Summary of Awards to Date

Analysis of the presence of Cyclospora in waters of the Mid-Atlantic States and evaluation of removal and inactivation by filtration


Jan. 1, 2020 - Dec. 31, 2020

Amount Awarded



Kalmia Kniel, Ph.D.
University of Delaware


The proposed project aims to address concerns surrounding fresh water availability and safety, as more outbreaks of foodborne illness caused by parasites have been linked to water used in produce production. Cyclospora cayetanensis, a parasite, has presented a unique challenge to the scientific community in understanding its persistence, transfer, and detection in the environment. Cases of domestically acquired foodborne illness associated with C. cayetanensis have drastically increased in the past five years. In 2018, the first documented domestic C. cayetanensis outbreak was linked to produce grown in the United States, previously outbreaks had often been associated with produce imported from countries endemic for this organism. Zero valent iron (ZVI), a by-product of the steel industry, is affordable and has been shown to be effective in removing and neutralizing bacterial, viral, and chemical contaminants from water. The efficacy of ZVI on parasites has not been studied but shows great potential in filtration applications. The objectives of this study are to determine the prevalence of C. cayetanensis in potential sources of irrigation water within the Mid-Atlantic region and to assess the effectiveness of ZVI filtration in removing and inactivating protozoa like C. cayetanensis from irrigation water to ensure the safety of produce.

Technical Abstract

Cyclospora cayetanensis is a protozoan parasite that causes gastrointestinal illness following consumption of contaminated produce or water. Cyclospora is still considered an emerging pathogen by many, due to the limited understanding surrounding the transmission and survival of oocysts in the environment along with difficulties and limitations in detection of oocysts. This project has two main objectives, which will address critical data gaps that affect the produce industry across multiple commodities. The first objective is to provide an understanding of the impact of C. cayetanensis on waters in the Mid-Atlantic region of the United States, a previously unstudied area. In many ways the Delmarva area serves as a model region, centered on a large watershed with active agriculture and within the urban heart of the East Coast. The water sources tested include those that could be used for irrigation of raw agricultural commodities such as surface water (pond, river), reclaimed wastewater, and reclaimed produce wash water. The second objective will elucidate the efficacy of ZVI filtration in the removal and inactivation of parasitic pathogens to improve pre-harvest food safety. This work will also facilitate the development of novel on-farm filtration technology and guidelines for commercial applications to control parasitic pathogens in agricultural water, thus improving the safety of produce and reducing parasitic foodborne illness. The proposed ZVI technology may offer advantages to growers including adaptation to existing filtration systems, feasibility, effective filtration and broad neutralization of numerous biological and chemical hazards with minimal environmental impacts. As the number of C. cayetanensis outbreaks associated with produce continue to increase, knowledge of the organism and novel intervention strategies will be crucial to ensure the safety of produce.