Case #397 – June 2015
A worm-like object approximately 11 mm in length was recovered from a PEG site (percutaneous endoscopic gastrostomy) of a 68-year-old patient and submitted to the state health department for identification. Digital images were taken using transmitted light and submitted to the DPDx Team for diagnostic assistance in identifying what they believed to be some type of fly larva (Figures A and B). After reviewing the images, the DPDx Team responded that it was a fly larva, but a more specific identification was not possible without observing the posterior spiracles. The larva was sent to the team for further testing. Figure C shows the entire larva using both transmitted and reflected light; Figure D shows a close-up of the posterior spiracles. What is your identification? Based on what criteria?
This was a case of facultative myiasis caused by Lucilia sp. (syn. Phaenicia sp.). Morphologic diagnostic features shown include:
- Mandible without accessory oral sclerite (Figure B)
- posterior spiracles as three straight slits pointing towards the button (blue arrows, Figure D)
- peritreme complete but weak in the area of the button (black arrow, Figure D)
More on: myiasis
This case, and images in-part, were kindly provided by the Texas Dept. of State Health Services Laboratory.
Images presented in the DPDx case studies are from specimens submitted for diagnosis or archiving. On rare occasions, clinical histories given may be partly fictitious.
DPDx is an educational resource designed for health professionals and laboratory scientists. For an overview including prevention, control, and treatment visit www.cdc.gov/parasites/.