For several years, environmentalists, scientists, farmers and other concerned groups have sounded the alarm: the exchange of germs is much more frequent than in the past. They notice that a new infection appears every 14 to 16 months. The conditions for these infections to develop, transmit and remain active are increasingly favorable.
While learning about COVID-19, you may have read or heard of "zoonoses". We were probably trying to explain the origin of this coronavirus which is causing the current pandemic. Zoonoses are diseases and infections whose agents are naturally transmitted from vertebrate animals to humans, and vice versa. In the case of COVID-19, the virus would have been transmitted from bats or pangolin to humans.
It is relevant to let our curiosity dwell on the eco-epidemiology which includes zoonoses. Eco-epidemiology (or environmental epidemiology) is concerned with the environmental factors that influence the transmission of diseases. We are talking about the influence of one animal to another, from animal to human, from human to animal, and we also include plants and all the surrounding ecology.
First, what kinds of diseases are we referring to? We are talking about diseases or germs that need a reservoir to develop and be transmitted. The reservoir can be a human, an animal, an insect, water, soil. These germs can develop in the form of viruses (e.g .: COVID-19, AIDS), bacteria (e.g .: meningitis, tetanus, cholera, Lyme disease), parasites (e.g .: pediculosis (louse), malaria, pinworm, ringworm) or prions (abnormal proteins that cause infectious diseases such as scrapie).
These germs therefore develop in reservoirs. Humans take up a lot of space on the planet; destroying animal habitats, polluting waterways, gathering large concentrations of animals for agriculture, moving contaminated goods from one continent to another, traveling to discover beautiful places ... human therefore unwittingly creates very favorable conditions for the propagation of germs. And then, we can also add global warming, which forces many animals to change their habits and move around in order to survive.
In Quebec, we are not immune to these germs. We only have to think of those who walk in schools: lice, pinworms, gastro, colds, chickenpox ... And if we walk in the forest, we must be careful of ticks which can be reservoirs of the disease. Lyme.
All these germs have a variable lifespan and require a reservoir to continue their transmission. To protect yourself, you have to break the chain. In the case of COVID-19, containment is one way to prevent the virus from spreading to each other. It is also essential to adopt a healthy hygiene by washing your hands regularly for example. We need to study eco-epidemiological phenomena to understand what allows organisms to become reservoirs and to see how germs are transmitted.
You will have understood that, germs, there have always been and there will always be! A better understanding of the causes therefore helps us to control epidemics, to put in place measures to avoid them or, at least, to reduce their consequences with vaccines and drugs. We then realize that it is necessary to inform as many people as possible so that future decisions are united and limit the transmission of germs in order to maintain a balance in ecosystems.
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