Food Poisoning: Severe Stomach Pain, Vomiting, Diarrhea—Dont Ignore These Symptoms

• Food poisoning Food poisoning is a condition caused by consuming contaminated food or drinks, such as those containing bacteria, viruses, parasites, or microbial toxins.
• In healthy individuals, food poisoning usually resolves without medical treatment. However, if diarrhea lasts more than three days, occurs more than six times a day, or is accompanied by a fever above 38.9°C, nausea, dizziness, loss of appetite, or vomiting, prompt medical attention is advised.

What is food poisoning?

Food poisoning Food poisoning is a condition caused by consuming contaminated food or drinks containing bacteria, viruses, parasites, or microbial toxins. It leads to gastrointestinal symptoms such as nausea, vomiting, abdominal pain, and diarrhea. Sometimes, multiple individuals who eat the same contaminated food develop symptoms. Symptoms can appear rapidly after eating or several days to weeks later. Each person’s response time, symptoms, and severity may vary.

Food contaminated with bacteria, viruses, parasites, or harmful chemicals can cause over 200 diseases, ranging from diarrhea to cancer. It can also cause malnutrition, particularly affecting infants, young children, and the elderly.

Food poisoning is caused by consuming food or water contaminated with pathogens such as bacteria, viruses, or natural toxins including heavy metals and toxins produced by animals.

Pathogens found in food that can cause food poisoning in Thailand

Food poisoning is a significant public health issue often caused by bacteria, viruses, and toxins contaminating food. Common pathogens include the following.

1. Bacterial pathogens in food

• Salmonella spp. is found in raw eggs, raw or undercooked meat, and can contaminate raw milk and dairy products.
• Escherichia coli (E. coli) is found in undercooked meat, fresh vegetables, and contaminated water. It may be present in food contaminated with animal or human feces. Symptoms include diarrhea and abdominal pain; some strains can cause kidney failure.
• Vibrio parahaemolyticus is found in raw or undercooked seafood such as shrimp, shellfish, crab, and fish, often contaminated from seawater. Symptoms usually include severe diarrhea, nausea, and vomiting.
• Bacillus cereus is found in rice, starchy foods, and foods left at room temperature too long, causing nausea, vomiting, and diarrhea.
• Staphylococcus aureus is found in foods handled by cooks, such as Khanom Jeen, sushi, and eclairs, potentially contaminated from hand wounds. Symptoms include sudden vomiting and abdominal pain.
• Clostridium perfringens is found in meat dishes such as stews, pies, and processed meats, often due to improper food storage. Symptoms include abdominal pain, diarrhea, and weight loss.

2. Viral pathogens in food

• NorovirusFound in seafood, fresh vegetables, and fruits; commonly affects children, causing nausea, vomiting, diarrhea, and fever.
• RotavirusContracted from contaminated food, causing diarrhea, abdominal pain, and fever. Sometimes diarrhea is severe or prolonged. Common in children but outbreaks among adults have been reported.
• Hepatitis A virus (Hepatitis A virus) is found in food and water contaminated with feces, such as fresh vegetables and raw shellfish. Symptoms include loss of appetite, fever, jaundice, and abdominal pain.

3. Parasites and other contaminants in food

• Liver fluke (Opisthorchis viverrini) is found in raw or undercooked freshwater fish, such as koi pla and fermented fish. Symptoms include bloating, abdominal fullness, and increased risk of bile duct cancer.
• Gnathostoma spinigerum Found in raw fish, frogs, snakes, or partially cooked aquatic animals. Symptoms include allergic reactions, itching rashes, and skin inflammation.

Factors affecting bacterial growth causing food poisoning

1. Time Bacteria can multiply rapidly under suitable conditions.
2. Temperature Bacteria grow best between 5°C and 60°C. Therefore, perishable foods should be stored either very cold or very hot to prevent bacterial growth.
3. Nutrients Many foods such as milk, eggs, meat, poultry, and seafood provide sufficient nutrients for bacteria to grow.
4. Water Bacteria require water to grow. Dry foods spoil less easily due to lack of water for bacterial growth.
5. pH level The acidity or alkalinity (pH) of food affects bacterial growth. Acidic conditions (low pH) generally inhibit bacterial growth, while neutral pH foods, common in many foods, support bacterial growth well.

Controlling these factors helps reduce the risk of food poisoning and ensures food safety.

Symptoms of food poisoning

Symptoms usually appear within hours or days after exposure to toxins. Patients may experience:

• loss of appetite, nausea, vomiting,
• diarrhea that may be watery, mucus- or blood-tinged, resembling rice water, or have an unusual fishy odor,
• abdominal cramps,
• fever and body aches,
• headache,
• and fatigue.

Food poisoning symptoms requiring urgent medical attention

In healthy individuals, food poisoning usually resolves without medical intervention, but if any of the following symptoms occur, immediate medical care is necessary:

• diarrhea persisting beyond three days or more than six bowel movements in one day,
• high fever, especially above 38.9°C,
• severe dehydration signs such as dry mouth and mucous membranes, very little urine output, dark urine, or no urination for over six hours,
• inability to drink fluids to replace lost water,
• diarrhea or vomiting containing blood,
• severe abdominal pain,
• lethargy or confusion,
• dizziness or lightheadedness, especially when standing up or changing position.

Diagnosis of food poisoning

Diagnosis is often made based on patient history and physical examination. Observing and reporting symptoms and stool characteristics can help identify the causative agent. Physicians may order blood tests or stool cultures to identify the pathogen, though sometimes the specific cause cannot be determined.

How is food poisoning treated?

Food poisoning usually resolves with self-care and symptomatic treatment, such as:

• drinking plenty of fluids or oral rehydration solutions to replace lost fluids,
• taking fever reducers to relieve fever, headache, or body aches,
• resting adequately and avoiding foods that may worsen symptoms, such as spicy, fatty, fried foods, undercooked items, and raw vegetables or fruits.

Medications for food poisoning

• Commonly used home remedies may relieve symptoms like abdominal pain and vomiting.
• Activated charcoal can help alleviate symptoms for poisoning caused by some toxins or chemicals.
• Certain bacterial food poisoning cases require antibiotics or antimicrobial treatment.
• Anti-diarrheal medications are generally not recommended, especially for children or suspected infectious food poisoning cases.

Is food poisoning life-threatening?

Although most cases resolve without complications, some patients are at risk of severe illness. High-risk groups include:

• children under five years old, due to their immature immune systems,
• elderly individuals over 65 years,
• pregnant women, who may experience immune changes and have limited safe medication options,
• people with chronic diseases, especially those affecting immunity,
• and those taking immunosuppressive drugs such as steroids.

Preventing food poisoning

Food poisoning can be prevented by following hygiene and food safety guidelines, including:

1. Choosing safe foods

• Select food that is cooked thoroughly, fresh, and clean.
• Buy food from reputable sources with proper sanitary storage.
• Avoid raw or partially cooked foods such as raw fish, raw shellfish, raw eggs, and undercooked meats.

2. Maintaining personal hygiene

• Wash hands regularly before eating, after handling pets or dirty objects, and after using the restroom. Use soap or disinfectant. Alcohol-based hand rubs can help but may not kill certain viruses like Norovirus and Rotavirus.

3. Safe food storage and preparation

• Wash fruits and vegetables thoroughly before consumption or cooking.
• Use separate utensils and cutting boards for raw and cooked foods to avoid cross-contamination.

• Store food at appropriate temperatures.
  - Keep refrigerators between 0-4°C.
  - Freeze meats below -18°C.
  - Avoid leaving food at room temperature for more than 1-2 hours.

• Most foods should be cooked to at least 75°C.

4. Avoid high-risk foods prone to contamination

• Leftover or room temperature food stored too long,
• unpasteurized milk,
• foods containing coconut milk, which spoil easily,
• papaya salad, spicy salads, or seafood that is not fresh or undercooked,
• fermented foods such as Khanom Jeen and pickled items,
• salad vegetables and ice or water from unreliable sources,
• undercooked meat,
• and juices or fruits prepared by food handlers of uncertain hygiene.

Information provided by Dr. Sasinee Thongprasert, gastroenterologist and hepatologist,Samitivej Srinakarin Hospital