Everything You Need To Know About Food Poisoning

Food Safety poster
(Credit: CDC)

Food poisoning is a short-term illness that is caused by eating contaminated food.  Also called as foodborne illness, it occurs due to the consumption of contaminated food.
The report by World Health Organisation which estimates the burden of foodborne diseases caused by 31 agents – bacteria, viruses, parasites, toxins and chemicals – states that each year as many as 600 million, or almost 1 in 10 people in the world, fall ill after consuming contaminated food. Of these, 420 000 people die, including 125 000 children under the age of 5 years.
According to the Centre for Disease Control and Prevention, the number of foodborne disease outbreaks is increasing year by year.

foodborne illness break out stats
(Credit: Centre for Disease Control and Prevention)

So, let us know everything we need to know about food poisoning so that we can take proper measures against this growing problem.

  1. What causes food poisoning?
  2. Types of harmful bacteria, parasites, and virus that cause food poisoning
  3. Food Poisoning Symptoms
  4. When is it important to consult a doctor?
  5. What to do in the case of food poisoning?
  6. Food poisoning is more harmful to:
  7. Food safety tips
  8. Conclusion

What causes food poisoning?

Food poisoning is any illness resulting due to pathogens bacteria, viruses, or parasites that contaminate food, as well as toxins such as poisonous mushrooms and various species of beans that have not been boiled for at least 10 minutes.

food production chain
Food production chain (Credit: CDC)

Harmful toxins and almost 250 different types of bacteria cause food poisoning and these can contaminate food at any stage of processing or production. We will get to know about the most common bacteria and toxins in the further sections.
Cross-contamination can take place right at your home if the food you eat is treated or cooked incorrectly. Since these foods are cooked incorrectly, there is a high chance that the food items aren’t cooked well enough and they are still raw and the harmful organisms are not destroyed before eating.   
So, just protecting our food from contaminating agent is not enough, we also have to cook it well

Types of harmful bacteria, parasites, and virus that cause food poisoning:

There are a large number of Bacteria, viruses, and parasites that cause food poisoning.
Bacteria and Virus: Bacteria and viruses are the most common reason for the contamination of food. The symptoms and the severity of food poisoning may although differ as it depends on what type of bacteria or virus has actually contaminated the food.
Most illness is caused by the below-mentioned bacteria and viruses.

  1. Salmonella: A rod-shaped bacterium belonging to the  Enterobacteriaceae family
  2. Campylobacter: A comma- or s-shaped bacteria belonging to Campylobacteraceae family
  3. Escherichia coli (E. coli): A rod-shaped bacteria belonging to Enterobacteriaceae family
  4. Clostridium perfringens: A rod-shaped bacteria belonging to Clostridiaceae family
  5. Norovirus (Norwalk Virus): A genetically diverse group of single-stranded positive-sense RNA belonging to Caliciviridae family
  6. Listeria: A rod-shaped bacteria belonging to Listeriaceae family

For exact details about each microorganism, its onset time, symptoms it shows visit FDA’s article or FSIS’s article
Parasites: Parasites are those organisms that derive required nutrients and protection from other living organisms known as the ‘’Host”. In the US, the most common foodborne parasites to be recorded are protozoa, tapeworms, and roundworms.
The most dangerous parasite which causes the most number of food poisoning in America is a parasite called Toxoplasma gondii and it causes Toxoplasmosis
Read about parasitic food poisoning in detail here MedlinePlus’s article
Mould, harmful toxins and other contaminants: Most food poisoning is caused by bacteria, viruses, and parasites rather than toxic substances in the food. But, some cases of food poisoning can be linked to either natural toxins or chemical toxins.
Read more about moulds in detail here on FSIS’s article
Food Allergies: Food allergy is an abnormal response of an individual to a food triggered by their body’s immune system. People can have allergic reactions to nuts, milk, eggs, seafood, berries, etc.  as these are most common allergy triggers in the US
Below is the pie chart which tells about Food That Sickened People in Outbreaks with a Single Known Source from 2009 to 2016 in the US
foods that sickened peopleSome of the most common contaminants and the foods that get contaminated because of them are:
Contaminant: Campylobacter
Foods that are affected: Meat and poultry items. This type of contamination mainly occurs during its processing. when animal faeces come in contact with meat and poultry surfaces. This also includes unpasteurized milk and contaminated water. The symptoms of Campylobacter infection can be experienced by the individual in between 2 to 5 days of consuming the contaminated food.
Contaminant: Listeria
Foods that are affected: Hot dogs, canned meats, unpasteurized milk, dairy products like cheese and raw produce. The symptoms of listeria-contaminated foods can be experienced by an individual within 9 to 48 hours. Expecting mothers need to be extra careful of Listeria because it can cause an early miscarriage.
Contaminant: Hepatitis A
Foods that are affected: Raw food, readymade produce, canned foods, raw fish and meat, shellfish or oysters which reside in contaminated water. Listeria also contaminates soil and water. The symptoms of Hepatitis based contamination can be experienced by an individual within 28 days.
Contaminant: Salmonella
Foods that are affected: Egg yolks, raw and contaminated milk, poultry, raw dairy products. It can be spread through uncleaned surfaces, dirty kitchen knives, and vessels, or an infected food handler.  The symptoms can usually be experienced by the individual within 1 to 3 days of the contamination.
Contaminant: Rotavirus
Foods that are affected: Raw food, canned food, infected food supplier or handler. The symptoms can usually be experienced within 1 to 3 days by the individual.

Food Poisoning Symptoms

Every individual has a different body and their immune system may function in a different manner. If someone has low immunity, they are much likely to be suffering from this illness for a longer period of time. Whereas someone with a strong immunity may recover from food contamination quickly. The way their bodies react to diseases depends upon the intensity of the contamination too.
Some individuals may experience severe symptoms while some might experience really mild ones. In either way, it is important to receive medical help and consult a doctor.
Food poisoning symptoms may vary with the source of the poisoning. Most of the types of food poisoning cause one or more of the following signs and symptoms.

food posioning symptoms
Food poisoning symptoms(Credit: CDC)

  • Nausea
  • Vomiting
  • Diarrhoea
  • Abdominal pain
  • Stomach cramps
  • Fever
  • Headaches

An individual may experience the signs and symptoms within hours after consuming the contaminated food or they may even begin after a few days. The sickness can generally last from a few hours to a span of several days.

When is it important to consult a doctor?

If one experiences any one of the following symptoms, seek immediate medical attention:

  • Inability to eat
  • A frequent episode of vomiting
  • Blood stools or vomit
  • Extreme body pains and aches
  • Severe abdominal cramps
  • Dehydration
  • Absence of urination
  • Weakness or light-headedness
  • Dizziness
  • Neurological weakness such as a blurred vision, weakness in muscles and faint tingling in the arms.
  • High fever.

What to do in the case of food poisoning?

Food Poisoning Medication: Treatment of food poisoning tends to depend on the main source of their illness and the seriousness of their symptoms. The disease resolves within a few days for most individuals without treatment and therapy, although some severe cases of food toxicity may last longer.
Individuals who have food contamination in a mild range may get relief from loperamide (Imodium A-D), or bismuth subsalicylate also known as Pepto-Bismol. These are the medicines recommended by doctors.
It is always recommended to visit a doctor and never take medicines without doctor’s prescription.
A doctor will also prescribe certain antibiotics if you have specific types of bacterial poisoning and the symptoms range from severe to critical.

For instance, food poisoning caused by the contaminant Listeria needs treatment with an intravenous antibiotic during hospitalization,  Antibiotics will not assist a patient if they have a food poisoning that is caused by viruses. Antibiotics may often worsen the symptoms in various kinds viral food contamination.
Another treatment for food poisoning may include the replacement of lost fluids from your body.
Due to persistent diarrhoea, a lot of bodily fluids are lost. Fluids and electrolytes that contain minerals such as sodium components and are rich in potassium and calcium maintain the balance of healthy fluids in the body and also contribute to keeping your heartbeat normal. All of this needs to be replaced during food poisoning.
The patients diagnosed with food poisoning will receive intravenous treatment such as salts and fluids through the veins to prevent and treat dehydration in the body.
Alternatively, you can sip water throughout the day or have small ice chips if you need to.
Since diarrhoea and incessant vomiting can throw off your body’s share of fluids and protective electrolytes, you can drink more water, soups or broths, or an electrolyte solution to replace the fluids and minerals that have been lost.
It is important to stay away from carbonated soda or any other fizzy drinks, caffeine or alcohol. It is advised to stay away from spicy and fatty foods.
You can consume small quantities of bland and nonfatty foods such as dry crackers, mild flavour biscuits or toast and rice.

Food poisoning is more harmful to:

  • Adults and old age groups of people who are 60 years and older.
  • Babies and children
  • Pregnant women
  • People with an existing chronic illness.
  • Those who have a weak immune system

Food safety tips

To prevent food poisoning at home, keep the following things in mind.

food safety tips
food safety tips(credit: CDC)

  • Always consume fresh foods.
  • Avoid raw food and unprocessed food
  • Wash your hands always before eating
  • Keep utensils clean and place them on a clean surface.
  • Cook foods to the proper temperature and avoid eating raw meat or uncooked meat
  • Refrigerate leftovers or freeze the perishable foods.
  • Defrost food and do not thaw it at room temperature.
  • Avoid unpasteurized foods such as juices, milk and dairy products and ciders.
  • Avoid soft cheese such as Feta, blue-veined cheese, and unpasteurized cheese and dairy products.
  • Those with weakened immune symptoms and children should avoid consuming raw or undercooked eggs, meat, shellfish including oysters, clams, and scallops.
  • Avoid raw sprouts such as bean and radish.
  • Throw away leftover food whenever in doubt.

Let nature do its job:

Health conditions and illness is a part of our life, unlike many other things. Its quite natural that when you experience the symptoms of food poisoning and contamination, you will need to rest.
You would need quick relief but as tempting as that sounds, it is advisable to avoid some over the counter medications to stop the vomiting and diarrhoea. The vomiting and diarrhoea are practically helping your body fight the harmful toxins and get rid of whatever is making you feel sick.
If you think you require medications, consult a doctor and seek medical advice. And make sure not to take any medications without a prescription and give the same to children. The side effects of that could be pretty dangerous.
Food poisoning usually seems to go away on its own, but make sure to visit a doctor if the symptoms you experience are severe. Talk to your doctor and tell him about your condition in detail and he will prescribe the right medicine for you.


Taking care of your body is an integral part of your life. Make sure to take the necessary precautions and prevent the cases of food poisoning before they can actually affect you for a long time. Children, feeding mothers and those who have a weakened immune system should take extra steps and be careful from food poisoning.
Food poisoning generally doesn’t last for a long period of time but can cause severe illness and dehydration of the human body. Take the necessary steps and precautions to stay safe from such illnesses at all times.
Embed Image

An infographic on Food poisoning


Please enter your comment!
Please enter your name here