iSeeChange: The lone star tick
A growing number of reports show that cases of tick-borne diseases are rising and spreading to new areas of the country. This is true not only for lyme disease, caused by the deer tick. but also the deadly heartland virus and the Rocky Mountain spotted fever. Those diseases have been linked to a species called the lone star tick.
The lone star tick is very aggressive. Unlike other ticks, its larval form can bite humans. Scientists believe it used to be mainly concentrated in Texas, Oklahoma and other southern areas, but over the last twenty years, has rapidly expanded into the Midwest and New England.
In our latest installment of iSeeChange, Delaware Public Media’s science reporter Eli Chen went to find out what’s causing them to spread.
The year was 2004 and Tina Moore was out of town at a training seminar.
“And I was in a strange hotel and I was breaking out in hives and I thought it was because of the detergent,” said Moore.
Tina thought she was reacting to whatever they used to wash the sheets at the hotel.
“And I figured, oh, no big deal when I get back home, I’ll be with my own detergent.”
But when Tina returned home from training, the hives didn’t go away.
“And the little hives turned into bigger hives, and then the bigger hives turned into... they merged together until it looked like I was one big hive," said Moore. "It looked like someone threw a bucket scalded water all over me. And I was totally scalded all over my body. And my skin was swollen and red. It was just terrible, terrible sensation.”
The hives, the swelling, went on for about six months and eventually became anaphylaxis. She went to the doctor, who prescribed steroids. But she thought it was just treating the symptoms, not the cause.
“I finally got upset with the doctor and I said. ‘You know, these steroids are really bad and I don’t like to be on this medication. And you need to find out what the answer is to my problem.’”
Tina went to an allergy specialist. That doctor eventually narrowed her reaction down to beef, pork, lamb, basically, mammal meat. Her doctors couldn’t put a name to her condition, so they just called it a red meat allergy. But it confused Tina. She never had any problems eating meat before.
A few years passed. And she started posting in food allergy message boards.
“I was on People’s Pharmacy, one of their boards, and someone sent me a message, a one-liner, saying, I bet you got bit by a tick," Moore recounted. And I answered, don’t be absurd, ticks don’t cause food allergies.”
But the respondent followed up with a study from the University of Virginia, describing a condition called Alpha-Gal -- an allergy to red meat, caused by a bite from the lone star tick.
“I was like holy smokes. I can’t believe it… this is what I got,” said Moore.
And she went and got tested for the disease. It came back positive. Suddenly everything clicked.
“I remember getting a tick bite, I remember getting a lot of tick bites. You know, I work outside.”
Tina lives on a farm in Frankford, Delaware, where she raises horses, so getting a tick bite wasn’t uncommon but she remembered getting a strangely aggressive bite.
“The tick got on me and where he bit. It was swollen, it was really red, it lasted for months, it didn’t heal, ” said Moore.
Tina had actually tried to get treated for lyme disease, after getting this bite. But a lyme disease bite is supposed to look more like a bullseye.
“And mine looked more like a yin and a yang, it looked really weird.”
And another weird thing, Tina’s lived in Delaware since the 1970s and in the many years she’s lived here and gotten bit by ticks, she’s never seen this particular tick species.
“It used to be that the deer tick was the big tick problem that we had. And now, I’ve never heard of the lone star tick before,” said Moore.
The little brown lone star ticks are known to be concentrated in areas like Texas and Oklahoma. But recent studies and news reports show that lone star ticks are becoming more present in places they haven’t been before, like New England, parts of the Midwest, even the eastern provinces of Canada.
“The million dollar question is why… why is that happening, I think the data is very clear that it is happening.” said Keith Clay, a biologist at Indiana University. He’s been working with ticks since the late 1990s.
“Back then, it was quite rare. We found them only in certain areas, only infrequently," Clay added. "And now they’re by far and away the most common tick. And they’re moving northwards.”
Clay says lone star ticks like humidity, fragmented forests and shrubby areas. And in southern Indiana and other parts of the midwest, Clay says those are the same places that they’ve seen a surge in deer populations.
“At least in Indiana, the deer population have really skyrocketed over the 10 or 20 years as well kind of in parallel with lone star ticks,” said Clay.
And the kind of deer they really like are white-tailed deer. Holly Gaff, a tick researcher at Old Dominion University in Virginia, says that urban development, has led to fragmented forests and disturbed areas--landscapes that lone star ticks really like. And we’ve also gotten rid of a lot of deer predators, so more food for the ticks.
“We’ve created a place where they can survive by manipulating the world around us,” said Gaff.
Tina Moore had also wondered if bird populations had anything to do with the rise in tick populations.
"I remember when I was little, you used to be able to sit out in the backyard and call a bobwhite. Now, there’s none around," said Moore.
Bobwhites are a species of quail. They’re ground-foragers, so they eat little bugs they can pick off the ground, like ticks. But since they’ve disappeared over the years, Tina wanted to know if these missing predators had anything to do with the rise in ticks.
“So birds do move some species of ticks, but not the lone star tick," said Gaff.
Ticks are more influenced by the movement of their food source than they are by predators.
"Lone star ticks really like very large animals," Gaff noted. "They feed on deer, humans, coyotes, if you have them.”
So, as deer expand their range, so do lone star ticks. Both scientists agreed that climate change could also encourage the lone star ticks to travel further north. But Gaff says that the lone star tick is traveling too quickly to be explained by climate change alone.
“If it was just a result of climate change, I could see it moving very slowly northward,” said Gaff.
Gaff is referring to the fact that temperatures have been rising at a slow rate in Long Island, Cape Cod -- places that have come to regard the lone star tick as a major pest. And the growth of their geographic range doesn’t reflect the pace of rising temperatures.
“That hasn’t tipped the balance as much as the changes in the host populations.”
DNREC currently doesn’t keep track of tick populations in the First State. The only measure of tick activity are the cases of tick-borne illnesses reported to the Division of Public Health. Neither DPH nor the CDC tracks Alpha-Gal, since it’s not considered an infectious disease. So it’s unknown at the moment how many lone star ticks are in Delaware, and if Delaware might expect more cases of lone star tick-related conditions like Alpha-gal.
It actually took Tina Moore seven years to discover that she had Alpha-Gal. And when she did, she felt like her doctor didn’t care.
“My doctor had no information for me, nothing. Nothing to offer, nothing to share. And I thought that’s terrible. I just went through all of this stuff, and just got diagnosed and now I’m just, like, shoved away," said Moore. "I’m thinking to myself I cannot be the only one out here with this. And I started thinking, there have got to be others. And that’s when I started the support group.”
She set up this support group for Alpha-Gal victims on Facebook. She also told as many people as she could.
“And it’s amazing, I have a cousin, four doors down, his coworker’s wife has it too. And I tell all the customers that I go to and it’s like almost 50 percent of them say, ‘Oh, I know someone who has that.’”
The Facebook group now contains close to 2,000 people--but not all of them have Alpha-gal. Some of them are family members seeking advice. And though most of them are located in the U.S., there are some from other continents where Alpha-Gal is caused by different tick species.
In the beginning, Alpha-Gal was tough on Tina. But over the years, she’s learned to deal with her dietary restrictions.
“I’ve never looked at it as all that terrible, since now I eat so much healthier.”
But knowing that her allergy was caused by a single tick bite has definitely made her more cautious about where she ventures outdoors.
We learned about Tina Moore’s story because she posted about Alpha-Gal on iSeeChange.org. The website went through a major makeover a few weeks ago, so tell us what you think and let us know if you have any questions about using the site. And, as always, if you’re seeing changes in your backyard that you’d like for us to investigate, let us know at iSeechange.org.