Salmonellosis, Frequently Asked Questions (cont.)
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.