ATLANTA, Ga. — The Asian longhorned tick (Haemaphysalis longicornis) has been found in New Jersey, New York and Pennsylvania and several other states since its discovery in 2017, according to the Centers for Disease Control and Prevention’ Morbidity and Mortality Weekly Report released on Nov. 30.

The CDC is working with public health, agricultural, and academic experts to understand the possible threat posed by the spread of this invasive tick species.

In New Jersey the ticks have been found in Bergen, Hunterdon, Mercer, Middlesex, Monmouth, Somerset, and Union Counties; Richmond, Rockland, and Westchester Counties in New York and Bucks and Centre Counties in Pennsylvania, according to the report.

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“The full public health and agricultural impact of this tick discovery and spread is unknown,” said Ben Beard, Ph.D., deputy director of CDC’s Division of Vector-Borne Diseases.  “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.”

New Jersey was the first state to report the tick on a sheep in August 2017. Since then, 45 counties or county equivalents have reported finding the tick on a variety of hosts, including humans, dogs, sheep, cattle, horses and other domestic animals, wildlife, and in environmental samples.

In contrast to most tick species, a single female tick can reproduce offspring (1-2,000 eggs at a time) without mating. As a result, hundreds to thousands of ticks can be found on a single animal, person, or in the environment. Livestock producers and pet owners should work with their veterinarians to maintain regular tick prevention and report any unknown tick species to their local department of agriculture, according to the report.

In other parts of the world where the Asian longhorned tick is common, it is a serious threat to livestock. In some regions of New Zealand and Australia, this tick can reduce production in dairy cattle by 25 percent, according to the report.

In New Jersey legislation that would task the state’s mosquito commission with working to help control ticks is pending. The measure was voted out of committee in the Assembly but remains in committee in the Senate.