Cross reactivity between venomous, mildly venomous, and non-venomous snake venoms with the Commonwealth Serum Laboratories Venom Detection Kit.
OBJECTIVE
Studies have noted the relatively common occurrence of positive urine results with the Commonwealth Serum Laboratories Venom Detection Kit (VDK) when testing patients with suspected snakebite who are not envenomed. Possible explanations have been false positive test results or subclinical envenoming. We investigated a third possibility, that there is potential for the venom (or saliva) from mildly venomous and non-venomous snakes to give a positive reading with the VDK.


METHODS
Venoms/saliva from three non-venomous and seven mildly venomous snake species were tested in the laboratory with the VDK, along with control venoms from four of the five major snake genera (Brown snake, Tiger snake, Death adder and Black snake).


RESULTS
Two of the venom/saliva samples, from Gould's hooded snake (Parasuta gouldii), a mildly venomous snake, and the Black-headed python (Aspidites melanocephalus), a non-venomous snake, caused a positive test for the tiger snake genus. There was also cross-reactivity between black snake venoms and the tiger snake well of the VDK.


CONCLUSIONS
This study provides a further possible explanation for 'false positive' VDK results, that is venom/saliva presence or absorption from mildly or non-venomous snakes and cross reactivity with venomous snakes on VDK testing. It has implications for antivenom use should it ever be required for more severe envenoming syndromes from mildly or moderately venomous snakes, and for further research. It reinforces the practice of only using VDK testing in patients who show definite evidence of envenoming.
Jelinek
George A
GA
Discipline of Emergency Medicine, School of Primary, Aboriginal, and Rural Health Care, University of Western Australia, Australia. sun_and_smiles6@hotmail.com
Tweed
Charles
C
Lynch
Dania
D
Celenza
Tony
T
Bush
Brian
B
Michalopoulos
Nick
N
D000818:Animals; D001315:Australia; D004632:Emergency Medical Services / Q000379:methods; D005189:False Positive Reactions; D006801:Humans; D011237:Predictive Value of Tests; D011933:Reagent Kits, Diagnostic; D012909:Snake Bites / Q000175:diagnosis*; D012910:Snake Venoms / Q000032:analysis*; D012911:Snakes / Q000145:classification*; D013045:Species Specificity
D011933:Reagent Kits, Diagnostic; D012910:Snake Venoms