Food poisoning

Disease Description (Causes and Symptoms)

• Definition: Foodborne illness is an infectious or toxic gastrointestinal disease caused by consuming contaminated food or beverages, and causes vomiting, diarrhea, abdominal pain, fever, and other symptoms. Depending on the cause, it is classified as bacterial (Salmonella, Staphylococcus aureus, Clostridium species, etc.), viral (such as norovirus), parasitic (such as Giardia), natural toxin-related (poisonous mushrooms, seafood toxins), or chemical (chemicals that contaminate food).
• Pathophysiology: Attachment and proliferation of pathogens on the intestinal mucosa or absorption of toxins in food can cause intestinal mucosal inflammation, secretory diarrhea, malabsorption, and systemic toxicosis. Some strains (e.g., E. coli O157:H7) can cause hemorrhagic enteritis and hemolytic uremic syndrome (HUS), while Clostridium botulinum causes paralytic symptoms through neurotoxins.
• Main symptoms: Nausea and vomiting, abdominal pain, watery or bloody diarrhea, fever, headache, muscle pain, and dehydration (decreased urination, dizziness). The onset time (incubation period) varies depending on the cause (e.g., Staphylococcus aureus: 2–6 hours, Clostridium perfringens: 6–24 hours, Salmonella: 6–72 hours, E. coli O157:H7: 3–9 days, cholera: several hours to several days).

Treatment Methods

• Basic principles: Most cases of foodborne illness improve with correction of dehydration and supportive care (fluid and electrolyte replacement).
  • Mild cases: Oral rehydration solution (ORS) is recommended, with gradual intake of easily digestible foods.
  • Severe cases/dehydration: Intravenous fluids (normal saline or Ringer's solution), with monitoring and correction of electrolytes.
• Drug treatment and specific treatment
  • Antiemetics and antispasmodics: May be used short-term to relieve vomiting and abdominal pain (as directed by a doctor).
  • Antibiotics: Not routinely used for all foodborne illnesses. They are used selectively in the following cases.
    • Antibiotics are necessary for cholera, severe Vibrio sepsis or wound infection, and severe Salmonella infection in immunocompromised individuals (e.g., in cholera, short-term treatment with azithromycin or doxycycline reduces the duration of symptoms).
    • When E. coli O157:H7 is suspected, the use of antibiotics and antidiarrheal medications may increase the risk of HUS and is therefore generally not recommended.
  • Specific toxin treatment: Botulinum poisoning requires administration of antitoxin and intensive care (securing the airway and mechanical ventilation).
• Precautions during treatment
  • Visit the emergency room immediately if bloody stool, high fever, severe abdominal pain, low blood pressure, impaired consciousness, respiratory symptoms, or neurological symptoms occur.
  • A specialist determines whether to use antibiotics or antidiarrheal medications based on the cause and clinical findings.
• Public health: Outbreaks or reportable pathogens (such as cholera and Salmonella outbreaks) must be reported to the relevant local public health center.

Checklist Before an Outpatient Visit (Including Sample Questions)

• Items to prepare and information to provide
  • Time symptoms began (exact date and time), symptom patterns (number and color of vomiting and diarrhea episodes, and whether there is bloody stool), and recorded body temperature
  • Foods consumed recently (especially raw foods, cooked foods, seafood, canned foods, etc.), and whether you ate out, attended a group meal, or traveled abroad
  • Whether household members or people who ate with you have symptoms
  • Underlying conditions (heart disease, kidney failure, liver disease, immunocompromised status, or pregnancy)
  • List of medications currently being taken (anticoagulants, immunosuppressants, antibiotics, etc.) and allergy history
  • Records of urine output and intake (beverage consumption), and symptoms of dehydration (dizziness, anuria)
  • If possible, recent test results (blood, urine, or stool tests) or a stool sample
• Sample questions to ask the patient at an outpatient visit (items to take notes on)
  • "When did the symptoms begin? What was the first symptom to appear?"
  • "Have you recently eaten fish/raw food/canned food/leftover food, etc.? Have you traveled abroad?"
  • "Are any of the other people who ate with you also sick?"
  • "How many times a day do you have diarrhea or vomit? Are you urinating? Have you ever felt dizzy or confused?"

General Sample Questions to Ask the Doctor

• "Given my current condition (symptoms and test results), do I need hospitalization or intravenous fluids?"
• "Do I need antibiotic or antitoxin treatment? What are the side effects?"
• "Is it okay to use an antidiarrheal medication (such as loperamide)?"
• "How many days does recovery usually take? When can I return to work or school?"
• "How should I manage fluids and nutrition at home? What foods should I avoid?"

Examples of Disease-Specific Questions

• Regarding E. coli O157:H7 (suspected hemorrhagic diarrhea): "When I have bloody diarrhea or blood in my urine, is it safe to use antibiotics or antidiarrheal medications? How will the risk of HUS be monitored?"
• Regarding suspected botulism (with neurological symptoms): "If I have respiratory muscle weakness or visual disturbances, is it urgent to administer antitoxin? How is the possibility of mechanical ventilation determined?"

(Diagnostic tests: The doctor determines whether to perform stool tests (microscopy, white blood cells, and occult blood), culture, molecular tests (PCR) and toxin tests, blood tests (electrolytes, kidney function, and hematology), imaging tests if necessary, and infectious disease reporting.)