Terranova (nematode)

Terranova is a genus of parasitic nematodes (roundworms) belonging to the family Anisakidae. These nematodes are primarily marine parasites, found in fish, marine mammals, and sometimes crustaceans. Terranova species are known for their potential to cause anisakiasis in humans upon consumption of raw or undercooked seafood.

Characteristics:

• Terranova nematodes, like other anisakids, have a typical roundworm body plan.
• They are characterized by their relatively small size, generally a few centimeters in length.
• Morphological identification to the species level can be challenging and often requires expert analysis.

Life Cycle:

The life cycle of Terranova is complex and involves multiple hosts. Typically, eggs are released into the marine environment from definitive hosts (usually marine mammals). These eggs hatch into larvae which are ingested by crustaceans. Fish then become infected by preying on the infected crustaceans. Marine mammals become infected by consuming infected fish, completing the cycle. Humans can become accidental hosts by consuming raw or undercooked fish containing Terranova larvae.

Role in Human Disease:

Terranova larvae can cause anisakiasis in humans, also known as herring worm disease. Symptoms can include abdominal pain, nausea, vomiting, and diarrhea. In some cases, the larvae can penetrate the intestinal wall, leading to more severe complications. Unlike Anisakis, Terranova larvae are generally thought to be less invasive in human tissues.

Diagnosis and Treatment:

Diagnosis of anisakiasis is often based on patient history, symptoms, and endoscopic examination of the digestive tract to identify and remove the larvae. In some cases, radiographic imaging may be used. Treatment typically involves removal of the larvae, either endoscopically or surgically.

Prevention:

The primary method of preventing Terranova infection is to avoid consuming raw or undercooked seafood. Freezing fish at -20°C (-4°F) for a minimum of 24 hours is effective in killing the larvae. Thorough cooking to an internal temperature of 63°C (145°F) is also effective.