The search is on for the source of a salmonella outbreak that has sickened hundreds of Americans in at least 42 states.

Officials with the Centers for Disease Control say the cases are all the same type of salmonella, known as Typhimurium, and have occurred over the last few months. The victims range in age from infants to senior citizens. Symptoms include diarrhea, fever, and abdominal cramps 12 to 72 hours after infection. The illness usually lasts 4 to 7 days. Most people recover without treatment, but severe infections may occur.

Some of the states affected:

Arizona
California
Colorado
Connecticut
Georgia
Idaho
Illinois
Iowa
Maryland
Massachusetts
Michigan
Minnesota
Nevada
New Hampshire
New Jersey
New York
North Dakota
Ohio
Pennsylvania
Rhode Island
Tennessee
Texas
Vermont

Since the food or foods causing the outbreak have not yet been identified, consumers are being advised to thoroughly cook all meats, poultry and eggs and to vigorously wash produce. Officials say an extra layer of protection is to wash hands more often.

While the CDC has not released a list of the 42 states involved in the outbreak, local media are reporting cases in the 23 states listed in the box at left.

The CDC is working with public health officials in many states, the United States Department of Agriculture Food Safety and Inspection Service, and the U.S. Food and Drug Administration to investigate the outbreak.

The last salmonella scare was the 1,400 cases of last spring and summer that were first blamed on tomatoes before the real source was revealed to be hot peppers from Mexico.