spacer.gif (807 bytes) spacer.gif (807 bytes) spacer.gif (807 bytes)

[Last Modified: ]

September 2008
Answer to Case 236

This was a case of anisakiasis cause by a larva of an anisakid worm.  Three genera of anisakid worms have been implicated in human infection:  Anisakis, Pseudoterranova, and Contracaecum.  The specimen in this case did not show enough morphological features to identify to the genus level.  Diagnostic features of an anisakid worm included:

  • a multi-layered, thick cuticle (CU, Figure B).
  • prominent muscle cells (MU, Figure B).
  • a folded intestine with a brush border (BB, Figure C).
Case 236 Answer Image C Case 236 Answer Image D
B C

Marine mammals are the normal definitive hosts for anisakid worms.  Humans usually become infected with larvae after eating undercooked fish (an intermediate host).  The anisakid larvae may be coughed up, spuriously excreted in feces, or burrow into tissue, causing gastritis and appendicitis. Rarely do they migrate to other parts of the body.

For more information on anisakiasis, please click here.

 
Close