Global warming may spread tick-borne disease

The brown dog tick (Rhipicephalus sanguineus) rarely bites people, far preferring the taste of dog. But global warming could be changing that, exposing people to dangerous diseases as a result.

In the spring of 2007, three men in France became seriously ill after sustaining bites from disease-infected dog ticks. The bites occurred after the hottest April since 1950, said Didier Raoult, a professor at the University of Marseille School of Medicine in France.

The incident reminded Raoult of two other recent cases. A 2004 outbreak of Rocky Mountain spotted fever in Arizona was also associated with dog ticks. And during the exceptionally hot summer of 2003, a man died after 20 brown dog ticks bit him at once.

Raoult suspected that, in each of these cases, hot weather made dog ticks turn on humans. He decided to investigate.

MSNBC