For the research, scientists have reviewed a large volume of published history relating to spider bites. From this review they have concluded that there is very little evidence of spider-vectored infection.
Popular literature might infer that spider bites lead to infections, however this is not backed up by reported medical cases. The medical cases considered took into account a vast range of spiders from a range of different countries. Here there was scant evidence of any arachnid-inflicted injury.
For example, a study published in 2012 looking at 182 Southern Californian patients presenting with complaint of spider bite, less than 4 percent had spider envenomations. Envenomation is the process by which venom is injected into some animal by the bite (or sting) of a venomous animal. In contrast, around 86 percent had skin infections.
The only spider species that any association with bacterial infections, in medical studies, was the Australian golden silk spider. The golden silk orb-weavers (genus Nephila) are a genus of araneomorph spiders noted for the impressive webs they weave. The venom of the golden silk orb-weaver is potent but not lethal to humans. It has a neurotoxic effect similar to that of the black widow spider, but not to the same intensity.
When humans are bitten by golden silk orb-weavers the resultant bite led to a pus-filled lesion that persist for some two months. The pus is triggered by bacteria. Pus is an exudate, typically white-yellow, yellow, or yellow-brown, formed at the site of inflammation during infection. Bacteria that cause pus are termed suppurative, pyogenic, or purulent.
The research concludes that the medical community and the general public should stop blaming spiders as the cause of bacterial infections.
The research was undertaken at University of California, with the results published in the journal Toxicon. The research is titled “Do spiders vector bacteria during bites? The evidence indicates otherwise.”
