Description

• Food poisoning or foodborne illness is caused by the consumption of food or water that is contaminated with bacterial, parasitic, or viral pathogens. Other causes can result from ingestion of molds, toxin, contaminants and/or allergens.
• Symptoms are most commonly gastrointestinal in nature.
• Foodborne illness is typically self-limited and resolves with supportive care, but in 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, with Norovirus being the most common (1). Other viral causes include hepatitis A, rotavirus, and adenovirus.
• Since 2013, Campylobacter and nontyphoidal Salmonella were the most common causes of bacterial foodborne illness in the United States.
• Other less common pathogens including Shiga toxin-producing Escherichia coli (STEC), Shigella, Cyclospora, Yersinia, Listeria, and Vibrio
• Salmonella (nontyphoidal) infections are the leading cause of foodborne illness associated with hospitalizations and deaths (2).

Incidence

• Roughly 1 in 6 Americans (48 million) and 1 in 10 across the world become ill from foodborne illness each year (3).
• In the United States, ~128,000 cases of foodborne illness require hospitalization and 3,000 result in death (3).

Etiology and Pathophysiology

• Short incubation period (1 to 6 hours)
  • Bacillus cereus toxin
    • Toxin can tolerate high temperatures.
    • Food sources: improperly cooked rice/fried rice and red meats
    • Symptoms: sudden onset of severe nausea; vomiting and diarrhea
  • Staphylococcus aureus (4)
    • Toxin mediated; toxin is heat stable.
    • Food sources: nonrefrigerated or improperly refrigerated meats and potato, mayonnaise and egg salads
    • Symptoms: sudden onset of severe nausea and vomiting; abdominal cramps and fever
• Medium incubation period (8 to 16 hours)
  • B. cereus (4)
    • Food sources: meat, stews, gravy, vanilla sauce
    • Symptoms: watery diarrhea, cramps, nausea
  • Clostridium perfringens (4)
    • Food sources: dry/precooked or undercooked meats, home-canned goods
    • Symptoms: watery diarrhea, nausea, cramps
• Long incubation period (>16 hours)
  • Toxin-producing organisms:
    • Clostridium botulinum (4)
      • Food source: commercially canned or improperly home-canned foods
      • Symptoms: vomiting, diarrhea, slurred speech, diplopia, dysphagia, and descending muscle weakness/flaccid paralysis
    • Enterohemorrhagic E. coli (e.g., 0157:H7) (4)
      • Food sources: undercooked ground beef, juice, unpasteurized milk; raw produce; and contaminated water (3)
      • Risk factors: daycare centers, nursing homes, extremes of age
      • Symptoms: severe diarrhea that often becomes bloody, abdominal pain, vomiting
    • Enterotoxigenic E. coli (“traveler’s diarrhea”) (5)
      • Food sources: food or water contaminated by human feces
      • Symptoms: watery diarrhea, abdominal cramps, tenesmus, fecal urgency, and vomiting
    • Vibrio cholerae
      • Food sources: contaminated water, fish, and shellfish, especially food sold by street vendors
      • Symptoms: profuse watery “rice water” diarrhea and vomiting, which can lead to severe dehydration and rapid death
  • Invasive organisms
    • Salmonella, nontyphoidal (1),(4)
      • Food sources: contaminated eggs, poultry; unpasteurized milk or juice, cheese; contaminated raw fruit and vegetables; and contaminated peanut butter
      • Risk factors: contact with animals
      • Symptoms: small volume, mucopurulent/bloody diarrhea; fever; cramps; vomiting
    • Campylobacter jejuni (4)
      • Food sources: raw and undercooked poultry, unpasteurized milk, and contaminated meats
      • Symptoms: diarrhea (bloody), cramps, vomiting, fever
    • Shigella (4)
      • Food sources: contaminated water, raw produce, uncooked foods, foods handled by infected food workers
      • Risk factors: men who have sex with men
      • Symptoms: abdominal cramps, fever, mucopurulent and bloody diarrhea
    • Vibrio parahaemolyticus (4)
      • Food source: undercooked or raw seafood, especially shellfish
      • Risk factors: cirrhosis
      • Symptoms: nausea, vomiting, diarrhea, abdominal pain
    • Vibrio vulnificus (4)
      • Food source: undercooked or raw seafood, particularly oysters
      • Symptoms: vomiting, diarrhea, abdominal pain, bacteremia, wound infections; can be fatal in patients with liver disease or those who are immunocompromised
    • Yersinia enterocolitica
      • Food sources: undercooked beef and pork, unpasteurized milk, tofu, contaminated water
      • Risk factors: cirrhosis, hemochromatosis, blood transfusion
      • Symptoms: abdominal pain, fever, diarrhea (possibly bloody), vomiting
    • Listeria monocytogenes (4)
      • Food sources: unpasteurized/contaminated milk, soft cheese, and processed deli meats
      • Risk factors: pregnancy
      • 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.

Risk Factors

• Recent travel to developing countries (1)
• 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 (1)
• Cross-contamination and subsequent ingestion of improperly prepared and stored foods
• Pregnancy
• Children >5 years and adults age >65 years
• Immunocompromised patients

General Prevention

• When preparing food:
  • 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 (6).
  • 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.
• When traveling to underdeveloped countries:
  • Eat only freshly prepared food.
  • Avoid beverages and foods prepared with nonpotable water.
  • Bottled, carbonated, and boiled beverages are safe to drink.
• Chemoprophylaxis for traveler’s diarrhea is recommended for high-risk travelers (e.g., immunocompromised) (5).

Commonly Associated Conditions

• Botulism—potentially lethal neuroparalytic condition characterized by symmetric neurologic deficits and changes in mental status because of 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 (HUS)—hematologic condition characterized by microangiopathic hemolytic anemia, renal impairment, and thrombocytopenia caused by both Shigella and STEC; can be precipitated in patients harboring enterohemorrhagic E. coli who are treated with antibiotics (1)
• 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