Shark Bite
Shark bites are rare but potentially devastating traumatic injuries that predominantly affect the extremities and require a trauma-based approach with special attention to hemorrhage control, marin…
Shark bites are rare but potentially devastating traumatic injuries that predominantly affect the extremities and require a trauma-based approach with special attention to hemorrhage control, marine-specific wound microbiology, and delayed primary closure. Overall mortality is approximately 8.3%, with death primarily driven by vascular injury and exsanguination.[1-2] Most injuries (42%) are minor (SIT Scale Level 1), but 55% of patients presenting to trauma centers require immediate operative intervention.[3]
1. History
- Circumstances of attack: provoked vs. unprovoked, activity at time (surfing, spearfishing, swimming, diving)[4-5]
- Shark species if known (white, tiger, and bull sharks account for most serious attacks)[5]
- Body part(s) bitten, number of bites, estimated duration of contact
- Water type (saltwater vs. brackish) — informs microbiology[6-7]
- Time from injury to presentation; prehospital interventions (tourniquet, direct pressure, immobilization)
- Submersion time, aspiration of water, loss of consciousness
- Estimated blood loss (pooling, soaked clothing, bystander reports)
- Tetanus immunization status[8]
- Immunocompromised state, liver disease, diabetes — increases risk of Vibrio infection[9-10]
2. Alarm Features
- Active arterial hemorrhage or uncontrolled bleeding despite direct pressure
- Hemodynamic instability (tachycardia, hypotension, altered mental status)
- Traumatic amputation or near-amputation
- Vascular injury to major vessels — mortality exceeds 50% in the La Réunion series when major vessels were involved[2]
- Compartment syndrome signs (tense compartment, pain with passive stretch)
- Deep wounds penetrating joints, abdomen, or thorax[11]
- Signs of hypothermia from prolonged water exposure
- Rapidly progressive cellulitis or hemorrhagic bullae (suggests Vibrio vulnificus)[10]
3. Medications
- Empiric antibiotics for saltwater-contaminated wounds — must cover marine gram-negative pathogens (Vibrio spp., Aeromonas, Pseudomonas):[6-7]
- First-line: Doxycycline 100 mg IV/PO q12h + ceftazidime 2 g IV q8h, OR a fluoroquinolone (ciprofloxacin 400 mg IV / 500 mg PO q12h or levofloxacin)[6-7][12]
- Oral alternative for minor wounds: fluoroquinolone monotherapy or doxycycline[11][13]
- Amoxicillin-clavulanate alone is insufficient — does not reliably cover Vibrio spp.[11]
- Penicillin, ampicillin, erythromycin, and first-generation cephalosporins are not acceptable for marine wound infections[11]
- Tetanus prophylaxis: Tdap if last dose >5 years ago or <3 lifetime doses[8]
- Pain management: regional nerve blocks, parenteral opioids, ketamine for procedural sedation
- Tranexamic acid (TXA) 1 g IV within 3 hours of injury if significant hemorrhage[14]
- Rabies prophylaxis is not indicated (sharks are not mammals)
4. Diet
- NPO if operative intervention anticipated
- No specific dietary triggers or long-term dietary management
- Adequate hydration and nutrition during recovery to support wound healing
5. Review of Systems
- Neurologic: numbness, weakness, or loss of function distal to wound (nerve injury in 32% of hospitalized cases)[4]
- Vascular: pulselessness, pallor, coolness distal to injury
- Musculoskeletal: inability to move affected limb, deformity (fractures in 18%)[4]
- Respiratory: dyspnea, cough (aspiration, near-drowning)
- Constitutional: fever, chills (early infection or systemic inflammatory response)
- Skin: spreading erythema, bullae, crepitus (necrotizing soft tissue infection)
6. Collateral History and Family History
- Bystander account of attack (duration, shark behavior, water conditions)
- Prehospital interventions by lifeguards or bystanders (tourniquet application is a key survival factor)[2]
- Family history is generally not relevant
- Social context: occupation (commercial fishers, dive operators), recreational activity, travel location
7. Risk Factors
- Activities: surfing, spearfishing (most common context, 32%), swimming, diving[4-5]
- Geographic hotspots: Florida (49% of US attacks), California, Australia, South Africa, Réunion Island[5]
- Time of day: bimodal distribution around noon and early evening[15]
- Murky water, presence of bait fish, spearfishing with catch
- Risk factors for severe wound infection: chronic liver disease, immunosuppression, diabetes, iron overload states (dramatically increase Vibrio vulnificus mortality)[9-10]
8. Differential Diagnosis
- Boat propeller injury — parallel lacerations, often more uniform pattern
- Other marine animal injury — barracuda bite (narrower, more linear), stingray (puncture with envenomation)
- Coral laceration — superficial, irregular abrasions with retained foreign body
- Blunt/penetrating trauma from underwater objects
- Distinguishing feature of shark bites: crescent-shaped or semicircular wound pattern, tissue avulsion, disarticulation (unique to shark attacks)[2][16]
9. Past Medical History
- Prior shark encounters or marine injuries
- Chronic liver disease, cirrhosis, hemochromatosis — dramatically increases Vibrio vulnificus mortality (>50%)[9-10]
- Immunosuppression (HIV, transplant, chemotherapy)
- Diabetes mellitus, chronic kidney disease
- Anticoagulant or antiplatelet use (increases hemorrhage risk)
- Splenectomy (increased infection risk)
- Surgical history relevant to affected limb
10. Physical Exam
- Primary survey (ATLS): Airway, Breathing, Circulation — hemorrhage control is the immediate priority
- Vital signs: heart rate, blood pressure, respiratory rate, temperature, SpO2
- Wound assessment: location, depth, tissue loss, exposed bone/tendon/joint, wound pattern (crescent/semicircular), number of bite sites
- Vascular exam: distal pulses (palpation and Doppler), capillary refill, skin color/temperature
- Neurologic exam: motor and sensory function distal to wound (nerve injury in 32%)[4]
- Musculoskeletal: range of motion, joint stability, crepitus, deformity
- Assess for compartment syndrome: tense compartments, pain with passive stretch
- Full secondary survey for additional injuries (13% had both upper and lower extremity injuries)[3]
11. Lab Studies
- Type and crossmatch — anticipate need for transfusion
- CBC, BMP, lactate, coagulation studies (PT/INR, PTT, fibrinogen)
- Blood gas (assess for acidosis from hemorrhagic shock)
- Wound cultures — alert microbiology lab to supplement media with NaCl for marine bacteria[11]
- Blood cultures if signs of systemic infection
- Consider viscoelastic testing (TEG/ROTEM) for massive hemorrhage to guide resuscitation[17-18]
- Liver function tests if concern for underlying liver disease (Vibrio risk stratification)
12. Imaging
- X-ray of affected area — identify retained shark tooth fragments (radiopaque), fractures[3][11]
- CT angiography if concern for vascular injury (27% of hospitalized cases)[4]
- CT of chest/abdomen/pelvis if truncal involvement
- Ultrasound (FAST exam) if concern for internal hemorrhage
- Imaging is unnecessary for superficial abrasions without deep tissue involvement
13. Special Tests
- Shark-Induced Trauma (SIT) Scale — severity scoring system (Levels 1–5) to standardize communication:[1]
- Level 1 (42%): superficial lacerations/abrasions
- Level 5 (8%): massive tissue loss, major vascular injury, fatal or near-fatal
- Injury Severity Score (ISS) — median ISS of 5 in US trauma data[3]
- Point-of-care ultrasound for vascular assessment and FAST
- Ankle-brachial index (ABI) if concern for lower extremity vascular injury
- Compartment pressure measurement if clinical suspicion
14. ECG
- Indicated if hemodynamic instability, significant hemorrhage, or near-drowning
- Assess for signs of hemorrhagic shock: sinus tachycardia, ST changes from hypoperfusion
- Evaluate for hypothermia-related changes (Osborn waves, bradycardia) if prolonged cold water exposure
- Electrolyte-related changes (hyperkalemia from crush injury or massive transfusion)
15. Assessment
Shark bites produce a unique injury pattern characterized by crescent-shaped lacerations, tissue avulsion, and potential disarticulation.[2][16] Injuries predominantly affect the extremities (47% lower, 40% upper).[3] The most common context is recreational water activity. Severity ranges widely — 42% are minor (Level 1 SIT), but 83% of trauma center patients require surgical debridement, flap coverage, or skin grafting, and 11% require amputation.[3] Infectious complications are relatively uncommon (~9%) when appropriate empiric antibiotics are administered, but identified pathogens are characteristically polymicrobial and marine-derived (Vibrio spp., Pseudomonas, Aeromonas).[4][13] Immunocompromised patients and those with liver disease are at extreme risk for fulminant Vibrio vulnificus sepsis.[9-10]
16. Treatment Plan
Initial stabilization
- Hemorrhage control: direct pressure, tourniquet for extremity bleeding — prehospital tourniquet application is strongly associated with survival in major vascular injuries[2][19]
- Damage-control resuscitation: permissive hypotension (target SBP ~80–90 mmHg until surgical hemostasis), balanced transfusion (1:1:1 ratio of PRBC:FFP:platelets), minimize crystalloid[17-18]
- TXA 1 g IV if within 3 hours of injury[14]
Wound management
- Copious irrigation with normal saline
- Thorough exploration and debridement under aseptic conditions[1][6]
- Remove retained foreign bodies (shark teeth fragments)
- Delayed primary closure at 24–72 hours is preferred over immediate closure for contaminated marine wounds[20]
- Deep wounds into joints, abdomen, thorax, or fascial compartments of hand/foot require OR exploration[11]
Antibiotics
- Empiric coverage for marine pathogens: doxycycline + ceftazidime (IV) or fluoroquinolone[6-7]
- Adjust based on wound cultures; alert lab to use NaCl-supplemented media[11]
- Tetanus prophylaxis per guidelines[8]
Surgical intervention
- 83% require debridement/grafting; 59% require orthopedic intervention; 28% have neurovascular injuries requiring repair[3]
- Amputation in ~11%[3]
17. Disposition
- Admission criteria: hemodynamic instability, major vascular/nerve injury, fractures, deep/extensive wounds requiring OR debridement, need for serial wound assessments, significant tissue loss[3]
- 96% of patients in the National Trauma Data Bank were admitted; 53% required ICU (median ICU stay 4.5 days)[3]
- Median hospital stay: 4–5 days[3-4]
- Discharge criteria: hemodynamically stable, minor superficial lacerations without neurovascular compromise, reliable follow-up — approximately 78% of ED-presenting patients in one series were safely discharged[15]
- Trauma center referral: all significant shark bites warrant referral to a trauma center capable of comprehensive surgical care (orthopedic, vascular, plastic surgery)[3]
- Specialist consultation triggers: vascular surgery (major vessel injury), orthopedics (fractures, joint involvement), plastic/reconstructive surgery (tissue loss, flap coverage), hand surgery (hand injuries), infectious disease (immunocompromised patients, Vibrio concerns)
18. Follow Up / Return Precautions
- Follow-up timing: wound check at 24–48 hours for delayed primary closure assessment; subsequent visits at 5–7 days for suture/staple management and infection surveillance[20]
- Return immediately for: fever, increasing wound pain/redness/swelling, purulent drainage, hemorrhagic bullae, red streaking (lymphangitis), signs of systemic illness
- Wound cultures should be obtained if signs of infection develop; alert lab to marine pathogen protocols[11]
- Physical/occupational therapy referral for nerve injuries and post-surgical rehabilitation
- Psychological support — PTSD screening is appropriate given the traumatic nature of the event[21]
- Expected recovery: highly variable depending on severity; minor wounds heal in 1–2 weeks; complex injuries may require months of reconstruction and rehabilitation
References
1. Mortality and Management of 96 Shark Attacks and Development of a Shark Bite Severity Scoring System. — Lentz AK, Burgess GH, Perrin K, et al. The American Surgeon. 2010.
2. Clinical Features of 27 Shark Attack Cases on La Réunion Island. — Ballas R, Saetta G, Peuchot C, Elkienbaum P, Poinsot E. The Journal of Trauma and Acute Care Surgery. 2017.
3. Shark-Related Injuries in the United States: A National Trauma Data Bank Analysis. — Ganske W, Sharma R, Kaminski S, Johnson A. The American Surgeon. 2021.
4. Shark Bites in New Caledonia: A Retrospective Study of 22 Hospitalized Cases and Surgical Management. — Gosselin C, Maillaud C, Jourdel F. Injury. 2025.
5. Shark Attack-Related Injuries: Epidemiology and Implications for Plastic Surgeons. — Ricci JA, Vargas CR, Singhal D, Lee BT. Journal of Plastic, Reconstructive & Aesthetic Surgery : JPRAS. 2016.
6. Management of Extremity Trauma and Related Infections Occurring in the Aquatic Environment. — Noonburg GE. The Journal of the American Academy of Orthopaedic Surgeons. 2005.
7. Antibiotic Prophylaxis in Injury: An American Association for the Surgery of Trauma Critical Care Committee Clinical Consensus Document. — Appelbaum RD, Farrell MS, Gelbard RB, et al. Trauma Surgery & Acute Care Open. 2023.
8. Zoonotic Exposures: Bites, Scratches, and Other Hazards. — Caitlin M. Cossaboom, Ryan M. Wallace, and Casey Barton Behravesh CDC Yellow Book. 2025.
9. Vibrio Vulnificus-a Review With a Special Focus on Sepsis. — Candelli M, Sacco Fernandez M, Triunfo C, et al. Microorganisms. 2025.
10. Rapidly Progressive Soft Tissue Infections. — Vinh DC, Embil JM. The Lancet. Infectious Diseases. 2005.
11. Marine Envenomations. — Auerbach PS. The New England Journal of Medicine. 1991.
12. Antibiotic Use for Vibrio Infections: Important Insights From Surveillance Data. — Wong KC, Brown AM, Luscombe GM, Wong SJ, Mendis K. BMC Infectious Diseases. 2015.
13. Antibiotic Susceptibilities of Bacteria Isolated Within the Oral Flora of Florida Blacktip Sharks: Guidance for Empiric Antibiotic Therapy. — Unger NR, Ritter E, Borrego R, Goodman J, Osiyemi OO. PloS One. 2014.
14. Initial Care of the Severely Injured Patient. — King DR. The New England Journal of Medicine. 2019.
15. Shark Related Injuries: A Case Series of Emergency Department Patients. — Tomberg RJ, Cachaper GA, Weingart GS. The American Journal of Emergency Medicine. 2018.
16. The Anatomy of a Shark Attack: A Case Report and Review of the Literature. — Caldicott DG, Mahajani R, Kuhn M. Injury. 2001.
17. Hemorrhagic Shock. — Cannon JW. The New England Journal of Medicine. 2018.
18. Resuscitation and Care in the Trauma Bay. — Van Gent JM, Clements TW, Cotton BA. The Surgical Clinics of North America. 2024.
19. Stopping Haemorrhage by Application of Rope Tourniquet or Inguinal Compression (SHARC Study). — Taylor NB, Lamond DW. Emergency Medicine Australasia : EMA. 2021.
20. A "Shark Encounter": Delayed Primary Closure and Prophylactic Antibiotic Treatment of a Great White Shark Bite. — Popa D, Van Hoesen K. The Journal of Emergency Medicine. 2016.
21. Increased Shark Bite Survivability Revealed by Two Centuries of Australian Records. — Tucker JP, Santos IR, Kelaher BP, et al. Scientific Reports. 2022.