Renowned Tufts tick researcher Sam Telford told a packed audience at the Vineyard Haven library Tuesday night that in terms of wickedness, Lyme disease doesn’t measure up to Rocky Mountain spotted fever, a bacterial infection transmitted by the dog tick.
Joined by biologist Dick Johnson and physician Michael Jacobs, Telford gave an overview of tick-borne pathogens found on the Vineyard and the types of ticks that harbor them.
The talk came on the coattails of a Centers for Disease Control report indicating tick-borne illness doubled between 2004 and 2016 and infected tick bites (mosquito and flea bites) tripled in the Northeast, among other regions.
Telford touched upon babesia microti, the red blood cell–munching parasite behind babesiosis, deer tick virus, and Powassan, the nearly indistinguishable viruses that can lead to encephalitis, and human anaplasmosis (also called human ehrlichiosis), a bacteria that consumes the very white blood cells meant to protect the body from bacterial infection. But of all tick-vector pathogens, there was one that he crowned the most sinister of them all. “Rocky Mountain spotted fever is the real killer,” Telford said.
“Doxycycline takes care of Rocky Mountain spotted fever very, very quickly,” he said. “With spotted fever, if you don’t treat as soon as you can, people can die very quickly. And in fact there have been a couple of horrific cases in the news in the past few years of people in the Midwest getting spotted fever — not being diagnosed in time,” he said.
Telford described the bacteria as a blood vessel assaulter. “What happens is the bacteria live in the cells lining the capillaries and destroy those capillaries,” he said. “You lose oxygen to those areas where those capillaries have been destroyed, and people have ended up having all four limbs amputated.”
The audience gasped in reaction.
“Martha’s Vineyard, oddly enough, is a hot spot in Massachusetts. It has historically reported a lot of spotted fever, and until Lyme disease came along, this was the infection of interest,” he said.
In a text message to The Times Wednesday morning, Telford wrote dog tick larvae (hatchlings) can inherit Rocky Mountain spotted fever from their mothers. The process is called transovarial transmission. However, unlike deer ticks and Lone Star ticks, dog tick larvae do not bite people — just the adults do, he wrote.
Richard Ostfeld, distinguished senior scientist at the Cary Institute of Ecosystem Studies in Millbrook, N.Y., told The Times Wednesday that Rocky Mountain spotted fever is a “serious disease,” but not the worst, in his opinion. Ostfeld said for the unlucky few who develop Powassan encephalitis, should they survive, half “are permanently disabled because of damage to the brain and central nervous system.”
Telford said Tuesday night he has not found evidence Powassan is on Martha’s Vineyard. However, since 1999 he’s found isolates of the almost identical deer tick virus.
Ostfeld still described Rocky Mountain spotted fever as quite dangerous, and said that not enough study is going into the ticks that transmit it.
“We don’t have systematic surveillance of the American dog tick,” he said. More research needs to be undertaken to suss out what locations are riskiest for that disease, he said.
He pointed out related pathogens can be found in deer ticks. “Rocky Mountain spotted is in the genus rickettsia,” he said. “We do know there are other rickettsia found in the gut of the black-legged tick [a.k.a. deer tick].”
There is no evidence the rickettsia bacteria in deer ticks affects people, he said. “It’s something we ought to be tracking more.”
At Tuesday night’s talk, Dick Johnson, who conducts tick surveillance on behalf of the Island’s boards of health, stressed the protective benefit of applying the insecticide permethrin on clothing and in yards. Johnson described permethrin as a chemical originally derived from flowers, but more effectively manufactured artificially at present. Permethrin-imbued socks he described as essential when in tick habitat. Johnson said permethrin can be bought on-Island in aerosol form and sprayed onto clothing, and pretreated socks can also be bought on-Island. He advised not putting too much on your skin, though he said the liver can break down permethrin absorbed by the body within reason. Not so for cats, he pointed out.
“One thing you don’t want to do is spray it on your cat,” he said. Unlike dogs, which have a liver enzyme that can deal with permethrin, cat livers are defenseless against the chemical, he said.
For bare skin, such as where feet are exposed in pair of sandals, Johnson recommended the insect repellent DEET (diethyltoluamide).
Johnson said there are many herbal protective sprays on the market, but he would not vouch for the protectiveness of any of them.
In the yard, Johnson said permethrin can be sprayed at the edge of woodlands for a good tick barrier. He advised requesting whatever professional is hired to do the work not to spray too liberally, and not to spray high on foliage, as permethrin is harmful to pollinators like bees. The chemical also comes in granular form, he said.
One audience member said her mother was convinced ticks can hail down from trees. “Is there ever a time when ticks are not coming from below but coming from above?” she asked.
“I have heard this over and over everywhere, and the only thing I can think of is that the mice do climb trees,” Telford said, “and they will live in bird nests, and birds certainly carry the ticks. So it’s possible that they could drop out of trees …”