Call made for Lyme disease research
Much remains unknown about tickborne disorder that’s on the rise
A federal funding agency has issued a national call for new Lyme disease research as the country’s population of disease-carrying ticks continues to climb.
The research initiative is the first step in the federal government’s recently announced $4-million, fouryear plan to combat Lyme disease, which is now the most common vector-borne illness in Canada.
“There are a lot of ticks now that carry the bacteria that cause Lyme disease so we have to be able to provide some answers on how to better prevent infection and treat the disease,” said Dr. Marc Ouellette, scientific director of the Institute of Infection and Immunity at the Canadian Institutes of Health Research (CIHR).
In concert with the Public Health Agency of Canada, CIHR intends to build a pan-Canadian network of Lyme disease experts to define a national research agenda.
“There are pockets of excellence in Canada on Lyme disease research but we want to bring them together to have more impact,” Ouellette said.
Many questions remain unanswered: Why do some people bitten by an infected tick not suffer any Lyme symptoms while a tiny minority will develop a painful, hardto-treat form of the disease? Does the disease leave telltale biomarkers in the bloodstream that would allow doctors to diagnose Lyme in its earliest, most treatable stages? How do previous Lyme infections affect a person’s immune system? Is it possible to develop a vaccine?
Dr. Tara Moriarty, an infectious diseases researcher at the University of Toronto, studies how the bacteria that causes Lyme disease, Borrelia burgdorferi, spreads in the body and makes people sick.
“It’s a complicated disease that is quite difficult to understand — and it’s turning out it be more complex than people originally thought,” Moriarty said.
Her lab has found that obesity and diabetes make mice more susceptible to the bacteria that causes Lyme; it has also discovered that the bacteria can cause bone loss in mice.
Ouellette said the research network will be asked to establish a large national cohort of patients to study and track their experiences with the disease.
The goal, he said, is to better understand how Lyme manifests itself in patients; how best to diagnose and treat it; and the extent to which the disease can persist in people who have been treated.
The first round of research proposals are expected to be reviewed later this year, with the first grants being issued in 2018.
The number of Lyme disease cases in Canada soared to 917 in 2015 from 144 cases in 2009. Public-health researchers now estimate that, by 2020, 80 per cent of Eastern Canada’s population will live in areas where blacklegged ticks have become established. The small arachnids carry the bacteria that causes Lyme disease.
In 2010, just 18 per cent of Eastern Canada’s population lived in places where they were at risk of contracting the disease.
Ouellette said Canadians will have to learn to live with Lyme disease since it’s unlikely that blacklegged ticks will be eradicated any time soon.
Last year, a record 75 people in Ottawa were diagnosed with Lyme disease — up from just seven in 2010 — and earlier this year, the city was officially designated an at-risk area.
Ottawa Public Health officials said Thursday that 16 per cent of the 166 local ticks examined this year have tested positive for the Lyme-causing bacteria.
Blacklegged deer ticks can be found anywhere outdoors, but tend to concentrate in forests and tall grasses. Since they can’t fly, the arachnids position themselves on grasses or leaves with their front legs outstretched to latch on to a passing mammal. They can populate new areas by travelling on a host bird.
Public health officials recommend using insect repellent with DEET and wearing long pants and sleeved shirts in wooded areas. They also recommend scanning pets and children for ticks after being outdoors.
Ticks should be removed with tweezers as soon as possible since it takes at least 24 hours for ticks to transmit the bacteria that causes Lyme disease.
If it’s discovered early, the flu-like illness can usually be treated with antibiotics, but left untreated it can cause arthritis, numbness, paralysis, heart disorders and neurological problems. Some people report symptoms that last years after treatment in a condition now referred to as post-treatment Lyme disease syndrome (PTLDS).