Description

• Food poisoning or foodborne illness is caused by the consumption of food or water that is contaminated with bacterial, parasitic, or viral pathogens; less commonly molds, toxins, contaminants and/or allergens
• Symptoms are most commonly gastrointestinal in nature and are typically self-limited. Some cases can lead to severe dehydration and critical illness.

Epidemiology

• The cause is unclear in up to 80% of cases. Most foodborne illnesses are secondary to viral causes, Norovirus being the most common. Other viral causes include hepatitis A, rotavirus, and adenovirus.
• Campylobacter and nontyphoidal Salmonella are the most common causes of bacterial foodborne illness in the United States. Other pathogens include Shiga toxin-producing Escherichia coli (STEC), Shigella, Cyclospora, Yersinia, Listeria, and Vibrio.
• Salmonella (nontyphoidal) infections are the bacterial foodborne illnesses most commonly associated with hospitalizations and deaths.

Etiology and Pathophysiology

• Invasive pathogens:
  • Campylobacter jejuni: timing: 2 to 5 days; symptoms: diarrhea (bloody), cramps, vomiting, fever; food sources: raw and undercooked poultry, unpasteurized milk, and contaminated meats
  • Salmonella, nontyphoidal: timing: 6 to 48 hours; symptoms: small volume, mucopurulent/bloody diarrhea, fever, cramps, vomiting; food sources: contaminated eggs, poultry; unpasteurized milk or juice, cheese; contaminated raw fruit and vegetables; and contaminated peanut butter
  • Clostridium perfringens: timing: 8 to 16 hours; symptoms: watery diarrhea, nausea, cramps; sources: dry/precooked or undercooked meats, poultry, home-canned goods
  • Enterohemorrhagic E. coli (ETEC): timing: 1 to 8 days; symptoms: severe diarrhea often becoming bloody, abdominal pain, vomiting; sources: undercooked ground beef, juice, unpasteurized milk, raw produce, and contaminated water
  • Shigella: timing: 4 to 7 days; symptoms: abdominal cramps, fever, mucopurulent and bloody diarrhea; food sources: contaminated water, raw produce, uncooked foods, foods handled by infected food workers
  • Shiga toxin-producing E. coli (STEC); may present with hemolytic uremic syndrome
  • Yersinia enterocolitica: timing: 4 to 7 days; symptoms: abdominal pain, fever, diarrhea (possibly bloody), vomiting; food sources: undercooked beef and pork, unpasteurized dairy products, tofu, contaminated water; additionally, can be due to exposure to house pets with diarrhea
  • Vibrio parahaemolyticus: timing: 4 to 96 hours; symptoms: nausea, vomiting, diarrhea, abdominal pain; food source: undercooked or raw seafood, especially shellfish
  • Vibrio vulnificus: timing: 1 to 7 days; symptoms: vomiting, diarrhea, abdominal pain, bacteremia, wound infections; can be fatal in patients with liver disease or those who are immunocompromised; food source: undercooked or raw seafood, particularly oysters
  • Enterotoxigenic E. coli (“traveler’s diarrhea”): timing: 1 to 3 days; symptoms: watery diarrhea, abdominal cramps, tenesmus, fecal urgency, and vomiting; sources: food or water contaminated by human feces
  • Listeria monocytogenes: timing: 4 to 48 hours; symptoms: nausea, vomiting, fever, watery diarrhea; pregnant women may have a flu-like illness leading to premature delivery or stillbirth; immunocompromised patients may develop meningitis and bacteremia; food sources: unpasteurized/contaminated milk, soft cheese, and processed deli meats
• Preformed enterotoxin syndromes:
  • Staphylococcus aureus: timing: 1 to 6 hours; symptoms: sudden onset of severe nausea and vomiting; abdominal cramps and fever; sources: improperly refrigerated meats and potato, mayonnaise, and egg salads
  • Bacillus cereus: timing: symptom onset: 10 to 16 hours; symptoms: sudden onset of severe nausea, vomiting and watery diarrhea, nausea and cramps; sources: soil, improperly cooked rice/fried rice and red meats
  • Clostridium botulinum: timing: 12 to 72 hours; symptoms: vomiting, diarrhea, slurred speech, diplopia, dysphagia, and descending muscle weakness/flaccid paralysis; source: improperly canned foods

Risk Factors

Recent travel to developing countries; food handlers, daycare attendees, nursing home residents, recently hospitalized patients, or patients recently exposed to antibiotics; altered immunity due to underlying disease or use of certain medications, including antacids, H₂ blockers, and proton pump inhibitors; cross-contamination and subsequent ingestion of improperly prepared and stored foods; pregnancy; children aged <5 years and adults aged >65 years; immunocompromised patients

General Prevention

• Food preparation: Wash hands, cutting boards, and preparation surfaces. Wash fresh produce thoroughly before consuming. Keep raw meat, poultry, fish, and their juices away from other food (e.g., salad). Wear gloves when handling raw meat. Thoroughly cook the meat. Refrigerate leftovers within 2 to 3 hours in clean, shallow, covered containers. If the temperature is >90°F, refrigerate within 1 hour.
• Travel to underdeveloped countries: Eat only freshly prepared food and avoid beverages and foods prepared with nonpotable water. Bottled, carbonated, and boiled beverages are safe to drink.
• Chemoprophylaxis with bismuth subsalicylates reduces risk over 3-week period. Short-term prophylactic antibiotics are indicated for high-risk traveler’s (e.g., immunocompromised) (2).

Commonly Associated Conditions

• Botulism: symmetric neurologic deficits and changes in mental status due to ingestion of toxin types A, B, and E produced by C. botulinum; outbreaks typically involve home-canned foods such as fruits, vegetables and meats.
• Neonatal meningitis: Immunocompromised hosts, particularly neonates (<29 days old), can contract meningitis from systemic L. monocytogenes infection.
• Hemolytic uremic syndrome: microangiopathic hemolytic anemia, renal impairment and thrombocytopenia caused by Shigella and STEC
• Guillain-Barré syndrome: ascending paralysis strongly associated with C. jejuni infection
• Reactive arthritis: can occur after severe infections with Salmonella, Shigella, Yersinia, or Campylobacter species
• Irritable bowel syndrome: can occur after infections with Campylobacter, Salmonella, Shigella, STEC, and Giardia.