The Asian long-horned tick continues its march north

Updated April 29

The Asian longhorn tick, an invasive species from East Asia and Australia, continues to spread northward and is now found in Connecticut. Like time reported last summer, the tick was first found on sheep in New Jersey in 2017. It was later found in Maryland, New York, Virginia, West Virginia, North Carolina, Kentucky and Arkansas. Known to carry and transmit certain diseases in Asia, the tick has so far not been shown to be a pathogenic threat to people in the United States. Much of the concern about it revolves around its potential as a pest of livestock.

Although he has not yet been found in Massachusetts, his arrival is only a matter of time, Dukes County biologist Dick Johnson told The Times. The two ticks found in Connecticut were both in Fairfield County. One was found during an outdoor tick drive, while another was found on a child who was bitten by it, according to Goudarz Molaei, a researcher at the Center for Vector Biology and Zoonotic Diseases in Connecticut. Agricultural Experiment Station.

“Fortunately, we couldn’t find any infections,” he said of the tick that bit the child. Molaei not only performed tick tests for local pathogens, but also performed special panels for pathogens not found in the United States. He noted that in Asia, the tick has been shown to harbor strains of babesiosis, anaplasmosis and borreliosis. He also said he is known to transmit a type of rickettsia in his home environment. But he pointed out that in the United States, the tick’s transport and transmission capabilities could be different, and it should not be assumed that the tick can transmit anything – more research is needed. Pathogen studies are underway at the U.S. Department of Agriculture, the Centers for Disease Control and some universities to better understand what the tick is or is not able to transmit, he said. Whether or not it becomes a disease vector, its potential as a “major pest of livestock” is already known, he added.

“It’s only a matter of time before it’s plentiful in Connecticut,” he said, adding that he “wouldn’t be surprised” if it reached Massachusetts.

“There’s no reason to think this is going to end in Connecticut,” Johnson said. “For me, it’s not a question of if but when.”

“I think it’s going to be primarily a livestock issue, not a people issue,” said Larry Dapsis, Barnstable County entomologist. Dapsis intends to set up a livestock surveillance and tracking network in Cape Town, where he says alpaca and goats are common. He suspects that the tick will enter the Commonwealth through interstate livestock transport and wants to locate any animals attacked by ticks as soon as he can.

“These things can add up in huge numbers and bleed animals,” he said. The animals die from “significant blood loss” or are debilitated, making them more susceptible to disease, he said. As an example of what large multitudes of ticks can do, Dapsis noted a field study in Africa that found that a “medium-sized” giraffe died due to blood loss from 40,000 ticks. . Closer to home, he said his wife, who worked as a veterinary technician, treated a Great Dane covered with 600 engorged dog ticks. The animal was in a “severely anemic” condition.

“If we find it on a farm, that will suggest that it is spreading quickly,” he said. Its ability to spread rapidly may be due in part to a reproductive advantage it has. “They don’t need males to mate,” he says. “This is called parthenogenesis.”

In a nutshell, female ticks can self-fertilize and lay eggs.

Dapsis said farmers should be vigilant. “If they’ve acquired cattle from Pennsylvania or New Jersey – or even New York – they should give those animals a tick check,” he said. “If the tick is a rusty reddish brown, that’s a big clue.” Asian long-horned ticks are very different from other ticks commonly found in Massachusetts, he said.

Dapsis said the Asian longhorn tick has so far ignored a long-standing native threat. Blacklegged ticks, that is, deer ticks, remain “in the foreground” for the public health risks associated with ticks.

The best method to keep these or all ticks away is to use permethrin with caution on clothing and shoes, he said.

Crawling around New York

According to Columbia University eco-epidemiologist Maria Diuk-Wasser, Asian longhorn ticks are rampant on Staten Island, one of New York’s five boroughs., who studies ticks there. There are also many deer there.

“So far we have only found [them] on the deer, ”said Diuk-Wasser. “They’re not about mice, for some reason.”

New York City is engaged in a program to reduce the number of deer on Staten Island through a vasectomy program for male deer, she said. As the New York Times and several other news outlets have reported, car collisions with deer and Lyme disease have both increased in the borough in recent years.

Diuk-Wasser and his colleagues took the opportunity to examine sedated deer in the process of vasectomy for ticks. Many blacklegged (deer), solitary star, and long horned Asian ticks have been found on these deer. But she has also found Asian ticks with long horns in backyards, parks and even on sidewalks.

University of Rhode Island tick researcher Tom Mather visited Staten Island last summer. He said he and a colleague didn’t have to spend much time in front of a parking lot to capture an abundance of these ticks. “What we found was a shock,” he said.

On their first trail, they captured numerous larvae of Asian long-horned ticks. He soon discovered that the tick was quite abundant there. Mather said he saw evidence suggesting the ticks could be moving up the I-95 corridor on dogs.

“I think it’s only a matter of time,” he said of their arrival in Rhode Island.

“It’s alarming,” Cornell entomologist Jody Gangloff-Kaufmann said of the tick abundance in New York state.

Gangloff-Kauffmann, community outreach coordinator for the New York State Integrated Pest Management program, said her colleagues had collected more than 100,000 Asian longhorn ticks in the Hudson Valley.

A key factor as to why these ticks are able to multiply so quickly, she said, is the absence of males. Not only do they reproduce by parthenogenesis, but all offspring appear to be females, so all offspring are able to breed more ticks. She said she was not aware of any long-horned male Asian ticks found in the United States. “A single female can trigger a new infestation in a given area,” she said.

Currently, the tick is found in high concentrations where cattle are not abundant but deer are, but she said that could change, and the cash cow for New York cattle is dairy cattle, has she declared. She pointed to Otsego County, where Chobani yogurt has brought a boom to the dairy industry. It would be problematic if ticks assault livestock there, especially organically fed animals.

“It’s a problem for organic dairy products because they can’t use miticide,” she said. Miticides are pesticides that kill mites and ticks.

The “host range,” all types of animals on which Asian long-horned ticks can be found, has yet to be explored, Gangloff-Kauffmann said. But as with the diseases he carries, she believes scientists are on the verge of turning a corner. “This year I think it will be a defining year for a lot of information,” she said. She holds this opinion because of the intense scientific research devoted to the tick.

Longtime Tufts tick researcher Sam Telford said he was a bit disappointed with the Asian longhorn tick. In New England, he said, herding is so developed that he cannot imagine the cattle being invaded by these ticks. New England cattle are well maintained and cared for, he said.

He agreed it was “only a matter of time” before the tick reached Massachusetts, but said research dollars are currently best spent on the blacklegged tick, the carrier of Borrelia bungefori. , the bacteria that causes Lyme and other illnesses, and the solitary tick, which harbors several illnesses and can trigger alpha-gal meat allergies. He said the Asian long-horned tick is not proven to carry anything.

Michael Skvarla, director of the insect identification laboratory at the College of Agricultural Sciences at Pennsylvania State University, said he was very concerned about the tick.

It is found in areas around Philadelphia, but “hasn’t gone very far west yet,” he said.

In addition to its sheep and pigs, Pennsylvania is a major producer of beef cattle. “For cattle, this could be a very big problem,” he said.

He doesn’t seem to prefer humans, said Diuk-Wasser, but temper that by the fact that he’s known to harbor disease in his native Asia: “The big question right now is, will this tick go to be a vector for man? pathogens in the United States?

Updated with more details – Ed.

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