"Rocky Mountain spotted fever is a nasty disease.

"It's super, super scary,' says F. Scott Dahlgren, an epidemiologist with the Centers for Disease Control and Prevention.

'If you don't treat for Rocky Mountain spotted fever by the fifth day of illness, there's a really good chance you're going to die,' says Dahlgren. 'And it's an ugly, ugly death, too,' he adds. 'It's a horrific thing to go through and to see a loved one go through.'

The number of reported cases has surged since 2000, with about eight times as many cases reported by 2012. But since then, the incidence of hospitalization and death from the disease dropped by half. That confused epidemiologists."

Rae Ellen Bichell reports for NPR October 28, 2015. [2]