Chlamydia is a serious debilitating disease that can be fatal to koalas. In the Clarence Valley the most common symptom of the disease is ocular conjunctivitis, where one or both eyes become watery, gummy and increasingly inflamed, to a point where the koala is blinded by the swollen membrane. Urine-stained wet fur around the tail-end is also a sign of a urogenital form of the disease, which is related to infertility, uterine and ovarian cysts in females, and death.
All koala populations carry the chlamydia bacterium: however the actual onset of disease is triggered by chronic stress. Each year large numbers of koalas die through vehicle collisions, domestic animal attacks, habitat destruction and fragmentation by land-clearing and logging; and from starvation and thirst where moisture and nutrients are removed from eucalypt leaves by drought. However any koala that survives the initial trauma will inevitably suffer an onset of chlamydia, sounding its death knell if left untreated.
This means that if chlamydia can only be targeted and eliminated, koala populations will have a much better chance of stabilisation and survival in the wild (Rhodes et al., 2011). To target chlamydia therefore is the obvious option, and research has been underway for some time in developing an effective vaccine.
Now the outcome is looking excitingly positive. While some work still needs to be done, vaccinations performed on both healthy and diseased koalas are providing strong evidence that a chlamidial vaccine will be successful.
Vaccination trials currently underway in SE Queensland will shortly be moving outside that state, and from captive animals to wild koalas. These will include koalas taken into care by wildlife care groups within NSW. Dr Adam Polkinghorne of Queensland University of Technology states that the work and collaboration of the latter groups will be essential to the success of this koala chlamydia vaccine.
Happily this will mean that koalas brought into care by Clarence Valley WIRES will also be taking part in this exciting, groundbreaking research to save our iconic marsupial.
- Patricia Edwards
|Koala in care. Rusty brown fur indicates poor health.|