Despite a lack of scorpions and spiders among its awesome collection of exhibited wildlife, the Bronx Zoo earlier this year offered its educational facilities to EMS and search and rescue personnel instruction on how to treat attacks that might occur when people interact badly with these venomous creatures.
The program was part of a daylong series of presentations called “Bite me!” that included presentation by Joshua Silverberg, MD, on snake bite treatment, presentation by Stephen P. Wood, MS, ACNP-BC, and former EMS provider and SWAT team medic, on bee, ant and mosquito stings. Wood was one of the organizers of the program which was offered for the first time this year. The program also included a behind the scenes tour of the zoo’s snake and reptile house that included explanation of their safety procedures and anti-venom storage and collection system.1
The presenter was wilderness physician Sanjey Gupta, who began with a lighthearted-clarification that he was not the TV doctor Sanjay Gupta but the wilderness medicine doctor Sanjey Gupta (note the difference in the spelling of the first name). Gupta teaches and advises in the field of wilderness medicine at several medical schools and residency programs in the Greater New York City area. He is also a certified fellow of the Academy of Wilderness Medicine and is regularly invited to speak on wilderness medicine subjects at national and regional conferences. Gupta is the chair of the Emergency Medicine at South Shore University Hospital, and also a professor of Emergency Medicine at the Zucker School of Medicine at Hofstra/ Northwell.
Accompanied by power point, he surveyed the types of venomous spiders and scorpions, both domestic and foreign, that pose threats to humans. For each, he described their normal territory, the effect of their venom, and the best EMS response.
Spiders Came First
Gupta began by emphasizing that there are approximately 30,000 species of spiders and few pose any real risk to humans. When they do bite, spiders normally only produce a local reaction, and death and long term morbidity from spider bites are rare. Spiders, even when they bite, cannot spread communicable diseases to humans.
However, some species do have toxic venom which can cause skin lesions, systemic illnesses and neurotoxicity.
The most common venomous spider type are widow spiders. These come in a variety of colors and species and live on all continents except Antarctica.
Their bite injects venom containing a substance called a-latrotoxin. A-latrotoxin is a powerful nerve toxin that produces a pre-synaptic release of most neurotransmitters. This produces several, diverse systemic health problems. Possible effects include cardiac issues such as hypertension, tachycardia, and cardiac arrhythmias, issues involving muscle cramps, involuntary contractions, and a rigid abdomen, as well as pulmonary edema and renal problems. Other issues seen include generalized pain, anxiety, mental excitation, sweating, vomiting, fear of death (A.K.A. “pavor mortis” ) and excessive salivation (sialorrhea) The envenomed bite itself can produce intense local pain as well as raised areas of flesh called erythematous papules.
Treatment should include local wound care as week as treatment focusing on issues that stem from the toxicity of the neurotoxin. Treatment of the venom and its effects would include use of antivenom, administration of calcium, benzodiazepines, analgesics, and treatment for tetanus.
Another Spider to Know About
The second species he named was the recluse spider.
The bite of the recluse spider, said Gupta, produces envenomization with very different signs, symptoms, pathology and effects from that caused by the Widow spiders. Recluse spider venom produces Necrotic Arachnidism Syndrome, a condition that’s initially painless but becomes much worse as the venom runs its course. The venom damages flesh and produces headache, impaired vision and joint pains.
As time goes on, the venom produces autoimmune effects. These include a drop in platelets about 36 hours after the bite, but the count slowly goes back up over time. Dermonecrotic ulceration, or destruction of the flesh, at the bite sites becomes increasingly worse over time. This condition is known as “loxoscelism,” a term that comes from the scientific name of the recluse genus of spiders, “loxosceles.”
Treatment consists of treating the wound and local tissue damage as well as the systemic problems caused by the toxins and their effects. Treatment of the tissue damage can be complex due to the dermonecrotic effects and can include excision, debridement, and grafting. Plastic surgeons can be an important part of the healing process. Hyperbaric treatments can help. Treatment for tetanus, and administration of analgesics and anti-histamines can help.
Although not native to America, Gupta also spoke of the Brazilian Wandering Spider, a particularly venomous South American spider. Its venomous bite can be deadly, particularly to children. Signs and symptoms include local pain, tremors, sweating, blurred vision, vomiting, restlessness and agitation, abdominal cramping, and a prolonged involuntary erection (priapism). Changes in heart rate (both tachycardia and bradycardia are possible) which can produce changes in blood pressure (likewise both hypo and hypertension are possible).
Treatment consists of administration of the correct antivenin as well as the treatment of symptoms.
The Funnel Web Spider is another dangerous spider that is not native to America, and while venomous, is rarely encountered in North America. It is seen mostly in southeast Australia, New Zealand, and sometimes in Europe and Chile. Its venom, a “delta-hexatoxin,” neuro-excitatory toxin, can be deadly to humans.
Onset of signs and symptoms is rapid and its bite is considered a true emergency. These signs and symptoms include muscle spasms, hypotension, loss of consciousness and coma, shock and multi-organ system failure.
Treatment consists of treatment of signs and symptoms, supportive care, and the administration of effective anti-venom.
Scorpions Came Second
The second part of Gupta’s teaching session was about scorpions.
Gupta began by saying that there is only one type of venomous stinging scorpion native to North America. It lives on cacti and trees, hence the name bark scorpion. According to Gupta, the lethality of a black scorpion sting is less than 1% among adults but can go up to 25% lethality for children under five.
Scorpion venoms are primarily neurotoxins and most work by interfering with neural signaling. Scorpion stings tend to produce pain at the site of the sting. The pain can then spread through the entire body. Common signs and symptoms of scorpion venom include numbness, tingling, anxiety, blurred vision, and nausea and vomiting. Envenomization also produces hypersalivation, poorly controlled, chaotic eye movements, involuntary muscle twitching, poor muscle coordination, and clonic twitching. Possible issues include cholinergic (effects similar to neurotoxins) and cardiac effects.
As for the bark scorpion, it’s reported that its sting feels like an electric shock and common symptoms include numbness and tingling, vomiting, and blurred vision, with the possibility that the end result could be death. Its venom produces over-stimulation of the sympathetic and parasympathetic nervous systems. This causes excessive acetylcholine and catecholamine release, producing the described signs and symptoms.
Know the Signs
Signs and symptoms of a scorpion sting generally last up to 10 hours. If the sting victim survives the first few hours, he or she has a good prognosis, with survival being virtually guaranteed after 24 hours. Systemic symptoms, such as cardiovascular collapse, respiratory failure, seizures and / or coma indicate serious problems.
In children who have been stung by scorpions, metabolic acidosis, tachypnea (rapid breathing), myocarditis, pulmonary edema, encephalopathy and priapism are all signs of serious problems.
Although the program was held in one of the rooms for educational programs at the Bronx Zoo, and the Bronx Zoo carefully maintains stocks of anti-venom for all venomous creatures in the zoo as part of its safety plans, Kevin Torregrossa, the Bronx Zoo Herpetology Curator said that as the zoo does not house or maintain exhibits of venomous arachnids such as spiders or scorpions, it does not maintain or keep antivenoms for their bites or stings.
Footnote
1. According to Kevin Torregrosa, curator of Herpetology, at the Bronx Zoo:
“We maintain current – non-expired – antivenom for all venomous species kept at the zoo. The only qualifier is that not every venomous species has a dedicated antivenom. We also keep our expired antivenoms until we physically run out of room in our refrigerator. There have been instances of more than 20-year-old antivenom being used to treat envenomation successfully. Of course, we keep antivenom on-site as a precaution in case one of our keepers is bitten. However, we have not had a keeper bitten by a venomous snake at the zoo for more than 40 years. Most often, our antivenom is used to treat a bite to a private collector.
If someone from outside the zoo is envenomated, the response is generally coordinated through Poison Control. Poison Control can access the Association of Zoos and Aquariums (AZA) Antivenom Index. From there, they can determine which zoo carries the appropriate antivenom for a bite. Once Poison Control contacts us and confirms the correct antivenom, we will work with Jacobi Hospital to transfer it where needed. We let Jacobi Hospital and their snakebite team discuss the particular case and arrange for the transfer of antivenom if needed. Once it is decided that antivenom is needed, Jacobi will send a courier to the zoo. We will collect the appropriate antivenom and hand it off to the courier from Jacobi. If our antivenom is used for treatment, we get a case report to submit with our annual report to the USDA.”
