Norwalk virus: how infectious is it?

Journal Article (Journal Article)

Noroviruses are major agents of viral gastroenteritis worldwide. The infectivity of Norwalk virus, the prototype norovirus, has been studied in susceptible human volunteers. A new variant of the hit theory model of microbial infection was developed to estimate the variation in Norwalk virus infectivity, as well as the degree of virus aggregation, consistent with independent (electron microscopic) observations. Explicit modeling of viral aggregation allows us to express virus infectivity per single infectious unit (particle). Comparison of a primary and a secondary inoculum showed that passage through a human host does not change Norwalk virus infectivity. We estimate the average probability of infection for a single Norwalk virus particle to be close to 0.5, exceeding that reported for any other virus studied to date. Infected subjects had a dose-dependent probability of becoming ill, ranging from 0.1 (at a dose of 10(3) NV genomes) to 0.7 (at 10(8) virus genomes). A norovirus dose response model is important for understanding its transmission and essential for development of a quantitative risk model. Norwalk virus is a valuable model system to study virulence because genetic factors are known for both complete and partial protection; the latter can be quantitatively described as heterogeneity in dose response models.

Full Text

Duke Authors

Cited Authors

  • Teunis, PFM; Moe, CL; Liu, P; Miller, SE; Lindesmith, L; Baric, RS; Le Pendu, J; Calderon, RL

Published Date

  • August 2008

Published In

Volume / Issue

  • 80 / 8

Start / End Page

  • 1468 - 1476

PubMed ID

  • 18551613

Electronic International Standard Serial Number (EISSN)

  • 1096-9071

Digital Object Identifier (DOI)

  • 10.1002/jmv.21237


  • eng

Conference Location

  • United States