Snakes and Insects
CVHC Hike Leaders Snakebite Epidemiology
• US: 7000 bites w 15 deaths
• March to November VENOMOUS SNAKES INDIGENOUS TO USA
SUBFAMILY Crotalinae (pit vipers) Micrurus (coral)
GENUS Crotalus (rattlesnakes) Agkistrodon (copperheads and cottonmouths) Sistrurus (massasauguas)
Pit Viper
Southern Pacific Rattlesnake Red Diamond Rattlesnake Sidewinder Speckled Rattlesnake Western Diamondback Mojave Rattlesnake Snake Venom
• Venom: proteins, polypeptides, enzymes • Hemotoxin, Cytotoxin, Myotoxin and Neurotoxin Clinical Manifestations of a Snakebite
• Mild local reaction to life-threatening systemic reaction
• Painful within 5 minutes, then local swelling Clinical Effects of Venom
HEMOTOXIN NEUROTOXIN • Intense pain • Minimal pain • Edema • Eyelid lag • Rapid heart rate • Weakness • Redness • Double vision • Muscle twitching • Difficulty swallowing • Unusual metallic taste • Salivation • Vomiting • Sweating • Confusion • Shallow breathing • Bleeding disorders • Tingling • Kidney failure • Paralysis Snakebite First Aid
Do Not Physically exert Take medication Eat or drink Drink alcohol Cut, bite or suction wound Apply tourniquet Apply ice, cold or hot pack Apply electric shock Use snake stones Catch the snake Snakebite First Aid
DO Protect from further bites Keep victim calm and quiet Arrange for transport to ED w antivenom Keep bitten limb below or at heart level Nothing by mouth Remove constricting clothes, jewelry “Time is tissue”
Crotalidae Polyvalent Immune Fab (ovine) antivenom - CroFab
• Available Dec. 2000 • Made from sheep • Used venom from WDB, Mojave, EDB, Cottonmouth • Used for any rattlesnake bite Snakebite Prevention
• Do not startle, corner a snake • Tread heavily, boots, long pants • Step away silently, slowly • Avoid alcohol + snake • Avoid dead snake Spiders and Stuff
Brown Recluse Spider Loxosceles reclusa
Brown Recluse Habitat Desert Recluse BROWN RECLUSE VENOM
• Sphingomyelinase D causes pain, itching, fever, chills, n/v
• 12 hours later purple lesion
• 24-72 hours later - necrotic lesion BLACK WIDOW SPIDER
Widow Spider Range Widow Spiders Clinical Findings Black Widow Spider Bite • Muscle pain and spasm of abdomen, chest and back, priapism, seizures, burning feet • Rapid heart rate and respiration, sweating, flushing, hypertension and nausea • Severe muscle cramps and weakness - days to weeks
Scorpion Scorpion Habitat Bark Scorpion Centruroides exilcauda
Telson Scorpion sting statistics
• Worldwide ~ 5,000 deaths per year (India, Africa, S. America and Mexico) • US 13,900 stings per year –9,000 in Arizona (100 serious) –2,000 in children • May to October Clinical presentation Bark Scorpion sting • Violent uncoordinated neuromuscular hyperactivity • Oculomotor and visual abnormalities • Increased respiratory secretions, airway obstruction, occasional noncardiogenic pulmonary edema • Site hyperesthesia Treatment of Scorpion Sting
• Clean wound with soap and water
• Cool compress
• Tylenol
• Seek medical care if increase salivation, fast breathing, blurry vision
• Anascorp antivenin (equine) available in AZ for Bark scorpion