Virulence Factors in Cryptosporidium and Infective Dose in Humans

EPA Grant Number: R824759
Title: Virulence Factors in Cryptosporidium and Infective Dose in Humans
Investigators: Chappell, Cynthia L. , DuPont, Herbert L. , Okhuysen, Pablo C. , Sterling, Charles R.
Institution: The University of Texas at Houston , The University of Texas Health Science Center at San Antonio
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1995 through September 30, 1998 (Extended to September 30, 2000)
Project Amount: $829,551
RFA: Human Health Risk Assessment (1995) RFA Text |  Recipients Lists
Research Category: Health Effects , Human Health , Human Health Risk Assessment , Health


The purpose of this project is to determine if isolates of Cryptosporidium parvum derived from different hosts and geographic regions differ in virulence. Virulence will be evaluated in vitro by genetic, biochemical and immunological markers and in vivo by mouse infectivity. The infectious dose for humans will be tested in healthy adult volunteers by using isolates that have shown differences in one or more of the laboratory analyses. In addition to establishing an infectious dose (ID50) for each isolate, the cellular and humoral immune responses from each volunteer will be examined. These laboratory and volunteer model studies will reveal the capacity of various isolates to cause infection and disease in humans and to relate those differences to one or more laboratory parameters, thus providing a convenient marker of C. parvum pathogenicity. Also, understanding both the common and unique responses involved in the control (clearance) of the infection will allow a rational approach to diagnosis and to the selection of potential candidate antigens for vaccine development.

Publications and Presentations:

Publications have been submitted on this project: View all 55 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 11 journal articles for this project

Supplemental Keywords:

RFA, Health, Scientific Discipline, Water, Genetics, Health Risk Assessment, Risk Assessments, Biochemistry, Drinking Water, vaccine development, infective dose, detection, dose-response, genetic analysis, virulence factors, human exposure, antigens, microbial exposure, cryptosporidium, human health risk, immune response, biomarker, genetic susceptibility

Progress and Final Reports:

  • 1996
  • 1997
  • 1998
  • 1999
  • Final Report