What infections can be transmitted through consuming sushi?

Infections Associated with Sushi Consumption

Consuming raw or undercooked fish in sushi can transmit several potentially serious infections, including parasitic, bacterial, and viral pathogens that may cause significant morbidity and mortality if not promptly diagnosed and treated.

Parasitic Infections

Anisakiasis

• Caused by ingestion of Anisakis larvae (marine nematodes) in raw fish 1, 2
• Common in fish species used for sushi: salmon, mackerel, herring, cod, and squid 2
• Clinical presentation:
  • Acute onset of severe abdominal pain within hours to 5 days after consumption
  • Nausea, vomiting, diarrhea
  • Can present as bowel obstruction requiring surgical intervention 1
  • May cause allergic reactions including urticaria, angioedema, and anaphylaxis 3
• Treatment:
  • Early endoscopic removal of larvae (within 12 hours) is recommended 3
  • Surgical intervention may be necessary for intestinal invasion or obstruction 1

Pseudoterranovosis

• Caused by Pseudoterranova decipiens larvae
• More common in Chile and generally less invasive than Anisakis 4
• Clinical presentation:
  • Typically milder symptoms than Anisakiasis
  • Larvae rarely migrate beyond the stomach
• Treatment:
  • Often spontaneously eliminated
  • May require endoscopic removal 4

Liver Flukes

• Associated with consumption of raw freshwater fish
• Can lead to cholangiocarcinoma through chronic inflammation and biliary damage 5
• Prevention:
  • Avoid consuming raw freshwater fish
  • Regular screening with abdominal ultrasound for those with known infection 5

Bacterial Infections

Escherichia coli and Staphylococcus aureus

• Higher prevalence in fresh sushi from sushi bars compared to frozen commercial sushi 6
• Can cause gastroenteritis with diarrhea, abdominal cramps, and vomiting

Salmonella and Listeria monocytogenes

• Found in approximately 1.2-1.6% of sushi samples 6
• Can cause severe foodborne illness, particularly dangerous for immunocompromised individuals, pregnant women, and the elderly

Shiga Toxin-Producing E. coli (STEC)

• Can cause severe bloody diarrhea and potentially hemolytic uremic syndrome (HUS)
• Low infectious dose (<100 organisms) 7
• Prevention:
  • Avoid raw or undercooked fish and shellfish 7

Viral Infections

Norovirus

• Leading cause of foodborne disease outbreaks in the US 7
• Raw foods (including seafood) are commonly implicated in outbreaks 7
• Clinical presentation:
  • Acute onset of vomiting, watery diarrhea, abdominal cramps
  • Highly contagious with secondary person-to-person transmission

Risk Factors and High-Risk Populations

Certain populations should be particularly cautious about consuming sushi:

1. Immunocompromised individuals:

   • HIV-infected patients
   • Cancer chemotherapy recipients
   • Transplant recipients on immunosuppressive medications 7

2. Pregnant women:

   • Higher risk of severe Listeria monocytogenes infection 7
   • Potential for miscarriage

3. Young children and elderly:

   • More susceptible to severe illness from Salmonella and E. coli 7

4. Individuals with liver disease:

   • Higher risk of severe infections from raw shellfish 7

Prevention Strategies

1. Avoid raw fish entirely if you're in a high-risk group 7

2. Choose commercially frozen sushi when possible, as it typically has better microbiological quality than fresh sushi from sushi bars 6

3. Ensure proper food handling practices:

   • Proper refrigeration
   • Clean preparation surfaces
   • Separation of raw and cooked foods 7

4. Consider frozen fish:

   • Freezing raw fish prior to preparation can inactivate parasitic larvae 4

5. Look for reputable establishments with good hygiene practices and proper food safety certifications

When to Seek Medical Attention

Seek immediate medical attention if you experience:

• Severe abdominal pain after consuming sushi
• Persistent vomiting or diarrhea
• Bloody diarrhea
• Signs of dehydration
• Fever with gastrointestinal symptoms

Early diagnosis and treatment are crucial, particularly for parasitic infections like anisakiasis where prompt endoscopic removal can prevent complications and the need for surgery 3.