Chris never thought that his pet iguana would make him sick. But
when he started having a fever, abdominal cramps, and
diarrhea, the doctor diagnosed him with an infection called
salmonellosis and said that the iguana may have been the
cause.
It's not just pets like iguanas and turtles that carry the
Salmonella
bacteria. Sometimes, these bacteria can find their way into foods.
And recent food poisoning outbreaks involving tomatoes show that
these foods aren't always animal products.
What Is Salmonellosis?
An infection with
Salmonella
bacteria usually affects the gastrointestinal system (the stomach
and intestines) in humans. In more severe cases,
Salmonella
can spread to the blood, the bones, or even to the fluid around the
brain, but these types of infection are less common.
An American scientist named Daniel E. Salmon is credited with
the discovery of the
Salmonella
family of bacteria in the late 1800s. Since then, scientists have
identified more than 2,400 types of
Salmonella
bacteria. They've also figured out where
Salmonella
live, how they spread to humans, and how to reduce their spread
among the general public. Even so, each year the United States has
about 40,000 cases of salmonellosis. And many more cases go
unreported.
Salmonella
bacteria are often found in the feces (poop) of some animals,
particularly reptiles. Iguanas, for example, carry
Salmonella marina
. People who have these animals as pets are at more risk of getting
salmonellosis because the bacteria from a reptile's feces can
get on its skin. Then, when people handle the reptiles, they get
the bacteria on their hands. (Hand washing is a good way to reduce
the risk of getting salmonellosis.)
Other strains of
Salmonella
can spread to people in foods that have come into contact with
infected animal feces. These exposures happen when foods such as
poultry, eggs, and beef are not cooked enough. Fruit and vegetables
can also become contaminated from feces in the soil or water where
they are grown.
If fruit and vegetables are not washed thoroughly before they
are eaten, they can spread
Salmonella
. The bacteria can also be spread through prepared foods if
infected food handlers do not wash their hands properly after using
the bathroom.
Who Is at Risk?
Lots of different things influence whether someone will be
infected, including the person's age, general health, and
immune system strength. Whether a person becomes sick or not can
also depend on how many bacteria enter the digestive system.
People who are more likely to become ill from
Salmonella
include:
- young children and infants (their developing immune systems
have a harder time fighting off the infection)
- older people
- those with weakened immune systems (such as people with HIV
and those with sickle cell anemia)
- people who take cancer drugs
- people who take antacids or stomach acid suppression
medication
In these higher risk groups,
Salmonella
is more likely to invade beyond the gastrointestinal tract and
cause
bacteremia
(bacteria in the bloodstream). From there the bacteria can spread
deeper into the body and cause more serious diseases, like
meningitis.
What Are the Symptoms?
Symptoms of salmonellosis can include diarrhea that may be
bloody, abdominal cramping and pain, and fever. These symptoms can
take anywhere from 6 to 72 hours to appear after someone ingests
the bacteria. Not everyone who swallows the bacteria will become
ill. In most people, the illness lasts 4 to 7 days once symptoms
begin.
Some strains of
Salmonella
can cause a more serious form of the disease known as typhoid or
enteric fever. The symptoms of typhoid fever can include a
prolonged fever, abdominal pain, headache, tiredness, a distinct
rash, constipation or diarrhea, and a change in mental state.
Typhoid fever is rare in the United States, but it can be common in
developing countries.
What Can You Do to Protect Yourself and Others?
- Wash your hands.
Good hygiene is important if you want to reduce your risk of
getting salmonellosis and other food-borne illnesses. You can
help prevent salmonellosis by encouraging your family to wash
their hands thoroughly and frequently, particularly after going
to the bathroom and before preparing food.
- Be cautious with pets, especially reptiles.
Wash your hands thoroughly after touching them or cleaning their
cages. Small children should not have reptiles, especially
turtles, as pets.
- Be careful about food preparation.
Because the bacteria appear most often in animal foods, avoid
eating raw or undercooked eggs, poultry, or meat. Proper cooking
will kill
Salmonella
, so poultry and meat should be cooked to the proper temperature.
Eggs can carry
Salmonella
bacteria both inside and outside the shell. Infection from
contamination outside the shell is much less common today because
egg producers follow strict procedures for cleaning and
inspecting eggs. But another form of
Salmonella
infection can contaminate eggs before the shells are formed. Your
best bet is to avoid eating raw or undercooked eggs, like
sunny-side up or poached eggs with a soft center.
Unpasteurized milk and juices can also be contaminated, so stick
with pasteurized.
- Avoid cross-contamination.
When raw meat or eggs touch other food, it can lead to
salmonellosis. And meat or eggs don't have to touch the food
directly - sometimes cutting boards, counters, or utensils can
transfer the bacteria from raw meat to foods like fruits and
vegetables. To protect against this, keep uncooked meats and eggs
separate from all other foods, cooked or raw. Avoid cutting raw
meat with a knife and then using the unwashed knife to cut
another food you are preparing - use a clean knife. And when
you're done preparing raw meat, wash your hands, cutting
boards, counters, and knives thoroughly with soap and hot
water.
If you're planning to travel overseas - especially to a
developing country - be sure to receive a typhoid vaccine before
traveling if it is recommended. And once you're there, be
cautious about drinking nonbottled drinks and eating foods sold by
vendors on the street.
How Is Salmonellosis Treated?
If you think you may have salmonellosis, make an appointment to
see your doctor. Because many different illnesses can cause similar
symptoms, the doctor may send a stool (poop) sample to the lab for
testing.
If you do have salmonellosis and the infection is not severe
(that is, it has not spread beyond the gastrointestinal system),
your doctor will probably let you get better on your own.
The doctor probably will not give you antibiotics unless you
have a severe infection or you're in a high-risk group and
unable to fight off the infection. Antibiotics do not appear to
benefit healthy teens with nonsevere
Salmonella
- and may actually lengthen the amount of time someone is carrying
the bacteria. Some people with salmonellosis may have to stay in
the hospital to be treated for dehydration (an abnormally low level
of fluid in the body), which can be a complication of any type of
diarrhea.
A severe
Salmonella
infection will require further testing to determine the specific
type behind the illness and which antibiotics can be used to treat
it.
People who are infected with
Salmonella
may still be contagious from several days to several weeks after
they've been infected - even if their symptoms have disappeared
or they've been treated with antibiotics. So while you recover,
be sure to wash your hands frequently and don't share your food
or drinks with anyone. And if you work in a restaurant or your work
involves handling food, check with your doctor before returning to
work.
What Can I Do to Help Myself Feel Better?
Because any diarrhea can lead to dehydration - and because the
diarrhea caused by
Salmonella
can be severe - drink plenty of water or drinks that contain
electrolytes (such as sports drinks).
You may be tempted to treat yourself with antidiarrhea
medicines, but they're not usually recommended for people with
salmonellosis. They can make the infection last longer, so be sure
to check with your doctor first. If you have a fever, you can take
acetaminophen or ibuprofen to reduce your temperature if your
doctor says it's OK.
Reviewed by:
Mary L. Gavin, MD
Date reviewed: June 2008
Originally reviewed by:
Catherine L. Lamprecht, MD
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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