Online Program

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

Tuesday, November 3, 2015 : 3:10 p.m. - 3:30 p.m.

Benjamin Ashraf, MPH, CHES, Environmental and Occupational Safety and Health, Oregon State University, Corvallis, OR
Alexandria Ashraf, MPH Candidate, BS, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA
Jan Medlock, PhD, College of Veterinary Medicine, Oregon State University, Corvallis, OR
Jeffrey Bethel, PhD, College of Public Health and Human Sciences, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR
(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.


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.


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.  


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.

Learning Areas:

Environmental health sciences
Protection of the public in relation to communicable diseases including prevention or control
Public health biology
Public health or related education
Public health or related research

Learning Objectives:
Describe the impact of historic precipitation levels on Lyme disease cases Describe the impact of historic temperature levels on Lyme disease cases Discuss the potential impact the changes in climatic factors may have on vector-borne diseases.

Keyword(s): Veterinary Public Health, Environmental Health

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am a doctoral student with a research interest in modeling the spread of vector borne diseases. I have previously presented original research at public health conferences in the past.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.