Police race anti-venom to victim

[Vegez]

Spot on Jonno, all bites are confirmed by VDK.

It is interesting the P. textilis Qld is represented in th AV Program and yet still there are cases of this "poor" response.

Definately worth a bit of investigation.

Cheers all.

 

[Wild~Touch]

I've learnt something new today. That's good prettypython

Never stop learning

I find the subject quite fascinating

 

[jedi_339]

I'd love to read your work Vegez whether in draft form, or when published, sounds like a fascinating study you're involved in, have you any idea how long until completion? About the article, I don't believe I read anywhere in there about the initial first aid the woman received on her property, if she were away from the house or even if she didn't receive pressure immobilisation of the bite area initially then her chances of recovery may well have been significantly reduced. Always unfortunate though.

 

[Jonno from ERD]

G'day Vegez,

I'd hazard a guess that the "poor response" to Brown Snake antivenom is attributable to the doctors poor understanding of how it works. I've discussed this previously with Dr Bill Nimo from the AVRU and it's generally a case of doctors trying to reverse symptoms and effects when the only option is to let the body replenish the resources itself. I think you'd gain a lot of knowledge from talking with Bill - you can get in touch with him via the AVRU website.

 

[mmafan555]

Unidentified bites are determined with the VDK (as mentioned above), there is also a polyvalent antivenom which is effective against most of the medically significant genera.

If the species proves to be P. textilis, there is a very worrying trend starting to form here. For some unknown reason, people envenomated by P. textilis primarily from Qld, tend to respond poorly to antivenom therapy when compared to treatment stats for Vic or NSW. There may be a cryptic species involved here? Another explanation could be that P. textilis from some Qld populations are feeding on a particular (different) kind of prey that has resulted in some molecular change in the venom, and thus the antivenom doesn't bind as effectively.
Certainly an area that needs to be investigated.
Cheers all.

Easy explanation...Snake venom varies based on location in the SAME snake...An eastern brown from South Australia would have a different venom composition/toxicity than an Eastern Brown from Queensland...This is probably true for most if not all venomous snakes


Apparently the eastern browns from Queensland are significantly more toxic than the eastern browns from South Australia

Comparison of active venom components between Eastern brown snakes collected from South Australia and Queensland.

Abstract:

"The abundance and activity of the prothrombin activator (pseutarin C) within the venom of the Eastern brown snake (Pseudonaja textilis textilis) is the primary determinant of its coagulation potency. Textilinin-1, also in this venom, is a plasmin inhibitor which is thought to exert its toxic effects through the slowing of fibrinolysis. The aim of this report is to determine if there are differences in the potency of the venom from Eastern brown snakes collected from South Australia (SA) compared to those from Queensland (QLD). A concentration of 0.4 microg/ml venom protein from six QLD specimens clotted citrated plasma in an average time of 21.4+/-3.3 s compared to 68.7+/-2.4 s for the same amount of SA venom (averaged for six individuals). The more potent procoagulant activity of the QLD venom was measured between 0.4 and 94 microg/ml venom protein in plasma. The anti-plasmin activity of textilinin was also greater in the venom of the snakes collected from QLD, causing full inhibition of plasmin at approximately 1.88 microg/ml of venom protein compared to approximately 7.5 microg/ml for the SA venoms. It is concluded that geographic differentiation of the Eastern brown snakes results in significant differences venom potency."

Heres the link to the whole study
SpringerLink - Ecotoxicology, Volume 15, Number 2

And the eastern browns from Queensland [near the Gold Coast Region] also had a significantly larger venom yield than the ones from South Australia[ Barossa Valley and Adelaide
regions]. The Queensland browns were also larger in body size than the South Australian browns.

Venom potency and yield for a given snake changed throughout the year from both regions. Their was also evidence that a snakes venom increases in potency if the snake has not had a meal for awhile. Mice were used as test animals for the venom

​

 

[Vegez]

Thank you mmafan555 for your input. I am aware of the study you mentioned above re: faster clotting times & larger yields in some Qld populations of P. textilis.

The easy explanation certainly tells us what we could expect, however, I'm more interested in the "why" behind this. Are there certain environmental issues at play here? What "forces/pressures or mechanisms" are involved here.

Although there is great gepgraphic variation seen in many venomous snakes, there are also examples that go the other way. For example, one of our most widely distributed species, Pseudechis australis, shows little to no variation in venom composition even though their distribution covers much of the country.

I appreciate your help, but I still believe there are many questions in this area that remain unanswered.

All the Best.

 

[-Peter]

Spot on Jonno, all bites are confirmed by VDK.

It is interesting the P. textilis Qld is represented in th AV Program and yet still there are cases of this "poor" response.

Definately worth a bit of investigation.

Cheers all.

I can vouch for one very recent instance where a VDK was not used and antivenom administered. It was quite obvious that envenomation had taken place and that the "victim" was able to fully identify the snake and thats the call the toxinocologist made.

In regards to the changes in P.textilis venom, I think David Williams made mention of that during his AHS talk the other month. I would love to know more when the info comes available.