LACONIA — Anaplasmosis and babesiosis, two varieties of tick-borne illness, have been occurring much more frequently over the last two years, even as incidence of Lyme disease has remained fairly constant, health officials say.
All three diseases are carried by blacklegged ticks, which appear prevalent in the Lakes Region this year after moist conditions from good snow cover and a wet spring.
Yearly cases of Lyme disease remain at about 1,500, although this is under-reported and may be as much as 10 times higher, Elizabeth R. Daly, chief of the state’s Bureau of Infectious Disease Control, said Tuesday.
New Hampshire ranks No. 4 nationally for incidence of Lyme disease, according to the U.S. Centers for Disease Control and Prevention.
Cases of anaplasmosis, an illness that mirrors many of the flu-like symptoms of Lyme disease, grew from 135 in 2016 to 317 last year in New Hampshire. In 2013, there were 23 cases of babesiosis, a parasite that attacks red blood cells and can cause anemia, compared to 78 cases last year.
It’s not clear why anaplasmosis and babesiosis appear on the rise.
Various factors contribute to tick prevalence, but the blood-sucking pest is known to thrive in moist conditions, Daly said.
“When there is more snow cover, they do better; they don’t dry out and are able to survive,” she said.
New Hampshire received an average of 4.59 inches of precipitation in April, or 119 percent of normal, according to the Northeast Regional Climate Center. Parts of the Lakes Region had 30 inches more snow than average from October to March.
Alan Eaton, a recently retired entomologist and extension professor at the University of New Hampshire who has made the study of ticks his life work, said there have been reports of a high tick population in Belknap and surrounding counties this spring.
Eaton said the environment has become very welcoming for ticks.
A hundred years ago, much of the state was deforested agricultural land that wasn’t an ideal habitat for these pests.
“Ticks don’t make a good living in that situation,” Eaton said. “They do better with trees, and where there are openings among the trees, even better.”
Health officials recommend precautions like use of insect repellent with 20 percent to 30 percent Deet, application of permethrin to clothing, wearing light-colored clothing covering arms and legs, tucking pants in socks, avoiding tick-infested areas, performing daily tick checks, showering after returning indoors and using tick preventatives on pets.
Tick habitat can be minimized by mowing grass short and placing crushed rock near homes.
If a blacklegged tick is attached to one’s skin for less than 36 hours, the chance of contracting an illness is greatly reduced. There are also successful medical interventions available for those with symptoms of tick-borne illness, particularly if caught early.