A Geospatial Analysis of Norovirus Outbreaks in California, and an Investigation of the Impact of Environmental Variables

I. Abstract Previous studies and empirical evidence suggest norovirus outbreaks in California exhibit correlation with environmental variables and exhibit spatial spread patterns. Few studies have been done looking at what causes norovirus seasonality in temperate climates and more research is needed on the regional level. This study aims to find what relationships exist with outbreak occurrence and environmental variables in California, as well as any spatial patterns of spread or clustering of outbreaks. Spatial analysis tools were used to find any relationships between California norovirus outbreak data and environmental variables. The results showed a south to north spread of outbreaks in California and potential correlation with outbreaks and lower temperatures and higher relative humidity. More research is needed to substantiate the correlation with outbreaks and environmental variables. Table 1 Advantages and disadvantages for various methods of testing for norovirus Figure 1 Shows direct and indirect transmission potential of norovirus over time. BLOCKIN 15 Figure 3 This graph shows how syndromic surveillance can help with early detection of an outbreak.