National Wildlife Health Center

...advancing wildlife and ecosystem health

Batrachochytrium salamandrivorans (Bsal)

Surveillance update January 2017

A newly introduced fungal pathogen from Asia, Batrachochytrium salamandrivorans (Bsal), has caused mass mortality events and severe population declines in European salamanders via introduction into wild populations from the pet trade. North America has the highest diversity of salamanders in the world and introduction of this pathogen could be devastating, not only to local populations but also to global salamander biodiversity. The NWHC is working collaboratively with the USGS Amphibian Research and Monitoring Initiative (ARMI), to determine the presence of Bsal in North American salamander populations in targeted locations with high biodiversity and increased risk of exposure to the Bsal pathogen. The NWHC and ARMI are working to reach a 10,000 sample goal in these high-risk locations to determine if Bsal is already present (and previously undetected) in the United States during 2016. As of August 2016, we have not detected Bsal in 7,425 salamander and newt samples tested from 19 states in 20 species.

Samples are being collected by live capture and swabbing of salamander and newt species. Results are based on real-time PCR test for Bsal DNA at the NWHC (Blooi et al 2013). Sampling and diagnostic testing is ongoing and, once completed, the results will be incorporated with previous risk assessments (Richgels et al 2016; Yap et al 2016) to produce updated estimates of Bsal detection and abscence in the U.S.

For information on Bsal diagnostic and epidemiological activities at the NWHC, contact Dan Grear, NWHC Bsal Coordinator, or C. LeAnn White, NWHC Wildlife Epidemiology and Emerging Diseases Branch Chief, For more information about Bsal field sampling and amphibian research activities, contact Hardin Waddle, USGS ARMI Bsal Coordinator,


Richgels KLD, Russell RE, Adams MJ, White CL, Grant EHC. 2016, Spatial variation in risk and consequence of Batrachochytrium salamandrivorans introduction in the USA. R. Soc. Open Sci. 3: 150616.

Yap TA, Koo MS, Ambrose RF, Wake DB, Vredenburg VT. 2015, Averting a North American biodiversity crisis: A newly described pathogen poses a major threat to salamanders via trade. Science, 349(6247), 481-482. doi: 10.1126/science.aab1052. UCLA: 926087.

Blooi, M, Pasmans F, Longcore JE, Spitzen-van der Sluijs A, Vercammen F, Martel A. 2013. Duplex real-time PCR for rapid simultaneous detection of Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans in amphibian samples. Journal of Clinical Microbiology 51:4173-4177.

BSAL chart

Map of BSAL

Accessibility FOIA Privacy Policies and Notices

U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Contact Form
Page Last Modified: Jun 20, 2018