Chlamydia Vaccine to Help Koalas
Preventing Bacterial Infection to Slow Koala Population Decline
Not endangered but falling, koala population suffers from an STD, causing reproductive rates to drop. Stress increases illness levels. Vaccine to slow spread of disease.
Koalas (Phascolarctos cinereus) are losing more than just habitat in Australia. Chlamydia infection rates are as high as 98% in some areas where human encroachment has put stress on koala populations. A vaccine being developed by Queensland University of Technology is intended to help stop the increase in Chlamydia cases in koalas. Reducing stress will help as well.
Habitat Loss and Other Threats
Habitat loss is a major problem for the koala. About 80% of their original forest ecosystems have been destroyed and the 20% that are left are mostly in private hands. Which means that the few wooded areas left are not protected. Agriculture, urban development and even homebuilding have resulted in koalas being forced into ever-smaller areas. Many of those areas now have overpopulation issues, such as lack of food. The few trees that are available have been heavily overgrazed by the koalas.
Close proximity to humans, and their pets has resulted in an average of 4000 koalas being killed, either by cars or dogs, every year. In addition, introduced foxes are known to prey on the koala.
Suburban development has isolated many koala groups. Isolated populations mean that genetic variability is at risk. Efforts are in place to work with local communities to make suburban areas more koala friendly. For example, creating wildlife corridors by adding trees and hedges along property boundaries allows the koalas to travel above ground, reducing the risk of being hit by cars or attacked by dogs.
Chlamydia Vaccine
Two types of Chlamydia are found in koalas, C. pneumoniae and C. pecorum. Chlamydia infection can manifest as upper respiratory disease, Sexually Transmitted Disease (STD) also called urogenital disease or conjunctivitis. It isn’t clear which type of Chlamydia is responsible for the STD form, which causes infertility in females. Newborn koalas can be infected during the birthing process.
Dr Peter Timm and his colleagues at Queensland University of Technology have been studying Chlamydia in koalas for some time. They are developing a vaccine that they hope will protect koalas from Chlamydia infection. Vaccines for humans are also in the early stages of testing as Chlamydia causes infertility and cardiac disease in humans as well.
Translocation and Chlamydia
Translocating koalas from overpopulated areas to places where the local population is considered threatened or endangered is a logical way to deal with the imbalance in species distribution. Unfortunately active Chlamydia infections have occurred in translocated animals that had been disease free before the move. One of the ways the vaccines could be used would be to prevent translocated animals from contracting the disease in their new location.
While the vaccine is certainly a method of reducing the number of Chlamydia infected koalas, in the long run the issues of habitat loss and human encroachment will need to be addressed more effectively if the koala is to survive.
