions.

Officials have not linked the outbreak in tomatoes to any deaths.