An Exotic Tick Is Turning Up In Some Parts of the U.S. Here’s What to Know

A tick that can cause “massive infestations” is spreading across parts of the U.S., the Centers for Disease Control and Prevention (CDC) warns — and in at least one area in the Northeast, its proliferation is growing more intense.

The Asian longhorned tick is not typically seen in the Western Hemisphere. Nonetheless, the pest has been found on people and animals in multiple U.S. states since 2017, the CDC says. The emergence of this new type of tick to the U.S. comes as ticks are becoming more widespread; diseases spread by tick, mosquito and flea bites tripled from 2004 to 2016, the agency reported last May.

“The full public health and agricultural impact of this tick discovery and spread is unknown,” said Ben Beard, deputy director of the CDC’s Division of Vector-Borne Diseases, in a statement. “In other parts of the world, the Asian longhorned tick can transmit many types of pathogens common in the United States. We are concerned that this tick, which can cause massive infestations on animals, on people, and in the environment, is spreading in the United States.”

Here’s what to know about the Asian longhorned tick.

What is the Asian longhorned tick?

The Asian longhorned tick, also known as Haemaphysalis longicornis, is native to Eastern Asia and has also become common in countries including Australia and New Zealand. It often plagues livestock, namely cattle, and a single animal can carry hundreds or thousands of the ticks at a time. The CDC says a single female tick can produce up to 2,000 eggs at once, even without mating, which contributes to the size of its infestations.

Where have they been found in the U.S.?

Since 2017, the Asian longhorned tick has turned up in at least 45 counties in nine U.S. states: Arkansas, Connecticut, Maryland, North Carolina, New Jersey, New York, Pennsylvania, Virginia and West Virginia. The species was first found in the U.S. in August 2017 on a sheep in New Jersey, and since then, health officials have discovered it on people, wildlife and domestic animals.

In a new study published in Emerging Infectious Diseases, researchers from Columbia University found that the pest population had grown dramatically on the New York City borough of Staten Island, largely thanks to the tick’s ability to “feed on a wide range of domestic and wildlife hosts, reproduce asexually and survive various environmental conditions.” Asian longhorned ticks turned up in 16 of 32 inspected Staten Island parks in 2018, as well as on deer living on Staten Island. The researchers found more than 1,500 ticks in a single park area where, just the year before, they found less than 100, according to a statement from Columbia.

Is the tick dangerous?

So far, there’s been no evidence to suggest that Asian longhorned ticks have spread disease in the U.S., the CDC says. Nonetheless, like other tick species, this variety is known to carry disease, according to the CDC. Pathogens transmitted by the pests can cause flu-like symptoms — including muscle aches, fever and chills — as well as hemorrhagic fever and Powassan virus, both of which can be deadly. Cattle and other livestock carrying these ticks can also become ill, the CDC says. In some areas where the bug is common, dairy production has been known to drop by around 25%.

What should people do about the Asian longhorned tick?

The CDC is working to understand and curtail the spread of the Asian longhorned tick within the U.S. In the meantime, people should follow the same practices they use to prevent tick bites from other types of ticks, including wearing tick repellant on skin and clothing, manually checking for ticks and showering soon after being outdoors. Pet owners should also check their animals for ticks and talk to a veterinarian about products that can prevent tick-borne illnesses in pets.