This commonly occurring disease spectrum ranging from simple abdominal cramps, diarrhea to fatal dehydration, sepsis and nervous system damage; contracted following ingestion (within 48 hrs.) of toxin contaminated food items is called food poisoning.
Millions of people worldwide are affected at a given time with food poisoning. It’s distinguished from food borne infections by the rapidity of onset of illness (<48hrs), mainly because clinical features of food poisoning are brought about by preformed (mainly bacterial) toxins already present in food at the time of ingestion. Whereas food borne infections occur as a result of infection of gut by the pathogens present in food, which usually takes about 2 – 5 days to clinically manifest.
Causes of food poisoning;
A. Infectious agents and their products
• Viruses – e.g. norovirus, rotavirus
• Bacteria – e.g. salmonella, shigella, E-coli, staphtlococci, campylobacter and clostridium botulinum (botulism).
• Rarely parasites – e.g. giardia
B. Other toxins
• Mushrooms
• Improperly prepared exotic foods – e.g. barracuda (ciguatera)
• Pesticides and other agrochemical residue in plants Food items can be contaminated at any time of process, from production and harvesting to preparation and serving.
Poor sanitary practices of food handlers, unsafe preparation and storage (contamination by house flies) accounts to majority of food poisoning cases.
Signs and symptoms of food poisoning (can develop as rapid as within 30mins. Following ingestion)
• Abdominal cramps
• Diarrhea – ranges from simple watery diarrhea to frank blood in stools
• Nausea
• Vomiting
• Dehydration
• Fever
• Blurred vision
• Double vision
• Difficulty in speaking
• Difficulty in swallowing
• Muscle weakness and paralysis
• Difficulty in breathing
Most cases of food poisoning are self-limiting. Proper first aid care will be the only modality of management required. However, first aid training should render proper knowledge on identification of danger signs and symptoms that requires prompt admission to hospital.
Signs and symptoms that require urgent hospitalization
• Development of neurological features described above under botulism
• Difficulty in breathing
• Collapse and loss of consciousness
• Features of severe dehydration – e.g. confusion, no urine output, sunken eyes, dry mouth etc.
• Severe vomiting or diarrhea
• Vomiting blood or passage of blood in stools
• Fever > 1020F
• Development of symptoms following seafood or mushroom ingestion
• Development of abdominal swelling
• Children • Pregnant women.
First aid management
1. Reassure the patient as most are self-limiting conditions.
2. Look for danger signs and call for medical help immediately.
3. If unconscious; secure the airway by head tilt, chin lift and jaw thrust maneuvers. Check for breathing and circulation. Start CPR immediately and follow basic life support guidelines.
4. Control vomiting; do not give solid foods until vomiting stops. Give frequent sips of small amount of water to keep patient hydrated. Keep patient lying on side to prevent aspiration.
5. Oral rehydration solutions can be used much effectively for rehydration.
6. Avoid alcohol, caffeine and sugary drinks.
7. Light diet is preferred in first days of illness.
8. Always watch for signs of dehydration, specially with children. Urine output is a good indicator of hydration status.
9. Oral anti-diarrheal medications are not recommended. In children avoid these entirely. These may slow elimination of toxins worsening the condition.
10. When vomiting and diarrhea settles, start introducing normal solid foods gradually.
11. Prebiotics present in certain foods (e.g. lactobacillus – in yoghurt) help the recovery of damaged intestines and will shorten period of diarrhea.
12. Get plenty of rest for the patient.
Prevention
1. Wash hands thoroughly before preparing and eating food.
2. Do not eat suspicious looking food items.
3. Buy prepared food only from safe outlets that adhere to sanitary guidelines.
4. Check the expiry dates on packaging before consuming food.
5. Do not buy canned foods that look damaged, bloated up or crushed.
6. Keep raw foods away from prepared meals.
7. Refrigerate or freeze foods properly. Adhere to the instructions given by the manufacturer.
8. Be careful on eating previously un-encountered exotic foods. Specially mushrooms and seafood.