A hidden "double strike" in Black Mamba venom that can undermine standard treatments has been uncovered by scientists, explaining a long-standing and deadly mystery in snakebite care.
Research led by Professor Bryan Fry at The University of Queensland has revealed that the venoms of the Black Mamba, Western Green Mamba, and Jameson's Mamba are far more complex and dangerous than previously known. The study, published in Toxins, shows these snakes launch a coordinated two-pronged attack on the nervous system.
"For three out of four mamba species, the venom first causes flaccid or limp paralysis by blocking nerve signals to the muscles," explained Professor Fry. "Current antivenoms can treat this initial phase, which is why patients may seem to improve."
The critical discovery is what happens next. The study found that the same venoms also contain a second type of toxin that attacks a different part of the nervous system.
"The antivenom neutralizes the first wave of toxins, but this then unmasks the second wave, which overstimulates the muscles and causes painful, uncontrolled spasms known as spastic paralysis," Professor Fry said. "It's like treating one disease and suddenly revealing another."
This dual mechanism resolves the puzzling clinical reports of snakebite victims initially responding to antivenom, only to later develop severe and painful muscle spasms.
The research, which included experimental work by PhD candidate Lee Jones, also found that the potency and function of mamba venom vary by geographic location. For example, Black Mamba venom from Kenya differs from that of South African populations.
"This further complicates treatment strategies across regions because the antivenoms are not developed to counteract the intricacies of these different venoms," said Mr. Jones.
The findings translate into an urgent call for action. Mamba bites account for an estimated 30,000 deaths annually in sub-Saharan Africa, and the limitations of current antivenoms are now clearer than ever.
"This isn't just an academic curiosity," Professor Fry emphasized. "It's a direct call to clinicians and antivenom manufacturers. By understanding the full range of venom activity, we can directly inform evidence-based snakebite care and develop more specialized antivenoms to increase efficacy rates and save lives."
The lab work was completed in collaboration with the Monash Venom Group.