Objective: To investigate species-specific envenoming rates
and spectrum of severity of funnel-web spider bites, and the
efficacy and adverse effects of funnel-web spider antivenom.
Data sources: Cases were identified from a prospective study
of spider bite presenting to four major hospitals and three state
poisons information centres (1999–2003); museum records of
spider specimens since 1926; NSW Poisons Information Centre
database; MEDLINE and EMBASE search; clinical toxinology
textbooks; the media; and the manufacturer’s reports of
Data extraction: Patient age and sex, geographical location,
month, expert identification of the spider, clinical effects and
management; envenoming was classified as severe, mild–
moderate or minor/local effects.
Data synthesis: 198 potential funnel-web spider bites were
identified: 138 were definite (spider expertly identified to
species or genus), and 77 produced severe envenoming. All
species-identified severe cases were attributed to one of six
species restricted to NSW and southern Queensland. Rates
of severe envenoming were: Hadronyche cerberea (75%),
H. formidabilis (63%), Atrax robustus (17%), Hadronyche sp.
14 (17%), H. infensa (14%) and H. versuta (11%). Antivenom was
used in 75 patients, including 22 children (median dose,
3 ampoules; range, 1–17), with a complete response in 97%
of expertly identified cases. Three adverse reactions were
reported, all in adults: two early allergic reactions (one mild
and one with severe systemic effects requiring adrenaline),
and one case of serum sickness.
Conclusions: Severe funnel-web spider envenoming is
confined to NSW and southern Queensland; tree-dwelling
funnel webs (H. cerberea and H. formidabilis) have the highest
envenoming rates. Funnel-web spider antivenom appears
effective and safe; severe allergic reactions are uncommon.
MJA 2005; 182: 407–411