Food Poisoning | Call Doctors on Call

1. Overview of Food Poisoning

Food poisoning, also called foodborne illness, is an illness caused by eating contaminated food.

Typically most foodborne diseases cause vomiting and diarrhea that tend to be short lived and resolve on their own, but dehydration and electrolyte abnormalities may develop.

The Center for Disease Control and Prevention (CDC) estimates approximately 48 million people become ill from food-related diseases each year resulting in 128,000 hospitalizations, and 3,000 deaths.

Infectious organisms — including bacteria, viruses and parasites — or their toxins are the most common causes of food poisoning.

Infectious organisms or their toxins can contaminate food at any point of processing or production. Contamination can also occur at home if food is incorrectly handled or cooked.

2.  Symptoms of Food Poisoning

Food poisoning symptoms often include nausea, vomiting or diarrhea. Most often, food poisoning is mild and resolves without treatment. But some people need to go to the hospital.

Food poisoning symptoms vary with the source of contamination. Most types of food poisoning cause one or more of the following signs and symptoms:

  • Nausea
  • Vomiting
  • Watery or bloody diarrhea
  • Abdominal pain and cramps
  • Fever

Signs and symptoms may start within hours after eating the contaminated food, or they may begin days or even weeks later.

Sickness caused by food poisoning generally last from a few hours to several days.

3.  Causes of Food Poisoning

Contamination of food can happen at any point of production: growing, harvesting, processing, storing, shipping or preparing.

Cross-contamination — the transfer of harmful organisms from one surface to another — is often the cause. This is especially troublesome for raw, ready-to-eat foods, such as salads or other produce. Because these foods aren’t cooked, harmful organisms aren’t destroyed before eating and can cause food poisoning.

Many bacterial, viral or parasitic agents cause food poisoning.

4.  Diagnosis of Food Poisoning

Food poisoning is often diagnosed based on a detailed history, including how long you’ve been sick, your symptoms and specific foods you’ve eaten. Your Doctor or Doctors-on-Call will also perform a physical exam, looking for signs of dehydration.

Depending on your symptoms and health history, your doctor or Doctors-on-Call may conduct diagnostic tests, such as a blood test, stool culture or examination for parasites, to identify the cause and confirm the diagnosis.

For a stool culture, your doctor or Doctors-on-Call will send a sample of your stool to a laboratory, where a technician will try to identify the infectious organism. If an organism is found, your doctor or Doctors-on-Call may notify your local health department to determine if the food poisoning is linked to an outbreak.

In some cases, the cause of food poisoning can’t be identified.

5.  Treatment of Food Poisoning

Treatment for food poisoning typically depends on the source of the illness, if known, and the severity of your symptoms.

For most people, the illness resolves without treatment within a few days, though some types of food poisoning may last longer.

Treatments of food poisoning may include:

  • Replacement of lost fluids. Fluids and electrolytes — minerals such as sodium, potassium and calcium that maintain the balance of fluids in your body — lost to persistent diarrhea need to be replaced.
  • Some children and adults with persistent diarrhea or vomiting may need hospitalization, where they can receive salts and fluids through a vein (intravenously), to prevent or treat dehydration.
  • Antibiotics. Your doctor may prescribe antibiotics if you have certain kinds of bacterial food poisoning and your symptoms are severe. Food poisoning caused by listeria needs to be treated with intravenous antibiotics during hospitalization.
  • The sooner treatment begins the better. During pregnancy, prompt antibiotic treatment may help keep the infection from affecting the baby.

Antibiotics will not help food poisoning caused by viruses. Antibiotics may actually worsen symptoms in certain kinds of viral or bacterial food poisoning. Talk to your doctor about your options.

6.  Risk factors

Whether you become ill after eating contaminated food depends on the organism, the amount of exposure, your age and your health.

High-risk groups include:

Older adults.  As you get older, your immune system may not respond as quickly and as effectively to infectious organisms as when you were younger.

  • Pregnant women. During pregnancy, changes in metabolism and circulation may increase the risk of food poisoning. Your reaction may be more severe during pregnancy. Rarely, your baby may get sick, too.
  • Infants and young children. Their immune systems haven’t fully developed.
  • People with chronic disease.  Having a chronic condition — such as diabetes, liver disease or AIDS — or receiving chemotherapy or radiation therapy for cancer reduces your immune response.

7.  Complications

The most common serious complication of food poisoning is DEHYDRATION — a severe loss of water and essential salts and minerals.

How do you know if you are Dehydrated?

Symptoms of dehydration include:

  •  little or no urine, or urine that is darker than usual
  • dry mouth
  • sleepiness or fatigue
  • extreme thirst
  • headache
  • confusion
  • feeling dizzy or lightheaded
  • no tears when crying

If you’re a healthy adult and drink enough to replace fluids you lose from vomiting and diarrhea, dehydration shouldn’t be a problem.

Infants, older adults and people with suppressed immune systems or chronic illnesses may become severely dehydrated when they lose more fluids than they can replace. In that case, they may need to be hospitalized and receive intravenous fluids. In extreme cases, dehydration can be fatal.

8.  How to Reduce Your Risk of Food Poisoning

Here are some simple tips to help minimize your risk of food poisoning:

  • Practice good hygiene: Wash your hands with soap and hot water before preparing food. Always wash your hands right after touching raw meat and poultry.
  • Avoid washing raw meat and poultry: This does not kill the bacteria — it only spreads it to other foods, cooking utensils and kitchen surfaces.
  • Avoid cross-contamination: Use separate chopping boards and knives, especially for raw meat and poultry.
  • Don’t ignore the use-by date: For health and safety reasons, foods should not be eaten after their use-by date. Check use-by dates on your food regularly and throw it out once they’ve passed, even if the food looks and smells ok.
  • Cook meat thoroughly: Make sure ground meat, sausages and poultry are cooked through to the center. Juices should run clear after cooking.
  • Wash fresh produce: Wash leafy greens, vegetables and fruits before eating them, even if they are pre-packaged.
  • Keep food at a safe temperature: 5–60°C is the ideal temperature for the growth of bacteria. Don’t leave leftovers sitting at room temperature. Instead, put them right in the fridge.

9.  What Steps Should You Take After Food Poisoning?

Let your stomach settle. After you experience the most explosive symptoms of food poisoning, like vomiting, diarrhea, and upset stomach, experts recommend letting your stomach rest. That means avoiding food and drink altogether for a few hours.

1.     Stay hydrated

Liquid intake is crucial for helping your body fight off food poisoning effects. Vomiting and diarrhea can cause dehydration, so sucking on ice chips or taking small sips of water is a good starting point.

Sports drinks that contain electrolytes are the best way to prevent dehydration during this time. Other suggested liquids include:

  • clear sodas (such as Sprite, 7UP, or ginger ale)
  • decaffeinated tea
  • chicken or vegetable broth

2.     Eat bland food

When you feel you might be able to hold down food, eat foods that are gentle on your stomach and gastrointestinal tract. Stick to bland, low-fat, low-fibre foods. Fat is harder for your stomach to digest, especially when it’s upset. Avoid fatty foods to prevent upsetting it further.

Foods that are gentle on the stomach include:

  • bananas
  • cereal
  • egg whites
  • honey
  • oatmeal
  • peanut butter
  • plain potatoes, including mashed potatoes
  • rice
  •  saltines
  • toast
  • applesauce

The BRAT diet (Bananas, Rice, Applesauce and Toast) is a good guide to follow when you have food poisoning.

10.  When to See your Doctor or contact Doctors-on-Call

If you experience any of the following signs or symptoms, seek medical attention.

  • Frequent episodes of vomiting and inability to keep liquids down
  • Bloody vomit or stools
  • Diarrhea for more than three days
  • Extreme pain or severe abdominal cramping
  • An oral temperature higher than 38 C
  • Signs or symptoms of dehydration — excessive thirst, dry mouth, little or no urination, severe weakness, dizziness, or light-headedness
  • Neurological symptoms such as blurry vision, muscle weakness and tingling in the arms


  • Doctors-on-Call, your house-call-doctor service, are able to advise & assist you with the diagnosis and treatment of food poisoning.
  • Doctors – on – call operate in the Johannesburg area including Rosebank, Melrose & Sandton, as well as in Cape Town.
  • It is a good idea to have a ‘house call doctor’ like Doctors-on-Call  number on hand, if you or anyone in your family are suffering from some of the symptoms of food poisoning
  • It is especially important to contact Doctors-on-Call if food poisoning symptoms are severe; symptoms do not clear after a few days or take a turn for the worse.
  • If you or anyone in your family are at RISK OF SEVERE DEHYDRATION from food poisoning DO NOT HESITATE TO CONTACT  Doctors – On – Call IMMEDIATELY