Anisakiasis

Anisakiasis is a disease caused by tiny roundworms (nematodes) that live in some raw or undercooked marine fish and squid. When a person eats fish or squid that contains a live larva, the worm can stick to or burrow into the lining of the esophagus, stomach, or intestine. This can cause sudden stomach pain, nausea, vomiting, or later problems that mimic other illnesses. The worms do not grow into adults in people. They die after days or weeks, but the irritation and inflammation they cause can last longer. Doctors usually diagnose the problem by seeing and removing the worm during endoscopy, or—less often—by surgery or imaging when the worm is deeper in the bowel wall. Cooking or deep-freezing fish the right way kills the larvae and prevents anisakiasis. CDC+1

Anisakiasis is a stomach or intestinal infection caused by swallowing live larvae of marine roundworms (usually Anisakis or Pseudoterranova) in raw or undercooked fish or squid. Symptoms can start within hours to days and include sudden stomach pain, nausea, vomiting, or diarrhea; some people develop allergic reactions (from hives to anaphylaxis) to parasite proteins. Endoscopy can both diagnose and cure gastric cases by removing the larva. Freezing or thoroughly cooking seafood prevents infection. CDC+2CDC+2

The worms live in a sea-mammal–fish cycle. Fish flesh can carry infective larvae. If we eat the fish raw or undercooked, a larva can attach to and burrow into our stomach or intestinal lining, causing pain and inflammation. Even dead larvae can trigger allergy in sensitized people because several Anisakis proteins are heat-stable. CDC+2PMC+2

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Other names

You may also see these names:

• Herring worm disease (very common plain-language term). CDC

• Herringworm, codworm, and sealworm (nicknames for these larvae in fish markets and lab manuals). CDC

• Anisakidosis (an alternative medical name used in research and public-health papers; it includes infection by close relatives like Pseudoterranova). CDC

• Cod worm disease and seal worm disease (older or lay terms you may see in clinical summaries). Merck Manuals

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Types

1. Gastric anisakiasis
   The larva attaches to the stomach lining. Symptoms usually start within hours of eating the fish: sharp upper-abdominal pain, nausea, or vomiting. Doctors often find and remove the larva during an upper endoscopy. Merck Manuals+1

2. Intestinal anisakiasis
   The larva reaches the small intestine. Symptoms may appear days to 1–2 weeks later and can look like appendicitis or Crohn’s disease (pain, obstruction, fever). Imaging or deep enteroscopy may be needed to find it. Merck Manuals+1

3. Ectopic anisakiasis
   Rarely, larvae are found outside the gut, such as in the peritoneal cavity, mesentery, esophagus, or even tongue. These unusual sites can confuse the diagnosis. CDC

4. Allergic or “gastro-allergic” anisakiasis
   Proteins from Anisakis can trigger allergic reactions, from hives to, rarely, anaphylaxis—sometimes even when the larva is dead after freezing. Allergy can occur alone or together with gastric symptoms. CDC+1

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Causes

1. Eating raw fish (sushi/sashimi)
   Raw marine fish can carry live anisakid larvae. If the fish was not frozen according to safety guidelines, infection can occur. CDC

2. Eating raw or undercooked squid
   Squid can also host larvae, and raw preparations carry the same risk. CDC

3. Ceviche, carpaccio, or other acid-marinated dishes
   Marinating or pickling does not reliably kill anisakid larvae; the dish may still be infectious. Merck Manuals

4. Cold-smoked or lightly salted fish
   Light salting or cold smoking is not sufficient to kill larvae unless validated freezing steps were used first. Merck Manuals

5. Inadequate home freezing
   Prevention requires very specific time-temperature steps (see below). Home freezers that don’t meet these settings may fail to kill larvae. CDC

6. Predatory fish species
   Larvae are most common in predators such as herring, cod, mackerel, and others; many marine fish can be affected. CDC

7. Salmon and rockfish
   These are frequently implicated in case reports and reviews. PMC

8. Anchovies and sardines
   Small schooling fish used for raw or lightly processed dishes have been repeatedly linked to cases.

9. Consumption soon after catch without proper evisceration
   Larvae can move from viscera to muscle after the fish dies, raising risk if not handled correctly. CDC

10. Eating “street” or informal raw-seafood dishes
    When freezing or sourcing is uncertain, the risk increases. (General risk statement supported by CDC prevention guidance.) CDC

11. Geographic food traditions
    High case numbers occur where raw seafood is popular (e.g., Japan, parts of Europe, and South America). CDC Travelers’ Health

12. Cross-contamination in the kitchen
    Raw fish juices or pieces transferred to ready-to-eat foods can carry larvae if not controlled. (Food safety principle consistent with CDC/FDA guidance.) CDC

13. Raw fish roe or offal
    Larvae can be concentrated in viscera; consuming raw viscera or roe increases exposure risk. CDC

14. Raw fish sold as “previously frozen” without validated freezing
    If freezing did not meet time-temperature targets, risk remains. CDC

15. Undercooked grilled or pan-seared fish
    If the core does not reach ≥63 °C (145 °F), larvae may survive. CDC

16. Eating raw squid (“ika”) or similar dishes
    Documented vector similar to fish. CDC

17. Eating pickled herring or gravlax not properly frozen
    Again, salt/acid alone is unreliable. Merck Manuals

18. Allergic sensitization to Anisakis proteins
    Even dead larvae can leave allergens in fish muscle that trigger hives or anaphylaxis in sensitized people. CDC

19. Eating wild-caught fish without parasite controls
    Wild fish have higher natural parasite loads than farmed fish from controlled systems. (Public-health reviews highlight wild species as typical sources.) PMC

20. Lack of awareness of freezing rules
    Not knowing the FDA/CDC freezing recommendations leads to preventable exposures. (See prevention section below.) CDC

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Symptoms

1. Sudden upper-abdominal pain
   Often starts within hours after eating raw fish; caused by a larva attaching to stomach lining. Merck Manuals

2. Nausea
   The irritated stomach can trigger persistent nausea soon after the meal. CDC

3. Vomiting
   Some people vomit; occasionally the larva is expelled this way. CDC

4. Abdominal swelling or bloating
   Inflammation can cause a sense of fullness or visible distension. CDC

5. Diarrhea
   Irritation of the gut can lead to loose stools. CDC

6. Blood or mucus in stool
   Mucosal injury may cause minor bleeding or mucus. CDC

7. Mild fever
   A low-grade temperature can occur with the inflammatory response. CDC

8. Tingling or crawling feeling in mouth/throat while eating
   People sometimes feel the moving larva and cough it out. CDC

9. Lower-abdominal pain days later
   Intestinal disease may appear later and may mimic appendicitis or Crohn’s disease. Merck Manuals

10. Hives (urticaria)
    Allergic skin reaction soon after eating infected fish. CDC

11. Itching or flushing
    Another allergic-type response to parasite proteins. CDC

12. Anaphylaxis (rare)
    Severe, life-threatening allergy with breathing trouble and low blood pressure can happen in sensitized people. Seek emergency care. CDC

13. Coughing up a worm
    A few patients spontaneously cough up the larva from the esophagus/stomach. CDC

14. Obstruction symptoms
    Crampy pain, vomiting, and inability to pass gas/stool can occur with small-bowel involvement. PMC

15. Symptoms that settle, then linger
    Even after the larva dies, local inflammation can keep symptoms going for days to weeks. Merck Manuals

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Diagnostic tests

A) Physical examination

1. Vital signs and general exam
   Doctors check pulse, blood pressure, temperature, and overall distress. Fever may be mild, and patients often look uncomfortable from abdominal pain. Physical exam guides urgency. CDC

2. Abdominal palpation
   Tenderness—often in the upper abdomen for gastric cases—helps point toward stomach involvement after a raw-fish meal. PMC

3. Rebound or guarding
   If there is marked peritoneal irritation (rare), it suggests deeper inflammation or perforation and pushes clinicians toward imaging or surgery. CDC

4. Skin exam for allergy
   Hives or flushing shortly after eating fish can suggest gastro-allergic anisakiasis. ASM Journals

5. Hydration assessment
   Vomiting/diarrhea can dehydrate patients; exam findings guide supportive care while the diagnostic work-up proceeds. CDC

B) Manual / procedural tests

6. Upper GI endoscopy (esophagogastroduodenoscopy)
   This is the key test. Doctors can see the larva attached to the stomach or esophagus and remove it with forceps, which often stops symptoms quickly. CDC+1

7. Deep enteroscopy (e.g., double-balloon enteroscopy)
   If imaging suggests small-bowel disease, a specialized scope can reach the jejunum/ileum to find and remove the larva. Case reports show rapid relief after extraction. PMC+1

8. Colonoscopy
   Rare intestinal or terminal-ileal cases may be seen and removed during colonoscopy when symptoms or imaging point to the right colon/ileum. Karger

9. Diagnostic laparoscopy
   If a patient has obstruction, peritonitis, or unclear acute abdomen, surgeons may do laparoscopy; tissue can then confirm the diagnosis. parasite-journal.org

10. Skin-prick testing for Anisakis allergy
    Allergy specialists may use skin tests when there is a history of immediate allergic reactions to fish and suspected Anisakis sensitization. Results help with counseling but can cross-react with other allergens. MDPI

C) Laboratory & pathological tests

11. Complete blood count (CBC)
    Eosinophilia may appear, especially with intestinal/ectopic disease, but it is not specific and may be normal in early gastric cases. (General feature in reviews.) PMC

12. Serum total IgE and Anisakis-specific IgE (sIgE)
    Blood tests can show allergic sensitization (IgE) to Anisakis. They support—but do not confirm—diagnosis and may cross-react with other parasites or seafood allergens. MDPI

13. Histopathology of removed larva or biopsy
    Under the microscope, pathologists recognize anisakid features in the worm or tissue reaction. This is definitive when a specimen is available. CDC

14. Molecular testing (PCR) on the larva
    Laboratories can identify the species (Anisakis simplex, A. pegreffii, Pseudoterranova, etc.), which is useful for public-health tracking though not required for patient care. CDC

15. Inflammatory markers (CRP/ESR)
    These may be elevated with intestinal inflammation but are nonspecific; they help judge severity, not the specific cause. (Supported by clinical reviews.) PMC

16. Stool ova-and-parasite exam (O&P)
    Usually not helpful because the parasite does not mature or lay eggs in humans; stool exams are generally negative in anisakiasis. Merck Manuals

D) Imaging tests

17. Abdominal CT scan
    CT may show thickened bowel loops, localized edema, inflammatory masses, or signs of obstruction, guiding the need for endoscopy or surgery in intestinal disease. PMC

18. Abdominal ultrasonography
    Ultrasound can show bowel wall swelling or a “target sign” and helps evaluate complications when radiation is a concern. (Used alongside CT and endoscopy in case series.) Gutn Liver

19. Plain abdominal X-ray
    Can reveal air-fluid levels in suspected obstruction and support urgent management, though it does not show the worm itself. (General imaging approach referenced in small-bowel anisakiasis series.) Gutn Liver

20. MRI (selected cases)
    Rarely used, but MRI can demonstrate small-bowel edema or masses when other tests are inconclusive or radiation should be avoided. (Adjunctive role inferred from intestinal case literature.) PMC

E) Electrodiagnostic tests

1. There are no electrodiagnostic tests (like EMG or EEG) used to diagnose anisakiasis. Diagnosis relies on endoscopy, pathology, selected labs (IgE), and imaging. CDC

Non-pharmacological treatments (therapies & “other” care)

These measures either remove the parasite, protect the gut while the larva dies, or manage complications. I include purpose and mechanism in simple terms.

1. Immediate endoscopic removal (first-line for gastric cases).
   Purpose: cure by extraction. Mechanism: a flexible scope grabs and removes the larva with forceps; pain typically resolves quickly. PMC

2. Targeted visualization (NBI/zoom endoscopy).
   Purpose: find subtle larvae. Mechanism: narrow-band imaging highlights mucosal details so the worm can be located and removed. PMC

3. Topical L-menthol during endoscopy (optional aid).
   Purpose: ease removal. Mechanism: smooth-muscle relaxant sprayed on the stomach wall can reduce spasms and help immobilize the larva for safe extraction. PMC

4. Watchful waiting for intestinal disease when stable.
   Purpose: avoid unnecessary procedures. Mechanism: many intestinal larvae die within about a week; careful observation with symptom control is often enough if there’s no obstruction or peritonitis. PMC

5. Bowel rest (temporary “nothing by mouth” then gentle diet).
   Purpose: calm irritation. Mechanism: resting the gut reduces mechanical stimulation while inflammation settles, then advancing to a bland, low-fat diet. PMC+1

6. Oral rehydration (ORS) or IV fluids as needed.
   Purpose: prevent or correct dehydration from vomiting/diarrhea. Mechanism: balanced salts/glucose solutions replace fluids and electrolytes; IV fluids if ORS not tolerated. World Health Organization+1

7. Nasogastric decompression for ileus/obstruction (selected cases).
   Purpose: relieve distension and vomiting. Mechanism: a soft tube drains stomach contents and reduces pressure while the bowel recovers or while arranging definitive care. Oxford Academic

8. Allergy action plan & trigger avoidance.
   Purpose: prevent repeat reactions. Mechanism: strict avoidance of raw/undercooked fish; discuss that some Anisakis allergens are heat-stable—so even cooked fish can trigger allergy in sensitized individuals. PubMed+1

9. Dietary step-up (short-term bland choices).
   Purpose: reduce irritation. Mechanism: small, frequent meals; low-acid, low-fat, easy-to-digest foods for a few days, then gradual return to normal nutrition. NCBI

10. Education on safe seafood handling (home and food-service).
    Purpose: prevent reinfection. Mechanism: cook seafood to ≥145°F (63°C) or freeze per CDC/FDA specifications before raw service. CDC

11. Restaurant/vendor HACCP adherence.
    Purpose: upstream prevention. Mechanism: hazard analysis and controls (e.g., mandatory freezing steps for fish served raw). U.S. Food and Drug Administration+1

12. Surgical consultation for suspected complications.
    Purpose: timely escalation. Mechanism: surgeons evaluate for obstruction, localized peritonitis, or mass-forming granuloma needing resection. CDC

13. Repeat endoscopy if symptoms persist after removal.
    Purpose: ensure no second larva or retained fragment. Mechanism: careful re-inspection and extraction if needed. PMC

14. Allergy referral/testing when reactions occur.
    Purpose: confirm sensitization and counsel long-term risk. Mechanism: history, specific IgE (e.g., Ani s 7), and supervised challenges where appropriate. PMC

15. Workplace/occupational counseling (fish handlers).
    Purpose: protect at-risk workers. Mechanism: PPE, proper cold-chain, and avoidance of tasting undercooked product. FAOHome

16. Food labeling/consumer advice for at-risk diners.
    Purpose: informed choices. Mechanism: menus/labels indicating raw seafood risks and freezing practices. FAOHome

17. Community education during local spikes.
    Purpose: reduce outbreaks. Mechanism: public health messaging when cases rise with seasonal fish catches. CDC Travelers’ Health

18. Careful visual inspection when prepping fish.
    Purpose: reduce larval load. Mechanism: trimming visible worms (“codworms”) during filleting—still combine with cooking/freezing. CDC

19. Avoid unreliable “cold cures.”
    Purpose: dispel myths. Mechanism: salting, pickling, and cold-smoking do not reliably kill larvae; use proper freezing or heat. PMC

20. Documentation of the suspect meal.
    Purpose: improves diagnosis. Mechanism: noting the exact fish, where eaten, and timing helps clinicians decide on endoscopy vs. watchful waiting. CDC

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Drug treatments

Important: Medicines do not substitute for endoscopic removal when a larva is in the stomach. Drugs below are either (A) anti-parasitic options used in case reports/series, or (B) supportive medications for pain, nausea, acid injury, or allergy. Always follow local medical guidance.

1. Albendazole (primary anti-parasitic when used).
   Class: benzimidazole. Typical report-based doses: 400 mg by mouth twice daily for 6–21 days in presumptive/intestinal disease; some reports used up to 28 days. Purpose/mechanism: inhibits worm microtubules; may help kill residual larvae when removal isn’t feasible. Side effects: GI upset, liver enzyme rise—monitor if prolonged. Evidence is from case series/case reports; efficacy is variable. CDC+2PMC+2

2. Mebendazole (limited reports).
   Class: benzimidazole. Dose used in reports: 100 mg twice daily for 3 days, sometimes after surgery. Purpose/mechanism: similar to albendazole; evidence sparse. Side effects: GI upset; rare liver effects. Parahostdis

3. Ivermectin (not standard; experimental/limited evidence).
   Class: macrocyclic lactone. Dose: no established dose for anisakiasis; evidence comes from in-vitro/animal data and scattered clinical mentions; not recommended routinely. Purpose: theoretical paralytic effect on nematodes. Risks: drug interactions, neurotoxicity at high doses. PubMed+1

4. Epinephrine (adrenaline) for anaphylaxis.
   Class: adrenergic agonist. Adult dose: 0.3–0.5 mg IM (1 mg/mL) into the thigh; repeat every 5–15 min if needed. Purpose: first-line life-saving treatment for severe allergic reactions to Anisakis proteins. Side effects: tremor, palpitations; benefits outweigh risks in anaphylaxis. NCBI+1

5. H1 antihistamines (e.g., cetirizine, diphenhydramine) for hives/itch.
   Class: H1 blockers. Typical adult doses: diphenhydramine 25–50 mg; cetirizine 10 mg. Purpose: reduce cutaneous symptoms; not a substitute for epinephrine. Side effects: sedation (first-generation agents). NCBI+1

6. H2 antihistamines (e.g., famotidine) as adjuncts.
   Class: H2 blockers. Adult IV dose example (emergency settings): famotidine 20 mg IV. Purpose: adjunct for refractory hives with H1 blocker; not primary therapy. Side effects: headache; rare arrhythmias with rapid IV push. NCBI

7. Systemic corticosteroids (e.g., prednisone) for significant allergic inflammation.
   Class: glucocorticoid. Dose: individualized short course. Purpose: decrease prolonged urticaria/angioedema; adjunct to epinephrine, not acute substitute. Risks: hyperglycemia, mood change. Medscape

8. Proton-pump inhibitors (omeprazole/pantoprazole) for gastritis/ulcer-type pain after larval injury.
   Class: PPI. Common dose: omeprazole 20–40 mg daily. Purpose: reduce acid so injured mucosa can heal. Side effects: headache; long-term risks if used chronically. NCBI+1

9. Sucralfate for mucosal protection (short term).
   Class: mucosal protectant. Dose: 1 g four times daily before meals/bed. Purpose: coats irritated mucosa after larval removal. Side effects: constipation; drug binding interactions. NCBI

10. Ondansetron for nausea/vomiting.
    Class: 5-HT3 antagonist antiemetic. Adult dose: 4–8 mg PO/IV; avoid high single IV doses due to QTc risk. Purpose: symptom control to maintain hydration. Side effects: constipation, headache, QT prolongation. NCBI

11. Acetaminophen (paracetamol) for pain/fever.
    Class: analgesic/antipyretic. Dose: typical 500–1,000 mg every 6–8 h (max per local guidance). Purpose: pain control without GI bleeding risk. Risks: liver toxicity if overdosed. (General drug monograph data.) NCBI

12. Antispasmodics (selected settings).
    Class: anticholinergics (e.g., hyoscine). Purpose: ease cramping; note this is symptomatic only and used cautiously. (General symptomatic care.) NCBI

13. Topical L-menthol (endoscopic aid) — listed above as a procedure but is a medication applied during endoscopy to reduce spasm and aid removal. PMC

14. IV crystalloid fluids (medication order) for moderate/severe dehydration when ORS isn’t tolerated. Purpose: rapid rehydration. Risks: fluid overload if misused. NCBI

15. PPI plus short-term H2RA “step-down” (selected cases of severe acid symptoms after removal). Purpose: symptom control during healing; taper as pain settles. NCBI

16. Topical/oral anesthetics are not recommended.
    Reason: no evidence they aid anisakiasis; may mask worsening pain. (Practice caution; no specific benefit shown.) PMC

17. Antibiotics are not routine.
    Reason: anisakiasis is not a bacterial infection; use only if a separate infection is proven. (Stewardship principle.) PMC

18. Opioids are not first-line.
    Reason: can mask peritoneal signs or worsen ileus; reserve for carefully selected cases. (General surgical caution.) PMC

19. Bismuth subsalicylate (select cases) for mild diarrhea after exclusion of bleeding risk and interactions. Purpose: symptomatic relief only. (General OTC guidance.) NCBI

20. No “anti-worm cocktail.”
    Reason: outside albendazole/mebendazole reports, there’s no proven multi-drug regimen; rely on endoscopy and supportive care. CDC

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Dietary molecular supplement

No supplement treats anisakiasis; these are optional, short-term supports for hydration and gut comfort. Always clear supplements with a clinician.

1. Oral Rehydration Salts (ORS).
   Dose: frequent small sips (adults often ~1–2 L over 4 h, then as needed). Function/mechanism: glucose-sodium co-transport speeds water absorption to reverse dehydration. World Health Organization+1

2. Electrolyte broths (sodium/potassium).
   Use: replace salts with gentle fluids; avoid very sugary drinks. Mechanism: maintain extracellular fluid balance. PMC

3. Probiotics (strain-specific, optional).
   Note: evidence for acute infectious diarrhea in adults is mixed and inconclusive; not specific to anisakiasis. Mechanism: microbiome modulation. Cochrane Library+1

4. Soluble fiber (e.g., psyllium) after acute phase.
   Use: normalize stool once vomiting stops. Mechanism: forms gel to steady bowel movements; start low. (General GI support evidence.) NCBI

5. Zinc (short-term in diarrhea).
   Dose: follow local guidance; evidence mainly pediatric; adult benefit variable. Mechanism: supports epithelial repair and enzymes. WHO Apps

6. Ginger (nausea aid).
   Use: tea/capsules if approved by clinician; may help mild nausea. Mechanism: anti-emetic effects on gastric motility/serotonin pathways. NCBI

7. Vitamin D / general multivitamin (short course if intake poor).
   Purpose: cover temporary dietary gaps; not a treatment for anisakiasis. NCBI

8. Plain yogurt with live cultures (food source of probiotics).
   Use: re-introduce during recovery if tolerated; avoid if lactose-intolerant. PMC

9. Oral glutamine (consider only under guidance).
   Rationale: sometimes used for mucosal support; evidence in this context is limited. NCBI

10. Peppermint tea (non-capsule) for mild cramping.
    Mechanism: smooth-muscle relaxation; avoid reflux-prone patients. NCBI

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Immunity-booster / regenerative / stem-cell drugs

There are no approved “immunity booster,” regenerative, or stem-cell drugs for anisakiasis. Using such products outside clinical trials can be unsafe and ineffective. The proven pillars are endoscopic removal, watchful supportive care, short courses of albendazole in selected non-gastric cases, and allergy management when needed. If you’re immunocompromised or have severe reactions, management must be individualized by a clinician. CDC+1

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Surgeries

1. Laparoscopic small-bowel resection.
   Why: for confirmed obstruction, ischemia, or perforation due to an inflammatory mass (“eosinophilic granuloma”) from a larva. What happens: minimally invasive removal of the diseased segment with reconnection. PMC

2. Open small-bowel resection.
   Why: when laparoscopy isn’t feasible (extensive adhesions, instability). What happens: open incision, segmental resection, and anastomosis. PMC

3. Appendectomy (rare).
   Why: if larva-induced appendicitis is proven or strongly suspected. What happens: remove inflamed appendix. CDC

4. Segmental colectomy (rare).
   Why: colonic mass or complications mimicking cancer. What happens: remove affected colon segment. BMJ Case Reports

5. Endoscopic mucosal resection of persistent submucosal lesions.
   Why: selected “tumor-like” granulomas after infection. What happens: endoscopic snare resection for diagnosis and relief. BMJ Case Reports

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Prevention tips

1. Cook seafood to ≥145°F (63°C). CDC

2. If serving raw, freeze properly: −20 °C (−4 °F) for 7 days; or blast-freeze to −35 °C (−31 °F) until solid and hold 15 h; or −35 °C until solid + hold at −20 °C for 24 h. CDC

3. Don’t rely on marinating, salting, or cold-smoking to kill larvae. PMC

4. Buy from reputable suppliers who follow HACCP/food-code controls. U.S. Food and Drug Administration

5. Gut fish promptly (commercial practice) and keep cold chain. FAOHome

6. At home, keep raw fish separate from ready-to-eat foods and sanitize surfaces. CDC

7. If you’ve had Anisakis allergy, discuss whether even well-cooked fish is safe for you; some allergens are heat-stable. PubMed

8. Restaurants that serve raw fish should use freezing logs and supplier guarantees. U.S. Food and Drug Administration

9. Consider aquacultured fish from controlled systems (still follow safety guidance). PMC

10. When in doubt, choose cooked seafood. PMC

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When to see a doctor

• Severe or worsening abdominal pain, vomiting, or blood in vomit/stool after eating raw/undercooked fish (hours to days). Reason: you may need urgent endoscopy. PMC

• Any signs of allergy (hives, swelling, wheeze). Reason: risk of anaphylaxis. Use an epinephrine auto-injector if prescribed and seek emergency care. Medscape

• Persistent pain/fever/obstruction symptoms (distension, no gas). Reason: intestinal complications may require surgery. PMC

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What to eat—and what to avoid—during recovery

1. Start with clear fluids/ORS and advance as nausea settles. World Health Organization

2. Small, frequent meals; avoid large, fatty meals early on. NCBI

3. Bland choices for 24–48 h (e.g., rice, toast, applesauce, bananas, oatmeal)—then diversify to a balanced diet. NCBI

4. Lean proteins (poached chicken, baked fish that’s fully cooked). NCBI

5. Avoid alcohol, spicy, very acidic, or greasy foods while the stomach heals. NCBI

6. Limit caffeine if it aggravates symptoms. NCBI

7. Yogurt with live cultures if tolerated, to re-introduce gentle probiotics. PMC

8. Re-hydrate steadily even if appetite is low. NCBI

9. Avoid raw/undercooked seafood entirely until fully recovered (and longer if allergic). CDC

10. Long-term: return to a normal, varied diet; bland “BRAT-only” patterns are not nutritionally complete. NCBI

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FAQs

1) Can anisakiasis cure itself?
Sometimes intestinal cases resolve as the larva dies within ~1 week, but gastric cases often need endoscopic removal for rapid relief and to rule out look-alikes. PMC+1

2) What fish can carry Anisakis?
Many wild marine fish and squid (e.g., cod, salmon, anchovy). Risk depends on species and region; assume wild marine fish can harbor larvae. CDC

3) Does freezing make raw fish “safe”?
Freezing to CDC/FDA specs kills larvae and prevents infection; however, people already allergic to Anisakis may still react to heat-stable allergens. CDC+1

4) I had hives after sushi—what now?
Seek medical care. An allergist can test for Anisakis sensitization; carry and use epinephrine for severe reactions if prescribed. PMC+1

5) Is farmed fish safer?
Aquaculture can reduce exposure but is not an absolute guarantee; continue standard safety steps. PMC

6) How is anisakiasis diagnosed?
Gastric: endoscopy sees and removes the larva. Intestinal: history plus imaging; sometimes surgery confirms. Serology can support the diagnosis. CDC

7) Are antibiotics helpful?
No, unless there is another bacterial infection. PMC

8) Can cooking alone prevent infection?
Yes—cook seafood to at least 145°F (63°C). CDC

9) Do marinating, salting, or cold-smoking kill larvae?
No—use proper freezing or cooking. PMC

10) Can allergy persist for years?
Yes; IgE sensitization can last for years, so discuss long-term avoidance with your clinician. PMC

11) Do I need albendazole if the worm was removed?
Usually no; after successful endoscopic extraction, most patients recover without anti-parasitic drugs. Some clinicians consider albendazole for presumed intestinal disease. PMC+1

12) What about mebendazole or ivermectin?
Mebendazole has only small case-level support; ivermectin lacks established clinical evidence for anisakiasis—neither is routine. Parahostdis+1

13) Does Anisakis mimic other diseases?
Yes—it can look like peptic ulcer, gallbladder disease, or even GI cancers; that’s why endoscopy and imaging matter. BMJ Case Reports+1

14) After I recover, can I eat fish again?
If you’re not allergic, yes—with proper cooking or freezing. If allergic, consult your allergist; some may still react to allergens in dead larvae. PMC

15) What’s the single best prevention step?
Eat seafood cooked or properly frozen before raw service; choose reputable vendors. CDC

Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical  history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.

The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members

Last Updated: September 17, 2025.

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