Science Inventory

You are here:

EPA Home » Science Inventory » DETECTING CCL-RELATED, EMERGING AND REGULATED WATERBORNE HUMAN PROTOZOA FOR EXPOSURE ASSESSMENT

DETECTING CCL-RELATED, EMERGING AND REGULATED WATERBORNE HUMAN PROTOZOA FOR EXPOSURE ASSESSMENT

Contact

http://cfpub.epa.gov/si/si_public_comments.cfm

Impact/Purpose:

1) Refine new, practical methods for the detection of CCL-related and emerging waterborne human protozoa.

2) Perform field tests of devices or methods that have been developed under this task.

3) Evaluate these methods or devices in a variety of water matrices and parasite concentrations.

This work in this task supports CCL2 and 3 and is expected to be completed by 9/07.

Description:

Pathogenic intestinal protozoa (Giardia, Cryptosporidium) are significant etiological agents in the transmission of waterborne disease. Other emerging protozoa are also likely causes of waterborne disease. Toxoplasma gondii has been implicated in causing waterborne disease in North America and elsewhere. Toxoplasmosis is the disease caused by ingestion of infective forms of T. gondii, including the oocyst. In pregnant women, this disease is readily transmitted from mother to fetus. In individuals having incomplete or compromised immune systems, like unborn fetuses and newborns, the elderly or HIV patients, the illness is devastating and possibly fatal.

In the past several years, several outbreaks of cyclosporiasis have occurred in North America. Cyclospora cayetanensis, the causative agent of cyclosporiasis, is considered to be an emerging parasite. Evidence exists for waterborne transmission of this parasite in the Americas, but the role of waterborne transmission, and the entire epidemiology of this parasite is poorly understood. Microsporidians, which are on the Agency's Contaminant Candidate List, are obligate intracellular parasites of invertebrates, fish, laboratory rodents, rabbits, and primates. With the advent of the AIDS epidemic, microsporidians have become fully recognized as emerging agents of human disease. These protozoan parasites are transmitted in a fecal-oral route, by contaminated food, fomites, or water. Since several microsporidian genera from humans localize in either the gastrointestinal and urinary tracts, they can challenge wastewater treatment facilities and eventually get into surface drinking water sources.

The parasites Giardia sp. and Cryptosporidium sp. are regulated organisms. There is customer demand for research on these organisms from the Regions, the Office of Water, and the scientific community.

This task focuses on the development, evaluation and standardization of innovative methods, technologies and procedures to determine the parasite burden of source and drinking water. This task also addresses children's health, in that children are particularly susceptible to dehydration caused by several of these infections. In addition, they are at increased risk because their immune systems are not so sophisticated as the immune systems of adults, and thus children are less well equipped to fight of these serious diseases. Finally, T. gondii is an important cause of birth defects in the U.S., and there is evidence that children borne to infected mothers may suffer serious sequelae even if obvious birth defects are not readily discernable. This task also addresses community health, in that these diseases often occur in epidemics affecting an entire community. Information as to the presence of infectious stages of these organisms in a water supply may assist communities to make informed decisions concerning their public health and infrastructure. Finally, this task addresses contaminated sediments, as these parasites may remain infective for days, months or possibly years under appropriate conditions. Thus contaminated bodies of water may have recurrent contamination problems, as sediments are disturbed releasing infectious stages of the parasites back into the water column.

Record Details:

Record Type:PROJECT
Start Date:10/11/2001
Projected Completion Date:09/01/2007
OMB Category:Other
Record ID: 56083