Further to the progress reported in the March issue of Treetops (see p.9), the Koala Infectious Disease Research Group (KIDRG) at the University of Sydney reports that the Prevention and treatment of chlamydiosis and cryptococcis study, which is now at the end of its second year, has achieved some surprising preliminary results and appears to be leading to really practical outcomes with regards treatment and management of chlamydiosis and cryptococcosis in koalas.

Treatment of subclinical disease has been a real success story and is the source of the best opportunity for intervention in chlamydiosis especially.  Underpinning this has been the important development of quick screening tests for chlamydiosis and the capacity to follow up with more sophisticated measurements of response to treatment.

Severe chlamydiosis with structural disease continues to defy successful eradication of the causative organism.  A focus on the functioning of the koala immune system and the genetic basis of immune function is helping the group understand more about the development of severe chlamydiosis.

With both infectious diseases, KIDRG takes a holistic view on the cause, development and progression of disease, considering as many components of the host-pathogen-environment interaction as possible.  Apart from the successful management of clinical cases, this is especially so with cryptococcosis, where a considerable amount of effort has been spent on examining the causative fungus (Cryptococcus gattii) in its environmental niche as well as in its association with colonised, subclinically affected and clinically diseased koalas.

These environmental investigations have led to a dramatic increase in knowledge about the organism and is helping to fill the gaps in how a fungus that lives in a tree can make the jump to cause disease in people and animals.  We are in the process of characterising the epidemiology of the two major molecular types of C. gattii in Australia, which will have a global impact, and has involved thinking beyond just the koala to look at different parts of the country and look at the eucalypt hosts and other microbes that influence the fungus in the environment.

The KIDRG team is large and now includes Professor Paul Canfield, Dr Mark Krockenberger, Dr Damien Higgins, Dr Merran Govendir, Dr Susan Hemsley, Professor Richard Malik, Joanna Griffith, Sarah Jobbins, Nathan Saul, Alison Stuart and Quintin Lau.

Several areas of research that have resulted from the ongoing initial study have already attracted complementary extra funding, with two additional three year grants for the group, meaning that the team will grow even larger over the coming years. It is hoped that collaboration between KIDRG and Friends of the Koala will also grow during that time.

Critical to the success of such a large research program continues to be the financial and logistical support of the Australian Koala Foundation (AKF), the Koala Preservation Society of NSW, Pfizer Australia, Symbion Vetnostics and WIRES, as well as research granting bodies.  The future of koalas depends on the productive collaboration between the major groups involved in koala welfare, animal health and researchers.

Mark Krockenberger

KIDRG