Deforestation and pandemics: what’s the connection?

Uncontrolled deforestation can be an inviting door for new pandemics – that tend to become increasingly adaptable to the surrounding environment.
But where does this connection between deforestation and new infectious diseases, epidemics, and even pandemics, come from?

Deforestation is one of the leading causes – maybe even the main cause – of habitat destruction. These habitats provide essential services to many living beings, including Mankind, such as carbon retention and oxygen production. The threat of species extinction, animal or plant, is evident. And what are the causes of deforestation? The main explanations are agricultural activities, livestock husbandry, mining, increasing urbanisation – both housing and road construction – or the overexploitation of natural resources.

Another consequence of the decrease in forest areas is animals being deprived of their habitats and forced into closer proximity with humans, which promotes direct interspecies contact. Some of these animals, especially wild ones, can be carriers of viruses and bacteria, some potentially lethal for other species, including humans.

Looking back over the last 40 years, it becomes noticeable that there is an accelerated increase in zoonoses which have rapidly grown into epidemics.

The list of such zoonoses is wide: rabies, dengue (also called breakbone fever), malaria, brucellosis, toxoplasmosis, or Ebola virus disease, are just a few.

The Covid-19 pandemic, the disease caused by the SARS-CoV-2 virus, has also originated in animals. Scientific consensus suggests that the novel coronavirus has been passed on to humans through the consumption of meat of infected animals; that the disease has been passed on among animals that are normally consumed by people; or that this virus is a mutation of previous coronaviruses.

Deforestation plays an important role in the proliferation of zoonoses, but it is not at all the only factor. The lack of hygiene and food safety, namely in local markets that are commonly associated with developing countries, are also responsible for disease transmission.

Not even wealthy countries can avoid some of these diseases. Let’s remember the bovine spongiform encephalopathy (BSE) epidemic, more commonly called the mad cow disease, that has ravaged the UK in the 1980’s and 1990’s and spread to several countries.

This disease is likely due to have started with bovines being fed contaminated fodder. The export of infected livestock from the UK helped to disseminate the disease through other countries, and it finally reached humans – by ingestion of meat of sick cattle. Once in humans, BSE manifested as a new-variant Creutzfeldt-Jakob disease (vCJD), a degenerative brain disease. Ten years after the outbreak, and with very strict rules, it was possible to control the disease in animals and its repercussions in humans.

It is obvious that the role of governments and authorities in the control and prevention of diseases is extremely important – as a matter of fact, strict rules and a tight grip were what allowed the mad cow disease to get under control.

Stopping deforestation is not as “easy”, but each and every one of us can play a part in it. For instance, by supporting institutions and organisations that fight deforestation, or by purchasing products and food produce with a certification of sustainable origin and production. What is currently being done about promoting and supporting sustainable palm oil is a good way to put words into actions.

Sources: Nature, article “Stopping Deforestation Can Prevent Pandemics” (Scientific American), Rainforest Alliance, EMRO.