SYDNEY, July 11 (Xinhua) -- Nearly two-thirds of a koala colony in Australia's Victoria state have been hit by chlamydia, with the major disease threatening to spread and devastate marsupial populations, according to Monash University research findings released on Wednesday.

Koala chlamydia, which causes infertility in the iconic Australian animals, is "widespread" in the state's South Gippsland area, the research showed.

The researchers, who analyzed koala droppings in their study, said the latest findings helped point to further strategies for marsupial conservation, which includes work on a vaccine for the disease.

Their research, which was published in the Wildlife Research journal, also showed that the occurrence of an AIDS-like retrovirus in the animals that was seen as another major cause behind their death was lower than previously thought, affecting less than 30 percent of the koalas studied.

"Further work exploring the dynamics of these pathogens in South Gippsland koalas is warranted and may help inform future conservation strategies for this important population," said the researchers.