The threat of Lyme disease has spread to all 50 states. Quest Diagnostics analyzed 6 million blood samples and found the tick-borne disease is now in 100 percent of the country. The most cases were in Pennsylvania, but the disease is also becoming more common in places like Florida and California.
Here & Now’s Jeremy Hobson speaks with Wendy Adams, research grant director for the Bay Area Lyme Foundation, which released research in July showing ticks capable of carrying Lyme have been found in 83 new counties across the country.
On Lyme disease, typically concentrated in the Northeast and upper Midwest, being reported in all 50 states, and the difference between testing and reporting
“I think it’s important to talk about the testing and the reporting here, because while it’s been reported in 50 states, it doesn’t mean that the bacteria is actually living in the ticks of all those 50 states. Lyme disease is reported where it’s diagnosed, but not necessarily where it’s contracted. So while we say that it’s been diagnosed in 50 states, it’s not necessarily in the ticks in all 50 states
“Somebody from a state that doesn’t have Lyme might go on vacation to California or New York, get infected there, but not be diagnosed until they’re back in their home state. That gets reported then as an infection from a state, which may not have Lyme disease actually in the ticks in that particular state, so it’s an important distinction.
“But nonetheless, the ticks really are moving. There are ticks in more counties than we thought there were, and there are different pathogens in the ticks than we had expected when we started the study.”
On the history of Lyme in California and recently increased reports in the state
“California’s had Lyme disease living in the ticks for, you know, ever since the late ‘70s. So we have the first documented cases seen in California in the late ‘70s.
“This isn’t something new. What we are seeing is a real increase in diagnosis or at least an increase in the positive tests, and that’s really interesting, because, for example, in 2017, about 500 were reported through Quest [Diagnostics], but only about 160 were reported to the county health departments that record the infection.
“The question really is, are more people getting infected, or are more people just getting diagnosed? And if more people are getting diagnosed, then how is the rate of diagnosis increasing so rapidly from the early 2010s when it was only about 100 cases being reported through Quest?”
On her own research of Lyme disease and findings that showed ticks in unexpected places
“What surprised us is that we really saw ticks in places we didn’t expect, specifically the ticks that have Lyme disease, but also other ticks, and we found pathogens in the ticks that we didn’t expect to see and that hadn’t been seen in those numbers before. For example, we saw Lone Star ticks, which are the ticks with the characteristic dot on the back. That’s thought really to be an East Coast, Southern tick. However, we’ve had two submissions from Northern California.
“In addition we saw Ixodes ticks, which are the ticks that carry Lyme disease. We saw the Lyme pathogen in the smallest ticks, in the larvae ticks, which are just from eggs that hatch — those ticks had the pathogen in them, and that really wasn’t expected.”
On doctors diagnosing tick-borne diseases
“Typically, people get a tick bite. If they see it, they go into their doctor and tell them they’ve been bitten by a tick. That helps the doctor determine if [the] tick-borne disease could be one of the reasons they’re feeling sick. When somebody doesn’t see a tick, that’s a critical piece of information that the doctor is missing, which might lead them more quickly to diagnosing the tick-borne disease.”
On a new invasive tick found in the U.S., the Asian longhorned tick
“We know it carries viruses, and those have shown to be … they cause a lot of human disease in the places where that tick is established. We haven’t linked them to human disease in the United States yet, but it does cause disease in cattle and livestock.
“That’s something we need to really be careful and look for in humans and also let the doctors know that there’s this new tick circulating that might have different pathogens that we haven’t recognized in humans yet.”
On climate change potentially being a factor in the increase in ticks and the ability for ticks to survive diverse climates
“We’ll have to watch this over several years. Ticks are very hardy creatures. They will use any environmental advantage that they can, but they will be around no matter what the climate is. So, I think it’s important to really study the ticks, study the level of pathogens in the ticks and then realize that you know a cold year, a hot year, they’re going to be there no matter what.”
On how to combat the uptick in ticks
“There are studies about novel genetic methods to control ticks in certain populations. It’s hard to do. I’ll speak from the perspective of California: California is a very ecologically diverse state, and so what might work in a tick in Sonoma County might not work in a tick in Monterey County, because the environments are different and the animals ticks feed on are different.
“People do need to look at their environment, look at plants and things they have in their backyard, how close they are to their house. They need to think about controlling ticks in their pets, because pets can bring ticks indoors, and those are the ways that we can kind of, in the near term, worry about controlling the tick. But using that as our only way of reducing the Lyme disease or the tick-borne disease burden is probably not going to happen in the near future.”
On safety precautions for preventing tick bites
“To reduce tick-borne infection, what you really want to do is, when you’re outside, try and stay away from long grasses, leaf litter and fallen trees. You want to stay in the middle of pathways when you’re out hiking or walking, and when you come in, you really want to throw your clothes in the dryer for 10 minutes, take a shower and then do a tick check, and that will reduce a good part of the risk of contracting tick-borne disease.”