Food Poisoning: The Uninvited Dinner Guest

Food poisoning: Signs and symptoms 

Food poisoning symptoms vary with the source of contamination; however many types share similar signs and symptoms: 

• Diarrhoea (Usually watery)
• Nausea
• Vomiting 
• Abdominal pain 
• Stomach cramps 
• Fever

Food poisoning signs and symptoms may start several hours after eating contaminated food. They can also be observable after 1-2 days, and in rare cases, several weeks later. The duration of sickness can be from several hours to several days. You should seek medication attention if you notice: 

• Frequent episodes of vomiting
• Inability to keep any liquids down 
• Bloody vomit
• Bloody stool
• Diarrhoea for more than 3 consecutive days
• Extreme abdominal cramps or pain
• Dehydration, manifesting as excessive thirst, little urination, dry mouth, weakness, dizziness, or lightheadedness

Food poisoning: Causes and risk factors 

Food poisoning is caused by eating contaminated food, and the contamination of food can happen at any point along the food production process. Raw or ready-to-eat foods are contaminated most easily.  When food is consumed raw or undercooked,  the harmful organisms are not destroyed by the heat of cooking, thus potentially leading to food poisoning. Food poisoning can be caused by different bacteria, viruses, or parasites. 

Risk factors for food poisoning include: 

• Age. As you get older, the immune system weakens and may not react or respond as promptly or efficiently. Children are another group at high risk 
• Pregnant women, as there are changes in metabolism and circulation that may make them more susceptible. In rare cases, it will affect the baby. Reactions to food poisoning tend to be more severe during pregnancy. 
• Those with chronic illnesses, because they have a reduced immune response. 

Food poisoning: Treatment 

Food poisoning is generally self-limiting, which means that it resolves on its own within a few days. Therefore, medication to stop diarrhoea is not routinely given. Prevention of dehydration is the most important part of treatment. Water, electrolyte drinks and oral rehydration solutions should be liberally consumed. If hydration cannot be maintained, due to vomiting and diarrhoea, hospitalisation for re-hydration is sometimes needed.

In special cases, the patient may be given 

• Antidiarrheal agents, such as Pepto Bismol or Imodium. This may be given in cases where the patient cannot access toilets for quite a long while, e.g. during an exam or when travelling.
• Painkillers and fever medication 
• Medications for nausea 

Food poisoning treatment may also include: 

• Replacement of fluids and electrolytes that were lost from vomiting or diarrhoea. This is the most important part of the treatment, as dehydration is the most significant  complication of food poisoning.
• Antibiotics, if the food was contaminated by bacteria, and the patient has severe symptoms. 

Food poisoning: Prevention 

Food poisoning is sometimes unavoidable depending on where you are eating, or the unknown conditions of the food. However, the risk of food poisoning can be reduced by: 

• Wash your hands before eating 
• Wash utensils before using them 
• Wash food before ingesting it, especially if it is not cooked
• Store raw food separately from ready-to-eat food to prevent cross-contamination 
• Cook food to a safe temperature to ensure that harmful organisms are killed 
• Refrigerate or freeze perishable foods. 
• Safely defrost food. Do not thaw the frozen food at room temperature. Instead, place it in the fridge. If you are microwaving it, cook it immediately
• Do not eat food that you doubt is appropriately prepared. If you are unsure that it is safe to eat, do not risk it.