Widespread trypanosome infections in a population of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) in Virginia, USA.

Eastern hellbender salamanders (Cryptobranchus alleganiensis alleganiensis) are declining in North America and because of this the health status of individuals in several populations is closely monitored by researchers. During a health survey of hellbenders from a stream in Smyth County, VA, USA, we examined Giemsa-stained blood smears of 71 animals captured during 2011 for the presence of blood parasites. We discovered an unknown species of trypanosome that was apparently widespread within this population; 40 of the 71 individuals (56.3 %) were infected. There are seven known trypanosome species of caudate amphibians; based on microscopic examination, the parasite we observed appeared most similar to Trypanosoma cryptobranchi, which was reported in this species only once before, 76 years ago, from a single animal apparently captured in Iowa. Given that some trypanosomes can adversely affect the health of their hosts, we recommend further monitoring be done in this and other hellbender populations to determine the geographic extent of the parasite and its effects on its increasingly rare host.