Study predicts medical and ecological disaster from red imported fire ants
Australia is facing one of its biggest ecological disasters because of a tiny ant known as the Red Imported Fire Ant (RIFA).
According to a study in the latest issue of the Medical Journal of Australia, up to 3000 Australians every year may suffer anaphylactic reactions to RIFA stings unless the ants are eradicated. They have the potential to impact on the economy, environment and society, according to an editorial in the same issue of the journal.
Two well-established populations of the ants have been found in Brisbane, although it is unknown how the species - native to South America and now rife in the southern United States - was introduced to Australia.
Allergist, Dr Graham Solley, from the Watkins Medical Centre in Brisbane, has studied the case of a 47 year old Brisbane gardener who was repeatedly stung by the RIFA in 2000 and developed an anaphylactic reaction.
He received two RIFA stings on his knee at the same time and then developed extreme pruritus (itching) and burning in both feet, quickly followed by widespread itching, nasal congestion, acute tightness of the throat and chest, as well as breathing difficulties. He was transported quickly to hospital and was able to be treated and later discharged.
Dr Solley said RIFA stings were recognisable in that they caused acute local pain at the sting site, leading to small pustules the following day which could take two weeks to heal.
"An examination of habitat preferences and estimates of the rate of uncontrolled spread suggest that, unless eradicated, S. invicta (RIFA) will occupy much of arable Australia within 30 years, and therefore exist in close proximity to a large portion of the Australian population," Dr Solley said.
"About 140,000 consultations and 3000 anaphylactic reactions are to be expected each year by 2030 if RIFA eradication is not successful," he said.
An editorial in the same issue of the journal by the Director of the Queensland Fire Ant Control Centre, Keith McCubbin and the Consultant Allergist at St Vincent's Hospital, Melbourne, Dr John Weiner, highlights the RIFA problems in the southern United States.
"This ant has the potential to be one of Australia's biggest ecological disasters…A study of the environmental impact of fire ants shows that areas infested with the ant have fewer native ant species, lower total biodiversity and an absence of scincoid lizards. The ants can decimate ground-nesting birds, turtles and frogs, and can damage farm, irrigation and electrical equipment," Mr McCubbin said.
"The Australian Bureau of Agriculture and Resource Economics estimates that the cost of fire ants over 30 years, if uncontrolled, would be $8.9 billion," he said.
Dr Weiner added that in some parts of the southeastern United States, stings by fire ants are the most common cause of anaphylaxis.
"This ant causes multiple severe stings and can result in life threatening attacks," Dr Weiner said.
The Medical Journal of Australia is a publication of the Australian Medical Association.
CONTACTS: Dr Cas Vanderwoude
Principal scientist
Fire Ant Control Centre, Oxley QLD
Phone: (07) 3310 2810 (B/H)
(07) 3201 0802 (A/H)
Dr John Weiner
Visiting allergist
Dept of Respiratory Medicine
- St Vincent's Hospital, Fitzroy VIC
Phone: (03) 9866 1790 (B/H)
Sarah Crichton, Public Affairs, AMA
Phone: (0419) 440 076