A model of exposure to rotavirus from nondietary ingestion iterated by simulated intermittent contacts.
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.
Julian
Timothy R
TR
Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, USA.
Canales
Robert A
RA
Leckie
James O
JO
Boehm
Alexandria B
AB
D018562:Disease Transmission, Infectious; D004781:Environmental Exposure; D006801:Humans; D008962:Models, Theoretical; D018570:Risk Assessment; D012400:Rotavirus Infections / Q000635:transmission*; D012680:Sensitivity and Specificity; D013269:Stochastic Processes