Social vulnerability and Lyme disease incidence: a regional analysis of the United States, 2000-2014

Background: Lyme disease (LD), which is highly preventable communicable illness, is the most commonly reported vector borne disease in the USA. The Social Vulnerability Index (SoVI) is a county level measure of SES and vulnerability to environmental hazards or disease outbreaks, but has not yet been used in the study of LD. The purpose of this study was to determine if a relationship existed between the SoVI and LD incidence at the national level and regional division level in the United States between 2000 and 2014.Methods: County level LD data were downloaded from the CDC. County level SoVI were downloaded from the HVRI at the University of South Carolina and the CDC. Data were sorted into regional divisions as per the US Census Bureau and condense into three time intervals, 2000-2004, 2005-2009, and 2010-2014. QGIS was utilized to visually represent the data. Logarithmic OLS regression models were computed to determine the predictive power of the SoVI in LD incidence rates.Results: LD incidence was greatest in the Northeastern and upper Midwestern regions of the USA.  The results of the regression analyses showed that SoVI exhibited a significant quadratic relationship with LD incidence rates at the national level.Conclusion: Our results showed that counties with the highest and lowest social vulnerability were at greatest risk for LD. The SoVI may be a useful risk assessment tool for public health practitioners within the context of LD control