Food Poisoning: See the Causes, Symptoms and Treatment

Nausea, vomiting and stomach pain with diarrhea . This is a very common picture after eating some spoiled or contaminated food.

The incidence is quite common, especially in people who usually eat outside the home. Although frequent, food poisoning deserves attention, and with some safety measures it is possible to prevent it from occurring!


What is Food Poisoning?

Food poisoning, also known as gastrointestinal (acute gastroenterocolitis), is caused by eating foods that contain organisms harmful to our body, such as bacteria, parasites and viruses.

The bacteria that usually cause food poisoning are Salmonella , Shigella , E. coli , Staphilococus , Clostridium , Rotavirus virus (or their respective toxins), fungi, toxic components found in certain vegetables (such as the “me-nobody-can” plant) and wild cassava) and chemicals.

These organisms are found in foods such as: raw meat, chicken, fish and eggs, however, they can also spread to any other type of food; in water and even during food handling, preparation, preservation and / or storage.

Commonly, patients affected by food poisoning have eaten food that has been left outdoors or that has been stored for a long time.

However, food poisoning can also occur when an individual does not wash their hands before touching food. In most cases, it is mild and disappears after a few days.

What you can do in these cases is to wait for the body to respond, to get rid of the germ that is causing the disease. The most serious types of the disease require the infected person to see a doctor urgently. When it affects children and the elderly, food poisoning can be a serious illness.

What are the causes?

When eating a food that is bad, there may be different microorganisms involved in it. Some are more associated with certain foods, such as:

Fruits and vegetables

Even fresh, they can be contaminated when washed with water contaminated by animal waste or human sewage.

Transmission of E. coli bacteria in contaminated water is common . Bacterial infection, in most cases, is the main cause of food poisoning. The different types of Salmonella and Staphilococus aureus are the most frequent agents of infection.

They are still able to live and multiply within the intestines. The Salmonella is transmitted through the ingestion of foods that have been contaminated by coming into contact with animal feces also infected.

The bacteria Staphilococus aureus , on the other hand, has a greater occurrence on people’s skin and does not cause damage, intoxication is caused by the toxin that the bacterium produces and, consequently, contaminates food at the time it is prepared or handled.

Another occurrence of infection is by the bacterium Clostridium that attacks the nervous system.

Meat and Dairy Products

Fish and seafood are also the most vulnerable to contamination, as they degrade quickly.

It is easier for pathogenic microorganisms to survive when food is not cooked or preserved properly. It is not advisable to use, for example, the same cutting board that was used to cut raw meat.

As well as cutting food with dirty hands, contamination can also occur.


Many organisms can contaminate food. Environmental conditions such as polluted water can be a major cause.

Food handling

Food can be contaminated if an infected person touches it. If your hands are not sanitized before cutting or handling food, you are also more at risk of being contaminated.

Symptoms: what can food poisoning cause?

The most common signs and symptoms in all acute food poisoning patients are:

  • Nausea.
  • Vomiting.
  • Diarrhea.
  • Fever.
  • Abdominal pain.
  • Cramps.
  • Malaise.
  • Dehydration, weight loss and drop in blood pressure: in the most severe cases.

If the food is contaminated by Clostridium , that is, when the intoxication is caused by one of the varieties of the bacteria responsible for the disease known as “Botulism”, the patient may have:

  • Gastrointestinal disorders: rare.

Neurological changes:

  • Double vision.
  • Difficulty focusing objects.
  • Difficulty speaking and swallowing.

Symptoms of food poisoning usually affect the stomach and intestines, with the most common sign being diarrhea. Other symptoms include:

  • Nausea.
  • Vomiting.
  • Watery diarrhea.
  • Abdominal pain and cramps.
  • Fever.

After eating the contaminated food, the symptoms can appear in a few hours or take days and even weeks; its duration is usually 10 days. Everything will depend on the bacteria that infected the patient and the state of health he was in.

Children and the elderly, in particular, may be the most affected by food poisoning, due to their symptoms having a longer duration, as well as some types of typically mild food poisoning can be fatal for these patients.

Pregnant women also fit into this group along with immunosuppressed people.

Not all food poisoning causes cramps, diarrhea, nausea or vomiting. There are types that have different or more severe symptoms, which can include:

  • Weakness.
  • Numbness.
  • Confusion.
  • Tingling in the face, hands and feet.

Which professional should I look for?

The general practitioner may be contacted together with the gastroenterologist. It is common for food poisoning to be mild and to pass in a few days, because of this, most patients do not seek a doctor to make the diagnosis.

How is the diagnosis made?

The specialist doctor will often diagnose food poisoning by investigating whether other people who have had the same diet have also been ill.

The initial diagnosis consists of assessing the symptoms and, when examinations or tests are requested, they may be:

  • Stool examination: ordered if symptoms are severe or diagnosis is uncertain.
  • Blood tests: help to discover the parasite that causes food poisoning or to rule out other causes.
  • Pregnant women: have a compromised immune system that may have been exposed to toxoplasmosis, in these cases, the doctor will order a toxoplasmosis test.

Food Poisoning Treatment and Remedies

Treatment for food poisoning will depend on the origin and severity of the disease. In most cases, it resolves without treatment within a few days. However, in some cases it can last for 1 week or more.

Generally the treatment indicated by the doctor consists of:

  • Replacing fluids lost due to diarrhea or vomiting intravenously in the hospital, intravenous hydration provides the body with water and essential nutrients more quickly.
  • Antibiotics: when the patient has bacterial food poisoning and has severe symptoms. During pregnancy, this type of treatment, when immediate, reduces the risk of contamination for the baby.
  • Intravenous antibiotic: this type of treatment is done in the hospital when the intoxication is severe.

The drugs indicated may be:

  • Amikacin .
  • Cephalothin .
  • Ciprofloxacin .
  • Cipro .
  • Doxycycline .

Diet for food poisoning: what to eat?

The patient who has had food poisoning must strictly follow the diet passed by the specialist doctor, to assist in the reduction of symptoms. Among the most recommended foods are:

  • Teas with sugar but without caffeine, avoiding black tea, mate tea or green tea.
  • Corn porridge.
  • Cooked and shelled pear and apple.
  • Banana.
  • Cooked carrot.
  • White rice or pasta without sauces or fats.
  • Baked potato.
  • Grilled or cooked chicken or turkey.
  • White bread with fruit jam.

In the first few days of symptoms, choose cooked unpeeled fruits and strained fruit juices; after the symptoms improve, it is recommended to eat vegetables, cooked or in soup, as they help to replenish nutrients and vitamins in the body.

Home treatment

Some ways to treat food poisoning at home are:


The patient must take 1 capsule of charcoal, 2 times on the day he has the symptoms, as it prevents the mucosa of the stomach and intestine from absorbing the microorganisms present in the contaminated food.


The patient should drink plenty of fluids, such as: water, teas, natural fruit juices, coconut water, oral rehydration salts or isotonic drinks, in order to replace the fluids lost by vomiting and diarrhea, to speed recovery and avoid dehydration.

The ORS is a great choice to hydrate, here ‘s how:

  • 1 liter of filtered, boiled or bottled mineral water.
  • 1 tablespoon of sugar or 2 shallow tablespoons of sugar (20 g)
  • 1 coffee spoon of salt (3.5 g)


It is essential to help treat food poisoning, because the body needs to save energy due to the loss of fluids, helping to prevent dehydration.

Make light feeds:

When vomiting and diarrhea are subsiding, you should eat lightly, choose chicken soup, mashed potatoes , vegetable cream or cooked fish for example, according to tolerance.

Groups and risk factors

Among the groups and risk factors for food poisoning are:

  • Eating or drinking unpasteurized juices, raw sprouts, unpasteurized milk and dairy products made from unpasteurized milk, such as certain types of cheese.
  • Eat raw or undercooked meat.
  • Eating or drinking food that has been contaminated during processing or carelessness when handling.


As the individual ages, the immune system does not respond as quickly to infectious agents. In addition, it is common that, with advanced age, there are other adjacent diseases, which can further weaken the immune system.


During pregnancy, changes in metabolism and circulation can increase the risk of food poisoning. In rare cases, the baby may also become ill.

Babies and children

The immune systems of children and babies are still developing. In addition, it is common for them to have a habit of putting things in their mouths, such as objects and toys, so that it is easier for health-damaging agents to invade the body.

People with chronic diseases:

As diabetes , hepatitis or AIDS , or still being chemotherapy / radiotherapy for cancer reduces the immune response.

Complications: can food poisoning be serious?

The food poisoning patient can develop some complications if there is no treatment or the disease gets worse. Among them are:

  • Severe dehydration.
  • More serious infection.
  • Renal failure: in rare cases.

After passing intoxication, you should avoid eating or drinking anything for a few hours; this helps the stomach to fight the infectious agent more effectively and prevents the patient from suffering from new vomiting or diarrhea.

Taking small sips of water also helps, as well as drinking clear broths and sports drinks. Affected adults should try to drink at least 8 to 16 glasses of liquid a day, with frequent small sips.

Gradually returning to eating, the ideal is to start with light and easy-to-eat foods, such as crackers, gelatin, toast, fruit and rice. If the nausea comes back, you need to stop.

How to prevent food poisoning?

In addition to a balanced and careful diet, other factors that can help prevent food poisoning are:

  • Always sanitize your hands, utensils and food surfaces often.
  • Utensils and other surfaces used to cut food should always be washed with soap and hot water.
  • Raw foods should be kept separate from ready-to-eat foods.
  • Keep raw meat, poultry, fish and seafood away from other foods when storing them.
  • Cook food at a safe temperature, using a thermometer suitable for cooking food.
  • Refrigerate or freeze perishable food.
  • Defrost food safely, not at room temperature.

For young children, pregnant women, the elderly and people with weakened immune systems, it is recommended to take extra care, avoiding:

  • Raw or undercooked meats and poultry.
  • Raw or undercooked fish or seafood, including oysters, clams, mussels and scallops.
  • Eggs or foods that may contain risks, such as raw or undercooked cookie dough and undercooked homemade ice cream.
  • Raw sprouts, such as: alfalfa, beans, clover or radish sprouts.
  • Non-pasteurized juices and ciders.
  • Non-pasteurized milk and dairy products.
  • Soft cheeses (such as feta, brie and camembert), blue cheese and unpasteurized cheese.
  • Chilled pates.
  • Hot dogs, cooked and cold meats.