The Times tried out TickReport recently, the University of Massachusetts Amherst tick-testing service run by the Laboratory of Medical Zoology. The laboratory takes mailed-in ticks, grinds them up, and uses DNA and RNA analysis to learn what pathogens the ticks harbor.
The fee for this service typically runs $50 for DNA testing, which covers bacterial and protozoan diseases such as borrelia (the Lyme bacteria) and babesia (the babesiosis protozoa). But because of a state grant, TickReport is offering the DNA test for a limited time at $15. RNA testing was similarly reduced due to the grant, but the funds for that testing have been exhausted. RNA tests show viral pathogens like Powassan and Colorado tick fever. The cost of this test is $100. DNA testing comes along with it.
The Times sent in two sample ticks, one from the edge of the Lucy Vincent Beach parking lot and one from Chilmark’s hills. The submitter for the Lucy Vincent tick was codenamed “Capt. Quint,” the hills tick “Chief Brody”.
“Quint’s tick is a dog tick, and not surprisingly, it was not infected with any pathogens tested,” laboratory director Stephen Rich wrote. “For years we did not test dog ticks for Lyme because we know they are not vectors of that pathogen. Some clients would push back and insist that they found (some obscure) reference to dog ticks vectoring Lyme pathogen. In point of fact, we were testing the dog ticks for Lyme pathogen as part of standard procedure (controls), but we weren’t charging people, nor were we reporting results because we thought it would be misleading.”
However, so many people requested their dog ticks be tested for Lyme, the lab acquiesced and reported the negative results, he wrote.
“Lo and behold, they were all pleased,” he wrote. “It seems that quoting published references to John Q. Public that his dog tick is not a threat was not credible. But when we showed him that we tested his tick, he believed and was satisfied. We learned a lesson there about public health messaging.”
“We see very little infection in dog ticks,” Rich said in a follow-up phone call, “much less than 5 percent.” Tularemia is one of the diseases dog ticks can carry, he pointed out, and it can have a rapid onset. In its pneumonic form, Lyme can be a “walk in the park” comparatively, he said.
“Brody’s tick is an adult male deer (black-legged) tick,” Rich wrote “It was positive for two tests. The first test is a general [Borrelia] test … The second test is more specific, and tells us that the very type of Borrelia in the chief’s tick is the one that causes canonical Lyme disease. About half of the adult ticks will be positive. Brody is lucky because his tick is not positive for the several other things we test.”
Chief Brody’s tick also underwent RNA testing, and was negative for five viruses.
“Those viruses are quite rare,” Rich wrote, “but we have detected Powassan Type-2 in an Edgartown resident. We followed up with that resident, who never showed signs of illness.”
The laboratory has received 15 ticks that tested positive for Powassan type 2, also known as deer tick virus, Rich said — most from the Cape. Powassan and deer tick virus are extremely similar, according Tufts tick expert Sam Telford. “The two viruses differ by 15 percent of their RNA; they differ by 4 percent of their amino acids,” he said at a tick talk in Edgartown last year.
Rich said none of the people who submitted the positive ticks to his lab came down with serious disease.
The quality assurance testing his lab performs is unparalleled in tick testing, Rich said. The staff tests each tick’s DNA prior to conducting pathogen testing to ensure it’s a viable specimen.
“If we can’t detect tick DNA, we would never ever be able to detect pathogen DNA,” he said.
So long as a specimen is viable, he said the DNA testing is 99.9 percent accurate.
Bleach or another strong base would ruin a tick specimen, he said, but so far his lab hasn’t received any bleach-marinated ticks.
As The Times reported in May, Rich and Telford, two of America’s preeminent tick researchers, disagree on the value of tick DNA testing.
Telford has argued that data from such tick testing puzzles clinicians, as they don’t know how to utilize it. Among other things, he strongly advocates for consultation with a physician and use of the doxycycline prophylactic, if necessary.
Rich contends the data from tick report provides piece of mind to the submitter and valuable data to doctors. Certain pathogens can be ruled out both by the testing and by tick identification, he has said.
Since 2006 Rich said his lab has tested 55,000 ticks. Submissions from the Vineyard have doubled since last year, he said.