Lyme disease is now found in all states; meanwhile, a new tick species threatens U.S. livestock

Asian long-horned tick (CDC photo)

Lyme disease has now officially spread to the entire nation: Every state "has residents who have tested positive for Lyme, a bacterial infection that can cause a wide variety of symptoms, including joint aches, fatigue, facial palsy and neck stiffness," Linda Searing reports for The Washington Post.

The news comes from clinic laboratory Quest Diagnostics, which analyzed the results of 6 million diagnostic blood tests ordered by doctors. Pennsylvania had the most positive cases last year at 10,001; it, combined with the six states of New England, accounted for about 60 percent of all cases, Searing reports.

Between 2016 and 2017, positive results spiked in states traditionally linked to the disease — by 50 percent in New England and 50 percent in Pennsylvania — but also in states that aren't. "Florida, for instance, had 501 infections, up 77 percent since 2015. California had 483 people with positive test results — a 194.5 percent increase from 2015," Searing reports. A May report from the Centers for Disease Control and Prevention said that diseases spread by ticks and mosquitoes tripled in the U.S. between 2004 and 2016, aided by warm winters that keep pests alive longer.

The spread of ticks is especially concerning because, for the first time in 50 years, a voracious new tick species has been identified in the U.S. The Asian long-horned tick was first found last summer in western New Jersey, and is now rapidly spreading in the eastern U.S. Specimens have since then been reported or sighted in New York, Pennsylvania, Arkansas, North Carolina, Virginia, and West Virginia. Donald McNeil Jr. reports for The New York Times.

The tick hasn’t been found to carry any human diseases in the U.S., but does threaten livestock and other animals. "Known in Australia as bush ticks and in New Zealand as cattle ticks, long-horned ticks can multiply rapidly and suck so much blood from a young animal that it dies. The ticks bloat up like fat raisins until their tiny legs are barely able to support them," McNeil reports. "After a blood meal, females can lay hundreds of fertile eggs without mating."

Scientists say people should use the same precautions to protect against both domestic and long-horned ticks: wear long pants and sleeves, use repellent, and check for ticks after walking in the woods or tall grass.