Late treatment with antivenom in prolonged red-back spider envenomation

Venom and Antivenom of the Redback Spider (Latrodectus hasseltii) in Japan. Part II. Experimental Production of Equine Antivenom against the Redback Spider

This is the first report on large-scale experimental production of an equine antivenom against the redback spider (Latrodectus hasseltii) lived in Japan. We captured 10,000 redback spiders in Japan and prepared the toxoids of crude venom extract, mixed the toxoids with a mineral oil adjuvant, and immunized healthy horses repeatedly over a period of several weeks. Thereafter, we separated the horse plasma, purified the γ-globulin fraction, and stocked it as a purified antivenom concentrate. Consequently, we manufactured approximately 6,500 vials of a single-dose freeze-dried test lot from a portion of the purified γ-globulin fraction, equivalent to the extract derived from 520 spiders. This test lot had an antitoxin titer comparable to that of a similar drug commercially available overseas (a liquid preparation), and the other quality met all quality reference specifications based on the Minimum Requirements for Biological Products and other guidelines relevant to existing antivenom drug products in Japan.

Widow spider envenomation (latrodectism): a worldwide problem

The objective of this study was to review widow spider envenomation on a worldwide basis, with an emphasis on regional variability in management, particularly between the United States and Australia. Data sources were the Medline database (1966-1997) for English language references using as key words widow spider, latrodectism, and red back spider, and Mesh headings. Textbooks of toxinology were also used. Studies involving clinical reports and series were selected. The data indicated that envenomation by widow spiders (latrodectism) is common worldwide. Local pain and sweating predominate, in about 25% of cases becoming generalized or developing in remote sites. The mortality in published series varies from 5% to 10%, although these may be overestimates. Australia may have the highest rate of latrodectism in the world. The literature reveals regional disparities in the treatment and outcome of latrodectism. In Australia, intramuscular antivenin has been used liberally for more than 40 years with a very low rate (0.5% to 0.8%) of allergic reactions and no deaths recorded since its introduction. Antivenin is routinely successful in relieving the effects of latrodectism. In the United States, the antivenin is given intravenously, is usually reserved for very severe cases, and the rate of allergic reaction is high (from 9% up to 80% in those skin testing positive). Deaths have been recorded after antivenin. The literature suggests that antivenin to one species of Latrodectus is likely to be effective against other species. The conclusion drawn was that latrodectism is a common envenomation worldwide. There is a strong case for a comparative trial of Australian vs US antivenin in treating latrodectism due to the black widow spider in the United States.

A red-back spider bite in a lymphoedematous arm

We administered a record eight ampoules of antivenom over one week to a 55-year-old woman with a red-back spider bite on her chronically lymphoedematous right arm. She had severe local signs of envenomation but relatively little systemic effect. The final antivenom dose, injected subcutaneously at the bite site, had a good effect.