As ticks attached to the cloth, the team counted them and put them in jars for further study at their lab at the Connecticut Agricultural Experiment Station in New Haven. Japanese barberry bushes grew thickly beneath the trees at this private horse farm that for years has cooperated with Lyme disease researchers.
As the group dragged cloths, they noticed ticks on each other’s pant legs and coats, and began to pick them off. This seemed to prove what the team leaders, biologists Scott C. Williams and Megan Linske, have found in one of their previous studies: More ticks thrive beneath tangles of Japanese barberry, with its year-round leaves and thorns, than in landscapes without barberry.
About an hour earlier, surveying The Preserve—public land in Old Saybrook—the team had found just one tick. That forest has no visible barberry and few invasive plants.
Throughout 2019, the scientists sampled 40 forested places in all corners of Connecticut. This study aims to calculate which landscapes attract ticks and which don’t. The early results, which they made public for the first time last week, reveal astonishing densities of the ticks that carry Lyme and four other diseases. In Fairfield and Litchfield counties, scientists found more than 20,000 adult biting ticks per square mile. The densities were almost as high in New Haven and New London counties, with more than 18,000 and almost 17,000 ticks per square mile respectively.
Their tick samples also reveal the grim truth of how Lyme disease increases in ticks if they survive into adulthood. Only 15% of nymphs (young ticks) that the team collected carry Lyme, but within a year of feeding on mice that carry the disease, almost half adult ticks carry Lyme disease. Nymphs are a threat to humans because they are so small and their bites often go undetected.
The town of Lyme, of course, is like ground zero for Lyme disease, which was discovered there in the 1970s. The blacklegged ticks carry Lyme disease and four other deadly diseases: anaplasmosis, borrelia miyamotoi disease, babesiosis, and Powassan virus.
Williams said infection with Powassan in 2019 was low, just five cases in the state. But Powassan is a dangerous illness. Former U.S. Sen. Kay Hagen of North Carolina died of Powassan in October. Congress is considering a bill called the Kay Hagan Tick Act for tickborne disease research funding.
Lyme disease has become a national health crisis. It is caused by a microscopic spirochete that enters the bloodstream and hides in the tissues. In 2018, Connecticut ranked fourth in the nation for Lyme cases, with 1,859 reported new cases that year, the Centers for Disease Control and Prevention (CDC) said. But the actual cases are probably 10 times that number (or roughly 18,500), the CDC reported.
Nationwide, the CDC estimates 300,000 cases a year. In 2015, a study at Johns Hopkins University estimated that as many as 440,000 new cases of Lyme are diagnosed each year, costing the health system $712 million to $1.3 billion a year.
The State’s Altered Forests
Lyme disease has been around for millennia. It evolved into ticks that bite humans because the landscape now favors those ticks.
Christine Woodside Photo.
Biologist Scott Williams holds one of the tiny blacklegged ticks before putting it in a jar.
Since about 1900 Connecticut has changed from mostly farmland into a land of small forest patches interrupted by grassy areas. The white-tailed deer and white-footed mouse, two important animals whose blood ticks need to survive, all thrive here.
Although 60% of Connecticut is forest, much of that forested land is cut up into narrow segments. Such fragmented woods create lots of places at the edge of woods where sunlight encourages the shrubs that deer eat—and where ticks survive.
At a forum on urban forests three months ago, Williams told a group of scientists and amateurs that deer have created landscapes that favor ticks. They eat native plants and leave behind invasive plants that tend to shelter the ticks through the winters.
Both scientists said that the time has come to understand why these forests harbor ticks. At the same forum, Linske called the life cycle of the blacklegged tick “quite the process.” It goes like this: In the ticks’ first year, as nymphs, they feed on mice. Not all ticks are infected, but those that are pass the diseases on to the mice. The mice then pass on those diseases to other uninfected ticks that bite them.
After feeding, the ticks drop off the mice. They then spend another season feeding on other animals, especially deer. Thousands of ticks can be found feeding on a single deer.
Unlike mice, deer can’t spread diseases ticks carry to other ticks from their bodies. The deer’s most important roles in spreading Lyme is they provide blood meals to ticks just before they lay their eggs.
The blacklegged tick has been called the “deer tick.” It would be truer to call Connecticut a deer landscape. Williams said deer don’t pass on Lyme disease the way mice do, but deer are pivotal to keeping ticks healthy so they can lay their eggs. Deer also disperse seeds of some plants that encourage ticks.
“This is an important study, and the hope is to have it continue every year,” Williams said last week, “but the Centers for Disease Control and Prevention only gave us enough funding for this first year.” He said they need state or federal funding to continue sampling.
Their work could better define areas where people are more likely to contract dangerous tickborne diseases. And it will help Connecticut residents understand better how to avoid ticks.
TIPS
Japanese barberry.
• Homeowners should cut back Japanese barberry bushes on their property every five years.
• Change clothing after coming inside. Scientists often put their clothes right into a dryer.
• If spending extended time outdoors, people might prefer protective clothing treated with insecticide, available through outdoor outfitters.
• People can avoid tick bites by learning how to check themselves for ticks. Click here for information.
To view the locations where the team collected ticks click here.
]]>Lyme disease is carried by the tiny blacklegged tick, commonly known as a deer tick. When a blacklegged tick infected with Lyme bites a human, it can transmit a tiny microscopic organism, called a spirochete, that moves around the human body, evading easy detection.
Derek Torrellas Photo.
Dr. Paul Fiedler, chair of pathology and laboratory medicine at WCHN, looks through a microscope as a spirochete is displayed on a monitor.
Researchers in Danbury have been trying to detect that spirochete, similar to those that cause syphilis and other diseases, in people’s blood. Pathology research scientist Donna Guralski powered up her microscope and computer recently to show the culprit: a fluorescent green corkscrew-shaped organism that twisted around the screen, just as it would burrow through a person’s blood vessel walls and into tissue.
But scientists have learned that they can’t view the spirochete in fresh blood samples. “We gave up on this method,” Guralski said.
Growing Problem
About 300,000 Lyme cases have been reported nationally from 2006-2016, and an estimated 3,000 cases are reported in Connecticut yearly, according to the Centers for Disease Control and Prevention (CDC). In 2015 9.5 percent of all confirmed Lyme cases were reported in 14 states including Connecticut, Vermont, Rhode Island and New Hampshire. But the CDC says that Lyme disease is 10 times as common as the number of cases confirmed each year.
But the CDC says that Lyme disease is 10 times as common as the number of cases confirmed each year.
Part of the reason for the explosion in Lyme cases is the changing climate. Warmer falls and earlier springs have helped spread Lyme disease, the U.S. Environmental Protection Agency (EPA) determined four years ago.
Tick eggs lie dormant through cold weather, and adult ticks are very clever at surviving under buried leaves, in basements and sheds. “People say, ‘We’ve had a really bad winter; there was a lot of snow’,” said Kirby Stafford III, state entomologist at the Connecticut Agricultural Experiment Station. “I say the ticks are doing just fine. Snow is an insulator.” One of his researchers discovered that winters with more snow and rain lead to summers with more ticks, he said.
And Lyme ticks aren’t the only ones thriving these days. The mostly southern lone star tick showed up in Connecticut last year on a deer found dead near Norwalk.
Two of the most crucial carriers of the disease are white-footed mice and chipmunks. Those animals thrive in forested suburban landscapes, and they’re responsible for infecting the nymph (baby) ticks every spring, starting the whole cycle again.
Difficult Diagnosis
Lyme disease isn’t easily diagnosed. If a person isn’t producing antibodies just as blood is drawn and analyzed, the test result is often negative. Only about one in 10 cases can be confirmed using diagnostic tests, leaving the rest to guesswork by doctors, according to a 2012 analysis of the failed Lyme vaccine trials of the 1990s by Robert A. Aronowitz in the Milbank Quarterly. “Only a small fraction of initially suspected cases were confirmed as definite Lyme disease (in the 10 percent to 20 percent range), suggesting widespread overdiagnosis (or alternately, that the diagnostic criteria were too narrow),” according to Aronowitz.
Derek Torrellas Photo.
Donna Guralski, WCHN scientist, demonstrates the procedure for the quantitative PCR test for detecting Lyme.
The difficulty in diagnosing Lyme has left possibly thousands of Connecticut patients suffering myriad painful symptoms, including flu-like aches, arthritis, Bell’s palsy and headaches.
Suffering with undiagnosed Lyme disease “changed my life,” said Kimberly Ruggiero of Madison, who finally received antibiotics after three years of joint pain, excruciating headaches and confusion, before a lab test confirmed she had Lyme disease.
The disease, named after the town of Lyme in Connecticut, is the most common vector-borne disease in America. It was discovered in the late 1970s when 51 people, mostly children who lived in or near Lyme, all suffered similar arthritis-like symptoms. Willy Burgdorfer, a medical entomologist, verified the connection to the blacklegged tick and identified the spirochete in 1982.
But the signs and symptoms of Lyme disease are often nonspecific, appear in stages and can be linked to other conditions, making it difficult to diagnose, according to the Mayo Clinic. Early signs include a rash in the form of a bull’s-eye and flu-like symptoms, such as fever, chills and body aches.
No test was needed when Deborah Livingston of Bolton took her son, Shep, to a pediatrician as soon as he developed a circular dark-pink rash under his arm. “When the pediatrician saw the rash, she knew right away,” Livingston said.
Annie Atwood of New Haven said that in 2008 her then 4-year-old son, Roddy, was complaining of ankle pain, and within a few weeks lay on his side, moaning. “The next morning, he couldn’t even walk,” Atwood said. A test confirmed Lyme disease and he was cured after several weeks of antibiotics.
Antibiotics, such as doxycycline, are often prescribed, but there is no official consensus on how long treatment should last.
Right now, the diagnostic and treatment criteria, last updated in 2006, are under review by the Infectious Diseases Society, the American Academy of Neurology, the American College of Rheumatology, and other collaborators.
Progress at Danbury Lab
At the Danbury lab, researchers have tested various methods in search of the best diagnostic tool.
They have tried going to the molecular level. Scientists amplified Lyme patients’ DNA from their blood using a test known as PCR, or polymerase chain reaction. Srirupa Das, a pathology research associate, demonstrated the process on a screen showing 48 patients’ test results using this ultra-sensitive technology. Each patient’s DNA sample is divided into 770 tiny square segments. If even one out of 770 squares show red, Lyme disease is present. In some patients, most of the 770 squares turned red; in others, just a few (those people were sick, too, just not as sick). “It’s very hard to detect because infection levels in humans are less,” Das said. “They hide in the joints.”
Derek Torrellas Photo.
Blood and urine are stored for testing.
The PCR test is so sensitive that it would be too expensive to use widely, said Dr. Paul Fiedler, chairman of the lab’s pathology research group. He said a simpler test known as QPCR (quantitative PCR) also works at the molecular level, looks for the Lyme spirochete’s genes, and divides each patient sample into 96 segments. Das used graphs showing rising colored lines that revealed Lyme, and other graphs showing no rising lines, or no disease. He said someday soon this test might become a standard to diagnose the rising number of Lyme cases.
The lab hopes to develop one test that detects three of the diseases carried by the blacklegged tick: Lyme disease, anaplasmosis, and babesiosis. The tick also carries Powassan virus, another serious illness.
The scientists’ challenge is that the Lyme spirochete does not remain in the blood, as other tick-borne organisms do. Lyme spirochetes hide from detection. They can curl up into a ring and break up into blobs to survive. They don’t stay in red or white blood cells, as some other tick-borne bacteria do. They move around, pushing through blood cells and into tissue, scientists explained.
“The big debate is how long do they live?” Fiedler said. “And, why can’t they be seen easily?” He said the current diagnostic tests are not reliable because “if a patient is treated and improves, we won’t see the antibody.”
A prime supplier of blood samples for study is the Western Connecticut Health Network’s Lyme disease biobank. Joann Petrini, director of the bank, said the bank begins signing up patients for study as early as March. The biobank is currently looking for new study participants. To participate, subjects must be at least 5 years old and have been diagnosed by a doctor as having Lyme disease. Participants donate both blood and urine for research studies. Some of the samples are studied right away, and others are labeled and frozen.
“Some people who come in are very sick,” Petrini said. “We’re very fortunate that people are willing to come and do this.”
To donate to the biobank, call 203-739-8383.
About Lyme and other tick-borne illnesses:
Tick-borne illnesses in the United States, CDC
Description of the current CDC protocol for two-stage testing.
Map showing extent of Lyme disease in the northeast
Western Connecticut Health Network Lyme Disease Biobank
Northeast Regional Center for Excellence in Vector-Borne Diseases
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