Food Poisoning: Symptoms, Diagnosis, Treatment

Food poisoning, also called foodborne illness, is an infection of your digestive tract caused by consuming contaminated food or beverages.

Most cases of food poisoning are due to eating food that has specific types of bacteria or viruses. Food can be contaminated in various ways throughout the food production chain, including production, processing, distribution, and preparation. When you consume these foods, the bacteria continue to grow in your digestive tract which leads to an infection.

Germs can multiply rapidly in food left out too long at room temperature. Simply reheating or boiling food after it has been left out may not always make it safe as some germs can produce toxins that are not eliminated by heat.

Bacteria such as Campylobacter, Salmonella, Norovirus, Clostridium perfringens, Escherichia coli (E. coli), Staphylococcus aureus, Clostridium botulinum, Vibrio or Listeria are amongst those that can contaminate food, leading to food poisoning.

How is food poisoning different from stomach flu?

Food poisoning and stomach flu (gastroenteritis) are both illnesses that affect the digestive system, but they differ in their causes, symptoms, and duration.

Food poisoning

Caused by consuming contaminated food or beverages.
The contamination can be due to bacteria (e.g., Salmonella, E. coli), viruses, parasites, or toxins present in the food.

Stomach flu (gastroenteritis)

Typically caused by viral infections, such as norovirus or rotavirus. It can also be caused by bacteria or parasites, but viral infections are the most common cause.
Spreads through contact with an infected person, contaminated surfaces, or consuming contaminated food or water.
It is more contagious than food poisoning.

What are the symptoms of food poisoning?

Sometimes, food poisoning symptoms can look similar to stomach flu (gastroenteritis) symptoms, which leads many individuals with mild cases of food poisoning to think they have stomach flu instead.

The time needed for food poisoning symptoms to appear can vary. Illness usually begins in approximately 1 to 3 days. However, symptoms can also start at any time ranging from half an hour to 3 weeks after consuming contaminated food. The length of time is dependent on the type of bacteria or virus causing the illness.

Symptoms may vary from person to person, ranging from mild to severe. They can persist from a few hours to days. Food poisoning symptoms may include:

Stomach cramps
Watery or bloody diarrhoea
Nausea or vomiting
Headache
Fever

What are the potential complications?

Dehydration: The most common complication of food poisoning. This leads to your body not having sufficient fluid and electrolytes to function well. Dehydration is specifically dangerous in children, older adults, and people with weakened immune systems. It can lead to serious and potentially life-threatening complications if not treated promptly.

Sepsis: The body’s extreme reaction towards an infection, which is a life-threatening medical emergency. This is a medical emergency that can lead to organ failure, shock, and death if not treated aggressively.

Haemolytic uremic syndrome (HUS): This is a rare but potentially severe complication, particularly associated with E. coli infections, where the red blood cells are destroyed, leading to kidney failure.

Guillain-Barré Syndrome: A rare neurological disorder that can occur after infections like Campylobacter. It causes the immune system to attack the nerves, leading to muscle weakness and paralysis.

How is food poisoning diagnosed?

Food poisoning is typically diagnosed based on a combination of a patient’s symptoms, medical history, and sometimes laboratory tests.

Stool sample analysis: If the illness is severe, prolonged, or if there is blood in the stool, a stool sample may be collected and sent to a lab for analysis. This test can identify specific bacteria, viruses, or parasites causing the illness.

Blood tests: To look for signs of infection or inflammation and can help detect serious complications such as dehydration, kidney damage, or sepsis.

Food testing: In outbreak situations, samples of suspected food may be tested to identify the contaminant. This is more common in public health investigations to prevent further cases. This helps trace the source of contamination and identify the specific pathogen.

Specific testing: For specific toxins, such as botulinum toxin or certain types of fish or shellfish poisoning, more specialised tests may be required.

How is it treated?

Treatment for food poisoning primarily focuses on relieving symptoms and preventing dehydration. In most cases, food poisoning resolves on its own within a few days, but more severe cases may require medical intervention.

Medication

Antibiotics may be prescribed to treat certain types of bacterial food poisoning.
Antidiarrheal medications such as loperamide may be used for severe diarrhoea, but only under a doctor’s guidance, as they can sometimes prolong the infection.
Antiemetic medications such as ondansetron may help reduce nausea and vomiting.
Pain relievers or antipyretics such as paracetamol can help reduce fever and discomfort.

Dietary adjustments

While recovering from food poisoning, you can eat bland foods such as toast, crackers, bananas, and rice until you start feeling better.
Avoid fried food, processed and dairy products as they may worsen your symptoms.

Hydration

Drink plenty of water, clear broths, and oral rehydration solutions (ORS) to replace lost fluids and electrolytes to prevent dehydration.
Avoid coffee, tea, soft drinks, and sweetened beverages.
For severe dehydration, intravenous (IV) fluids may be administered in a healthcare facility setting.

How to prevent food poisoning?

Basic hand hygiene

Always wash your hands after:

Using the toilet
Changing diapers
Blowing your nose
Coughing or sneezing
Being in contact with animals

Food and drinks to avoid

Unpasteurised milk
Food made with raw or undercooked eggs, poultry, and meat

Food preparation guidelines

Wash your hands with soap before and after being in contact with raw meat, poultry, shellfish, fish, eggs, or produce.
Wash all fruits and vegetables properly before consuming.
Use plastic cutting boards to cut raw fish, poultry, or meat, as they are easier to keep clean.
Wash all utensils and surfaces used to prepare food with soap and water before and after use.
Make sure food is cooked to the right internal temperature and appropriate amount of time.

Food storage guidelines

Leftover cooked perishable foods should be refrigerated or frozen immediately.
Fruits and vegetables, cooked foods, and prepared foods should be stored away from raw meat and raw eggs to avoid cross contamination.
Mayonnaise, salad dressings, and any foods that contain them should be refrigerated.
Throw away food if you are unsure how long they have been not refrigerated. Consider the food unsafe for consumption if they are at room temperature for over 2 hours.
If you are unsure if the food has gone bad, throw it away.

When to see a doctor?

Be sure to consult a doctor immediately if you have any serious symptoms, such as:

Bloody diarrhoea.
Diarrhoea that persists longer than 3 days.
Persistent high fever (temperature over 38.9°C).
Vomiting constantly that you are unable to keep liquids down.
Showing signs of dehydration (not urinating much, mouth and throat feel dry, feel dizzy when standing up).

Make an appointment at Pantai Hospitals

Consult our doctors if you are experiencing symptoms of food poisoning. A dedicated and expert team of Gastroenterologists at Pantai Hospitals is available for consultation to provide the best care and assistance.

Get in touch with us to book an appointment today if you have concerns or questions regarding food poisoning. We assure you the best possible care tailored to your specific needs.

Pantai Hospitals have been accredited by the Malaysian Society for Quality in Health (MSQH) for its commitment to patient safety and service quality.