211389 Analytical models of zoonotic pathogens in agricultural watersheds

Monday, November 9, 2009: 5:00 PM

Steven Chapra, PhD , Civil and Environmental Engineering, Tufts University, Medford, MA
Graham B. McBride, PhD , National Institute of Water and Atmospheric Research, Hamilton, New Zealand
Zoonoses can dominate reported human diseases in countries with agricultural economies. For example, 65–80% of New Zealand's reported notifiable disease cases in recent years are zoonoses, much of which is campylobacteriosis, a major cause of enteric illness worldwide. Commonly, the efficacy of BMP (Best Management Practices) interventions in freshwater environments is assessed using a faecal indicator, most notably E. coli. But in so doing an important question arises: “If the interventions result in a reduction in E. coli loads by X%, what is the concomitant reduction in the zoonotic pathogens?” We will present two simple mathematical models to examine this question: one for E. coli and one for Campylobacter (as a typical zoonotic pathogen). They predict the relative removal efficacy for these bacteria after implementation of BMPs, and also the prevalence of Campylobacter infection among farm animals. Dimensionless numbers and simple graphs are developed to assess how prevalence is influenced by a number of factors including animal density and farm spacing.

Learning Objectives:
Discuss the control of zoonotic disease.

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am an expert in Water Quality modeling of waterborne diseases
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.