Batrachochytrium dendrobatidis in Hungary: an overview of recent and historical occurrence

Abstract

Batrachochytrium dendrobatidis (Bd) is a fungal pathogen which causes the emerging infectious disease chytridiomycosis. Bd presents low host specificity and threatens amphibians worldwide, thus systematic inventory is the key in order to detect and mitigate the effects of the disease. Extensive data collection was conducted in Hungary in 2009-2015 from fourteen different areas. Combined data – recent field sampling on sixteen taxa and the examination of archived Bombina spp. specimens – from 1360 individuals were analysed with qPCR. Two sentinel taxa, Bombina variegata and the members of the Pelophylax esculentus complex were marked to monitor the occurrence of Bd in two core areas (Bakony Mts and Hortobágy National Park, respectively) of sampling. Climatic variables were also examined in core areas to test their effect on prevalence and infection intensity. Among the sixteen sampled amphibian taxa seven tested positive for Bd and the overall prevalence in Hungary was 7.46%. Among the ethanol-fixed Bombina spp. individuals Bd was not detected. In the first core area (Bakony Mts) the overall prevalence in B. variegata was 10.32% and juvenile individuals showed significantly higher prevalence than adults. On the other hand there was a significant negative relationship between infection prevalence and monthly mean air temperature. Finally, in the other core area (Hortobágy National Park) the overall prevalence in P. esculentus complex was 13.00%, and no differences were found in prevalence or infection intensity between sexes, sampling years or age classes.