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Microbiological and Chemical Exposure Assessment Staff

Eric N. Villegas

Title: Research Microbiologist

EPA Division: Microbiological and Chemical Exposure Assessment Research Division

EPA Branch: Biohazard Assessment Research Branch

Expertise is in the development and application of molecular methods for monitoring microorganisms in aquatic environments. Developed in vitro and in vivo models of infection to measure parasite infectious dose and determine treatment efficacies of current and new disinfection treatment technologies. Recent work focuses on using next generation sequencing technology to better understand risks associated with waterborne parasites (e.g., Cryptosporidium, Giardia, Toxoplasma gondii, etc.)


  • Ph.D. Immunology/Parasitology, 2001
  • B.A. Biology, California State University, Northridge, 1994

Professional Experience:

  • Research Microbiologist, USEPA, ORD, NERL-MCEARD, Cincinnati, OH, 1991 – present Adjunct Associate Professor, Dept. of Biological Sciences, University of Cincinnati, OH 2010 – present
  • Adjunct Assistant Professor, Dept. of Biological Sciences, University of Cincinnati, OH 2007 – 2010
  • Instructor, Center for Biological Laboratory Studies, San Francisco State University, CA 2002 – 2004
  • Post-doctoral Research Fellow, Cancer Research Laboratory, Division of Immunology and Pathogenesis, University of California, Berkeley, CA 2001-2005

Professional Societies and Affiliations:

  • American Society of Parasitologist
  • American Society for Microbiology
  • American Water Works Association
  • Sigma Xi

Select Awards and Honors:

  • NERL Special Achievement Award, 2011
  • Editorial Board, The Scientific World Journal, 2011 – present
  • Executive Editor, Hydrology Research, 2010 – 2015
  • ORD Honor Award, 2009
  • Mayor’s Choice Award, Volunteers of America, 2007
  • Outstanding Government Services, Greater Cincinnati Earth Coalition, 2007
  • Saul Winegrad, M.D. Outstanding Doctoral Dissertation. University of Pennsylvania, Perleman School of Medicine. 2001.

Select Presentations:
(* denotes senior corresponding author; § denotes presenter)

  • Nwa, U., Brescia, C. C., Boczeck, L. A., Johnson, C. H., and Villegas, E. N.§*. 2012. Detecting Viable Giardia duodenalis Cysts Using Propidium Monoazide in Combination with Real-Time PCR. IV International Giardia and Cryptosporidium Conference. Wellington, New Zealand.
  • Villegas, E.N.§* 2011. The Molecular Detection Toolbox: Applications and Implications on Current and Future National Monitoring Efforts. US. Environmental Protection Agency, Long Term 2 Enhanced Surface Water Treatment Rule: Cryptosporidium Analytical Method Improvements and Update on Source Water Monitoring Public Meeting. Washington, DC.
  • Ware, M.W., Augustine, S., Villegas, L. F., See, M. J., Erisman, D., Hayes, S. L., Wymer, L., Lindquist, H. D. A., Schaefer, F. W. III, Dubey, J. P., and Villegas, E.N.§* 2010. Evaluating the Effects of Chemical Sanitizers and UV Irradiation on Toxoplasma gondii Oocyst Viability. 11th International Workshop on Opportunistic Protists. Hilo, HI.
  • Brescia, C. C., Hunt, S. M., Egorov, A. E., and Villegas, E. N. §* 2009. Using Propidium Monoazide as an Enrichment Step to Remove Extraneous DNA and Non-Viable Organisms for Cryptosporidium Genotyping. Global Conference on Microbial Contaminants in Drinking Water. Singapore.
  • Villegas, E.N.§* 2009. Surveillance Systems for Waterborne Cryptosporidium: US EPA Method 1623 and Beyond. USDA CSREES National Water Conference. St. Louis, MO.
  • Villegas, E.N.§* 2007. Cryptosporidium Source Tracking to Enhance Source Water Protection Implementation in the Potomac River Watershed. A Regional Applied Research Effort (RARE) Project. Laboratory Technical Information Group Meeting. US EPA Region 5, Chicago, IL.
  • Villegas, E.N.§* 2007. Cryptosporidium Research Projects within the Biohazard Assessment Research Branch. Workshop on Cryptosporidium Research Associated with Monitoring and Analytical Efforts in the Mid-Atlantic. US EPA Region 3, Philadelphia, PA.
  • Villegas, E.N.§* 2007. Protozoan Pathogens: Towards understanding microbial interactions with humans and the Environment. University of Cincinnati, Department of Biological Sciences Seminar Series. 2007.

Published & Presented Research (1999-Present)

Contact Info:

Eric N. Villegas
Microbiological and Chemical Exposure Assessment Research Division
National Exposure Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
27 W. Martin Luther King Jr. Drive
Cincinnati, OH 45268
Telephone: 513-569-7017

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