Hi friends! Today I thought I’d chat about zoonotic diseases. Lately, zoonotic diseases are frequently mentioned in the media, likely because COVID-19 is a zoonotic disease. But what are zoonotic diseases? And how do human interactions with the environment impact zoonotic disease transmission?
We will chat about what they are, and how things like animal agriculture and climate change influence disease transmission rates. Because yes, human interactions with the environment impact zoonotic disease risk and transmission rates in a major way.
First of all, what are zoonotic diseases?
Zoonotic diseases are diseases spread between animals, insects, ticks, and people.
There are many zoonotic diseases. Examples we hear about often include things like rabies, Lyme disease, SARS, Ebola, Avian (‘bird’) flu, salmonella, and of course, COVID-19.
What causes zoonotic diseases to spill over from animals to humans?
Scientists have identified three major types of changes that increase the likelihood that a pathogen will move from animals to humans: they include changes to the environment, host (the person or animal carrying the disease), or pathogen itself (meaning the pathogen may alter or mutate or develop resistance, etc).
But what factors increase the risk of these changes, and thus, increase the risk of transmission of zoonotic disease to humans?
What increases the risks of zoonotic disease transmission to humans?
Turns out, a lot of human activities are influencing the spread of these diseases, many of which have to do with how we interact with our environment.
In 2016, the UN Environment Program published a report detailing “Emerging Issues of Environmental Concern.” Zoonotic diseases were among the noted concerns.
The report noted that there has been a dramatic reduction in natural ecosystems and biodiversity, and that humans now keep more animals than ever before, which presents more opportunities for pathogens of animal diseases to spill over into humans.
The integrity of natural ecosystems is essential to maintaining a buffer zone that normally prevents spill over of certain pathogens from animals to people.
Unfortunately, human activities, including deforestation, mining, building, and use of land agriculture, have fragmented a lot of these buffering ecosystems, increasing the risk of pathogen spill over.…