There’s some good news in New Jersey about a potentially deadly tick-borne bacterium. Rutgers researchers examined more than 3,000 ticks in the Garden State and found only one carrying Rickettsia rickettsii, the bacterium that causes Rocky Mountain spotted fever. But cases of tick-borne spotted fevers have increased east of the Mississippi River, and more research is needed to understand why, according to a study in the American Journal of Tropical Medicine and Hygiene.