Chytridiomycosis is an infectious disease that affects amphibians worldwide. It is caused by chytrid fungus (Batrachochytrium dendrobatidis).
Some frog species are hit harder than others; among some species, some die from the population while other species become completely extinct.
Chytridiomycosis has been around since the 1990s and has been the cause of many extinct frog species. It is still unclear where the disease originated and how it originated. However, it has been theorised that the disease spread from African dwarf frogs that have been exported across the world.
The first discovery of dead frogs was in Queensland in 1993. The infection spreads easily between frogs and kills a large number of frogs. The fungus is found all over Australia and has been in the country since the 1970s. The eradicating frog disease is also found in New Zealand, Africa, Europe, Asia and the Americas.
Chytridiomycosis has been found in all Australian States and in the Australian Capital Territory, but not in the Northern Territory. It seems to thrive in relatively cool areas that are very humid. In these areas, the fungus easily takes root, and there are not many such places where it does not ravage freely. Within these infected regions, there are some isolated sites that have not been affected. This is due to the isolated nature of these amphibious populations.
Chytridiomycosis / B. dendrobatidis is on Australia’s list of notifiable diseases among aquatic animals. Chytrid fungi are most commonly found in water or soil, but it is sometimes found on live plants and insects. They are asexual and have spores that swim through the water to multiply.
Chytridiomycosis is known to infect vertebrates. Frogs become infected when their skin comes in contact with water that contains spores from
Frogs that live in slow-moving water are most easily affected. The higher the temperature, the milder the disease strikes. It is possible to see how the outbreak of the disease takes place seasonally when the temperatures change.
There is a lot we do not know about the disease in the wild. How it kills its host animal and how it survives without frogs to parasitize on, and how it spreads. What is known is that the environment is important for the survival of the fungus. The Australian Highlands is the place hardest hit by Chytridiomycosis. Several frog populations have been reduced or completely eradicated. Climate change and other things that stress the environment can be a factor in the emergence and spread of Chytridiomycosis. The increased exposure to UV radiation can make frogs more vulnerable to infections.
Chytridiomycosis causes damage to the frog’s outermost skin condition, the outer keratin layer.
The frogs’ skin is unique as it regulates respiration, water and electrolytes. How the frogs die from Chytridiomycosis is still unclear, but when the skin’s normal functions are disturbed, it creates an imbalance in the frog.
There are fungicides that can save frogs and their fry, so they recover completely. At least four frog species in Australia have been completely eradicated due to Chytridiomycosis. At least ten other species have been hit so hard that the frog population has declined drastically. The species that have survived the disease have decreased significantly in number. The species affected by Chytridiomycosis disease have continued to decline in the population for decades. There are many other species of frog in other countries that has been eradicated as well