Lyme disease may spread further by helping ticks survive cold winters

Ticks infected with the bacterium responsible for Lyme disease are more likely to survive winter, contributing to the spread of the disease as the world warms

By Michael Le Page

The ticks that can infect people with Lyme disease have expanded their range northwards in North America and Eurasia as the climate warms. Now a study has found that the bacteria that cause Lyme disease may aid this expansion by boosting the survival rate of overwintering ticks.

“This infection helps them get through some of these difficult winters,” says Shelley Adamo at Dalhousie University in Halifax, Canada. “It really has a big punch in terms of population numbers.”

In people, Lyme …