Download Avian Bot ulism - City of Belmont

Ci t y o f Be l m o n t
I n f o r m a t i o n Sh e e t –
A v i a n Bo t u l i sm
What is avian botulism?
Avian (bird) Botulism is a serious disease which causes progressive weakness, paralyses and death in birds. Botulism
is a reportable disease through the Department of Agriculture and Food in certain situations and is taken seriously by
the City and other state and federal government departments.
What causes the disease avian botulism?
The naturally occurring bacteria Clostridium botulinum is the cause of botulism and water birds generally become
infected during periods where there is an increase in bacteria numbers. C. botulinum occurs naturally in the mud/soil
of wetlands and lakes around the world and its numbers increase during favourable conditions. Birds become affected
by the disease by ingesting food (insects, maggots, snails, worms etc) which has consumed or come into contact with
the C. botulinum bacteria. When this occurs the bacteria then further develops in the bird’s digestive system and
releases the botulism toxin causing paralysis and mortality.
When do cases of avian botulism arise?
The bacteria C. botulinum is found in greater numbers during summer months when water and oxygen levels are low,
the water is much warmer and there is a large abundance of decaying organic matter such as decomposing algae
blooms (see Algae Information sheet), other plants and even from other animals.
Water birds often search the bottom of the water body for food such as worms, snails and other insects. When there is
an increase in the number of C. botulinum cells there is an increase risk that the birds may ingest food which contains
increased concentrations of the botulism causing bacteria.
Once environmental conditions return to normal (oxygen levels, increase flushing and stabilised nutrients) the risk of
birds becoming infected with botulism reduces.
City of Belmont – Avian Botulism Information Sheet
March 2011
City of Opportunity
City of Belmont – Avian Botulism Information Sheet
March 2011
City of Opportunity
How do you prevent avian botulism?
medication have been tested and none, except an
antitoxin for botulism, have any beneficial effect.
As the botulism causing bacteria is natural and always
present it is difficult to prevent the disease when
environmental conditions work against you.
Am I at risk?
To reduce the risk of avian botulism, the occurrences
of algal blooms, large deaths in fringing vegetation and
decaying organic material should be prevented and
managed. This in addition to aeration of the water
body and water quality improvement through
establishment of native flora, will minimise the
conditions that promote botulism causing bacteria. In
addition, any dead birds suspected to have botulism
should be removed immediately from the water body,
to prevent its spread.
No known spray would be selective enough to kill the
bacteria and not kill other harmless and beneficial
bacteria in the environment.
The only reasonable avoidance measure is to prevent
nutrient loading of water bodies which leads to
increases in algal blooms and consequently increases
in decaying organic materials. Many kinds of
Human botulism is rare due to minimal or no contact
with C. botulinum infected material, contaminated
foods and other animals exposed to decaying
materials (i.e. birds, fish). However, exposure is still
possible through open wounds, predominantly in small
children playing around lake edges and in areas which
could become exposed high amounts of C. botulinum
(i.e. in mud or soil around lakes). Therefore there is
still the risk of exposure to the bacteria and onset of
botulism, and as such it still is a management issue.
The public should also be notified that in the event of a
break in the skin (scratch, cut, graze etc) caused by, or
exposed to, potentially contaminated substances (i.e.
sand, foliage and grass) antiseptic measures should
be applied as soon as practicable and the wound
cleaned. At the sign of any medical symptoms report
immediately to a doctor or hospital.
Where can I find more information?
There are various places you can find information on botulism. Below are sources recommended to ensure the
information you receive is correct.
Phosphorous Awareness Project- advice on reducing nutrient inputs into lakes and waterwayswww.sercul.org.au/pap.html
Australian Wildlife Health Network – Fact Sheet - Diagnosing Botulism in Birds in Australia www.wildlifehealth.org.au
Department of Environment and Conservation – Fauna Notes No.34 – Sick Water Birds –
www.dec.wa.gov.au. You can also call the WILDECARE Helpline on 08 9474 9055. The WILDCARE Helpline
operates 24 hours a day, seven days a week, diverting to after hours numbers at nights and weekends, to
provide immediate assistance for sick, injured or orphaned native animals.
Department of Heath - Communicable Disease Control Directorate – Botulism - www.public.health.wa.gov.au
World Health Organisation – Fact Sheet – No.270 – Botulism – www.who.int
People may wish to contact the City of Belmont Parks and Environment Department for updates on wetlands
and lakes around the City on 9477 7222.
City of Belmont
Parks and Environment Department
215 Wright Street Cloverdale WA 6105
Ph: (08) 9477 7222 Fax: (08) 9478 1473