Australian authors of a study in this week's issue of THE LANCET highlight how immunisation to desensitise people to the venom of the jack jumper ant shows great promise for preventing severe systemic reactions in people allergic to this venom.
The jack jumper ant (Myrmecia pilosula) is responsible for about 90% of severe systemic reactions to ant venom in southeastern Australia; around 1% of people are at risk of severe systemic reactions to jack-jumper stings in Tasmania. Simon Brown from the Royal Hobart Hospital, Tasmania, Australia, and colleagues assessed the effectiveness of venom immunotherapy (VIT) to prevent life threatening jack jumper sting reactions in otherwise healthy adults.
68 healthy volunteers who were allergic to jack jumper ant venom were randomly allocated to VIT (deliberate exposure to ant venom )or placebo. Jack jumper stings were given one week later in the resuscitation room of a hospital emergency department.
There were no severe reactions among people given VIT compared with three-quarters of those given placebo. The effectiveness of VIT was confirmed when those originally given placebo later received VIT (resulting in only one systemic reaction after ant sting). Around a third of people had systemic reactions during VIT. Some of these were severe, underscoring the importance of performing VIT in areas with immediate access to resuscitation equipment.
In an accompanying Commentary (p 979), David Warrell from the Nuffield Department of Clinical Medicine, John Radcliffe Hospital, Oxford, UK, comments: "This prophylaxis [VIT] can be recommended for susceptible patients in Australia. It will require a sustained supply of M pilosula and, perhaps, some other ant venoms." He concludes: "…the demonstration by Brown and colleagues of such impressive evidence of the efficacy of immunotherapy with jack-jumper ant venom now justifies more research investment in this area."
Contact: Ann Hunt, Media and Public Relations Advisor, Department of Health and Human Services, 3/34 Davey Street, Hobart TAS 7001, Australia;
T) 61-362-336-134;
M)61-438-336-134;
F) 61-362-333-882;
E) ann.hunt@dhhs.tas.gov.au
Professor David A Warrell, Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Headington, OXFORD OX3 9DU, UK;
T) 44-186-522-1332/220968;
F) 44-186-522-0984;
E) david.warrell@clinical-medicine.oxford.ac.uk
Journal
The Lancet