Anisakidosis

Question 1

What is Anisakidosis?

Answer 1

A parasitic infection caused by anisakid larvae penetrating the gastric and intestinal mucosa.

Question 2

Name a species of Anisakis.

Answer 2

• Anisakis pegreffii
• A. physeteris
• A. schupakovi
• A. simplex

Question 3

What is the definitive host (FH) and location for Anisakis species?

Answer 3

FH: Marine mammals
Location: Digestive tract

Question 4

What is the intermediate host (IH) for Anisakis species?

Answer 4

Aquatic crustaceans.

Question 5

What is the paratenic host (PH) for Anisakis species?

Answer 5

Any marine fish, squids.

Question 6

Describe the morphology of Anisakis larvae.

Answer 6

“Watch-spring coil”-shape, roughly 2 cm long uncoiled.

in mammals: longer, thicker, more sturdy

Question 7

What is the maximum length L3 larvae can grow to in the peritoneal cavity?

Answer 7

Up to 3 cm in length.

Question 8

What are the symptoms of anisakosis in humans?

Answer 8

• Severe abdominal pain
• Vomiting and nausea

Question 9

What are possible allergic reactions to Anisakis in humans?

Answer 9

Gastroenteritis, rheumatological, and dermatological symptoms.

Question 10

What temperature conditions affect adult worms and larvae?

epidemiology

Answer 10

Both high and low temperatures.

Question 11

What is the treatment for Anisakidosis?

Answer 11

No drugs; removal with biopsy forceps.

Question 12

How can Anisakis infestation be prevented?

Answer 12

By blast freezing or cooking
Do not eat raw, undercooked, salted, or pickled fish.

Infestation rate is high in fishes: cod, herring, salmon and mackerel

Question 13

What fish have a high infestation rate of Anisakis?

Answer 13

• Cod
• Herring
• Salmon
• Mackerel

Question 14

How is Anisakidosis frequently diagnosed?

Answer 14

With endoscope and immunodiagnosis.

Question 15

Species causing anisakidosis

Answer 15

Contracaecum rudolphii
Pseudoterranova decipiens
A. pegreffii
A. physeteris
A. schupakovi
A. simplex

Question 16

Pathogenesis of anisakidosis

Answer 16

• Usually asymptomatic
• If larvae penetrate the mucosa, it can cause pain, nausea and vomiting.
• If larvae migrate, damage to tissues and can mimic other diseases.
• Anisacidosis occurs in humans. Can see possible allergic reactions to the parasite (gastroenteritis, rheumatological and dermatological symptoms).

Question 17

Life cycle of anisakidosis

Answer 17

1. Unembryonated eggs produced by adult females are passed in the feces of marine mammals. The eggs become embryonated in the water, and the L1 larvae are formed in the eggs.
2. The larvae moult, becoming L2 larvae & hatches from the eggs. They become free-living.
3. L2 released from the eggs are ingested by crustaceans. L2 develop into L3
4. L3 are infective to fish and squids. The larvae migrate from the intestine to the tissues in the peritoneal cavity and grow up to 3cm in length.
5. Upon the host’s death, larvae migrate to the muscle tissues, and through predation, the larvae are transferred from fish to fish. Fish and squid have L3 larvae that are infective also to humans and marine mammals.
6. When fish or L3 larvae are ingested by marine mammals, the larvae moult twice (L4 & L5) and develop into adult worms.
7. Humans become infected by eating raw or undercooked infected marine fish. After ingestion, the anisakid larvae penetrate the gastric and intestinal mucosa, causing the symptoms of anisakosis.