It’s been nearly two decades since the last publication of a nationwide survey on the distribution of blacklegged ticks — the primary transmitters of Lyme disease. That survey, released in 1998, reported the tick in 30 percent of U.S. counties. Today, a new study using similar surveillance methods has found the tick in more than 45 percent of counties.
Last year, reported cases of West Nile virus in the United States hit their highest levels in nearly a decade. It's a good reminder to keep protecting yourself from getting bitten, but it also begs the question: Is this just a sign of a much bigger threat? The answer is just as wily as the pesky mosquito.