Salmonellosis, Frequently Asked Questions
What is salmonellosis?
Salmonellosis is an infection with a bacteria called Salmonella. Most persons
infected with Salmonella develop diarrhea, fever, and abdominal cramps 12 to 72
hours after infection. The illness usually lasts 4 to 7 days, and most persons
recover without treatment. However, in some persons the diarrhea may be so
severe that the patient needs to be hospitalized. In these patients, the
Salmonella infection may spread from the intestines to the blood stream, and
then to other body sites and can cause death unless the person is treated
promptly with antibiotics. The elderly, infants, and those with impaired immune
systems are more likely to have a severe illness.
What sort of germ is Salmonella?
The Salmonella germ is actually a group of bacteria that can cause diarrheal
illness in humans. They are microscopic living creatures that pass from the
feces of people or animals, to other people or other animals. There are many
different kinds of Salmonella bacteria. Salmonella serotype Typhimurium and
Salmonella serotype Enteritidis
are the most common in the United States.
Salmonella has been known to cause illness for over 100 years. They were
discovered by a American scientist named Salmon, for whom they are named.
How common is salmonellosis?
Every year, approximately 40,000 cases of salmonellosis are reported in the
United States. Because many milder cases are not diagnosed or reported, the
actual number of infections may be twenty or more times greater. Salmonellosis
is more common in the summer than winter. Children are the most likely to get
salmonellosis. Young children, the elderly, and the immunocompromised are the
most likely to have severe infections. It is estimated that approximately 1,000
persons die each year with acute salmonellosis.
How do people catch Salmonella?
Salmonella live in the intestinal tracts of humans and other animals,
including birds. Salmonella are usually transmitted to humans by eating foods
contaminated with animal feces. Contaminated foods usually look and smell
normal. Contaminated foods are often of animal origin, such as beef, poultry,
milk, or eggs, but all foods, including vegetables may become contaminated. Many
raw foods of animal origin are frequently contaminated, but fortunately,
thorough cooking kills Salmonella. Food may also become contaminated by the
unwashed hands of an infected food handler, who forgot to wash his or her hands
with soap after using the bathroom.
How can Salmonella infections be diagnosed?
Many different kinds of illnesses can cause diarrhea, fever, or abdominal
cramps. Determining that Salmonella is the cause of the illness depends on
laboratory tests that identify Salmonella in the stools of an infected person.
These tests are sometimes not performed unless the laboratory is instructed
specifically to look for the organism. Once Salmonella has been identified,
further testing can determine its specific type, and which antibiotics could be
used to treat it.
How can Salmonella infections be treated?
Salmonella infections usually resolve in 5-7 days and often do not require
treatment unless the patient becomes severely dehydrated or the infection
spreads from the intestines. Persons with severe diarrhea may require
rehydration, often with intravenous fluids. Antibiotics are not usually
necessary unless the infection spreads from the intestines, then it can be
treated with ampicillin, gentamicin, trimethoprim/sulfamethoxazole, or
ciprofloxacin. Unfortunately, some Salmonella bacteria have become resistant to
antibiotics, largely as a result of the use of antibiotics to promote the growth
of feed animals.
What can I do to prevent salmonellosis?
There is no vaccine to prevent salmonellosis. However, the following
precautions should be considered to prevent salmonellosis:
- Since foods of animal origin
may be contaminated with Salmonella, people should not eat raw or undercooked
eggs, poultry, or meat. Raw eggs may be unrecognized in some foods such as
homemade hollandaise sauce, caesar and other salad dressings, tiramisu, homemade
ice cream, homemade mayonnaise, cookie dough, and frostings.
- Poultry and meat,
including hamburgers, should be well-cooked, not pink in the middle. If you are served
undercooked meat, poultry or eggs in a restaurant, don't hesitate to send it
back to the kitchen for further cooking.
also should not consume raw or unpasteurized milk or other dairy products.
- Produce should be thoroughly washed before consuming.
- Cross-contamination of foods should be avoided. Uncooked meats should be keep
separate from produce, cooked foods, and ready-to-eat foods. Hands, cutting
boards, counters, knives, and other utensils should be washed thoroughly after
handling uncooked foods. Hand should be washed before handling any food, and
between handling different food items.
- People who have salmonellosis should not prepare food or pour water for
others until they have been shown to no longer be carrying the Salmonella
- People should wash their hands after contact with animal feces. Since
reptiles are particularly likely to have Salmonella, everyone should immediately
wash their hands after handling reptiles. Reptiles (including turtles) are not
appropriate pets for small children and should not be in the same house as an