Brian, sorry for the long delay in response, I have been in the field and on the go over most of the past two weeks. To answer your question, no, that polyvalent antivenin is not used best to treat all vipers; it is only best used to treat our green pit vipers that we have here, those of the
Trimeresurus complex, because they are so closely related. It is specifically produced from
Trimeresurus (
Cryptelytrops)
albolabris. This does not work with equal efficiency for
Calloselasma rhodostoma (Malayan Pit Viper),
Daboia russelii (Russell’s Viper) or any other viper of a different, more distantly related clade. For
Calloselasma rhodostoma and
Daboia russellii there are different antivenins that are produced. If you are bitten by some other rare viper, such as
Ovophis monticola, they would probably treat you with the antivenin from the more closely related
Trimeresurus Complex antivenin.
If bitten and the snake cannot be identified, the hospital will not be experimenting (or should not be experimenting) with different types of antivenin. The most deadly of Thailand’s venomous snakes are rather distinct and easily identifiable, such as the different types of truly dangerous vipers (
Daboia russelii and
Calloselasma rhodostoma), cobras and kraits. In the case where the venom is taking serious effect and the snake was not properly identified, they are likely to administer a polyvalent antivenin for the general group of snakes, which is not as effective as a monovalent antivenin (produced for a specific species), except in the case that I gave earlier- snakes that belong to the same closely related clade.
Here are the antivenins produced here in Thailand (Queen Saovabha Memorial Institute):
Trimeresurus (
Cryptelytrops)
albolabris: for green tree vipers
Calloselasma rhodostoma: for Malayan pit viper
Daboia russelii: for Russell’s viper
Bungarus fasciatus: for kraits
Ophiophagus hannah: for individual cobra
Naja kaouthia: for cobras and spitting cobras
LA, whoever wrote that Wikipedia page appears to have a rather poor knowledge of snake venom. Something that should stand out is the page is very poorly sourced with references. Reptile venoms are a highly technical and complex subject and as reference we see only one technical article consisting of one page concerning the effects. The header at the top says it all: “This article is in need of attention from an expert on the subject.”
One problem with simply categorising reptile venoms is that venom is very complex and rarely can be placed completely into a single category, e.g. monocle cobra venom is categorised as a neurotoxin, when it also causes localised tissue damage (which would also categorise it as a hemotoxin). The snake that you referred to in the US is
Crotalus scutulatus (Mojave Rattlesnake). What makes this snake dangerous, besides having complex venom with more effects of a neurotoxin, is that its venom is distinct enough from the other members of its genus that the polyvalent used for the genus is not as effective with this species.
Cytotoxicity is not a major effect of any snake venom that I am aware of and such an effect would be the result of necrosis brought about by a strong hemotoxin’s effect, such as localised tissue damage resulting in necrosis. This is something that better describes the effect of a spider bite, like that of the ‘Brown Recluse’.
There are other categories of venom that one could list. One could have been venoms that cause a systemic or anaphylactoid reaction. Many snakes, to include those that most consider non-venomous have been found to have the ability to cause this reaction, which ranges from localised swelling at the bite area to shutting down of the respiratory system; the latter is seen only with more dangerous rear-fanged snakes. This is how one would simply describe the effect of bee venom, a venom that kills more 3-4 times more people in the US than all the different US snake bites combined. Snake venom, like that of
Rhabdophis subminiatus have a venom that overwhelm the body with a toxin that destroys the kidneys, leading to renal failure- not sure how that would be categorised simply into one of the existing pigeon holes.
There is no snake that is going to rapidly kill you in a matter of seconds or even a minute; that is a myth. Someone could go into shock from fear, but then that would not be from the venom. I have been on a great many dives following sea snakes in the Pacific and Indian Ocean to watch their behaviour at close quarters and never had one act aggressively. The only bites that I know of are from people grabbing them or after they have been caught up in fishing nets. A great many people have survived a number of bites from the most venomous snakes, such as Bryan Fry. Speaking of Bryan, he has quite an informative website on venom:
http://www.venomdoc.com/index.html Look at the left column to learn about different topics. He has also made most of his publications available on the website. Unfortunately, much of what is on his website requires a good understanding of biochemistry.
Bryan Fry wrote: There is more wrong information spread about sea snakes than just about any other type of snake. One 'fact' that is constantly repeated is that sea snakes have small fangs, so small that they have to bite you between the fingertips. Not sure where this one started from but its completely wrong. A little lucid thought should be enough to reveal this. Think about it for a minute, what do they feed on? Fish and eels. Which have tougher skin, us or fish and eels? Fish and eels of course. So, a sea snake has no problem getting through our skin. Indeed, the Stoke's sea snake can have fangs almost a centimeter long! Another wrong 'fact' constantly battered around is that sea snakes have tiny venom yields. The Stoke's is another good example of how wrong this is, they can deliver up to 150 milligrams! The most widely spread yet utterly incorrect statement is that sea snake venoms are vastly more toxic than land snake venoms. While sea snake venoms are certainly highly toxic, both the Inland taipan (Oxyuranus microlepidotus) and Eastern brown snake (Pseudonaja textiles) are more toxic than the most toxic sea snake (the Dubois' sea snake, Aipysurus duboisii).