Scoty Hearst, PhD

Dangerous Waters: Surveillance of Emerging Environmental Contaminants and Parasitic Pathogens of Human Health Concern in the Mississippi River

Emerging contaminants and infectious diseases pose an ongoing threat to human and animal health. Heavy metals and zoonotic parasites in aquatic environments are a growing global human health concern requiring vigilant surveillance.  The Mississippi River is home to hundreds of species of wildlife including fish species harvested for human consumption potentially exposing humans to pathogenic parasites and heavy metals. The river is also used as a source for drinking water and crop irrigation. The Mississippi River passes through 10 states—Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana, where pollution from landfills, agriculture, and industrial sources leach into the river potentially causing human exposure to heavy metals. However, the levels of toxic metals and zoonotic parasites in the Mississippi River are currently unknown.  Measuring the level of toxic metals in river water is extremely difficult due to the high level of suspended solids and the detectable levels of toxic metals in water samples.  Since aquatic organisms bioaccumulate toxic metals, we purpose using fish as sentinels for surveying heavy pollution in the Mississippi River.  Next generation sequencing of parasitic communities in fish and other species has been very challenging due to rDNA primers amplifying host DNA.  To overcome this challenge, we will use a new technique that leverages host blocking primers to reduced host background noise to detect parasitic communities in Mississippi River fish.  The major challenge for monitoring environmental parasitic diseases, is the lack of sensitive and rapid diagnostic tools to detect free-living parasites in aquatic environments. To address this challenge, we will use eDNA metabarcoding to detect zoonotic parasites of human health concern using aquatic samples from the Mississippi River. Using these three approaches, we will use aquatic and fish samples to surveil both heavy metal pollution and zoonotic parasites concealed within the treacherous waters of the Mississippi River.