Salmonella is a Gram-negative, rod-shaped, motile bacterium. Salmonella serotype Typhimurium and Salmonella serotype Enteritidis are the most common in the United States, and have been known to cause illness for over 100 years. They were discovered by an American scientist named Salmon, for whom they are named.
Although Salmonella is typically associated with raw and undercooked poultry products, the pathogen has also been found in a wide variety of other foods, including raw beef, milk and dairy products, fish and shrimp, frog legs, yeast, salad dressings, cake mixes, cream-filled desserts and toppings, dried gelatin, peanut butter, cocoa, chocolate and various pet foods. S. enteritidis creates additional challenges with respect to shell eggs, because, when present, the organism can survive inside the egg.
In addition to direct contamination from source food products (such as eggs), Salmonella can also be transmitted from the contaminated feces of carriers (such as infected individuals) to foods, food product surfaces and other people. Acute symptoms include nausea, vomiting, abdominal cramps, diarrhea, fever, and headaches. In extremely rare cases, chronic symptoms such as arthritis may develop 3-4 weeks following the onset of acute symptoms. Typically, the incubation period ranges between 12 and 36 hours. Although the infective dose usually requires only a relatively small number of bacteria, the amount ultimately depends upon the age and health of host. In most cases, acute symptoms will only last for 1 to 2 days, and often do not require treatment other than oral fluids. Persons with severe diarrhea may require rehydration with intravenous fluids. Antibiotics, such as ampicillin, trimethoprim-sulfamethoxazole, or ciprofloxacin, are not usually necessary unless the infection spreads from the intestines.
As is the case with many other pathogens, illness from Salmonella can be easily avoided. Preventative measures include:
- Cooking poultry, ground beef, and eggs thoroughly to 160 degress F. If you are served undercooked meat, poultry or eggs in a restaurant, do not hesitate to send it back to the kitchen for further cooking;
- Avoiding foods containing raw eggs, or raw (unpasteurized) milk;
- Washing hands, kitchen work surfaces, and utensils immediately after they have been in contact with raw meat or poultry products;
- Being particularly careful when handling foods prepared for infants, the elderly, and those with weak immune systems;
- Washing hands with soap after handling reptiles, birds, or baby chicks, and after potential contact with pet feces; and
- Avoiding direct or even indirect contact between reptiles (turtles, iguanas, other lizards, snakes) and infants or immunocompromised persons;