Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA.
A Model of Exposure to Rotavirus from Nondietary Ingestion Iterated by Simulated Intermittent Contacts
Article first published online: 31 JAN 2009
© 2009 Society for Risk Analysis
Volume 29, Issue 5, pages 617–632, May 2009
How to Cite
Julian, T. R., Canales, R. A., Leckie, J. O. and Boehm, A. B. (2009), A Model of Exposure to Rotavirus from Nondietary Ingestion Iterated by Simulated Intermittent Contacts. Risk Analysis, 29: 617–632. doi: 10.1111/j.1539-6924.2008.01193.x
- Issue published online: 2 APR 2009
- Article first published online: 31 JAN 2009
- Exposure assessment;
- microbial risk assessment;
- micro-level activity data;
- stochastic modeling
Existing microbial risk assessment models rarely incorporate detailed descriptions of human interaction with fomites. We develop a stochastic-mechanistic model of exposure to rotavirus from nondietary ingestion iterated by simulated intermittent fomes-mouth, hand-mouth, and hand-fomes contacts typical of a child under six years of age. This exposure is subsequently translated to risk using a simple static dose-response relationship. Through laboratory experiments, we quantified the mean rate of inactivation for MS2 phage on glass (0.0052/hr) and mean transfer between fingertips and glass (36%). Simulations using these parameters demonstrated that a child's ingested dose from a rotavirus-contaminated ball ranges from 2 to 1,000 virus over a period of one hour, with a median value of 42 virus. These results were heavily influenced by selected values of model parameters, most notably the concentration of rotavirus on fomes, frequency of fomes-mouth contacts, frequency of hand-mouth contacts, and virus transferred from fomes to mouth. The model demonstrated that mouthing of fomes is the primary exposure route, with hand mouthing contributions accounting for less than one-fifth of the child's dose over the first 10 minutes of interaction.