The perceived terror of visiting Central America’s pit viper country.

An actively hunting Bothrops asper beside a trail in Cockscomb Basin Wildlife Sanctuary, Belize.

Everyone who enters the tropical environs has fears of the unknown, and the biggest fear for most is venomous snakes.

A venomous snake bite is a serious matter – certainly a medical emergency that should be taken seriously.  Under no circumstances should a person bitten by a venomous snake fail to seek medical attention.

It is widely known that a bite by many tropical pitvipers does not guarantee an envenomation.  It is often stated that as many as 30% of such bites result in no envenomation, and there is lots of variation from that situation to a full dose.  A bite can mean no symptoms, or it can mean death – and everything in between.  To help students understand this, we use at least the two papers that are listed below.  Carr’s (1969) story describes a bite he received that resulted in no damage due to a lack of venom, and Hardy’s (1994) study describes many aspects of snake bite that every tropical naturalist should understand:  behavior ecology of Bothrops asper, plan of action and first aid for a bite, discussion of first aid kits, first aid measures that should be avoided (very important), understanding intramuscular administration of antivenom in the field, testing for allergic reaction before using antivenom (and using epinephrine as an alternative), and, finally, hospital treatment.  He also discusses 10 bites associated with biological field work.

IF YOU ARE INTERESTED IN BIOLOGICAL FIELD WORK IN THE TROPICS (RESEARCH, CLASS, OR OTHERWISE), YOU SHOULD READ AND UNDERSTAND THESE PAPERS.  Very important is having a plan.  You need to know what to do in the case of a medical emergency, and those around you should know the plan as well.  It will vary from place to place due to venomous species that might be encountered and the proximity of medical care.  If a snakebite occurs, one definitely wants to go to an experienced and well equipped medical facility!

We are not medical doctors, and we are leery of administering antivenom in the field.  We’ve always felt that we wanted someone with emergency medical experience or immunological skill to do so to avoid the potential for anaphylaxis and other complications, which may be worse than the effect of the venom.  That said, we are also aware that a large dose of pitviper venom injected into an artery is akin to being run over by a Big Mac truck, not a Smart Car.  In this case, one needs to save one’s life!

Although tropical naturalists need to be informed, aware, and cautious, two things should give comfort.

  • One is that “dry” bites are common.  The snakes know the #1 function of their venom (to get food), and they know you are not a target for that.
  • The second is the information acquired by Hardy in a survey of four tropical field stations.  He gathered information of how many hours were spent in the field by how many people who were doing biological work in areas frequented by Bothrops asper.  He used information from field stations in Costa Rica, Guatemala, and Belize, and found that 1.5 million person hours in the field resulted in three bites by B. asper.  We doubt that novices who have not read Hardy’s paper would believe the odds are that low, and it should give heart.

These two facts are very important, but they mean nothing to the unfortunate individual who receives a dose of venom.  And that is why it is important to have a plan, know what to do, and what NOT to do.

Armed with this knowledge, go to the tropics and love every minute.

Important resources:
Carr, Archie. 1969.  A naturalist at large.  Natural History 78; 18-24, 68-71.

Hardy, David L., Sr.  1994.  Bothrops asper (Viperidae) snakebite and field researchers in Middle America.  Biotropica 26(2): 198-207.


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