Killer funnel-web spiders invade Sydney!
January 22, 2010, 1:37 am
The Independent (U.K.) reported today that the potentially deadly funnel-web spider (Atrax robustus) has had a banner year in the area around Sydney, Australia, where a combination of unusual moisture and cool temperatures have created ideal conditions for the creatures to breed. Funnel-webs have not only long (4-5 mm) and extremely sharp fangs, but also a neurotoxin that can be fatal if not counteracted with antivenom. This neurotoxin causes wholesale relase of neurotransmitters, especially acetylcholine. The puncture wound is intensely painful. After an initial period of hypertension caused by α-adrenergic components, victims present with the typical muscarinic manifestations of cholinergic syndrome (mnemonic: SLUGBAM): Salivation, Lacrimation, Urination, Gastronintestinal emptying (Diarrhea), Bronchorrhea and Bronchospasm, Abdominal distress, and Miosis. Nicotinic manifestations — fasciculations, muscle spasms — also occur. Death can happen early from the “Killer Bs” — bronchorrhea and bronchospasm — or later from pulmonary edema and cardiovascular collapse. Fortunately, the Indepedent‘s headline — “Killer funnel-web spiders” — was somewhat hyperactive. Although the bite of Atrax robustus can be and has been fatal, there have been no reported deaths since the introduction of the antivenom in 1981. This may be because all Sydney funnel-webs live within commuting distance of the Opera House, a relatively small area dense with well-supplied hospitals.
The initial treatment of funnel-web spider bites involves the so-called pressure immobilization technique. The affected limb is wrapped entirely in an elastic compressive bandage (to decrease lymphatic spread of the toxin) and splinted. The patient is then transported to the nearest hospital where antivenom can be administered if indicated. As in cases involving other cholinergic toxins such as organophosphate insecticides or nerve agents, atropine can be used to diminish airway secretions.
This clip from World’s Deadliest Animals: Urban Jungle gives another look at this fascinating spider:
Finally, as always when I read about Australia’s many poisonous creatures, I’m drawn back to Bill Bryson’s brilliant travel book In a Sunburned Country:
“As you can imagine, I was particularly attracted to all those things that might hurt me, which in an Australian context is practically everything. It really is the most extraordinarily lethal country. Naturally they play down the fact that every time you set your feet on the floor something is likely to jump out and seize an ankle. . . .
“Sydney has no box jellyfish, I was pleased to learn. The famous local danger is the funnel web spider, the most poisonous insect in the world with a venom that is ‘highly toxic and fast-acting’ A single nip, if not promptly treated, will leave you bouncing around in the grip of seizures of an incomparable liveliness; then you turn blue; then you die. Thirteen deaths are on record, though none since 1981, when an antidote was devised.”