Introduction
Stings from the Jack Jumper ant (Jumper Ant, Hopper Ant, Bulldog
ant) are an important cause of serious allergic reactions in Australia.
Less commonly, the Queensland "Green Ant", and introduced
South American "Fire Ant" also trigger allergic reactions.
Ants sting, not bite!
These ants are a type of "bull-ant", distantly related
to other stinging insects such as honey bees and wasps. They are
members of the genus known as Myrmecia. Generally 1.5 to 2.5cm
long, they have a black body and orange/brown jaws/pincers and
limbs. The major species are M. pilosula and M. nigrocinta. They
are aggressive, typically walk with a hopping motion. They do
not bite, but rather grasps the victim in their jaws, then turn
around and sting them.
Distribution is widespread
These ants are found in Tasmania, Victoria, The ACT, the Snowy
Mountains of New South Wales and coastal New South Wales, with
some pockets reported in the Blue Mountains, the Adelaide Hills
in South Australia and some parts of Western Australia.
Nests are often difficult to find
Ants live in underground nests, often in dry sandy soils.
The openings are often difficult to find, and may be present under
rock, with the entrance surrounded by a small pile of fine gravel.
"Sentry ants" are often present at the entrance. It
is very difficult to avoid being stung by jumper ant in endemic
areas, when nests are located close to human inhabitants.
Allergic reactions may occur to ant stings
There are different types of allergic reactions to stinging
insects. Stings from jumper ants, like those of bees and wasps,
are very painful. Local swelling is very common. Large local swellings
can also occur, lasting a few days at a time. The most serious
reactions are known as generalised allergic reactions, of which
the most severe is called anaphylaxis. This results in potentially
dangerous symptoms such as difficulty breathing, a drop in blood
pressure ("shock"), loss of conciousness or severe stomach
upset, often accompanied by hives, itching and swelling.
Allrgic reactions are not rare
In areas where jumper ants are common, population surveys
have shown that between 2-3 % of the population have had generalised
allergic reactions, sometimes life-threatening. Deaths have also
been recorded. The allergy does not appear to disappear in a hurry,
lasting many years in most cases.
Confirming a diagnosis of Jumper Ant allergy
There is currently no widely available skin allergy test for
jumper ant sensitivity. In the meantime, a blood allergy test
is available from SouthPath Laboratories, Flinders Medical Centre,
Bedford Park, South Australia 5042. Tests can be arranged with
your doctor and local pathology laboratory.
Management Principles
Avoid Jumper ants
Ideal, but not always possible. It is sensible to wear heavy
clothing such as boots and gloves when in the bush or when gardening
seems sensible, but the ants can still sting through heavy clothing.
Emergency Action Plan
After a sting, patients with life-threatening (anaphylactic) reactions
are advised to seek urgent medical assistance, carry (and know
how to use) injectable adrenaline (such as EpiPen) to treat serious
allergic reactions. This is available on PBS Authority for patients
with anaphylaxis.
Other issues to consider
o Carry a means of summoning assistance if stung, such as a mobile
telephone.
o Don't travel or work alone in remote areas, and consider carrying
an emergency satellite beacon and additional emergency medication
if traveling in areas without easy access to medical assistance,
and when telephone coverage is unreliable.
o Some medicines can interfere with the action of adrenaline used
to treat allergic reactions. Patients taking blood pressure or
heart medication should discuss their use with their heat and
allergy specialist.
o Patients with stinging insect anaphylaxis should be referred
to an immunology/allergy specialist for assessment.
Future prospects for immunotherapy
Commercial venom extracts are available in Australia for the
diagnosis and treatment of patients allergic to honey bees and
wasps. At this time, there is no commercial venom extract available
for skin allergy testing or treatment. In the last couple of years
however, a study performed by Australian doctors in Tasmania demonstrated
that Jumper Ant venom extracts were very effective at switching
off Jumper Ant allergy, and preventing allergic reactions when
patients were re-stung. This is the subject of ongoing research
by Australian doctors and scientists.
For additional information
Check the ASCIA website from time to time regarding research
projects in this area and updated information on Jumper Ant allergy.
http://www.allergy.org.au/aer/infobulletins/jumper_ant.htm
CURRENT RESEARCH March 2006
Members of ASCIA are developing a detailed national map of the species responsible for anaphylaxis, compiling a panel of reference venoms and allergic sera, so that accurate diagnostic tests and high quality venom extracts can be provided for human use. More information on study recruitment can be obtained HERE and by followijg the related links.
References
Web links
Ant allergy support group (Australia)
CSIRO Information on Jumper ants