In a 13 year period (1963-1976) over 2000 cases of Redback Spider bite were reported to the Commonwealth Serum Laboratories (Sutherland and Trinca 1978); many more bites are reported to doctors, hospitals, and poison information centres throughout Australia.
Prior to the introduction of the specific antivenom in 1956, 13 deaths in Australia were caused by Redback Spider bite.
Only the female is large enough to bite people effectively. The initial bite is often felt but is apparently painless, although some victims have reported burning sensations (Taylor and Murray 1946). Puncture marks are not always evident. In the majority of bites intense local pain is experienced about five minutes after the bite (Sutherland 1983). According to Weiner (1961), in about 40 percent of bites the symptoms included sweating and/or some neuromuscular activity such as muscular weakness, paralysis, stiffness, loss of coordination, tremors, and paresthesiae; and in about 10 percent, muscular weakness, nausea, vomiting, local swelling, dizziness or fainting, local redness, tachycardia, palpitations, insomnia, rigors, fever, and muscle spasms were also recorded. Some reactions can be quite unusual (Sutherland 1983): tetanic spasms, tingling in the teeth, swelling of the tongue, infection of the bite site, convulsions, thirst, diarrhoea, shock, rashes, patches of sweating, periorbital oedema, and others. However, the diagnostic indication of a Redback Spider bite is localised sweating at the site of the bite.