Invasive Asian longhorned ticks infesting parts of SC, DHEC says. Here’s what to know

A large population of Asian longhorned ticks that can cause severe illness in people and animals has been identified in South Carolina, health officials say.

Specifically, the insects were identified infesting a pasture at a cattle farm in York County. The invasive species is not commonly found in the U.S. and could spread to other counties and cause severe illnesses in people and animals, according to the South Carolina Department of Health and Environmental Control.

The Asian longhorned ticks were identified through the state’s tick surveillance program — a collaborative effort between DHEC, the University of South Carolina Arnold School of Public Health and Clemson University Livestock Poultry Health.

Asian longhorned ticks are light brown in color and tiny. Because of their small size and quick movement, they are difficult to detect. These ticks can feed on any animal but are most commonly found on livestock, dogs and humans.

“While no documented cases of diseases such as Lyme disease, Rocky Mountain spotted fever, or anaplasmosis have been reported in the United States due to bites from Asian longhorned ticks, the ability of this tick species to spread diseases that can make people and animals ill is a concern,” Dr. Chris Evans, State Public Health Entomologist with DHEC’s Bureau of Environmental Health Services, said in a Friday press release. “However, more research is needed in the United States to better understand what diseases the Asian longhorned tick can spread and to what degree they are a health risk to people, livestock, and other animals. The ability of this tick species to increase its populations very quickly, leading to large infestations in a short amount of time, is also concerning.”

Unlike other ticks, a single female Asian longhorned tick can produce 1,000 to 2,000 eggs at a time without mating. This means a single animal could host hundreds or thousands of ticks.

As of June 2022, the U.S. Department of Agriculture (USDA) reports Asian longhorned ticks were first identified in the United States in 2010 and have since been found in 17 states. In South Carolina, a small number of the ticks were identified in 2020 on shelter dogs in Lancaster and Pickens counties.

Dr. Michael Neault, South Carolina State Veterinarian and Director of Clemson University’s Livestock Poultry Health Department, advises that animal owners should consult their veterinarian about the use of products approved in the United States for other tick species that are found to be effective in treating animals with the Asian longhorned tick.

“Livestock owners especially should be aware that these ticks can carry the parasite Theileria,” Neault said in a Friday press release. “In Virginia, they already have spread this infection in sheep and it also may spread to cattle.”

To help state officials learn more about the prevalence of Asian longhorned ticks in South Carolina, residents are asked to carefully submit ticks suspected to be Asian longhorned ticks for confirmatory identification. This surveillance will help determine tick species presence, distribution, seasonality and potential tick-borne disease risks.

To participate in the tick surveillance project, carefully collect a tick by using gloved hands, tweezers or another tool and send collected ticks, alive or dead, in a puncture-resistant sealable vial or zippered storage bag to Laboratory of Vector-Borne and Zoonotic Diseases, 921 Assembly Street #417A Columbia, SC 29201. Please include:

• Your name and phone number

• Address of where the tick was collected (if not a street address, provide directions and distances from nearby road intersections)

• Date of collection

• Indicate if the tick was found on a human or animal and specify the type of animal

For additional information about Asian longhorned ticks, visit Clemson University’s South Carolina Ticks and Animal Health webpage. To more learn about tick-borne illnesses in South Carolina and the University of South Carolina’s Arnold School of Public Health tick identification program, visit scdhec.gov/ticks.