Food poisoning is an illness caused by eating foods contaminated with organisms that cause infections or toxins.
Food poisoning caused by toxins can start as soon as two but more commonly six to eight hours after eating. If the cause is a foodborne infection, the time period is longer (anywhere from 12 hours to 5 days) because the infectious organisms take some time to multiply inside the person's intestines. Usually, once symptoms start they get worse quickly.
Food poisoning can cause: nausea and vomitingabdominal crampsdiarrhea, usually watery but sometimes bloody feverweaknessheadachedehydration
The most common types of food poisoning are named for the bacteria and organisms that cause the condition. Common types of foodborne infections are caused by Salmonella, Shigella, Campylobacter, or E. coli bacteria, or by noroviruses. Staphylococcus aureus (called "staph" for short) is the most common cause of foodborne illness caused by a toxin. Occasionally, chemical toxins or mild poisons found in seafood, plants, or contaminated foods are responsible for foodborne illness.
Food must be properly prepared and stored to prevent food poisoning. Food poisoning can occur when food is left unrefrigerated for long periods of time, often at picnics or large parties.
Sometimes, mishandling or misidentification of foods, especially certain exotic dishes, causes food poisoning. Those who handle or prepare food should wash their hands to prevent contaminating food. A person with diarrhea should never prepare food for others.
Many times the diagnosis is presumed because of the timing of events. A person often eats somewhere unusual, then feels sick within a few hours. Most cases of food poisoning go away within 24 hours. With a history like this, if the person gets better, further testing is usually not necessary.
If needed, such as in large outbreaks, the suspect food can be examined, along with affected people's stool and vomited material. In a foodborne outbreak, investigators attempt to determine the infecting organism, the responsible food item, and the specific food handling error that led to the outbreak. In this way, future outbreaks can be prevented.
Treated victims usually recover fully within 24 hours. The very young, the very old, and those who have weakened immune systems can become severely very quickly and can die if not treated promptly.
Food poisoning per se cannot be passed from one individual to another. Those who ate the same food as someone with food poisoning are at risk of getting the condition.
Occasionally, bacterial infections such as shigellosis can be acquired from a foodborne source and then passed on from person to person.
Food poisoning usually causes dehydration from the loss of body fluids in diarrhea and vomit. Replacing fluids and various salts in the body is important, and can usually be accomplished by drinking plenty of liquids at home.
If a person cannot keep liquids down, he or she can receive fluids through an intravenous line in the hospital or clinic. Certain drugs such as promethazine (i.e., Phenergan) can relieve nausea and diphenoxylate/atropine (i.e., Lomotil) or loperamide (i.e., Imodium) can relieve cramps or diarrhea, but are rarely needed.
Specific side effects depend on the drugs given, and are usually mild.
People generally recover within 24 hours and feel back to normal within 2 days. A return to normal activities is usually allowed as soon as a person feels better.
A healthcare professional will help monitor the disease if a person becomes very ill. If symptoms last for more than 24 hours, or if a person becomes lightheaded, is unable to stand, or has blood in the vomit or diarrhea, a healthcare professional should be contacted.