Pathology and diagnostic case definition of Severe Perkinsea Infections of frogs
Severe Perkinsea infection (SPI) is an emerging disease of frogs caused by protozoa belonging to the phylum Perkinsozoa and responsible for mass mortalities of tadpoles across the USA. In this work, we 1) provide detailed description of gross and histologic lesions from 178 naturally infected wild frogs including ten species from 22 mortality events and six amphibian health monitoring studies from diverse geographic areas; 2) compare the pathology associated with SPI with that observed in ranavirosis, an epidemiological and pathologically overlapping major infectious diseases of immature frogs in North America; and 3) propose a case definition for SPI to promote standardized communication of results and consistent national reporting of this disease. Based on the current information about SPI, laboratory criteria for confirmation of SPI as cause of death requires: DNA amplification by PCR and subsequent identification of PPC by sequencing of the SSU rDNA from one or more internal organs and presence of histologic evidence suggestive of SPI, which includes multiorgan necrosis and replacement by myriads of extracellular and intracellular Perkinsea-like protozoa.
ARMI Organizational Units:Pacific Northwest - Biology
National Wildlife Health Center