Norovirus transmission dynamics: a modelling review

Abstract

Norovirus is one of the leading causes of viral gastroenteritis worldwide and responsible for substantial morbidity, mortality and healthcare costs. To further understanding of the epidemiology and control of norovirus, there has been much recent interest in describing the transmission dynamics of norovirus through mathematical models. In this study, we review the current modelling approaches for norovirus transmission. We examine the data and methods used to estimate these models that vary structurally and parametrically between different epidemiological contexts. Many of the existing studies at population level have focused on the same case notification dataset, whereas models from outbreak settings are highly specific and difficult to generalise. In this review, we explore the consistency in the description of norovirus transmission dynamics and the robustness of parameter estimates between studies. In particular, we find that there is considerable variability in estimates of key parameters such as the basic reproduction number, which may mean that the effort required to control norovirus at the population level may currently be underestimated.

Keywords: Basic reproduction number; estimating disease prevalence; mathematical modelling; norovirus; transmission.

Fig. 1.

Diagram of citations between reviewed works divided by setting [, , , , , , –, –54, 59, 69]. Boxes show first authors of each study. Arrows denote that the study may have been influenced by earlier studies, established through citation, and arrow colour varies for ease of reading. Boxes with white backgrounds indicate a study has estimated and provided a novel value of a reproduction number. Superscript symbols denote co-authorship with * indicating co-authorship with Lopman; ^° Simmons and ^~ Zelner.

Fig. 2.

Reproduction number values for the subset of studies, shown in Fig. 1, where reproduction numbers are explicitly mentioned; the x-axis denotes first author [, , , , , , , –54, 69]. Squares denote individual values of the basic reproduction number according to the definition given in the Aims section; circles denote individual values of the effective reproduction number according to the definition given in the Aims section. Filled shapes denote that the value was estimated, empty shapes denote that the value was assumed and lines denote 95% confidence interval ranges if provided. Where mutliple reproduction number values are estimated for different situations, detailed in text, all values are shown.