Anisakiasis: Causes, Symptoms, Diagnosis, and Prevention

Anisakiasis is a parasitic infection caused by the ingestion of larvae from the Anisakis genus, commonly found in marine fish and squid. This zoonotic disease primarily affects individuals who consume raw or undercooked seafood. The life cycle of Anisakis involves multiple hosts, starting with crustaceans, which consume the eggs. In turn, these crustaceans are eaten by fish or squid, where the larvae mature further. Marine mammals, such as whales and dolphins, serve as definitive hosts, with the larvae developing into adult worms within their gastrointestinal tracts. Humans become accidental hosts when they consume infected seafood, disrupting the natural life cycle of the parasite.

Once inside the human body, Anisakis larvae penetrate the gastrointestinal tract’s walls, leading to a range of symptoms that typically appear within a few hours to a few days after ingestion. The severity of symptoms depends on the location and extent of the infestation. Common manifestations include severe abdominal pain, nausea, vomiting, and diarrhea. In rare cases, the larvae can cause bowel obstruction or perforation, leading to more severe complications that require surgical intervention. Additionally, some individuals experience allergic reactions such as urticaria, angioedema, and even anaphylaxis due to immune responses triggered by the parasite’s proteins.

Diagnosis of anisakiasis is challenging as its symptoms mimic other gastrointestinal disorders, such as peptic ulcers and Crohn’s disease. A combination of clinical history, imaging studies, and endoscopic examination is often required for accurate diagnosis. During endoscopy, live larvae may be visualized and removed, providing immediate relief. In cases where larvae have deeply penetrated tissue, surgical intervention may be necessary. Symptomatic treatment includes pain management and the use of antihistamines or corticosteroids for allergic reactions.

Preventing anisakiasis relies on proper seafood handling and preparation. Cooking seafood to an internal temperature of at least 145°F (63°C) effectively kills Anisakis larvae. Alternatively, freezing seafood at -4°F (-20°C) for at least seven days or at -31°F (-35°C) for 15 hours can eliminate the parasites. Given the increasing popularity of raw seafood dishes such as sushi, sashimi, and ceviche, public awareness campaigns and stringent food safety regulations are essential to reduce the risk of infection. Educating consumers and food industry professionals about the dangers of consuming improperly prepared seafood plays a critical role in preventing anisakiasis and ensuring public health.
Anisakiasis: Causes, Symptoms, Diagnosis, and Prevention