Lyme Disease Risk Increased by Climate Change?

April 11/2013

TBC April 24, 2013
For immediate release

Lyme disease rate increasing in northern US states

The incidence of Lyme disease has increased approximately 80% in the United States between 1993 and 2007, although rates vary between states, according to a new study in CMAJ Open. Latitude and population density were correlated with higher increases, with states in the north seeing increases and southern states seeing stable or declining rates.

Lyme disease and other tick-borne illnesses have been increasing and spreading with ticks moving from warmer areas into more northern latitudes. It is projected that this trend will continue with warmer temperatures associated with climate change.

“Our findings are consistent with the hypothesis that increases in Lyme incidence in recent decades are attributable at least in part to the effects of climate change, with increasing rates of change at more northerly latitudes, and declines in disease incidence in the southernmost states,” writes Dr. David Fisman, Dalla Lana School of Public Health, Toronto, Canada, with coauthors in an article published online in CMAJ Open.

“Public health agencies need to ensure that existing surveillance systems are sufficiently flexible and sensitive to identify climate change-driven changes in infectious disease epidemiology,” the authors conclude.

Read the full research paper: Effect of latitude on the rate of change in incidence of Lyme Disease in the United States

Contact for interviews: Nicole Bodnar, Media Relations and Communications Specialist, Faculty of Medicine, University of Toronto, Tel: 416-978-5811, for Dr. David Fisman

About CMAJ Open
CMAJ Open is an online open-access journal that publishes high-quality medical and health research, without the need for authors to demonstrate high impact. Content is available online to readers at no charge. It comes from the same family as the Canadian Medical Association Journal (CMAJ).

Media contact: Kim Barnhardt, CMAJ Open, tel: 613-520-7116 x2224,