Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
There many causes of food poisoning. Sometimes they classified by how quickly their symptoms begin after eating potentially
contaminated food. Think of this as the incubation time from when food enters
the body and symptoms begin. The following are several examples how this time
classification can be arranged:
Short incubation or less than 16 to 24 hours
Scombroid poisoning usually is due to poorly cooked or stored fish. The
affected person will experience flushing, itching, shortness of breath, and difficulty swallowing
within 1 to 2 hour of eating.
Ciguatera poisoning is another fish toxin that occurs after eating fish
such as grouper, snapper, and barracuda. Symptoms include vomiting and diarrhea,
muscle aches, and neurologic complaints including
headache, numbness and
tingling, hallucinations, and difficulty with balance (ataxia).
Mushroom ingestions can cause initial symptoms like vomiting and diarrhea.
Eating Amanita mushrooms can cause liver and
kidney failure leading to death.
Staphylococcus aureus poisoning is due to a toxin that is pre-formed in food
before it is eaten. It causes vomiting within 1 to 6 hours after eating the
Bacillus cereus is an infection that occurs after eating poorly cooked or
Clostridium Perfringens is a spore that infects cooked meat that has been
stored in an environment that was too warm. Within 8 to 12 hours, it may cause profuse
Intermediate incubation from about 1 to 3 days
Infections of the large intestine or colon can cause bloody, mucoid diarrhea
associated with crampy abdominal pain.
Campylobacter, according to CDC data, is the number one cause of food borne
disease in the United States.
Shigella spp contaminate food and water and cause dysentery (severe
diarrhea often containing mucus and blood).
Salmonella infections often occur because of
poorly or undercooked cooked, and poor handling of the
chicken and eggs. In individuals with weakened immune systems, including the
elderly, the infection can enter the bloodstream and cause potentially life-threatening infections.
Vibrio parahaemolyticus can contaminate saltwater shellfish and cause a
Diarrhea due to small bowel infection tends not to be bloody, but infections
may affect both the small and large intestine at the same time.
Botulism is caused by
Clostridium botulinum toxin and may present with
fever, vomiting, mild diarrhea, numbness, and
weakness leading to
Long incubation 3 to 5 days
Hemorrhagic E. coli (mainly E. coli 0157:H7) can cause inflammation of the
colon leading to bloody stools. In some children, about a week after infection,
it can progress to hemolytic uremic
syndrome (HUS). Elderly individuals may contract
thrombotic thrombocytopenic purpura (TTP). Toxins from the bacteria enter the
blood stream and hemolyze or destroy red blood cells (hemo=blood +
lyse=disintegrate). In addition, the toxins cause kidney failure and uremia,
where waste products build up in the body.
Giardiasis may occur after drinking water from lakes or rivers that have
been contaminated by beavers, muskrats, or sheep that have been grazing. It also can be passed from person to person, for example in day care settings.
Amoebiasis is encountered in contaminated drinking water, usually in
tropical or semitropical climates and can be passed person to person.
Trichinosis is due to an infection from eating undercooked pork or wild
game such as bear meat. Aside from fever and gastrointestinal complaints, symptoms
include muscle pain, facial swelling, and bleeding around the eyes and under the
Cysticercosis is often seen in developing countries where water is
contaminated with pork tapeworms and the person drinks the ova form the
tapeworm. The infection can invade the brain (neurocysticercosis) causing
Listeriosis usually occurs after foods contaminated with
are ingested. These include unpastruized, raw milk, soft cheeses, and processed
meats and poultry. Vegetables and fruits may also become infected with
Listeria. The bacteria may lay dormant in or on the surface of the food
products for weeks.
Brucellosis occurs by ingesting raw or unpasteurized milk and cheese,
especially goat's milk contaminated with Brucella spp
Toxoplasmosis is usually transmitted to humans from cat feces containing
Toxoplasma parasites; most infections are asymptomatic, but people
who are immune depressed can develop systemic disease symptoms.
Bovine Spongiform encephalopathy (mad cow disease) is acquired by eating
foods containing prions (transmissible agents that induces abnormal folding of
brain protein) contaminating brain or spinal cord from infected cows.
Reviewed by Charles Patrick Davis, MD, PhD on 10/18/2011