The Institut national de santé publique du Québec (INSPQ), now considers the west of the island of Montreal as an endemic area for the presence of ticks carrying Lyme disease.
The municipalities concerned are Baie-D’Urfé, Beaconsfield, Dollard-des-Ormeaux, Dorval, Kirkland, L’Île-Dorval, Pointe-Claire, Sainte-Anne-de-Bellevue and Senneville. Located a few kilometers from Vaudreuil-Soulanges, these municipalities have seen their status enhanced following analysis carried out in 2020.
The above mentioned municipalities are all located only a few kilometers from Vaudreuil-Soulanges. The situation must therefore be taken seriously. It is important to know that ticks move according to the path of the base on which they attach themselves.
Earlier and later
Ticks have been noticed much earlier than usual for some time. As of March, ticks are active. In the past, they appeared in May and in October they were once again untraceable. In fact, with the mercury being too cold before May and after October, ticks would hibernate. However, now with global warming the period in which ticks are active has increased from six to nine months.
Lyme disease is spread by the bite of a tick that carries the bacteria Borrelia burgdorferi. This disease was first described in 1977, following an outbreak of arthritis in children living in the town of Lyme, Connecticut, United States. A dozen species of ticks are present in Quebec. The only species that can transmit Lyme disease in Quebec and northeastern North America is the Ixodes scapularis tick, also known as the “deer tick” or “blacklegged tick”.
Since ticks can be transported by birds, they are found in almost all regions of Quebec. However, not all ticks carry the bacteria. The greatest risk of contracting Lyme disease is in areas where populations of blacklegged ticks carrying the bacteria Borrelia burgdorferi are established.
Thus, since 2011, there has been an increase in the number of Lyme disease cases reported to Quebec public health authorities as well as an increase in the proportion of cases having acquired their infection in the province. This proportion increased from approximately 50% in 2013 to 76% in 2019.
In 2020, the proportion of cases acquired in Quebec was 93%. This greater proportion of cases acquired in Quebec can be explained by the closure of borders and the reduction in trips outside Quebec.