A Rapid and International Applicable Diagnostic Device for Cobra (Genus Naja) Snakebites

Abstract

Cobra snakes (genus Naja) are some of the most dangerous snake species in Asia and Africa, as their bites cause severe life-threatening respiratory failure and local tissue destruction, especially in the case of late diagnosis. The differential diagnosis of snakebite envenomation still mainly relies upon symptomatology, the patient’s description, and the experience of physicians. We have designed a rapid test, immunochromatographic test of cobra (ICT-Cobra), which obtained fair results in improving the diagnosis and treatment of Naja (N.) atra snakebites in Taiwan. In this study, we further investigated the feasibility of applying the kit for the detection of other cobra venoms based on the potential interspecies similarity. We firstly demonstrated the cross-reactivity between eight venoms of medically important cobra species and the rabbit anti-N. atra IgG that was used in ICT-Cobra by Western blotting and sandwich enzyme-linked immunosorbent assay. Then, ICT-Cobra was used to detect various concentrations of the eight venoms to elucidate its performance. Noticeable correlations between the cross-reactivity of venoms from genus Naja snakes and existing geographical characteristics were found. ICT-Cobra could detect venoms from other Asian cobras with variable detection limits comparable to those observed for N. atra, but the kit was less successful in the detection of venom from African cobras. The similar but slightly different venom components and the interaction between venom and rabbit anti-N. atra IgG led to variations in the detection limits. The transcontinental usage of ICT-Cobra might be possible due to the cross-reactivity of antibodies and similarities among the larger-sized proteins. This study showed that the close immunological relationships in the genus Naja could be used to develop a venom detection kit for the diagnosis of cobra envenomation in both Asian and African regions. Additional clinical studies and technical adjustments are still needed to improve the efficacy and broadening the application of ICT-Cobra in the future.

The 20-minute whole blood clotting test (20WBCT) for snakebite coagulopathy—A systematic review and meta-analysis of diagnostic test accuracy

“…The considerable cost associated with SVDK’s have contributed to their limited uptake in other regions. SVDK’s using immunochromatographic technology are currently in development for Daboia and Naja genera [ 49 ] and require comprehensive validation before commercial role out. Due to the need for sophisticated laboratory equipment, the detection of venom in serum samples both pre and post antivenom have not been used to guide clinical practice.…”

Influential Factors of Local Tissue Necrosis after Taiwan Cobra Bites: A Secondary Analysis of the Clinical Significance of Venom Detection in Patients of Cobra Snakebites

“…Fifth, the data we used here are almost 2 decades old, and this will raise the question of whether we can use these data presently. However, Hung and colleagues used a similar ELISA method recently [ 22 ].…”

Cytotoxin antibody-based colourimetric sensor for field-level differential detection of elapid among big four snake venom

“…Its ease of production at low cost has made it a valuable diagnostic method in resource limiting settings. Recently, a polyclonal antibody based immunochromatographic test has been developed for detection of various species of cobra venom with a detection limit of 5 ng/mL [ 29 ]. But there is no substantial data for its application as a kit for differential diagnosis of envenomation.…”

“…Despite the attempts made for miniaturization of conventional assays with enhanced sensitivity, its field applicability remains questionable due to the requirement of costly chemicals and sophisticated analytical tools. With the swift transitions being made in the field of diagnostics, few polyclonal antibody-based immunochromatographic tests have been developed for detection of specific snake venoms [ 29 ]. Scientific advancements have been made to develop venom detection kits but till today none of them have been commercialised except the snake venom detection kit from Australia.…”