New diagnosis tool for disease that causes blindness and infertility and affects up to 90% of koalas in some locations is quicker than conventional testing methods

Medical imaging equipment designed for humans is being used to help combat the spread of chlamydia in koalas, with wildlife workers hopeful the equipment could be used to aid conservation efforts with other species.



Chlamydia has been blamed for crippling koala populations, causing blindness and infertility in the marsupials. In some parts of Australia, koala infection rates are as high as 90%.

Scientists working on a potential vaccine have expressed concern about the spread of chlamydia in koalas, which is a different strain of the infection that can affect humans.

The Featherdale Wildlife Park in New South Wales has started using ultrasound technology to detect the symptoms of the infection in its population of 33 koalas.

A special perch has been constructed for the koalas to be assessed by the ultrasound, with wildlife staff looking out for signs of “fungal balls” or thickened walls in the bladder or reproductive system.

The diagnostic tool is quicker than the conventional method of testing for the infection via a swab, leading to prompt treatment of antibiotics. Koalas have to spend 28 days on antibiotics before being fully clear of chlamydia.

“We’ve started including the ultrasound in our monthly protocols with the koalas to see what’s going on inside,” Chad Staples, chief curator of Featherdale Wildlife Park, said.

“If we see any urinary tract or reproductive system problems, we don’t have to wait for a true positive test. We can start treatment straight away, which is really important given the time factor. The ultrasound isn’t intrusive or painful for the koalas, so we can just give them a few leaves and they are happy.”

Staples said chlamydia is now “rampant” among the wild population of koalas, but that imaging could be used more widely in wildlife hospitals to help reduce the disease.

“Unfortunately, it can spread very quickly,” he said. “We can help keep a lid on it, but the difficult factor in wildlife hospitals is time, given that koalas need a long course of antibiotics.”

Staples said that he has used the ultrasounds on other species. Analysis of the ovaries of endangered female broad-headed snakes can indicate when they are ready for mating. Meanwhile, work on chicken embryos suggests the technology could be used to monitor different bird species while they are still in their eggs.

Fiona Mildren from GE Healthcare Systems, which supplied the equipment, said: “This is really exciting because we can prevent koala populations becoming sterile. We had one koala, Skye, which had a huge fungal ball in her bladder. After 16 days, it was gone.”