New tick species can transmit deadly disease
ASIAN LONGHORNED TICK IS THE FIRST INVASIVE TICK TO REACH THE U.S. IN 80 YEARS.
A new invasive tick species capable of transmitting several severe diseases is spreading in the United States, posing an emerging threat to human and animal health, according to a pair of reports issued Thursday.
The Asian longhorned tick is the first invasive tick to arrive in the United States in about 80 years. It’s native to eastern China, Japan, the Russian Far East and the Korean Peninsula, and is now also established in Australia and New Zealand.
In August of last year, it was discovered on a 12year-old pet Icelandic sheep in western New Jersey. Since then, the tick has been found in Arkansas, Connecticut, Maryland, New York, North Carolina, Pennsylvania, Virginia and West Virginia.
The species has been found found on pets, livestock, wildlife and people. So far, though, there is no evidence that the tick has spread pathogens to humans, domestic animals or wildlife in the United States, according to a report from the Centers for Disease Control and Prevention.
But public-health officials are worried about the potential for Haemaphysalis longicornis to spread disease. In other parts of the world, it is a major livestock pest; its bites can make people and animals seriously ill. In some parts of Australia and New Zealand, the ticks can suck so much blood from dairy cattle that they cause milk production to drop by 25 percent, researchers have found.
In Asia, the tick carries a virus that causes human hemorrhagic fever and kills up to 30 percent of its victims. Although that virus is not in the United States, it is closely related to the Heartland virus, another life-threatening tick-borne disease that circulates in the United States. Health officials are particularly concerned about the tick’s ability to adapt to be a vector for that virus and other tickborne illnesses in the United States.
The tick “is potentially capable of spreading a large number of diseases,” said Lyle Petersen, director of CDC’S Division of Vector-borne Diseases. “We really don’t know if diseases will be spread by this tick in the United States, and if so, to what extent. But it’s very important that we figure this out quickly.”
The female tick can also lay hundreds of fertile eggs without mating, “resulting in massive host infestations,” the CDC report said.
Illnesses from mosquito, tick and flea bites more than tripled in the United States from 2004 to 2016, according to the CDC. The increase in these vector-borne diseases has many underlying causes: expanding travel and trade, urbanization, population growth and increasing temperatures.
Warming temperatures and climate change make the environment more hospitable to ticks or mosquitoes that spread pathogens and increase the length of the season when ticks are active, Petersen said.
Next week, officials from several federal agencies – including the CDC, the Department of Agriculture, the Environmental Protection Agency, the National Park Service and the Department of Defense – are meeting to develop a national coordinated strategy for fighting these vector-borne diseases.
“The problems are getting worse and worse,” Petersen said, noting that every state except Alaska is grappling with a rise in these diseases. “We’re losing this battle.”
Officials said they are trying to raise awareness among public health officials, health-care professionals and veterinarians about the potential threat from this species. In addition to the CDC report, Petersen and CDC colleagues published a companion paper in the American Journal of Tropical Medicine and Hygiene highlighting the “considerable gaps” in the ability of public health systems to respond to these diseases.
Many diseases spread by ticks are underreported.