Impact of historic temperature and precipitation on Lyme disease cases in Rhode Island

(In Progress)

Lyme disease is an endemic disease, found primarily in the United States. While prior studies have shown associations between certain historic climate factors and increases in the disease, a more detailed understanding of this association may serve as the foundation for a future prevention model.  This study will attempt to demonstrate if historic precipitation and temperature are associated with Lyme disease cases in Rhode Island.

Methods: 

Climate Data was obtained from the National Climatic Data Center, while case data, divided by month and county according to onset date, were obtained from the Rhode Island Department of Health. After matching climatic data to the reported cases it was then subdivided into six-month increments over the prior two years. Linear regression will be used to determine potential associations between the climatic variables and cases.  Significant variables will then be modeled using a zero-inflated Poisson regression to test for potential interactions.

Results:

A total of 8165 cases of Lyme disease were reported in the five counties of Rhode Island between 1992-2012.   After excluding 230 cases (2.81%) due to an unknown location, this left a remaining case total of 7935 (97.1%).  Climatic data is now being collected and will be followed by both statistical methods to test for potential associations between Lyme disease and the select climate variables.  

Conclusion:

This study seeks to create the foundation of a model that may aid with the prevention of Lyme disease transmission in Rhode Island by identifying potential associations between climatic factors and the disease.