Montreal is facing an insidious and creeping enemy. In the shadows, the brown rat, also known as the “Norway rat”, proliferates; Its consequences on public health are far from negligible. True vectors of disease, these rodents are proving to be a source of growing concern for residents and health authorities in the Quebec metropolis. This article looks at the different ways in which rat infestations in Montreal affect the health of citizens, and discusses the measures needed to control this threat.

The silent invasion of residential and commercial neighbourhoods by these pests is not a new phenomenon; However, the significant increase in their population raises alarming questions about the associated health risks. Rats are known to be hosts of parasites (fleas, ticks, etc.) and vectors of many diseases such as leptospirosis, murine typhus and salmonellosis. Their ability to adapt to urban environments makes them a tough opponent in the fight for a healthy city.

In this article, we will explore the public health implications of rat infestations by focusing on five key areas: disease transmission, structural and environmental degradation, psychological reactions of residents, associated economic costs, and municipal strategies implemented to curb this problem.

Disease transmission

Rats are a significant public health hazard because they carry an impressive array of pathogens… These organisms can be transmitted to humans directly – through contact with rodents or their feces – or indirectly – via vectors such as fleas that have bitten an infected rat. An infestation can therefore quickly turn into a source of infection if it is not controlled.

Sporadic cases of leptospirosis have been reported in Montreal following contact with water contaminated with the urine of rats. This disease can cause severe symptoms: fever, muscle aches and even kidney or liver damage in severe cases. It is therefore essential that citizens are informed of the risks and adopt appropriate preventive measures.

Although the Montreal health system is vigilant and reactive to the zoonotic risks associated with urban rodents, it is essential that this monitoring be constant. Prevention includes increased public education on hygiene and the safe handling of potentially contaminated food.

Structural and environmental deterioration

The persistent presence of rats also has a considerable material impact on the city… Public infrastructure can suffer from the relentless fishing behaviour of these animals: damaged electrical cables; impaired driving; Gnawed insulation. This unintentional vandalism often leads to expensive repairs and can even cause critical incidents such as short circuits or water leaks.

From an environmental point of view, the damage caused by these pests concerns both green spaces and fragile urban ecosystems. Rats disturb the natural balance by predating certain native species and competing with local wildlife for access to food and shelter.

Administrations must therefore be very vigilant in order to regularly assess the structural state of the urban heritage… (systematic inspection, targeted interventions), all of which represent a significant additional cost for the municipal budget dedicated to maintenance and public safety.