Envenoming by a Marine Blood Worm (Glycera)

Abstract

Bites from venomous marine annelid 'bloodworms' (e.g., Glycera spp.) do not appear to have been described in the medical literature despite being seemingly well-known to bait diggers and fishermen. The few laboratory study reports describe their venom composition and physiological effects in vitro to be primarily proteolytic enzymes and neurotoxins apparently used for predation and defense. Herein, we present the report of a symptomatic envenoming suffered by a marine ecologist bitten while performing her field research. The local effects included a rapid onset of pain, swelling, and numbness at the bite site "as if injected with local anesthetic". Additional signs and symptoms appearing over a two-week period were consistent with both delayed venom effects and potentially secondary infection. The late signs and symptoms resolved during a course of antibiotic treatment with doxycycline prescribed as a precaution and lack of resources to consider a wound culture. Comments about annelid bites sporadically appear in the popular literature, especially pertaining to the fishing industry, under names such as 'bait-diggers hand'. While these bites are not known to be dangerously venomous, they seem to produce painful local symptoms and possibly increase the risk of marine bacterial infections that could be associated with more serious outcomes. More cases need to be formally described to better understand the natural history of these types of envenomation.

Keywords: Glyceridae; Polychaetae; annelid; bait-diggers hand; cytotoxicity; envenoming; neurotoxicity; venom; worm.

Figure 1

The natural history of Glycera bites is unknown. Time course of the bite with an acute envenoming syndrome (day 0 and day 1) followed by possible delayed venom reaction, infection, or combination of both (day 8) and resolution (e.g., days 9 through 19).

Figure 2

(A) Characteristic four-fanged jaws of Glycera americana typical of the Glycera genus. Fangs reside inside the abdominal cavity and can be rapidly externalized for predation or defense when threatened such as what might have occurred in the case of this patient handling what appears to be an innocuous looking annelid, left top and bottom. (B,C) Glycera spp. worm similar to that which bit the patient was collected, photographed, and released at the locality where the patient was bitten.