The ecological challenge of future pandemics

It seems that the covid-19 pandemic does not find its final end. At the same time that enormous efforts are made to expand vaccination coverage around the world, the new Ómicron sublineages (increasingly prevalent, including in Argentina) are elusive to the available vaccines prepared with the previous variants of the virus, and to the natural disease produced by them.

The virus runs us more and more “the goal” of pandemic control. Not//however, the insurgency of new sublineages of the Omicron subvariant is characterized by a shorter incubation period –now it is only two to four days–, greater transmissibility and a lower incidence of pneumonia, without major repercussions in hospitalizations and cases fatal It is as if the virus had found (by means of a “formula” of low aggressiveness) not to send us to the hospital in order to persist among us, continue infecting us and continue spreading.

It is sufficiently proven that most of the human infectious diseases that have emerged in recent decades have their origin in wildlife, and that 65% of all human pathogens identified since 1980 to this part are responsible for zoonotic diseases, it is say, that they pass from an animal to a human.

In turn, zoonoses account for 75% of emerging infections: defined as those caused by a recently identified infectious agent and generally with the capacity to cause public health problems.

Zoonotic diseases are on the rise and, given the current situation, they may intensify in the future. Each year, around two million people die from these neglected diseases, mainly in low- and middle-income countries.

In recent years (in addition to covid-19), other diseases transferred from animals to humans have gained international attention: Ebola, Influenza or Avian Flu, H1N1 (swine) flu, Middle East respiratory syndrome (MERS), Valley fever Rift, Severe Acute Respiratory Syndrome (SARS), West Nile fever, Zika, and more recently Monkeypox. All of them exhibit diversity of characteristics, even in their mode and speed of transmission; although in common they carry the threat of pandemics. Ebola and SARS have already caused thousands of deaths.

The transfer of pathogens from wild species is particularly frequent these days, and various organizations dedicated to the study and the environment are trying hard to establish connections between the emergence of zoonoses and the abuses to which terrestrial ecosystems are exposed. Human beings, by interacting more and more with ecosystems, generate the bases of a close eliminable relationship between human, animal and environmental health.

The United Nations Environment Program of the United Nations Organization (UN) recognized, in 2020, five main pressures that increase the appearance of zoonoses: deforestation and other changes in land use; antimicrobial resistance; the intensification of agricultural and livestock production; the illegal and poorly regulated trade in wildlife; and climate change.

Intensive degradation activities have also undermined water safety, and with it good hygiene practices aimed at preventing infections. A fresh water supply is essential to prevent the transmission of germs from person to person through hand washing. According to a UN report (2019), some 785 million people still lack safe drinking water, sanitation and handwashing facilities. This same report indicates that “it is unlikely” that full implementation of the necessary water resources can be achieved before the year 2030.

The facilitation of practices such as the trade and consumption of wild animal meat and the promotion of “wet markets” degrade the natural barriers of ecosystems and increase the risk of contact: animal (infectious agent) human being to dangerous limits. This conversion of eating habits has been implicated in the emergence of SARS-CoV-2 from the Wuhan live animal market.

Population growth, its out of control, and climate change are also being cited as important drivers of the emergence of new emerging infectious diseases. The latter; for example; could increase the spread of some disease vector species towards higher latitudes.

The accelerated transmission of covid-19 and the appearance of new worrying variants of the virus in some needy countries were two events closely linked to low vaccination coverage rates. With which, it will not only end direct negative impacts on people, families and local communities in those places; but also created the necessary reservoirs for subsequent transfer to larger populations globally. In an increasingly interconnected world –which seems to clearly act in a negative way–, improved personal hygiene and universal equity in access to medical resources (especially vaccines) would undoubtedly have provided benefits for all and generated a strong wall of containment against the public health crisis unleashed by covid-19.

During 2020, while the pandemic hit humanity, in an attempt to respond to the loss and degradation of habitats, the UN, through its Pnuma Program, demonstrated a report identifying the trends that drive the increasing appearance of zoonoses and provided recommendations to avoid ten new outbreaks of pandemic zoonotic diseases. They tend to set limits to the overexploitation of ecosystems and try to restore humanity’s relationship with nature, promoting their regeneration and caring for the environment as a fundamental investment to prevent human diseases.

The environments described are buffer zones that act as “forest rangers”; separating humans from wild animals; their degradation substantially increases the opportunities for pathogens to spread by exacerbating rather than regulating transmission between species. are due, the changes inflicted on the environment offer opportunities for wild animals to spread into the human environment and eventually generate pandemics.

In addition to scientific and technological efforts, its prevention will affect an enormous collaborative effort by the international community, establishing care programs that will make it possible to efficiently manage the restoration of the capacity of ecosystems. The future of human health depends on its renewability and on aborting degenerative ecological cycles. Caring for the environment is urgent and impossible to avoid future pandemics.

*Medical Specialist in Clinical Medicine and Infectious Diseases. Professor at the Faculty of Biomedical Sciences of the Austral University.

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