- What is salmonellosis?
- What sort of germ is Salmonella?
- How common is salmonellosis?
- How do people catch Salmonella?
- How can Salmonella infections be diagnosed?
- How can Salmonella infections be treated?
- What can I do to prevent salmonellosis?
- Are there long-term consequences to a Salmonella infection?
- What else can be done to prevent salmonellosis?
- What is the government doing about salmonellosis?
- How can I learn more about this and other public health problems?
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.
- Persons 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 bacterium.
- 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 infant.
Are there long term consequences to a Salmonella infection?
Persons with diarrhea usually recover completely, although it may be several
months before their bowel habits are entirely normal. A small number of persons
who are infected with Salmonella, will go on to develop pains in their joints,
irritation of the eyes, and painful urination. This is called Reiter's syndrome.
It can last for months or years, and can lead to chronic arthritis which is
difficult to treat. Antibiotic treatment does not make a difference in whether
or not the person later develops arthritis.
What else can be done to prevent salmonellosis?
It is important for the public health department to know about cases of
salmonellosis. It is important for clinical laboratories to send isolates of
Salmonella to the City, County, or State Public Health Laboratories so the
specific type can be determined and compared with other Salmonella in the
community. If many cases occur at the same time, it may mean that a restaurant,
food or water supply has a problem which needs correction by the public health
department.
Some prevention steps occur everyday without you thinking about it. Pasteurization of milk and treating municipal water supplies are highly effective prevention measures that have been in place for many years. In the 1970s, small pet turtles were a common source of salmonellosis in the United States, and in 1975, the sale of small turtles was halted in this country. Improvements in farm animal hygiene, in slaughter plant practices, and in vegetable and fruit harvesting and packing operations may help prevent salmonellosis caused by contaminated foods. Better education of food industry workers in basic food safety and restaurant inspection procedures, may prevent cross-contamination and other food handling errors that can lead to outbreaks. Wider use of pasteurized egg in restaurants, hospitals, and nursing homes is an important prevention measure. In the future, irradiation or other treatments may greatly reduce contamination of raw meat.
What is the government doing about salmonellosis?
The Centers for Disease Control and Prevention (CDC) monitors the frequency
of Salmonella infections in the country and assists the local and State Health
Departments to investigate outbreaks and devise control measures. CDC also
conducts research to better identify specific types of Salmonella. The Food and
Drug Administration inspects imported foods, milk pasteurization plants,
promotes better food preparation techniques in restaurants and food processing
plants, and regulates the sale of turtles. The FDA also regulates the use of
specific antibiotics as growth promotants in food animals. The US Department of
Agriculture monitors the health of food animals, inspects egg pasteurization
plants, and is responsible for the quality of slaughtered and processed meat.
The US Environmental Protection Agency regulates and monitors the safety of our
drinking water supplies.
Quick GuideDigestive Disorders: Common Misconceptions

How can I learn more about this and other public health problems?
You can discuss any medical concerns you may have with your doctor or other
heath care provider. Your local City or County Health Department can provide
more information about this and other public health problems that are occurring
in your area. General information about the public health of the nation is
published every week in the "Morbidity and Mortality Weekly Report",
by the CDC in Atlanta, GA. Epidemiologist in your local and State Health
Departments are tracking a number of important public health problems,
investigating special problems that arise, and helping to prevent them from
occurring in the first place, or from spreading if they do occur.
This information has been provided with the kind permission of the Centers
for Disease Control (www.cdc.gov).