Answer to Case 509

Answer:Dirofilariasp.; most likelyD. repensbased on the presentation, geographic exposure, and morphology of the microfilariae in blood.Idzi and his group recently published this case in EID; you can read about all of the important diagnostic details such as the length of the adult worm, its cuticle, and the morphology of the microfilariae HERE.Here a just a few important points from this case:1.Not all round worms removed from the eye areLoa loa.While loiasis is the ocular roundworm infection that most physicians are familiar with, human dirofilariasis is an emerging infection that should be considered whenever a patient presents with a macroscopic worm moving across the cornea. UnlikeL. loawhich has a limited geographic distribution (West and Central Africa),Dirofilaria repensis widely distributed throughout parts of Africa, Asia, and Europe, including temperate climates. HERE is a great article outlining the distribution of vector-borne diseases in Africa; it has nice maps showing that loiasis is NOT in Senegal where this patient was presumably exposed.2.The adult worm of Dirofilariacan be easily differentiated fromLoa loaby examining its cuticle.Dirofilariahas longitudinal ridges, which are particularly prominent in this case, whileLoa loadoes not. To me, the longitudinal ridges look like the bark of a tree (awesome photo Idzi!):In comparison,Loa loahas irregularly-spaced cuticular bosses or ' bumps ' that are located along along the long axis of ...
Source: Creepy Dreadful Wonderful Parasites - Category: Parasitology Source Type: blogs