Biologists have found that “frog flu” has been raging in Africa for 20 years
(ORDO NEWS) — More than 40% of amphibians are now threatened with extinction due to the infectious, fungal disease chytridiomycosis, biologists from the University of California found out.
The fungus Batrachochytrium dendrobatidis (Bd), the pathogen that causes chytridiomycosis, is highly contagious and affects salamanders, newts, horseflies, and especially frogs and toads.
The disease rarely kills tadpoles and often adults. In them, the fungus causes skin exfoliation, lethargy, weight loss, and eventually cardiac arrest.
In their work, the scientists consulted the scientific literature from 1852 to 2017 in search of records of the presence or absence of visible chytrid infection in amphibians from across Africa.
They also performed PCR testing for Bd on about 3,000 museum specimens of amphibians. They were collected in Cameroon, Ethiopia, Kenya, Lesotho, Tanzania and Uganda between 1908 and 2013.
The researchers also took skin swabs from 1,651 live amphibians captured between 2011 and 2013 in Burundi, Equatorial Guinea, Cameroon and the Democratic Republic of the Congo.
The results show that the earliest Bd-positive amphibian appeared in 1933 in Cameroon.
Until 2000, the prevalence of the fungus was below 5%, but then there was a sharp jump to 17%, and in the 2010s to 21%. In some countries, prevalence has risen to 74%.
Since 2000, there has been a largely ignored but pronounced increase in the prevalence of Bd, which poses a threat to amphibians across Africa, the team says.
The regions most at risk are eastern, central and western Africa.
“We have a hypothesis that the stress caused by climate change may make amphibians more susceptible to pathogens.
Eliminating this microscopic pathogen in the wild is not possible, but we can try to mitigate its impact on nature,” the researchers concluded.
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