Comparison of Risk Predicted by Multiple Norovirus Dose-Response Models and Implications for Quantitative Microbial...

Area of Science:

• Environmental microbiology
• Risk assessment
• Public health

Background:

• Norovirus outbreaks are frequent globally, necessitating robust risk assessment.
• Quantitative Microbial Risk Assessment (QMRA) is crucial for understanding and mitigating norovirus risks.
• Dose-response analysis, a key QMRA component, mathematically links exposure dose to health outcomes.

Purpose of the Study:

• To review and compare norovirus dose-response models used in QMRA.
• To evaluate predicted risks from waterborne exposures using various models.
• To propose best practices for selecting and reporting dose-response models in norovirus QMRA.

Main Methods:

• Literature review of norovirus dose-response models in QMRA.
• Comparison of predicted infection risks across models for recreational and drinking water exposures.
• Analysis of model performance at different norovirus dose ranges.

Main Results:

• The ₁ F₁ hypergeometric model (α = 0.04, β = 0.055) is most frequently used in norovirus QMRAs.
• This common model predicts higher risks than others for doses of 1-1,000 genomic copies.
• Discrepancies among models are most significant at low norovirus concentrations, impacting drinking water assessments.

Conclusions:

• The choice of dose-response model significantly influences norovirus risk predictions, particularly for low-dose exposures.
• Best practices are needed for transparent reporting of assumptions in norovirus QMRA model selection.
• Using multiple dose-response models is recommended to provide a comprehensive risk range for norovirus infection probability.