Food poisoning

13 Min Read

What is it

Food poisoning is any illness caused by foodborne bacteria, yeasts, molds, parasites, viruses, or chemicals. Every home, and every person, is host to a variety of bacteria that can cause serious illness if they get into food and multiply. You can get mild food poisoning without realizing it. When people come down with a “bug” accompanied by symptoms such as headache and stomach distress, it’s often dismissed as “stomach flu” or “24-hour virus” but it may be food poisoning. And some types of bacteria and viruses can cause severe illness that can be fatal in the elderly, in children, in people with certain disorders (such as diabetics), and in people whose immune systems are depressed, such as cancer patients. It is estimated that 33 to 50 million Americans one out of every five get food poisoning each year.


The onset of symptoms can occur anywhere from one hour to seven days after eating contaminated food, depending on the infectious agent.

  • Bloody diarrhea or pus in the stool (the most common symptom).
  • Abdominal pain and cramps.
  • Fever (may not be present).
  • Headaches, stiff neck, and fever (may not be present).
  • Rapid heart rate, dizziness, or faintness after standing up suddenly, when accompanied by vomiting, nausea, or diarrhea (possible dehydration
  • Tingling in the arms and legs, sometimes around the mouth, blurred vision, weakness, or numbness (possible botulism poisoning).

Another sign of food poisoning is that people who have eaten the same food(s) all become ill.

What causes it

Food poisoning is primarily caused by a number of different bacteria and some viruses, with bacteria being responsible for the majority of cases. Just about every type of food unless it has been sterilized has bacteria in or on it, but most of them are harmless. In addition, bacteria can be introduced into foods from external sources.

The mere presence of bacteria or viruses in food isn’t enough to make you sick. They cause problems only when the food is improperly handled and prepared. Bacteria begin to multiply quickly in food left at room temperature and thrive on food that is kept warm on a stove. Moist foods, such as stuffing or cooked rice, are especially susceptible to bacterial growth. Refrigeration retards the growth of bacteria, and cooking at high temperature kills most of them. But if food has been left out long enough, some types of bacteria can form a toxin that will survive heat or freezing.

The bacterium Salmonella is by far the most frequent cause of foodborne illness, and it is rapidly becoming more prevalent. Poisoning by Salmonella called salmonellosis, accounts for upward of four million cases annually. The number of cases may actually be higher, since many individuals and even doctor’s mistake salmonellosis for “intestinal flu.” The increase in salmonellosis has been attributed principally to high-speed mechanical methods of slaughtering and eviscerating animals, especially poultry. According to a variety of estimates, at least half of all raw chicken marketed is contaminated by Salmonella and/or Campylobacter jejuni, a bacterium that that causes diarrhea, fever, abdominal cramps, and which may cause blood in the stool.

Of course, any animal may harbor Salmonella- no cow or chicken is completely free of bacteria. Raw eggs, too, can be a source of Salmonella, but in these cases poor handling may not be the only cause. Researchers suggest that the bacteria can come from inside the hen and are in the raw egg itself, rather than getting there by the usual route of cracked or dirty eggshells. While raw or soft-cooked eggs or foods made with them like eggnog or Caesar salad are potentially risky, commercial products made with eggs, such as mayonnaise, are safe because the eggs have been pasteurized.

There have also been periodic reports that the rise in salmonellosis is due to the practice of feeding antibiotics to cattle, pigs, and poultry to enhance their growth a practice that has allowed strains of Salmonella to develop that are resistant to antibiotics.

Fish and shellfish are another common source of food poisoning, particularly when they are eaten raw. Any fish or shellfish, no matter how fresh, may carry some bacteria and viruses and animals from sewage-polluted waters may carry large doses of them. Certain shellfish clams, oysters, mussels live by filtering water, and if the water they inhabit is polluted, they will retain bacteria and viruses along with the microscopic foodstuff they absorb. Raw shellfish can thus be a source of hepatitis, gastroenteritis, and other diseases. Raw fish, as used in sushi and sashimi, may be a source of parasites such as tapeworms and roundworms, as well as bacteria and viruses.

What if you do nothing

Most cases of food poisoning are not serious and recovery usually occurs within three days without any medical care. However, the disease can be fatal if the treatment of a serious food poisoning case is delayed.

Home remedies

Get in bed and keep warm

Your system is debilitated, and resting enhances recovery. Make sure you have easy access to a bedpan or bathroom.

Drink plenty of fluids

Diarrhea and vomiting function to clear the toxins out of your system, but they can result in a substantial loss of body fluids. To prevent dehydration from developing, drink six to eight ounces of clear fluids per hour throughout the day. These can include water, tea with sugar, bouillon, or any of the commercially prepared sports drinks. If vomiting continues and you can’t keep anything down, try to take small sips or suck on ice chips.

For children: Have a child with food poisoning drink five ounces of clear liquids per hour; infants should drink at least an ounce per hour.

Apply heat

If you have stomach pain or cramps you may get some relief by placing a heating pad (on the low setting) or a hot water bottle on your abdomen.

Reintroduce foods gradually

After your symptoms diminish, gradually reintroduce soft and easily digested foods such as cooked cereal, bananas, rice, applesauce, toast, potatoes, eggs, and noodles. Once the diarrhea has stopped and your appetite increases, you can return to your normal diet.

Avoid milk and milk-based products for several days after diarrhea has subsided

This will allow the enzymes in the small intestine needed to handle the lactose contained in milk and milk based products to be replenished.


You can take a number of simple measures to prevent food contamination and reduce your risk of getting sick from tainted food.

Stick to lean cuts of meat and poultry

When drugs and other chemicals are found in meat and poultry, they usually collect in the liver, kidneys, and fat. By avoiding organ meats and trimming excess fat, you significantly reduce the risk of contamination from these substances should they be present (and you will also reduce the amount of fat and cholesterol in your diet).

Keep your refrigerator below 40°F and the freezer below zero

Check it periodically with a thermometer, especially in the summer months. If needed, adjust the temperature-control dial.

Always refrigerate raw meat or poultry immediately

Once in the refrigerator, however, don’t keep it for more than two or three days.

Wash your hands thoroughly before you handle food

The proper way is to use soap and warm water for at least 20 seconds, working the soap into the hands, including the fingernail area and between the fingers. Use a fresh dish towel every time you cook.

Defrost frozen foods in the refrigerator

In the microwave, or under cold running water. You can defrost at room temperature, but only if you monitor the food carefully and cook it as soon as it has thawed. Use a microwave only if you plan to cook the food right away or refrigerate it until cooking time.

Wash thoroughly after food preparation

After preparing raw meat or poultry, wash the utensils, counter, cutting board, and your hands anything that touched it thoroughly in hot soapy water before making a salad or handling vegetables.

Marinate meats and poultry only under refrigeration

And don’t put cooked meat back into an uncooked marinade or serve the used marinade as a sauce unless you heat it to a rolling boil for several minutes.

Be aware of cooking temperatures for meats

Cook rare beef to at least 145°F (pink, not red). Pork and chicken should, of course, be thoroughly cooked not pink at all. Never leave food in a hot car.

Be careful at barbecues

Don’t serve barbecued meat on the same plate you used for the raw meat and don’t use the cooking utensils for serving.

Avoid uncooked meats

Whether at home or eating out, pass up the steak tartare and any other uncooked meat. Avoid raw fish and shellfish as well, including sushi. The risk of illness is simply too high.

Don’t leave normally refrigerated foods sitting out

Hold foods at room temperature no longer than an hour before or after cooking. Given the right conditions, the bacterial content in some foods can double in 20 minutes.

Promptly refrigerate leftovers

Particularly anything with a coating (bread or fat) or a tight wrapping. Divide large amounts of left-overs such as sauces, soups, stews, and casseroles into smaller containers so that they cool faster. Throw away any questionable leftovers. Store all starchy stuffing (rice, bread) separately from the poultry in which it was cooked.

Be careful canning

If you can fruits and vegetables at home, ask your county health department for guidelines about safe procedures to protect against botulism.

Be prudent

Pass up all food that smells or looks spoiled. Don’t buy or use any food in bulging, rusty, or leaky cans.

Check out the salad bar

Make sure food is protected by a sneeze guard.

Wash produce

Pesticides used on fruits and vegetables can cause food poisoning. Be sure to wash and peel your produce. Keep pets away from food preparation areas.

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