Food Poisoning: Causes and Treatment

What is food poisoning?

Food poisoning or foodborne illness is acquired by ingestion of contaminated food or water that contains a toxic organism that could be either a virus, bacteria, fungus or parasite. Food contamination happens with improper handling, storage and cooking. It is a common disease with increasing prevalence in developing countries.


Most of the cases can be self- limiting and resolve without treatment, but some might need hospitalization if the symptoms worsen. 

Causes of food poisoning

It can affect one person or group of people who shared the contaminated food or drinks. In general, the possible causes of contamination include:

  • Not fresh or not properly washed
  • Handled in a unsanitary manner
  • Cooked to an unsafe internal temperature
  • Undercooked meats or eggs
  • Not freeze promptly or improper storage

Known contaminants of our food or water are the following:

  • Bacteria, viruses, parasites, fungus
  • Toxins
  • Chemicals

Food poisoning has many types depending on the causative organism. Some of the most common causes and where they are found include:

    • Salmonella: Undercooked poultry products and raw eggs are common sources. It can also occur from beef, pork, vegetables and processed foods containing these items.
    • Escheria Coli: Can be found in undercooked meat and raw vegetables. This bacteria produces a toxin, also known as Shiga toxin that irritates one’s intestine. 
    • Shigella: Most typically found in uncooked vegetables, shellfish, cream or mayonnaise-based salads. It is also known as bacillary dysentery that can cause blood or mucus in your loose stools.
    • Listeria: Bacteria  that is commonly found in soft cheeses, deli meats, hot dogs and raw sprouts can cause a disease called Listeriosis which is notably dangerous for pregnant individuals.
  • Hepatitis A (Viral Hepatitis) It can be spread through shellfish, fresh produce or water and ice contaminated by stool. One can be infected by drinking unclean water, eating food that’s been washed or grown in unclean water, eating food that’s been handled by an infected person.
  • Norovirus: It may be acquired by eating undercooked shellfish, leafy greens, fresh fruits or by consuming food that an infected person prepared. They are a frequent cause of gastroenteritis outbreaks in community and institutional settings, also known as stomach flu. 
  • Staphylococcus Aureus: This bacterial infection occurs when people transfer the staph bacteria from their hands to food. It may be found in meats, poultry, milk and dairy products, salads, cream-filled baked goods, and sandwich fillings. 
  • Campylobacter: This bacterial infection can be acquired from undercooked poultry, meat or eggs, poorly processed meats, contaminated vegetables and raw (unprocessed) milk or water sources. The condition is generally self-limiting and rarely, causing death.

Signs and symptoms of Food Poisoning

  • Nausea or feeling the urge to vomit
  • Vomiting
  • Watery or bloody diarrhea
  • Abdominal pain and cramps
  • Headache
  • Fever (body temperature of 37.8c)
  • Body weakness

Classic symptoms may be experienced soon after ingestion of contaminated food or water, but some would take a few days to develop it.


This depends on the amount of pathogen or exposure and the immune system condition. Healthy individuals can fend off pathogens or germs without manifesting symptoms or maybe mild symptoms only. 

Risk Factors of Food Poisoning

You may have a more severe reaction or longer recovery to food poisoning, if you’re not immunocompetent. High risk groups are to be monitored closely and they are the following:

  • Elderly
  • Infants or young children
  • Pregnant women
  • Patients with chronic disease such as HIV, diabetes, kidney disease, cancer or those who are receiving immunosuppressant therapy

Prevention and Treatment for Food Poisoning

There are ways to prevent food poisoning at home:


  • Wash hands properly and wash utensils and food surfaces often
  • Keep ready to eat foods separate from raw foods to avoid cross contamination
  • Cook foods thoroughly and be reminded of the safe temperature
  • Refrigerate or freeze perishable foods promptly
  • Defrost food safely and cook it immediately once thawed
  • Discard food/drinks if you are in doubt of how it was stored or prepared


  Vulnerable individuals such as pregnant, young children or those with weakened immune system should take extra precautions by limiting the consumption of the following foods:


  • Raw or rare meat and poultry products
  • Raw or undercooked fish or shellfish, including oysters, clams, shrimps, mussels and scallops
  • Raw or undercooked eggs or foods that may contain them, such as cookie dough and homemade ice cream
  • Raw sprouts, such as beans, clover and radish sprouts
  • Unpasteurized juices and cider, milk and milk products
  • Soft cheeses, such as feta, blue-veined cheese; and unpasteurized cheese
  • Refrigerated pates and meat spreads
  • Uncooked hotdogs, deli and luncheon meats


Basic home management starts with good hydration since you are losing a lot of fluids with loose stools, vomiting, and fever. Diet should also not contain irritants (oily and highly spiced foods) that may further aggravate gastric symptoms.


Recommended food includes bananas, rice, apples, toast, and plain crackers. An oral rehydration solution could also be used to prevent dehydration.

Complications associated with Food Poisoning

  • Severe dehydration
  • Electrolyte Imbalance
  • Miscarriage and stillbirth
  • Kidney failure
  • Nervous or brain damage

When to consult a doctor

If symptoms are worsening or you belong to the high risk groups mentioned above, it is advisable that you seek a medical consultation. Children and elderly become dehydrated more easily than the general population. Call if you or your child have any unusual symptoms, such as:


  • Persistent, high-grade fever 
  • Inability to tolerate any food/fluids
  • Dry lips and sunken eyes
  • Bloody diarrhea or vomitus
  • Dark urine or lack of urine
  • Neurological changes such as blurred vision, dizziness or lightheadedness, delirium or confusion

How EVA Teleconsult can help you manage Food Poisoning?

Food borne illness is common and has to be addressed promptly to avoid serious complications. We can also guide you on ways to prevent its occurrence. EVA Teleconsultation is ready to handle your health concerns, including gastrointestinal concerns such as food poisoning. That’s because we can give you the utmost care through our


Timely appointments – No more time wasted while waiting outside a doctor’s office. With us, appointments begin right when they’re supposed to, even if they’re made the same day.


Guaranteed 30-minute consultation times – No more rushing or quickly dashed off prescriptions with no explanations. Our doctors take the time needed to give you information about your concerns, and are open to answering all your questions.


5-star ratings for our doctors – Because our doctors know how to explain things in a way patients can understand, we frequently get positive feedback from them. We have competent and caring doctors on board.


If you feel that you are having signs and symptoms of food poisoning, it is always best to seek medical advice from a primary care physician. Eva telemedicine is here for you from Monday to Sunday. Don’t hesitate to book an online consultation today so we can diagnose and help you manage your illness.

About The Author

Dr. Verns is a highly-skilled and compassionate physician who obtained her medical degree from Pamantasan ng Lungsod ng Maynila College of Medicine in 2014, and passed the Physician Licensure Exam in August of 2015. She is a certified Family Physician given by the Philippine Association of Family Physicians, and received her Diplomate in Family Medicine in 2022 and landed as top 6 in overall rankings in the Philippines. She is also a registered nurse both in the Philippines and the United States, having passed the US Nursing Licensure Exam in 2007. 


Dr. Verns is a strong advocate of preventive care and believes that it makes a huge difference in the outcome of disease development. In the future, she is looking to further her education and training to become a diabetologist or lifestyle medicine fellow. 

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