Monday, May 20, 2013

Frog Once Imported for Pregnancy Testing Brought Deadly Amphibian Disease to U.S.


http://www.sciencedaily.com/releases/2013/05/130515174350.htm

According to a recent study, the African Clawed Frog, a frog originally imported to the US for pregnancy tests, carried a highly infectious and deadly amphibian disease to the US.

It was long suspected that these frogs carried a fungus called batrachochytrium dendrobatidis, more commonly referred to as Bd, to the US. It has been speculated that this fungus has led to over 200 populations of different species of frogs to decline and in some cases go extinct. A previous study revealed that the fungus was originally discovered in South Africa, where the African Clawed Frog originated. The populations of these frogs in the US have not been tested for this fungus until now.

SF State biologist Vance Vredenburg said that a population of African Clawed Frogs that was introduced to California was found to be carrying the fungus. He also adds that these frogs may be responsible for introducing a deadly, non-native disease to amphibians in the US.

These frogs will ovulate when they are injected with the urine of a pregnant woman. This is why they were widely exported across the world between the 1930’s and 1950’s. They were also used for scientific research and kept as pets. Vredenburg suspects that these frogs are found close to urban areas because they may have been released by hospitals into the wild as new methods of pregnancy testing were developed. The reason why these frogs are so dangerous is the fact that they can carry the disease for a very long time without dying, which increases the risk of contaminating other species or individuals.

These frogs are still being imported into the states. Not for pregnancy tests, but for medical research and basic scientific research. Eleven states have already banned the importation of these species. 
Vredenburg stated that we must be very careful today with the food and pet trade because we may potentially be importing diseases that we don’t know about yet.

I chose this article because it relates to what we have learned about in ESS, regarding invasive species and factors that may lead to the loss of biodiversity. The conditions in California were perfect for these frogs. This is why they were able to survive for so long. The fungus they carried has led to many other species of frog in the California region to go extinct. This is interesting because it is a modern example of an invasive species, whereas most examples have happened decades in the past.

1 comment:

  1. Can you elaborate on how the frogs were used as pregnancy tests? I don't really get it...

    It really seems like this specie of frogs can begin a serious epidemic. On the other hand, its good that the species are being imported solely based on biological research. Scientist should examine possible ways on how the species can pass on the diseases to humans, or an even worse possibility, how they may pass it on into our food chains.

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