Tarantula Venom Can Cause Death Yes or No

[PinkLady]

i think you are missing my point. you are saying no human will ever die... ever, from being bitten by a tarantula/tarantula venom.

i am saying i can think of cases where it seems likely a human would die.

Being "Bitten" and being Injected by Syringe are 2 different theories wouldn't you think.

 

[Venom]

"Venom, to read a report and think they experienced symptoms which are dangerous and might even be fatal is another thing then read them for what they are."

By "read them for what they are," do you mean read them and then discredit, discard, and disbelieve everything they have said? How can you justify doing that? If they are telling the truth, and explaining to the best of their ability, then their account should be taken seriously.

"for what they are."

And what are they? Are they made up? Are they written by children? Are they intentional lies? No! They are the honest reports of what people have experienced. Really, even if they aren't scientists and physicians, do you not think they can give an estimate of what was happening to them, or how they felt? If someone passed out and their breathing was tight, do you think they are incapable of relating this fact with at least some medical accuracy? Give us some credit man, we're not stupid. Non-physicians can still give an approximate account of what happened to them.

"In the end, have you ever read a report where the victim is hospitalized and close to dying? No. They are on their feet in a day or two."

For the millionth time, I am not talking about healthy people dying, but those who are weakened from some disease, condition, age etc.

"That is the facts, not "mights" and "maybes"."


Crotalus, please try to get past the fact that no one in the hobby has yet died. I am speaking in the hypothetical tense: IF the venom has caused these non-fatal but serious symptoms in healthy hobbyists, THEN the venom might prove fatal in someone who is seriously impaired in the organs/ systems which the venom effected in the healthy hobbyists. I am using simple LOGIC. I don't need an actual instance of tarantula death to postulate that it could happen. All I need--all anyone needs-- is some evidence of strong effects in the healthy, to theorize that it could be much more serious for the very unhealthy.

 

[cacoseraph]

the background thread provided discusses beccas bad ticker... a pre-existing medical condition. i think that makes death a possibility.

plus, the question isn't if it is likely, the question is if it is possible

 

[zachari5678]

Escoubas P, Rash L. 2004. Tarantulas: eight-legged pharmacists and combinatorial chemists. Toxicon 43, pp. 555-574.

The authors review various symptoms reported after T bites. Most bites resulted in "mild to severe local pain, strong itching and tenderness which may persist for several hours, edema, erythema, joint stiffness and swollen limbs, burning feelings, and cramps." The most severe symptoms reported "involved strong pain, intense muscle cramps lasting several weeks, temporary paralysis, and a possible case of coma in a German breeder." They note further that "there is no properly documented case of human death following a tarantula bite."

I would be inclined to vote no.

 

[Nerri1029]

once more into the foray

http://www.aapcc.org/Annual Reports/03report/Annual Report 2003.pdf

Page 44 of 70 so don't print the whole thing..

comes down to this

..........Ages.............|reason.................adv|treated in|.......Outcome
# exp| <6| 6-19| >19| Unint|..Int| other|RXN| Med Fac| none| minor| Mod| Major| Death
243...|.19| 85...|.136|.232..|...6 |....0...|..5.|...56......|...7...|..73...|.11..| 0 .....| .. 0



I hope the table comes out..

 

[blacktara]

Yes, but

Here's how to think about this issue

Any envenomation, by any species, spider, snake, scorpion, or whatever, places a physiologic stress on the bite recipient. If that person has some underlying medical condition (a very weak heart, for example) such that they cannot handle what to a healthy adult might be only a mild (albeit painful) stress, then yes, they could die. The other thing to consider is that its always possible that the victim will have a bad allergic type reaction that could cause death.

Is either of these scenarios likely? In the case of T's, no.

Before the development of an effective anti-venom, a bite from any of several Australian funnel web species meant big trouble. If the victim is a healthy adult, spiderwise, I'd say that the only other species to really worry about being life threatening from a bite itself would be a bad tag from Phoneutria.

Recluse bites can be disfiguring, and there is a threat of superinfection, which can cause death if it progresses to frank sepsis. Widow bites can make a grown man feel like major s&*t, but unless you got multiple multiple bites, they will NOT kill a healthy adult (barring the impossible to predict allergic reaction)

All that said, I'd say that anyone bitten by any T should seek medical advice if they have any doubts or concerns.

The only spider I have ever kept is a black widow, so no, I am not an experienced keeper. But I am a physician who has treated a number of widow bites, real and suspected recluse bites (the suspected bites are almost certainly NOT spider bite, by the way), and a fair number of crotalid snakebites as well. Never treated an elapid bite or a T bite

 

[Sheri]

Here's how to think about this issue

Any envenomation, by any species, spider, snake, scorpion, or whatever, places a physiologic stress on the bite recipient. If that person has some underlying medical condition (a very weak heart, for example) such that they cannot handle what to a healthy adult might be only a mild (albeit painful) stress, then yes, they could die. The other thing to consider is that its always possible that the victim will have a bad allergic type reaction that could cause death.

Is either of these scenarios likely? In the case of T's, no.

Before the development of an effective anti-venom, a bite from any of several Australian funnel web species meant big trouble. If the victim is a healthy adult, spiderwise, I'd say that the only other species to really worry about being life threatening from a bite itself would be a bad tag from Phoneutria.

Recluse bites can be disfiguring, and there is a threat of superinfection, which can cause death if it progresses to frank sepsis. Widow bites can make a grown man feel like major s&*t, but unless you got multiple multiple bites, they will NOT kill a healthy adult (barring the impossible to predict allergic reaction)

All that said, I'd say that anyone bitten by any T should seek medical advice if they have any doubts or concerns.

The only spider I have ever kept is a black widow, so no, I am not an experienced keeper. But I am a physician who has treated a number of widow bites, real and suspected recluse bites (the suspected bites are almost certainly NOT spider bite, by the way), and a fair number of crotalid snakebites as well. Never treated an elapid bite or a T bite

I was under the impression that Atrax robustus was more of a risk than Phoneutria. (Male bites, of course) You have not said anything to dispute that, of course, but I would prefer to be tagged by a Phoneutria any day. (And there is also anti-venom for Phoneutria as well, though the Peruvians seem not to know this.)

As for allergic reaction to T bites, maybe you can help me understand this better but there has been research done to indicate that whatever properties are required to receive an immune response from someone when they receive a bite is just not present in T venom... or at least not in amounts needed...

Will search for more info (maybe even in this thread already) and report back.

 

[SpiderDork]

Just a little something I read, take it for what it's worth to you.

Web Site Link: http://www.spiderpharm.com/Selhuwena.htm#General biology

Direct quote:

"Biology
Ornithoctonus huwena ( Theraphosidae) is a robust burrowing tarantula which is native to Southern China and Vietnam. It is a nocturnal animal and comes out at night to find food. Like many other Asian tarantulas, this spider can be very aggressive when disturbed and will attack humans and cattle, in self defense. There are reports of cattle deaths as well as the death of a baby who was bitten on the buttocks while crawling in the garden.

In the wild, the spider takes about 3 years to become an adult and may live as long as 30 years. Under captive conditions, with appropriate care and nutrition, they can mature within 18 months. Adult females typically lay 50-100 eggs in the first reproductive year and 300-500 eggs in following years.

Venom characterization
The venoms of the spider is quite complex with a large of peptide and non-peptide toxins with diverse pharmacological activities. The LD50 of the crude venoms in mice is 1.16mg/kg. The venom contains hyaluronidase, alkaline phosphatase, protease and DNAse. A concentration of 3mg/ml of the venoms can block the neuromuscular transmission in the isolated toad sciatic nerve-sartorius preparation. The crude venoms can cause paralysis and respiratory failure in mice with a dosage of 5mg/kg. The venoms contain many toxins, including huwentoxin-I, huwentoxin-II and an lectin . The huwentoxins are novel neurotoxins with potent activities against mammals. Recent tests indicate that huwentoxin-I acts presynaptically, blocking neurotransmitter release. This is contrary to prior experiments that indicated a block of acetylcholine receptors."

 

[blacktara]

Response to Sheri

The issue of which is more venomous or more dangerous is always colored by all kinds of ifs and conditionals and by how things are defined. I believe that it's fact that since the development of antivenom, no healthy adult has died from an Atrax Robustus bite (one of the Aussie experts correct me if I am wrong)

Right now, I'd have to say that the spider whose bite is most likely to kill a healthy adult is the Northern Funnel Web - H Formidibalis. The reason is that it's bite is as bad or worse than Atrax, and where you have to be to get bitten (the hinterlands of Queensland, unless it's a captive specimen) you might well not be able to get to anti-venom before it's too late

Allergic reactions are a result of an adverse response to a trigger by certain portions of them immune system. Immune responses are triggered by chemical binding - something binds to a receptor on a cell and that binding triggers a response, or an antibody recognizes the 3-D surface of a foreign moiety, binds to it, and this sets of a chain of responses. Usually (nothing is ever 100% black and white) the surfaces and receptors and such that are players in this system are proteins or portions of proteins called peptides. Venoms are typically composed of a witches brew of peptides and proteins - so they can certainly trigger immune responses, even if present in only very small amounts. Remember, part of an immune response (to be effectiuve in the entire body of a large human) is to hugely amplify what is initially a local encounter with very small amounts of antigen.

Now, I am a practicing physician, who has a working knowledge of the common type allergic responses we might see in day to day practice. I am NOT an allergy, immunology, or toxicology PhD - If there is some aspect of T venom that makes it non-immunogenic or non-allergenic, I wouldnt know it or really have reason to know it. From where I'm coming from, anything foreign that makes it into the bloodstream has to be treated as potentially allergenic (except possibly the medicines used to suppress these responses)

Remember too that "allergic reaction" and "adverse reaction" (a response that wasnt desired) are NOT the same thing

 

[blacktara]

Response to spider dork

First off, thanks a bundle for your email regarding my other post about a beginner T

Next - that hodgepodge of compounds that make up that spider's venom is not atypical. Remember, venoms are either lytic to help break down and digest the animal's meal, or neurotoxic to stun or kill it (or, in many cases, a little or a lot of both). Will a bite be a nasty experience you wouldnt wanna relive? - quite possibly. Will it kill you? Highly unlikely (unless you're the poor toddler who was crawling around in the dirt)

Lastly, if you ask me, "aggressive when disturbed " is one of those oxy type morons - Aggressive is going after something that isnt messing with you in order to harm it. Fighting back when disturbed is self-defense

 

[Venom]

We could use the opinion of a physician in this thread.

Have you read the preceding discussion on this topic? This thread is part of a continuing debate, much of which can be found here:

http://www.arachnoboards.com/ab/showthread.php?t=45500

Anyway, would you mind taking a look at the symptoms/ manifestations described in some of these threads, and let us know what you think of them? I, and others here, would appreciate your taking the time to give us your professional opinion of these. Thanks.

http://www.arachnoboards.com/ab/showthread.php?t=21229

http://www.arachnoboards.com/ab/showthread.php?t=11996

http://www.thetarantulastoreforum.c...owtopic=248&hl=

http://www.arachnoboards.com/ab/showthread.php?t=939

http://www.bighairyspiders.com/poec.html

http://www.bighairyspiders.com/bites.shtml#cpaganus

http://www.bighairyspiders.com/bites.shtml#pregalis

http://www.arachnoboards.com/ab/showthread.php?t=1901

 

[Sheri]

Allergic reactions are a result of an adverse response to a trigger by certain portions of them immune system. Immune responses are triggered by chemical binding - something binds to a receptor on a cell and that binding triggers a response, or an antibody recognizes the 3-D surface of a foreign moiety, binds to it, and this sets of a chain of responses. Usually (nothing is ever 100% black and white) the surfaces and receptors and such that are players in this system are proteins or portions of proteins called peptides. Venoms are typically composed of a witches brew of peptides and proteins - so they can certainly trigger immune responses, even if present in only very small amounts. Remember, part of an immune response (to be effectiuve in the entire body of a large human) is to hugely amplify what is initially a local encounter with very small amounts of antigen.

Now, I am a practicing physician, who has a working knowledge of the common type allergic responses we might see in day to day practice. I am NOT an allergy, immunology, or toxicology PhD - If there is some aspect of T venom that makes it non-immunogenic or non-allergenic, I wouldnt know it or really have reason to know it. From where I'm coming from, anything foreign that makes it into the bloodstream has to be treated as potentially allergenic (except possibly the medicines used to suppress these responses)

Remember too that "allergic reaction" and "adverse reaction" (a response that wasnt desired) are NOT the same thing

Thanks for the information!
I recently had a conversation with a doctor about allergic reactions.. and what I recall of it was that there are 5 different levels of response from the immune systems that can determine how severe a reaction is, and when it occurs...
Of course, I had had a few beers so it's nice to be able to check that info.

 

[Crotalus]

Right now, I'd have to say that the spider whose bite is most likely to kill a healthy adult is the Northern Funnel Web - H Formidibalis. The reason is that it's bite is as bad or worse than Atrax, and where you have to be to get bitten (the hinterlands of Queensland, unless it's a captive specimen) you might well not be able to get to anti-venom before it's too late

H. infensa is located on a remote island, so that too makes it a bad candidate to get bitten by. Even Atrax is found in the outbacks around Sydney. Offcourse every bite you get in the field is much more serious then if you got a hospital around the corner. That goes for every venomous animal.
It really doesnt matter how low the LD50 are between the species, australian hexathelids are all to be considered very dangerous to man.

/Lelle

 

[blacktara]

Venom

I'll dig through those discussions in the next few days to weeks and let you know what I think

 

[blacktara]

Crotalus

I was just pointing out that "most venomous" as far as LD-50's in a lab and "most likely to result in the death of a human" are not one and the same

I think the second is more relevent from a practical point of view

The first, the issue of most venomous - leads inevitably to geekbabble about LD-50's and such. But who knows when LD-50's from mice translate to relative lethality in humans. Atrax for example, is, as I understand it, lethal to primates but not to other mammals

And the other thing about most venomous - Dead is dead. What I care about is whether I will die from the bite or not. If I will die, I could care less if it was .4 or 400mg of venom that killed me, and whether I died in 3 minutes or 30

Ya know?

 

[blacktara]

This may not be the most appropriate place for this

but here's a little something on snake venoms

Snake venoms are usually composed of multiple components which have two general types of effects.

The first are compounds that are neurotoxic. They block nerve function, by stopping nerves from firing, or by preventing nerves from responding to being stimulated, in one way or another. They can cause death because if they effect the nerves that control the muscles that you use to breathe, you stop breathing. If you can get the patient to a hospital and have a ventilator do the breathing for them until this component of venom wears off, they will be ok from that standpoint

The second group are compounds that are lytic, meaning that they break down big molecules into smaller pieces. To the snake, these are like digestive enzymes. To the bite victim who isnt a meal, the problem is that these compounds break down proteins. This leads to tissue destruction (the nasty limb wounds I'm sure many have seen in texbooks), which can lead to death if they get infected or gangrenous. However, the more immediate threat to life comes from the fact that these lytic components break down components of the coagulation cascade, thus causing a generalized activation of the coagulation process. (breaking down bigger proteins into smaller working pieces is how the coagulation factors work). In the case of snakebite, the massive, inappropriate, and unwanted activation of coagulation leads to the following - the materials needed to clot are used up because clots are formed in the small blood vessels throughout the body. Because the clotting factors are depleted, the blood actually takes longer to clot than it should, but it also clots when and where it shouldnt because of the continued stimulation of coagulation. The medical term for this is Disseminated Intravascular Coagulation, or DIC. The physiologic consequances from damage to the lining of blood vessels, and from end organ damage due to the clots all over the place can lead to multi-organ failure and death.

For example - clot forms in the small blood vessels of the lung - this leads to damage in the lining of these small vessels. They start to leak. Fluid seeps into the regions of the lung where gas exchange is supposed to take place. This fluid not only impairs gas exchange, it also contains activated clotting factors and mediators of the inflammatory process. The lung tissue becomes inflamed, and later scarred. It leads to something called ARDS - adult respiratory distress syndrome - Now breathing fails because the lung tissue is damaged. Breathing failure because the muscles dont work is easy to deal with, provided you get the patient on a ventilator in time. Breathing failure because the lung is damaged by an out of control inflammatory response is a much much more difficult problem to overcome

Confusing all this is the fact that the venoms tend to be some mixture of these two types and that there may also be direct non-lytic and non-neurotoxic effects of some of venom components on heart muscle. These are not well understood or characterized

All of this is simplified and somewhat generalized, but I hope it gives some idea of the concepts and the whys - which mean more in a practical sense (to us humans) than the doses needed to kill half of mice or how many mice one mg of venom can take down (which is what matters to the snake, I suppose)

 

[blacktara]

The funny thing about spider venom

Is when you start to ask "Why"

If the venom has the same effects as on prey, only to a much smaller degree in a human who is thousands of times larger than a spider's meal, ok, that makes sense - The dose of neurotixin that kills the cricket is only enough to cause tingling and cramps in a human

But Atrax - The component that's lethal to humans - It makes sense that it kills insects, and it makes sense that it's not lethal to larger mammals (which arent a run of the mill funnel web menu item). So why is it lethal to humans? What need does Atrax have to be able to kill people?

I'd be curious what folks think about this. As with most speculation, people tend to postulate something that jibes with their thinking. For example, the scientific community tends to think that this is an accident of genetics, a random unfortunate cross-activity that happens because the component of human physiology susceptible to the venom is structurally somehow related to that analogous compoent in Atrax food. Nature is full of recurrent themes, and in this case, our genes thematically similar to the target of this component of Atrax venom. The strongly atheist might say that it's proof that there isn't a God, because God's perfect plan wouldnt have included a screw up like this

I certainly do NOT want to start a religious "discussion", but the WHY of Atrax venom is interesting to ponder

 

[Sheri]

The first are compounds that are neurotoxic. They block nerve function, by stopping nerves from firing, or by preventing nerves from responding to being stimulated, in one way or another.

This may interest you... my doctor was born and trained in South Africa. He had the opportunity to treat a Black Mamba bite... he knew without doubt it was a black mamba because the snake was killed and brought in with the patient.
Now... the man was fine. Not presenting anything but mechanical injury and impatient to get back to work on the railway. But my doctor insisted on keeping him under observation, though at this point, I guess believing it was a dry bite.
Anyway, hours later he got a call that the patient was suffering a delayed but intense reation to the snake bite. After a few days in coma (I think) and on a respirator he recovered. Of course, the medical community was more than intriuged and after some testing discovered he had some sort of condition that affected the endings of his nerve cells - that inhibited the effect of the reaction to the bite. There was a name he have me for this, and he explained it far better than I just did... if it comes to you please let me know, it's driving me crazy.

The second group are compounds that are lytic, meaning that they break down big molecules into smaller pieces. The physiologic consequances from damage to the lining of blood vessels, and from end organ damage due to the clots all over the place can lead to multi-organ failure and death.

Right, this was explained to me, and I found it very interesting... this is why someone can appear to be ok, sent home, then wind up dead a few days later, is that accurate? How is this effect treated?
And did those 5 immune responses make any sense? Or did I totally remember that information inaccurately?

Confusing all this is the fact that the venoms tend to be some mixture of these two types and that there may also be direct non-lytic and non-neurotoxic effects of some of venom components on heart muscle. These are not well understood or characterized

Ok, now there is a term for this though, right? This non-lytic and non-neurotoxic effect? Is there any current thinking that you are aware of that explains or identifies the part of the venom responsible for this? Is there any species of snake or spider that is known to only have this cardiac effect without any noticeable lytic or neurotoxic impact?

Also, do most doctors have as keen a knowledge on these issues or did you take additional training in med school? Or were you just more naturally interested and therefore totally absorbing the standard information that everyone was taught?

 

[Sheri]

Is when you start to ask "Why"

If the venom has the same effects as on prey, only to a much smaller degree in a human who is thousands of times larger than a spider's meal, ok, that makes sense - The dose of neurotixin that kills the cricket is only enough to cause tingling and cramps in a human

But Atrax - The component that's lethal to humans - It makes sense that it kills insects, and it makes sense that it's not lethal to larger mammals (which arent a run of the mill funnel web menu item). So why is it lethal to humans? What need does Atrax have to be able to kill people?

You mentioned a random blip on the screen... my initial instinct would be that Atrax needed to fend off a mammal that was closely related to us in order to defend itself at some point in history. I do not know enough about Australia's development and evolution in terms of flora and fauna to speculate, but it seems unlikely that it was entirely random.

And a true atheist never needs to prove there is no god.

 

[blacktara]

Mamba bite

1. Offhand, I dont know the name of the condition

2. I think I may know a little more than most because I love animals and was interested enough to dig down and find out what's truth and what's fear driven myth about various venomous creatures

3. About mambas - one of the ER docs who works here is, like me, into this stuff, and knows snakes because his brother was a zookeeper for a while. His bro apparently once attended a conference where some American docs excitedly presented a case report of a keeper that got tagged by a mamba and survived (to their surprise) without antivenom, with only ventilator support and basic medical supportive care. Apparently, later on at that conference, a South African group presented a series of at least several DOZEN mamba bites and reported that the MAJORITY did ok with supportive care (including vent) but without antivenom. Next time my friend is working a shift, I'll ask he has the reference, and I'll try and do a med search

The mamba is one of those species where common perception, even among many in the medical field who have no experience with it, is that a bite from this snake is a death sentance without antivenom. Misunderstanding and lack of knowledge are rampant. I am NOT an expert, just interested in clearing up myths and discovering the facts

I'll get back to you if I uncover more on the mamba case report series, but if you get the chance, ask your friend. Being from there, he may have an easier time tracking down the reference