Survival Kinetics of Cryptosporidium Oocytes in Swine Facility Wastes of the Southern Piedmont and Coastal Plain Watersheds

<p>Non-Technical Summary: Cryptosporidium species are protozoans that infect a wide range of hosts, including livestock, wildlife, and humans. In the environment, Cryptosporidium persists as a resistant oocyst stage. When ingested in food or water, this stage of the parasite can lead to the gastrointestinal disease cryptosporidiosis, for which there is no treatment, only therapy to alleviate the symptoms of watery diarrhea, abdominal cramping, fever, and sometimes vomiting. A chronic form of this malady may develop in individuals with immature or compromised immune systems, i.e., the very young or old, people infected with the HIV, those undergoing immunosuppressive therapy, and/or those who are malnourished. In such cases, cryptosporidiosis may lead to death. The objective of this project is to minimize the impact of swine rearing facilities on the watersheds where these facilities are located by removing or reducing the number of oocysts of Cryptosporidium species in their waste streams. We will identify and characterize the different types of Cryptosporidium in swine waste lagoons. We will examine how fast the oocysts in waste treatment lagoons die in order to ascertain the impact of existing treatments on the viability of oocysts that are applied to land. It is believed that because the oocysts of Cryptosporidium are hardier than many other pathogens that they can be used to monitor how well the processes remove or destroy pathogens in general to protect the environment from infectious agents.</p>

<p>Approach: The oocysts of Cryptosporidium are more resistant to inactivation by swine waste lagoons treatment than Salmonella, enteric bacteria and viruses (exceptions are the spores of Clostridium perfringens and the eggs of the swine helminths, Ascaris suum and Trichuris suis.) Overall though, processes that effectively inactivate or minimize the transport of oocysts will have a greater capacity to inactivate, remove, or entrap viruses and bacteria present in swine waste. Therefore, because the oocysts of Cryptosporidium are likely to be present in most if not all swine lagoons, we believe that they can be used as indicators of the effectiveness of swine waste lagoons in pathogen reduction. This work will examine the viability of oocysts present in lagoons, define the effects of the lagooning of swine waste (primary and secondary lagoon treatment) on oocyst inactivation, and it will examine the effects of pretreating swine waste in lagoons on the ability of oocysts to survive after land application.</p>