Food Poisoning

"Salmonella enteritis from raw eggs in a salad. I can't even describe how bad this was. Not only did I think I was going to die, at a certain point I really wanted to..."



Food poisoning is a general term for a wide variety of diseases that are caused by ingesting food or beverages that contain toxins or are contaminated with harmful microorganisms, such as bacteria, viruses or parasites. Food poisoning is also known as food-borne illness.

Food poisoning typically causes irritation and inflammation of the gastrointestinal tract that can be severe and lead to serious complications in some cases. Food poisoning can often be prevented by taking simple hygiene and food preparation precautions.

Types of food poisoning

The most common form of food poisoning is salmonellosis, which is caused by Salmonella bacteria. Other common types of food poisoning and their causes include the following:

• Botulism is caused by Clostridium botulinum bacteria.
• Campylobacteriosis is caused by Campylobacter bacteria.
• Cryptosporidiosis (Cryptosporidium enteritis) is caused by Cryptosporidium protozoa.
• Escherichia coli food poisoning is caused by eating food or beverages contaminated with certain types of E. coli bacteria (for example, E. coli O157:H7).
• Listeriosis is caused by Listeria monocytogenes bacteria.
• Mushroom poisoning is caused by eating raw or cooked poisonous mushrooms.
• Shigellosis is caused by Shigella bacteria.
• Staphyloenterotoxicosis is caused by Staphylococcus bacteria.

Many types of food poisoning are spread through food or beverages that have been contaminated with human or animal faeces that contain infectious bacteria, viruses or parasites. Common sources of foods contaminated with infectious microorganisms include undercooked eggs, chicken, and poultry, or any undercooked or raw food that comes from animals, such as seafood, meat, milk, and dairy products. Any food or beverage can become contaminated with infectious microorganisms that cause food poisoning if it is handled by an infected person with unwashed hands or if it comes in contact with contaminated food or liquids.

Food poisoning can result in serious, potentially life-threatening complications, including dehydration, organ damage, meningitis, sepsis, stillbirth, and chronic arthritis. Seek prompt medical care if you have symptoms, such as vomiting, abdominal cramps, and diarrhea and suspect that you have food poisoning. Early diagnosis and treatment can minimize discomfort and the risk of complications and help prevent the spread of food poisoning to other people.

Seek immediate medical care if you, or someone you are with, have symptoms of food poisoning and a decrease in alertness or lack of urination.

What are the symptoms of food poisoning?

Symptoms of food poisoning vary depending on the specific type of food poisoning, the amount of infectious microorganisms or toxins ingested, your age, medical history, and other factors.

Classic symptoms of food poisoning affect the stomach and intestines and include abdominal cramps, diarrhoea, and vomiting. Symptoms of food poisoning and its complications can also affect other organs including the liver, skin, joints, and kidneys, and other body systems, such as the nervous system and respiratory system. Mild cases of certain types of food poisoning may not cause noticeable symptoms.

Symptoms of food poisoning can include:

• Dilated pupils, redness of the whites of the eyes, or blurred vision
• Dizziness
• Fever and chills
• Headache
• Multiple bouts of diarrhea that may be bloody
• Muscle weakness
• Nausea and vomiting
• Severe abdominal pain and cramps
• Skin symptoms, such as a rash, lesion or abscess

Symptoms that might indicate a serious or life-threatening condition

In some cases, food poisoning can result in serious or life-threatening complications, such as severe dehydration, meningitis, sepsis, stillbirth and miscarriage. Seek immediate medical care if you, or someone you are with, have any of these symptoms:

• Change in alertness or level of consciousness
• Lethargy or unresponsiveness
• Not urinating or urinating small amounts of tea-colored urine
• Seizure
• Severe difficulty breathing or severe shortness of breath
• Severe weakness or paralysis
• Unusual abdominal pain or vaginal bleeding during pregnancy

Seek immediate medical care if your infant displays a sunken fontanel (soft spot on the top of the head), lethargy, no tears with crying, and few or no wet diapers.

What causes food poisoning?

Many types of food poisoning are spread through food or beverages that have been contaminated with human or animal faeces that contain infectious bacteria, viruses or parasites. Any food can become contaminated with infectious microorganisms that cause food poisoning if it is handled by an infected person with unwashed hands or if it comes in contact with contaminated soil or water.

Contaminated foods

Foods that can be contaminated with infectious microorganisms include:

• Home-canned food
• Honey
• Raw vegetables and fruits
• Undercooked eggs, chicken and poultry
• Undercooked or raw food that comes from animals, such as seafood, meat and dairy products
• Unpasteurized apple cider and dairy products such as milk
• Water and other beverages

Other sources of food poisoning and ingestion of toxins

• Animals that are infected with Campylobacter jejuni bacteria or other infectious microorganisms
• Faeces of a person with food poisoning
• Food contaminated with the faeces of pets or reptiles with salmonellosis
• Soil contaminated with infectious microorganisms
• Toxic or poisonous mushrooms

 What are the risk factors for food poisoning?

Food poisoning can occur in any age group or population, but a number of factors increase the risk of developing the disease. Not all people with risk factors will get food poisoning. Risk factors for food poisoning and related diseases include:

• Advanced age
• Consumption of expired food
• Consumption of leftovers that have been stored for more than two to three days
• Consumption of raw or undercooked eggs or meats
• Contact with a person or animal who has an infection with microorganisms that cause food poisoning
• Exposure to pet faeces, handling reptiles, or touching raw foods or foods contaminated with microorganisms that cause food poisoning
• Pregnancy
• Swimming in pools, lakes, reservoirs, and other bodies of water that are contaminated with infectious microorganisms that cause food poisoning
• Travel to developing countries with untreated water or unpasteurized foods
• Weakened immune system due to such conditions as HIV/AIDS, diabetes, kidney disease, cancer or cancer treatment, and steroid treatment
• Young age (elementary school age and younger)

Reducing your risk of food poisoning and related diseases

You can lower your risk of developing or transmitting food poisoning and related diseases by:

• Avoiding contact with a person who has food poisoning or its symptoms, such as vomiting and diarrhoea
• Cleaning wounds promptly and keeping them covered with a sterile bandage
• Defrosting foods in the refrigerator or microwave, not on the counter
• Drinking bottled water and eating pasteurized dairy products when traveling to areas with poor sewage treatment facilities and unpasteurized foods
• Following swimming restrictions and beach closures of bodies of water that may be contaminated
• Not keeping reptiles as pets in homes with infants and young children
• Not picking and eating wild or unknown mushrooms or giving honey to infants
• Refrigerating or freezing leftovers right away and eating them within two to three days of refrigerating. Leftovers from restaurants should be eaten within 24 hours.
• Throwing out expired food, leftovers, or perishable food that has been sitting at room temperature for two hours or longer
• Washing plates, utensils, and cutting boards that have been exposed to raw meats or poultry in hot, soapy water before reusing
• Washing your hands frequently during and after contact with a person who has food poisoning, gastroenteritis, or symptoms such as vomiting and diarrhoea
• Washing your hands frequently, especially after using the bathroom, touching pet faeces, handling reptiles and other animals, changing diapers, or touching raw foods