If you’ve been outside in any snow-free location lately, it doesn’t take an analysis of 14,252 ticks collected from all over New Hampshire to tell you that everybody’s least favorite arachnid is back – in fact, it never left.
But if you want confirmation, BeBop Labs, an unusual volunteer-run program in Plymouth that keeps tabs on this public health scourge through citizen science, has published a peer-reviewed analysis of ticks that New Hampshire residents mailed to them from 2018 to 2021, as well as analysis of almost 4,000 ticks to see what diseases they carried.
The most depressing, if not surprising, conclusion from the study: The deer or black-legged tick, the main carrier of Lyme and other diseases spread to people, is showing up sooner each year.
“The peak of black-legged ticks, we did find them earlier every year, at least in the spring,” said Kaitlyn Morse, who runs BeBop Labs and was a principal author on the study. “Probably in the fall, too, but there were less collected, it was harder to tell a pattern there.”
Since it started in 2017, BeBop Labs has asked people in New Hampshire who discover a tick on themselves or their pet or crawling on their furniture, to mail it in along with a little information about where and how they were found. They send some of the ticks to labs for analysis about which pathogens they’re passing on when they latch onto us.
This makes it unusual, Morse said, because most tick population analysis is either much bigger – drawing conclusions on a national or regional scale, based on surveys and extrapolations from some sampling – or much smaller, after trained teams descend on a field or other plot and systematically collect ticks.
“Really what pushed this, makes this unique and publishable, is that it’s focused on New Hampshire only and focused on the species of ticks that we predominantly see,” said Morse. And it has a lot of data: “We’ve got more ticks than (studies) usually do.”
The only drawback, she said, is a shortage of samples from the North Country, probably a reflection of the small population. The study draws no conclusions about tick distribution north of the notches.
“I want to put out a call: People who go up north or live up north, we need a sampling methodology up there!” she said.
Some general conclusions from three years of data collection of ticks in New Hampshire:
Deer tick populations peak twice each year, in May and October, while dog ticks peak in June. The overlap of their peak periods makes late spring and the start of summer particularly dangerous.
Dog ticks have a biannual cycle in which they are more common every other year. Two years ago was big, so 2023 probably will be, too.
About 40% of black-legged ticks carry at least one disease. It’s often Lyme disease, but babesia and anaplasmosis are also common. Other tick-borne pathogens that cause human disease are very rare, at least so far.
About 7% of black-legged ticks carry more than one disease. Dog ticks rarely carry a disease that transmits to people, she said, although they do infect animals.
While there are places where more ticks were reported, that’s mostly a reflection of where people are. You should assume that both types of ticks are common everywhere in the state and take suitable precautions when heading into high grass, around leaf litter or going into the woods.
“I’m proud that we can do so much with so little money,” said Morse.
The non-profit depends on donations and grants to pay for testing and other costs, but nobody gets paid. (Morse’s main job is co-founder of VaxSyna, a company developing an HPV vaccine from plants.) “We have one of the strongest databases worldwide. A lot of organizations are copying this, how we operate,” he said.
The study, co-authored by Sharon McElroy of BeBop Labs with data analysis from two researchers in Spain, was published in the Journal of Medical Entomology, titled “Passive collection of ticks in New Hampshire reveals species-specific patterns of distribution and activity.” Online at https://academic.oup.com/jme/advance-article/doi/10.1093/jme/tjad030/7111333.