Answer to Case 684

Answer to theParasite Case of the Week 684: Anisakid L3 larvaeThe following is our third and final discussion from our amazing guest author and 3rd year medical student, Hadel Go. I ' m sure you will all agree that her discussions have been among the best we ' ve ever had on this blog. Congratulations on the excellent work, Hadel!_____________________ Worm cases are always my favorite because the comments are either “They are so beautiful!!” (@Parasite_Power on Twitter) or “…That’s a wholelottanope” (Valmik in the comments).This is a nematode in the Anisakidae family, likelyPseudoterranovaorAnisakis spp., the two most common cause of human anisakiasis, as many of you suggested. A third genus,Contracaecum, is also a possibility. Mario George Nascimento and Melinh Luong point out that its dark color implicatesPseudoterranova (vsAnasakis which is usually white/pink/red). However definitive identification to the genus level requires closer inspection of the intestinal cecum and its positioning as mentioned by Idzi P. in the comments and seen inCase 563 which he donated.Diagnostic features ofPseudoterranova andAnasakisspp. include a “mucron… and 3 poorly formed anterior lips with a small boring tooth” (seeCase 157 andCase 557). The table below shows some varying characteristics between the two more common culprits:LarvaAnisakis simplexPseudoterranova decipiensAppearanceWhite, milkyYellow-brownDimensions19-36mm long; 0.3-0.6mm wide25-50mm, 0.3-1.2mm ...
Source: Creepy Dreadful Wonderful Parasites - Category: Parasitology Source Type: blogs