Imported African species implicated in B. dendrobatidis epidemic
More evidence has just dropped into place suggesting that frogs once imported to the United States for pregnancy testing could have spread a fungus deadly to many native amphibian species.
From about the 1940s into the 1970s, medical labs tested for pregnancy-associated hormonal changes by injecting human urine into readily available and easy-to-work-with African clawed frogs. If a woman was pregnant, traces of hormones in her urine would accelerate egg development in the frog.
Frogs sometimes escaped or were set free, allowing African clawed frogs to get a foothold in North America.