Norovirus is the leading cause of foodborne illness outbreaks in the U.S. It can cause nausea, vomiting, diarrhea, and stomach cramps. It is often spread by contaminated food handlers or by eating raw or undercooked shellfish.

This bacterium can cause salmonellosis, which is characterized by diarrhea, fever, and abdominal cramps. It can also cause typhoid fever and paratyphoid fever, which are more severe infections that can affect other organs. Salmonella is commonly found in raw or undercooked poultry, eggs, meat, and dairy products.

This bacterium can cause perfringens food poisoning, which is marked by intense abdominal cramps and watery diarrhea. It is usually associated with meats, poultry, gravy, dried or precooked foods that are not properly reheated or refrigerated.

This bacterium can cause campylobacteriosis, which is manifested by diarrhea (sometimes bloody), cramps, fever, and vomiting. It can also lead to serious complications such as Guillain-Barré syndrome, a rare disorder that affects the nerves. Campylobacter is often found in raw or undercooked poultry, unpasteurized milk, and contaminated water.

This bacterium can produce toxins that cause staphylococcal food poisoning, which is characterized by sudden onset of nausea, vomiting, and stomach cramps. It can also cause skin infections and more serious conditions such as pneumonia and septicemia. Staphylococcus aureus is commonly found on the skin and in the nose of healthy people, and can contaminate food through improper handling or storage.

There are many strains of E. coli bacteria, some of which are harmless and some of which can cause serious illness. The most notorious one is E. coli O157:H7, which can cause hemorrhagic colitis, a severe form of bloody diarrhea that can lead to kidney failure and death. E. coli O157:H7 is mainly found in undercooked beef (especially hamburger), unpasteurized milk and juice, raw fruits and vegetables (especially sprouts), and contaminated water.

This bacterium can cause listeriosis, a rare but serious infection that can affect the brain, spinal cord, bloodstream, and placenta. It can cause fever, muscle aches, headache, stiff neck, confusion, loss of balance, and convulsions. It can also cause miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn. Listeria monocytogenes is often found in ready-to-eat foods such as deli meats, hot dogs, smoked seafood, soft cheeses, and raw sprouts.

This parasite can cause toxoplasmosis, an infection that usually causes mild flu-like symptoms in healthy people but can be dangerous for pregnant women and people with weakened immune systems. It can cause eye damage, brain damage, or death in the fetus or newborn. It can also cause encephalitis or other organ damage in immunocompromised individuals. Toxoplasma gondii is mainly transmitted by eating undercooked meat (especially pork or lamb) or by contact with cat feces.

This bacterium can produce a toxin that causes botulism, a rare but potentially fatal condition that affects the nervous system. It can cause

• blurred vision
• double vision
• difficulty swallowing
• muscle weakness
• respiratory failure

It can also affect infants who ingest honey or corn syrup contaminated with spores. Clostridium botulinum is often found in improperly canned foods (especially home-canned vegetables), fermented fish, and baked potatoes in aluminum foil.