Vett Lloyd saved the tick that latched onto her while she was gardening outside her home in New Brunswick, Canada in 2011. A biologist who specialized in cancer genetics, she plucked the blood-sucking creature from her skin and sent it to the local public health office to have it tested for the dangerous bacteria she knew it could carry.

But officials told her not to worry, Lloyd said. Lyme disease was exceedingly rare in the forested maritime province northeast of Maine. The tick was tossed untested.

The next year brought agony: Fatigue, fevers that would come and go, aching joints, and finally, trouble lifting her arms or walking.

Lloyd indeed had Lyme disease, but as with many Canadians felled by the tick-borne illness, her diagnosis and treatment were delayed because of a system slow to acknowledge that public health risks were changing as the climate warmed. In a concession that many patients say is overdue, Canadian authorities now admit that the most common vector-borne disease in the United States is an "emerging" threat north of the border.

"It's living hell," Lloyd said of her experience with Lyme. "Every day you wake up with less of your body working.... You are desperately sick, and then you have to fight for care."

Suffering longer

Lloyd is lucky. She knew she had been bitten by a tick and eventually insisted on treatment with antibiotics. After a "two-year journey," she is well now.

Other Canadians have suffered longer, without a clue what was ailing them. Just east of New Brunswick, at a clinic in Halifax, Nova Scotia, rheumatologists over the past four years saw an unusual run of 17 children, ranging in age from 2 to 15, with suspected arthritis – four cases so severe the children had been to the emergency room, and two cases that were treated as septic. In only one case had doctors correctly diagnosed the underlying problem: Lyme disease.

On the western side of Canada, in Victoria, British Columbia, Nicole Bottles was first diagnosed six years ago with "exercise-induced asthma" and then myriad illnesses, from lupus to eating disorders, before finally getting treatment for Lyme. Bottles could do cartwheels as a teenager. Now 21 and in a wheelchair due to lingering damage from the disease, she has been blogging and, in recent weeks, speaking out in favor of a national Lyme disease strategy in Canada.

That effort reached a crucial milestone this summer, when legislation to promote Lyme prevention and timely diagnosis and treatment passed the House of Commons by unanimous consent. Few bills that are not part of the administration's legislative plan ever clear the House in Canada's Parliament, but Green Party sponsor Elizabeth May of British Columbia's Saanich-Gulf Islands said the measure has garnered unusually widespread support because lawmakers are learning about Lyme directly from constituents.

"So many members of Parliament have been hearing these stories that are heartbreaking," she said. Patients tell of having to go to the United States for treatment – especially galling in a nation that has long prided itself on how its national health care system compares to the high-priced, private-insurance-dominated system in the United States. Even Canadian doctors who are knowledgeable about Lyme find they can't gain authorization to treat patients because of overreliance on flawed diagnostic tests, May noted. "We need to catch up."

Seen this coming

Canada should have seen this coming. In the United States, reported cases of Lyme disease have increased from fewer than 10,000 reported cases in 1991 to more than 27,000 cases by 2013. Canada was well-positioned to be affected by the spread of the disease. As early as 2005, modeling published by researcher Nicholas Ogden, then at the University of Montreal, indicated that the geographic range of the Lyme-carrying tick could expand northward significantly due to climate change in this century.

Scientists long have anticipated that global warming would harm human health, and the most recent Intergovernmental Panel on Climate Change report highlights the risk for poor populations that don't have access to quality health care or other public services. For example, the risk of heat stroke is greatest in areas without access to power for air conditioning, and water-borne illnesses like cholera and intestinal viruses flourish in areas without safe drinking water.

But one of the clearest signs of the changing health risks in a warming world has emerged in two of the world's most advanced economies, the United States and Canada, as Lyme disease spreads in North America.

The U.S. Environmental Protection Agency this year added Lyme disease to its list of climate change indicators, a report meant to aid in public understanding of the effects of warming that scientists have been able to document.

Spotted first by mothers

Lyme disease first was identified in Connecticut in 1977 in a cluster of arthritis cases in children – a pattern initially spotted not by trained scientists but by mothers in the town of Old Lyme, who reached out to state health officials and researchers at nearby Yale University for help. Today, the U.S. Centers for Disease Control and Prevention notes that 95 percent of Lyme cases today occur in 14 states in the Northeast, Middle Atlantic, and the upper Midwest. The range of the disease is expanding south in the United States, with large increases reported in Delaware, Maryland, and Virginia – a sign that climate change is not the only reason Lyme is spreading.

"The factors that are most obvious to us are reforestation and the expansion of suburbia," said C. Ben Beard, chief of the bacterial diseases branch of the CDC's division of vector-borne diseases. "The way suburbs are designed – with corridors of forest areas that allow deer to move and for the small rodents that live in wooded areas around houses – is perfect for the tick life-cycle."

But there are signs that warmer temperatures are allowing Lyme-carrying ticks to thrive farther north.

Canada's Public Health Agency only started tracking the disease in 2009. Last year, it reported 500 cases nationwide. By the 2020s, it expects 10,000 Canadians annually will be coping with the disease. The PHA attributes the astronomical growth to warming temperatures that have increased the favorable habitat for the primary disease carrier, the black-legged tick.

"The spread of Lyme disease is driven, in part, by climate change, as the tick vector spreads northwards from endemic areas of the United States," said Steven Sternthal, acting director of the PHA's infectious diseases prevention and control branch. "We are … using every means available to get the message out to the general public. We are telling Canadians that Lyme disease is here, how to recognize it, and how to protect themselves."

Speeding up tick life cycles

Ogden, who warned of the northward spread of the tick in 2005 and is now a senior research scientist at the PHA, said warming causes the tick's life cycle to speed up, meaning more of the bugs survive long enough to breed and reproduce.

Regardless of the cause, the CDC's Beard said that federal officials are "extremely concerned" about the spread of the disease, in part because they know reported case numbers tell just a small fraction of the story.

As the EPA was adding Lyme to its list, CDC scientists along with colleagues from several state health departments and Yale University confirmed what was long suspected: True numbers of Lyme disease infections are likely about 10 times higher – about 300,000 cases in the United States annually – based on private laboratory test results. Even that number could be an understatement, the researchers noted, since it doesn't capture patients who were treated without testing, because they had the telltale circular Lyme rash. The results also would not have reflected patients who were tested too early to have developed antibodies.

Canadian public health officials, for their part, maintain the disease is likely three times more common than reported cases indicate. Some patient advocate groups, who have felt that the PHA has been slow to address the Lyme threat, argue the agency's estimate is too conservative. But Canadian officials say it is based on the United States' experience with the disease in emerging areas.

"Lyme disease is a complex disease," PHA spokeswoman Sylwia Krzyszton said in an email. "As with any complex issue, it takes time to develop, assess and put in place new innovative approaches ... to effectively address this emerging infectious disease."

'I lost my brain completely'

For those who encounter Lyme disease, the effects can be life-changing.

Jim Wilson played on a team that won a Nova Scotia provincial softball tournament in 1991, just before he noticed a rash around his naval. Within weeks, the 37-year-old insurance investigator and small businessman became quite ill. "I drooled when I coughed. I choked on food. I had asthma. I lost my brain completely," he recalled. "My legs – I used to call them 'rubber legs' – were never steady."

With Lyme, symptoms are ever-changing. "You don't know what your day is bringing you," he added. "When you wake up in the morning, you don't know if it will be a good day, a bad day, or if you can't even get out of bed."

Wilson suffered two years before his wife found a book in a local library with a picture identifying Lyme's characteristic rash and the source of his woes. With some difficulty – and a recommendation from a Lyme disease group in New York – Wilson was able to find a Canadian doctor who would treat him with the antibiotics that helped him regain his health. Now president of the Canadian Lyme Disease Foundation, Wilson believes that public health officials have stymied diagnosis and treatment by stressing to doctors that risk is low outside geographic areas with established tick populations.

Carried into Canada

"The messaging [has an] over-emphasis on high-endemic areas and low-endemic areas," Wilson said. "That's all nonsense when you have a disease that is randomly transplanted by migratory birds."

There's some truth to that.

Ticks hitching rides – and grabbing dinner – from deer and rodents are the prime vectors for the spread of the disease. But as far back as 2008, Canada's Public Health Agency warned in one of its biweekly communicable disease reports for medical professionals that Lyme-infected ticks could be carried into Canada by the some 3 billion land birds that migrate north each year. And earlier this year, a joint two-year study by Canadian and U.S. researchers showed that the movement of migratory songbirds helped to establish a new Lyme-infected tick population in a remote woodland area of southeastern Ontario.

Back in 2008, the PHA called Lyme disease "a rising challenge," noting that there had been 69 cases voluntarily reported by doctors across Canada between 2004 to 2006. The report said that Ixodes scapularis, the black-legged tick, was only endemic in a few areas of south-eastern Canada, but its range was expanding. (On the West Coast, Lyme is carried by Ixodes pacificus, the Western black-legged tick; studies only are now underway to understand how climate change is affecting its range.)

Dissuaded from diagnosing

Despite that warning, statements from public health agencies continued to emphasize that the risk of contracting Lyme was low. Janet Sperling, an insect biology researcher at the University of Alberta, believes that doctors were dissuaded from diagnosing Lyme because voices in the Canadian health community highlighted concerns with overdiagnosis and warned against overuse of antibiotics.

Particularly influential, she believes, was a 2005 article in the Canadian Journal of Continuing Medical Education that concluded the majority of supposed Lyme cases in Canada were based on self-diagnosis from misinformation obtained on the Internet.

"Every Canadian doctor picks this up and thinks, 'I better not be the one to be snookered by people who think they have Lyme,'" Sperling said.

That's not true anymore, said Ogden, who added that views on the disease have evolved in Canada. Whereas health care professionals once viewed Lyme cases as an "oddity," it is now clearly seen by public health officials as an emerging disease, he said. Ogden said that one of the goals of a Lyme disease communication plan that the PHA began this past March has been to increase physician awareness.

Worse when untreated

Lyme disease causes far more patient suffering when left untreated, which makes the changing geography and slow response from public health officials such a cause for concern.

Caught early, the disease can often be treated effectively with a two-to-three-week course of mid-level antibiotics. But adult black-legged ticks are about the size of a sesame seed, while nymphs are the size of a poppy seed; either can bite and transmit the disease unnoticed. The rash signaling infection – often a bull's-eye shape around the bite – does not appear in all patients; many people simply don't know its significance if they see it.

Of the 17 children diagnosed with Lyme disease at IWK Health Centre in Halifax, most did not recall being bitten by a tick. Only three had any record of having a rash. But all lived in one of the areas of Nova Scotia known to have endemic black-legged tick populations; two-thirds of the patients were from Lunenburg County, where the province's first established tick populations were identified in 2003. Today Canada's PHA recognizes endemic populations of ticks that could carry the disease in six Canadian provinces: Manitoba, Ontario, Quebec, New Brunswick, Nova Scotia, and British Columbia.

Antibiotics cleared up the pain and swelling of arthritis in most of the children, though a few needed three rounds of treatment. But two children continued to have membrane inflammation and limited movement months after antibiotics; one had evidence of permanent joint damage despite extensive treatment with anti-inflammatory drugs and steroid injections, according to a published abstract of the analysis by the IWK rheumatologists.

'An emerging clinical problem'

The doctors presented their findings in April at an American College of Rheumatology symposium but declined to talk to The Daily Climate about their research until it is published in a medical journal. They are still working on finalizing their paper, an IWK Health Centre spokeswoman said. But in the abstract presented at that meeting, they called Lyme arthritis "an emerging clinical problem in Nova Scotia," with cases expected to continue to rise.

Untreated, Lyme disease can spread to joints, the nervous system, and even the heart. Heart block due to Lyme carditis can develop in minutes or hours, and is a rare but fatal complication. A more common problem that causes even greater concern in the health community: Lyme patients with symptoms persisting long after antibiotic treatment. There's great controversy over how long antibiotic treatment should be continued in such cases and who should bear the costs. The issue underscores the importance of early detection. "Almost always the persistent cases are in patients who were not treated early," said the CDC's Beard.

Robert Strang, Nova Scotia's chief public health officer, says one problem with diagnosis has been that Lyme involves "a lot of non-specific symptoms." Of the cluster of pediatric arthritis cases at IWK, he said, "that case series reminded us that there are joint and neurologic and cardiac ways that Lyme disease can present itself."

Keeping perspective

Lyme disease "is an issue we need to take seriously," said Strang, but he added, "we still need to keep it in perspective. The risk of Lyme disease in Nova Scotia remains low. We spend a lot of time focusing on simple, but effective basic prevention steps," such as using insect repellent in wooded areas, and checking skin for ticks. "We don't want to de-emphasize the risk, but we don't want to discourage people from being active in the summertime."

In New Brunswick, Lyme disease has changed Vett Lloyd's life in more ways than one. She has redirected the work of her laboratory at Mount Allison University from cancer to ticks. Her research now focuses on documenting new sites where the black-legged tick is endemic. "It's important because it's embedded in the medical policy that if you are in an endemic site you have better access to diagnostics and treatment," she said.

She and her students have been doing "tick drags" in different communities in New Brunswick, preparing blankets by rubbing them against wet dogs, and them dragging them across areas of woods and high grass in an effort to pick up ticks that are lying in wait for new hosts. In many communities, Lloyd says, she finds volunteers eager to help public health authorities document the tick's spread to new geographies.

"I've had people in wheelchairs due to Lyme disease say, 'Put a blanket behind my chair and push: I'm going tick dragging,'" Lloyd said. It's a sentiment to which she can relate personally.

"It means you're taking action against something that's got you."

This article originally appeared at The Daily Climate, the climate change news source published by Environmental Health Sciences, a nonprofit media company.