The farmers and I were chatting at the Farmers' Market today about the outbreak of salmonella in our public supply of tomatoes. I've been learning about food borne illness as part of the Master Food Preserver class and thought it would be worth offering a little primer. This comes via the "You Can Prevent Food borne Illness" publication available through WSU extension.
Two similar groups of bacteria, Salmonella and Campylobacter, are normally found in warm blooded animals such as cattle, poultry,and pigs. These bacteria may be present in food products that come from these animals— such as raw meat, poultry, eggs, or unpasteurized dairy products. Salmonella also may be present on fresh fruits and vegetables.
Rinse all fresh fruits, including melons and vegetables, thoroughly under running water before preparing or eating them. It is true this will not remove all microorganisms, but it will reduce the number present. Pathogens have been isolated from a wide variety of fresh produce, and outbreaks of food borne illness have been associated with many types of produce—cantaloupes and tomatoes, for example. If the skin of the fruit or vegetable is contaminated, the pathogens move into the fruit when it is sliced. Removing the skin or rind reduces the risk.
Here's the more official run down.
Salmonellosis and Campylobacteriosis Bacteria: widespread in nature; live and grow in intestinal tracts of humans and animals.
Examples of foods involved: Raw or undercooked poultry, meat and eggs. Unpasteurized dairy products. Contaminated raw fruits and vegetables.
Transmission: Eating contaminated food, or contact with infected persons or carriers of the infection. Also transmitted by insects, rodents, farm animals, and pets.
Symptoms: Diarrhea, fever, abdominal cramps and vomiting. Infants, elderly people, and immunocompromised persons are most susceptible. Severe infections cause high fever and may even cause death. In a small number of cases, can lead to arthritis and Gullian-Barre syndrome, an autoimmune disorder.
Onset: 1–5 days.
Duration: 2–7 days.
Prevention: Cook foods thoroughly. The bacteria are destroyed by heating the food to 140F for 10 minutes or to higher temperatures for less time— for instance, 160F for a few seconds. Chill foods rapidly in small quantities. Refrigerate at 40F. Wash hands, work surfaces and equipment after touching raw meat or poultry.