The number of Lyme disease cases in northern U.S. states is rising, while southern states are experiencing a significant decrease in cases, according to a new study.

The research was conducted by a team at the University of Toronto who used data on Lyme disease rates between 1992 and 2007 taken from the CDC (Centers for Disease Control and Prevention) and was published in the journal CMAJ Open.

The incidence of this tick-borne disease has risen by about 80% in the U.S., according to the experts, however, rates differ between states.

The northern states that saw an increase in the disease include New England along with:

  • Virginia
  • Pennsylvania
  • Ohio
  • Michigan
  • Wisconsin
  • Minnesota
  • North Dakota
  • Illinois

The states that experienced a decrease in the number of cases were mostly located in the Southeast and include:

  • Louisiana
  • Georgia
  • Wyoming
  • Kentucky
  • Tennessee
  • Oregon
  • California
  • Mississippi

Dr. David Fisman, Dalla Lana School of Public Health, Toronto, Canada, said:

“Our findings are consistent with the hypothesis that increases in Lyme disease incidence in recent decades are attributable at least in part to the effects of climate change, with increasing rates of change observed at more northerly latitudes, and declines in disease incidence in the southernmost states.”

With ticks moving from warmer areas into more northern latitudes, Lyme disease as well as other tick-borne illnesses have been rising and and spreading.

“It is projected that this trend will continue with warmer temperatures associated with climate change,” the authors said.

The scientists concluded:

“Public health agencies should consider whether existing surveillance systems are sufficiently flexible and sensitive to identify climate change-driven changes in infectious disease epidemiology.”

A study from last year showed that the risk of Lyme disease in the UK is greater than experts thought.

Lyme disease is a bacterial infection caused by the bacterium Borrelia burgdorferi. It is transmitted to people through the bite of blacklegged ticks that are infected, according to the CDC.

Common symptoms include headache, fever, fatigue, and a skin rash called erythema migrans.

Doctors can diagnose Lyme disease based on a person’s symptoms and the existence of a rash. Laboratory testing can also be used.

Antibiotics can successfully treat the majority of cases, however, if the disease is untreated, infection can spread to the heart, joints, and the nervous system.

In order to prevent Lyme disease, the CDC recommends:

  • to remove ticks right away
  • to use insect repellent
  • to reduce tick habitat
  • to apply pesticides

Written by Sarah Glynn