In 2017, a farmer shearing sheep in New Jersey reported being covered in tiny brown ticks she could not identify. They were new to America but were already causing problems on ranches and farms in Australia and New Zealand.
“It has been shown to be the primary vector of a blood borne parasite that causes anemia in cattle," says Virginia Tech veterinarian Kevin Lahmers. "We now have identified that pathogen in ten states.”
He diagnosed the first case in the nation here in the Commonwealth.
Most animals infected by the Asian longhorned tick are sick for about a week, but at least 90% recover. It’s now in 38 of Virginia’s counties.
“It seems to prefer the higher elevations along the I-81 corridor, and so we’ve investigated many of those counties," Lahmers says. "The tick if fairly promiscuous. It will feed on lots of different things – wildlife, livestock, but it seems to particularly love cows.”
So far, he says, these ticks pose little risk to people.
“We’re still investigating what they can and cannot transmit. We have found some viral pathogens in those ticks, which is of concern. They’re originally from the Pacific Rim, and in those areas they transmit a virus that has a fairly high mortality rate – not a high frequency, but a high mortality rate, so there is some concern that if that virus made it into the U.S. that could be threat to the human population.”
The longhorned ticks live in large clusters of hundreds to thousands, and they don’t need a mate to reproduce, so they are multiplying rapidly.
“A single tick deposited in a new, suitable environment can produce thousands of ticks in 12 months.”
Farm animals can be sprayed with insecticide to prevent Asian longhorn bites, and the same measures people use to ward off other ticks are also effective against these new arrivals. He also suggests a simple way to reduce the risk of hosting these creatures in your yard of park.
“They need high humidity in order to survive, and so one of the things that we can do is keep the lawn mowed, so that there’s lower humidity at the base of the roots.”
Lahmers says there’s no drug that can be used to treat infected people or cattle, although a blood transfusion may reduce the risk of death. He’s not happy about the arrival of longhorned ticks, but he’s glad to be on the frontlines – working to protect people and animals.
“I worked at a USDA facility in Washington State that does tick-borne disease investigation, and my PhD was on Anaplasma. I’m the son of a dairy vet, and I grew up on a beef farm" he explains. "It was like I was working towards this my entire life.”
He advises anyone who’s bitten to remove the tick and put it in a plastic bag or take a picture that can be shared with cooperative extension for identification.
For more information: https://www.cdc.gov/ticks/longhorned-tick/index.html
https://www.aphis.usda.gov/aphis/maps/animal-health/asian-longhorned-tick
