Foodborne Illnesses

Background

• Foodborne illnesses are acquired via ingestion of food or water contaminated with bacterial or nonbacterial toxins, pathogenic bacteria, viruses, parasites, and certain chemicals.
• About 48 million foodborne illnesses occur each year in the United States, resulting in over 128,000 hospitalizations and 3,000 deaths.
• The prevalence of causative pathogens and exposures varies with geography.
• The most common causes of foodborne illness in the United States include norovirus, nontyphoidal Salmonella species, and Campylobacter species.
• Additional important causes include:
  • bacterial toxin-mediated illnesses due to Bacillus cereus or Staphylococcus aureus
  • bacterial infections due to
    • pathogenic strains of Escherichia coli, Shigella, and Vibrio species
    • Listeria, with more complicated disease possible in pregnant persons, newborns born to infected mothers, the elderly, and immunocompromised persons.
  • viruses such as hepatitis A, norovirus, and rotavirus
  • parasites such as Giardia lamblia, Entamoeba histolytica, Cyclospora, and Cryptosporidium
  • marine toxin-mediated illness, such as ciguatera, scombroid, tetrodotoxin ingestion, and shellfish poisoning
• Most foodborne illnesses present with a mild and self-limited gastrointestinal illness.
• Some may be accompanied by or present with neurologic illness.
• Invasive illness is uncommon.
  • Occurs more frequently in infants, young children, pregnant women, older adults, and immunocompromised patients
  • Notable pathogens with particular invasive potential include infections with Salmonella, Listeria, and Vibrio species

Evaluation

• Suspect foodborne illness in patients with gastrointestinal or neurologic symptoms, particularly when that person has shared food with another person with similar symptoms.
• Ask about potential exposures including recent travel, ingestion of raw or undercooked meat or seafood, consumption for unpasteurized dairy products, and ill contacts.
• Diagnosis can be made based on clinical history alone and testing is often not needed.
• The decision to pursue diagnostic testing should be based on characteristics of illness and exposure history.
  • Evaluate patients with fever or bloody diarrhea for enteropathogens that may respond to antimicrobial agents, such as Salmonella enterica, Shigella, and Campylobacter (Strong recommendation).
  • Perform stool testing for Salmonella, Shigella, Campylobacter, Yersinia, Clostridium difficile, and Shiga toxin-producing Escherichia coli
    • In patients with diarrhea and fever, bloody or mucoid stools, severe abdominal cramping or tenderness, or signs of sepsis (Strong recommendation).
    • Under specific circumstances in other symptomatic patients, taking into account exposures (such as food, water, contact with healthcare, and travel), association with recent outbreaks, and underlying conditions (such as age and immunocompromise) (Strong recommendation).

Management

• Supportive care is the mainstay of treatment for most foodborne illness, focused on rehydration and correction of electrolyte abnormalities, particularly in those with diarrheal illnesses.
• Antimicrobials are indicated for most invasive infections with fever and/or dysentery, but should be avoided in patients with known or suspected Shiga toxin-producing Escherichia coli infection due to the risk of hemolytic uremic syndrome (Strong recommendation).
• Selection of antimicrobial varies with infecting pathogen and may be complicated by rising rates of resistance, which vary by region.
• For cause-specific management refer to specific causes above.
• Prevention of foodborne disease:
  • careful handling of animals, raw products, and processed foods all the way from the farm to the table, and on practices that reduce or eliminate contamination in food.
  • vaccination when available such as rotavirus and Hepatitis A virus.