The DNA a snake leaves behind when it bites someone can be used to identify its species and get the proper antidote to the victim quickly, New Scientist reports.
"At present, the standard of practice is no identification at all, a diagnosis from the symptoms, or more rarely identification of dead snakes that victims occasionally bring to the clinic," François Chappuis from Geneva University Hospitals in Switzerland tells New Scientist. It adds that Chappuis presented his work at the American Society of Tropical Medicine and Hygiene meeting.
He and his colleagues collected samples from the snakebite wounds of nearly 750 victims in Nepal for analysis. They amplified, sequenced, and searched the DNA they found against a DNA reference bank. With this approach, they determined the species responsible for 194 of the bites, including 87 instances in which the species' venom was poisonous.
Chappuis says that the low DNA recovery rate — they were able to isolate DNA from about a quarter of samples — was likely due to attempts to treat the bite that washed the snake DNA away. To address that issue, there would have to be a change to how people respond to snake bites, a change he notes would be difficult to make.
Still, Chappuis adds that his team is working to develop a simple test that can, within half an hour, determine whether the snake that bit someone was poisonous.