It is not news that human actions, especially deforestation, have long-term results that can be problematic for our society. Even the current Coronavirus pandemic has roots in human activities that facilitated the spread of the virus.

In earlier studies - which in this case reinforce the fact that we already know a lot about this type of risk - researchers have linked human activities to the risk of new epidemics. When isolated areas are affected by human activities, contact with wild species increases the possibility of spillover (i.e. the ability of a virus to "adapt" from an animal to humans).

In an activity where deforestation is practiced, those who work directly with this deforestation are at risk of contracting some disease. Besides those who are directly involved, the opening of an access road to the site facilitates the entry of other people in the area, which gradually increases the possibility of some disease arising. In some countries we can also have cases where there is ademand for bushmeat, which generates an economic incentive for activities that generate the risks cited here.

Stages of emergence of viral epidemics

Some steps are expected for pandemics like the current one to happen. The first situation is transmission between the reservoir (the animal carrying the source virus) and humans, or even domestic animals. The second step is transmission from human to human. Finally, having access to a large population. Besides these three basic steps, having low lethality and few symptoms alsocan contribute to the level of a pandemic.

These stages can happen with variations of many years. Some viruses, such as Monkeypex, can get stuck in the second stage, having a very limited human-to-human transmission, which causes some small outbreaks to happen and then fade away.

Human activities will further facilitate pandemics

According to a UN report, more than 70% of today's diseases are caused by contact with animals. It is easy to understand the reasons if we look at the way the world is going. We have the increasing development of agriculture and cattle breeding, an access to previously untouched and preserved areas, and, unfortunately, the management of all this development does not grow equally.

We can add to that the fast way we move today. In hours we go from one end of the continent to the other, we can carry new diseases and distribute them around the world quickly without even being aware of it.

An imminent danger but with solutions

It may seem hopeless to have all the time small outbreaks of viral variations that can cause serious diseases. However, we have the main thing to prevent this from becoming something bigger.

Having a notion of how this happens, and of the places with the best chances, puts us steps ahead. In this way, it is necessary to put pressure on the governments of all countries to take science seriously, to invest knowing that in the long term the return is enormous.

SOURCES / US National Library of Medicine / Cambridge University Press