Evidence-Based Management of Box Jellyfish Stings

Abstract

Introduction: Rapidly acting and highly effective management approaches are critically needed for potentially life-threatening and career-ending stings by box jellyfish (phylum Cnidaria, class Cubozoa) among underwater-operation warfighters working in austere environments. Cubozoan envenomation results in venom load- and time-dependent complex sequelae, including acute-phase hemolysis, cardiorespiratory collapse, hypovolemic shock, and death. Despite previously published studies demonstrating the failure of various generally advised, lay first-aid approaches (including fresh-water rinsing, ice-pack application, and skin scraping) to inhibit box jellyfish venom-induced hemolysis and tissue damage in vitro, ineffective and even deleterious management practices persist. In this report, we compared the efficacy of generally used first-aid measures and recently developed copper gluconate (CuGluc)-containing formulations in halting venom-associated tissue damage using a variety of assay systems, including an in vivo anesthetized piglet model.

Materials and methods: The comparative efficacy of common first-aid approaches, including vinegar dousing, hot- and cold-pack applications, gasoline, topical 2-hydroxypropyl-β-cyclodextrin (HPβCD), and novel therapeutics, including CuGluc-containing formulations, was assessed using a variety of platforms, including in vitro hemolytic assays, live-tentacle sting tissue-model assays on blood agar or freshly excised porcine skin, and an in vivo piglet model.

Results: Sequential topical application of CuGluc-containing formulations (StingNoMore Spray followed by StingNoMore Cream) surpassed all other management approaches in reducing sting-induced hemolysis and tissue damage in all in vitro and in vivo assay platforms. To a lesser extent, vinegar dousing of the sting site, followed by application of heat (42-45 °C) by hot pack for 45 minutes, also directly and irreversibly inhibited venom activity. Saltwater rinse and ice pack were totally ineffective and led to more tissue damage than the untreated sting itself.

Conclusions: Compared to all other tested first-aid approaches, CuGluc-containing topical spray and cream formulations resulted in far less cubozoan venom-associated tissue damage and represents the most effective method to manage box jellyfish stings.

Figure 1.

Cubozoan Morphology and Distribution. (A) Morphology of Order Carybdeidae, including Alatina alata, and excised tentacles. (B) Morphology of Order Chirodropidae, including Chironex fleckeri, and excised tentacles. (C) Distribution of Cubozoan species and overlapping U.S. Military Coastal Presence.

Figure 2.

In vitro assays: 96-well hemolytic assay and tentacle blood agar assay. (A) Schematic of hemolytic and (Ai) Tentacle Blood Agar Assays (TBAA). (Aii) Representative image of TBAA. Enclosed arrowhead indicates an Alatina alata tentacle laid upon blood agar. The empty arrowheads indicate areas of hemolysis following tentacle removal. (B) % Hemolytic activity of pre- and post-treatment of 0.5 mM Copper Gluconate (CuGluc) and 5 mM 2-Hydroxypropyl-β-cyclodextrin (HPβCD) with A. alata (0.17 µg/mL) exposed 1% RBC solution at 1 hour. Significance was determined by Sidak’s multiple comparisons test. (P-value: **** < .0001, ns = not significant). (C) Time-course hemolysis of A. alata tentacle exposed blood agar and (D) Chironex fleckeri tentacle exposed blood agar with pre- and post-treatment with 0.5mM CuGluc, 5mM HPβCD, Heat, or Ice. Significance determined by Bonferroni test or unpaired t-test (P-value: ** < .05, * < .1).

Figure 3.

In vitro porcine skin assay with freshly excised Chironex fleckeri tentacles. C. fleckeri tentacles were placed on newly-butchered porcine dermis for 20 minutes, followed by application of varying test measures. (A) Control, no treatment, (B) Vinegar, (C) Sting No More Spray, (D) Sting No More Spray and Cream, (E) Gasoline.

Figure 4.

In vivo porcine skin assay with freshly excised Alatina alata tentacles. (A–C) Tentacles were placed on axial and inguinal sites of anesthetized piglet(s) for 5 minutes, followed by application various test measures. (A) Left axillary site, control (5-minute sting, no treatment). (B) Right inguinal site, saline spray and ice pack (5-minute sting, saline spray to remove tentacles, 10-minute rest, ice pack for 45 minutes). (C) Right inguinal site, StingNoMore Spray and StingNoMore Cream (5-minute sting, StingNoMore spray to remove tentacles, 10 minute rest, StingNoMore Cream for 45 minutes). (D–G) Representative histology (10× magnification). (D) Control, No sting or treatment, (E) Tentacle exposed, no treatment, (F) Tentacle exposed, saline spray and ice pack, and (G) Tentacle exposed, StingNoMore Spray and StingNoMore Cream.