Severe Perkinsea Infections
A new study by the U.S. Geological Survey reveals a deadly amphibian disease called Severe Perkinsea Infections (SPI) is the cause of large-scale frogs die-offs in the United States. The new study suggests that SPI is the third most common infectious disease of frogs.
Currently, frogs and salamanders the most threatened groups of animals on the earth. The two most common frog diseases, chytridiomycosis and ranavirus infections linked to frog population declines worldwide.
Scientists studied 247 frogs die-offs in 43 states from 1999 through 2015. They found SPI caused 21 of the mass mortalities in 10 states spanning from Alaska to Florida, all involving tadpoles. Up to 95 percent of the tadpole population died during the SPI mortality events.
Amphibians such as frogs are valuable because they serve as pest control by eating insects like mosquitos, and they are food for larger predators,” said Marcos Isidoro Ayza, a USGS scientist.
The SPI die-offs occurred in tadpoles of 11 frog species, including the critically endangered dusky gopher frog in its only remaining breeding locations in Mississippi. Most of the SPI events occurred in states bordering the Atlantic Ocean and Gulf of Mexico. However, SPI also detected in Alaska, Oregon and Minnesota.
“Habitat loss, habitat fragmentation and disease are among the factors that contribute to amphibian declines,” said Jonathan Sleeman, director of the USGS National Wildlife Health Center. This study indicates that SPI is an additional disease that can further threaten vulnerable frog populations.
SPI caused by a tiny parasitic organism called a protist. The SPI-causing protist, called Perkinsea, is highly resistant to disinfection agents such as common bleach. As a result, it is difficult to prevent the spread of Perkinsea, and SPI can reoccur at known locations.
SPI in frogs may underdiagnosed because it is not a disease for which they typically screened. Incorporating routine screening of critical habitats for infected frogs is crucial to help understand the distribution of this destructive disease.
The disease kills tadpoles by causing multi-organ failure, and there is no cure or treatment for SPI now. SPI not known to affect humans or pets.
More information: [Scientific Reports]