Asian Longhorned Tick is a New Emerging Disease Threat, Says CDC

November 30, 2018
Michaela Fleming

Little is known about the ecology and biology of the dangerous tick that the CDC has labeled an emerging disease threat to both humans and animals.

The detection of the Haemaphysalis longicornis tick in several states has brought to light a new emerging threat to public health. It is critical to determine the potential public health and agricultural impacts that the ticks can cause, as this information is currently unknown.

H longicornis, also referred to as the Asian longhorned tick because of its roots in Asia, can transmit diseases—including Rickettsia, Borrelia, Ehrlichia, Anaplasma, Theileria—to animals and humans.

The tick was detected for the first time in New Jersey in August 2017, and again in the spring of 2018 at the same site. However, through surveillance conducted by the US Department of Agriculture’s Animal and Plan Inspection Service, with assistance from local and state health officials, investigators determined that H longicornis was collected from a deer in West Virginia in 2010, and a dog in New Jersey in 2013, indicating the tick has been present in the country longer than initially thought.

Through surveillance, investigators determined that H longicornis was detected in 8 states, in addition to New Jersey, between 2017 and 2018. Positive identifications have been made in New Jersey (16; 30%), Virginia (15; 28%), West Virginia (11; 21%), New York (3; 6%), North Carolina (3; 6%), Pennsylvania (2; 4%), Connecticut (1; 2%), Arkansas (1; 2%) and Maryland (1; 2%), according to a new article published in the US Centers for Disease Control and Prevention’s (CDC) Morbidity and Mortality Weekly Report.

Despite the presence of H longicornis, there have been no cases of illness in humans or other species, according to the report. Still, the presence of this dangerous tick exposes a need for surveillance measures and actions to prevent disease transmission before its onset in humans and other animal species.

The Asian longhorned tick is new to the United States and has the potential to spread germs. People should take steps to protect themselves, their pets, and livestock from this and other ticks. Learn more in @CDCMMWR: https://t.co/bdC3CEFJyK?rel=0" ?rel=0" pic.twitter.com/Cj8CEPi2Uj

— Dr. Robert R. Redfield (@CDCDirector) November 30, 2018

According to the authors of the report, surveillance for the tick will involve efforts from a multitude of health officials on the federal, state, and local level. Surveillance should include adequate sampling of companion animals, commercial animals, wildlife, and the environment.

“Where H longicornis is detected, there should be testing for a range of indigenous and exotic viral, bacterial, and protozoan tickborne pathogens potentially transmitted by H longicornis,” the authors wrote.

Some limitations of the report include that there were limited surveillance methods used to determine the presence of the ticks, due to the availability of information and potential biases in collection and submission of samples. Additionally, the number of cases included in the report reflect specimens that were positively identified via morphology or molecular barcoding.

In response to this threat, state and federal agencies are evaluating different intervention options, including insecticide and acaricide sensitivity testing. In addition, to increased surveillance, several states have distributed information about the ticks to the public, and have developed hotlines and methods to collect ticks submitted for identification.

>> READ: First Report of East Asian Tick Species in the United States

>> READ: New Aggressive Tick Species Is Spreading Through the United States