Sydney Funnel-web Spider - Venom

Venom

Funnel-web spider venom contains a compound known as atracotoxin, an ion channel inhibitor, which makes the venom highly toxic for humans and primates. However, it does not affect the nervous system of other mammals. These spiders typically deliver a full envenomation when they bite, often striking repeatedly, due to their defensiveness and large chitinous cheliceral fangs. There has been no reported case of severe envenoming by female funnel-web spiders, which is consistent with the finding that the venom of female specimen is less potent than the venom of their male counterparts. In the case of severe envenoming, the time to onset of symptoms is less than one hour; with a study about funnel-web spider bites finding a median time of 28 minutes. This same study revealed that children are at a particular risk of severe funnel-web envenoming, with 42% of all cases of severe envenoming being children. There is at least one recorded case of a small child dying within 15 minutes of a bite from a Sydney funnel-web spider, though that event occurred before the development of an antivenom. The antivenom was developed by a team headed by Struan Sutherland at the Commonwealth Serum Laboratories in Melbourne. Since the antivenom became available in 1981, there have been no recorded fatalities from Sydney funnel-web spider bites. In September 2012, it was reported that stocks of antivenom were running low, and members of the public were asked to catch the spiders so that they could be milked for their venom. One dose of antivenom requires around 70 milkings from a spider.