Lyme disease crossed the river

Cases were identified for the first time as having been acquired locally in regions north of the St. Lawrence

Philippe Teisceira-Lessard Philippe Teisceira- Lessard

La Presse

Previously confined to southern Quebec, Lyme disease has just crossed the river, according to data recently made public by the Ministry of Health.

For years, the St. Lawrence has seemed to act as a natural barrier to the spread of the disease, which can be very serious if not treated in time.

But the barrier fell: in 2019, between 10 and 30% of ticks tested in the Quebec region, in Laval, in Laurentides and Lanaudière carried the bacteria responsible for Lyme disease. These insects are the vector of transmission.

“Before, we did not see any north of the river and this year, they are definitely present north of the river,” said D re Geneviève Baron, from Estrie Public Health, the most affected from Quebec.

We were starting to see them in 2018, but there they are really present [au nord du fleuve].

D re Geneviève Baron, from Estrie Public Health, the most affected region in Quebec

“Cases were identified for the first time as having been acquired locally in the Laval [2 cas] and Capitale-Nationale [1 cas] region,” added Marie- Claude Lacasse, spokesperson for the Ministry of Health.

“The ticks concerned are already present in many regions, indicated the D r Yves Jalbert, one of the lieutenants of D r Horacio Arruda at the Directorate General of Public Health. It is their infection with the bacteria that causes the disease that is growing. This bacterium is transported by intermediate hosts such as deer and white-footed mice. “

500 new cases

The number of diagnoses north of the river is currently much lower than in the southern regions of Quebec, the epicenter of the phenomenon.

In Estrie, the number of new Lyme disease infections more than doubled last year, dropping from 88 in 2018 at 226 in 2019. The Granby region and that which includes Farnham, Dunham and Lac-Brome are particularly affected.

Compared to the last years, “the tick is more present in the region and it is more infected, so it contributes to the increase”, indicated the D re Baron, to explain the increase in cases. “Clinicians in our region are starting to be quite aware, so there are a lot of reports of early illness diagnosed in the first month of infection. […] By having more alert populations and more sensitized doctors, there are surely more diagnoses. “

The doctor Jalbert, of the National Public Health, does not believe that the low number of patients on the north shore of the St. Lawrence is linked to a lack of knowledge of the disease. “It is impossible to conclude that there is an underdiagnosis problem,” he said. Lyme disease is “very well known to clinicians in all regions.”

In total, 500 Quebecers received a Lyme disease diagnosis in 2019, against 304 in 2018. For each year, about a quarter of the patients would have contracted the disease outside Quebec.

The disease is in constant progression: there was only 125 cases counted in Quebec in 2014, while it was extremely rare there are 10 or 15 years. Global warming is pointed out to explain its progression to the north.

A controversial subject

Lyme disease is a bacterial disease transmitted by a tick bite, often caught during walks in the wild, especially in tall grass.

It often causes significant redness around the place of the bite, often accompanied by fever and exhaustion like a cold, explained the D re Baron. At this stage, it is still mild and easily treatable with antibiotics.

If it is not treated in time, it can take a “diffuse” form with which are associated motley symptoms which can be serious, continued the doctor.

A whole alternating current developed around this form of the disease, to which adhere individuals who self-diagnose a chronic Lyme disease to explain health problems in front of which the doctors remain impotent . While scientists are not aware of any other form of transmission of the disease other than the tick bite, many members of this virtual community believe they have been infected by other means, such as sexually.

The Ministry of Health recommends simple ways to prevent Lyme disease infection during outdoor activities: “preferably walk the trails” in nature, “put on your sweater in his pants and the bottom of the pants in socks or boots “and examine his body on return. “If a tick has caught on the skin, [il faut] remove it carefully, as soon as possible, ideally within 24 hours following the activity “, continues the Ministry .