The world is not getting ready to stop future pandemics at their source, an error that makes no sense even from an economic point of view: it would be 20 times cheaper to opt for prevention than to bear the costs, in lives and money, brought by diseases. emerging.
The calculation, made by a multidisciplinary team of researchers, takes into account what is needed to invest so that the infectious diseases of the future are identified and fought before they leave their main source: wild animals and, to a much lesser extent, domestic animals.
In fact, as shown by those responsible for a new study on the subject, which has just appeared in the specialized journal Science Advances, practically all pandemics since the beginning of the 20th century have emerged as zoonoses.
In other words, diseases that jumped from animal hosts — mainly wild ones — to the human organism. This is the case with the Spanish flu of 1918-1919, with AIDS and, most likely, with Covid-19 (although the hypothesis that the virus, originally coming from an animal, may have “escaped” from a laboratory).
This means that the so-called primary prevention of pandemics needs to be done by mapping the diversity of pathogens (disease-causing), especially viruses, that affect wild animals.
In addition, this mapping needs to be accompanied by measures capable of mitigating the main factors that have put the human population in increasingly intense contact with the hosts of future pandemic diseases.
Among these factors, deforestation, the advance of agricultural frontiers and the trafficking of wild animals stand out (in the latter case, the commercial breeding of these species in captivity also contributes to the problem).
The point is that, even after the advent of Covid-19, some of the main international organizations, such as the WHO (World Health Organization) and the World Bank, speak only of investment in vaccines, medicines and diagnostic tests to face pandemic threats from the world. future. These investments are critical, but could end up being the equivalent of crying over spilled milk if there isn’t a greater focus on the processes that lead to a pathogen emerging as a threat.
“The response to pandemics is largely in the hands of extremely capable scientists, biomedicalists and doctors, who may not be familiar with the means of primary prevention,” says Brazilian demographer Marcia Castro, a researcher at the School of Public Health at Harvard University (USA), co-author of the study and columnist for the leaf.
“Prevention is always better and cheaper than cure. And the return on investment in prevention goes beyond the health benefits of the population, as it also benefits the environment and economic growth. What we did is to quantify this argument “, she explains.
Using data on zoonoses outbreaks (and the pandemics that can be derived from them) over the last century, Castro and his colleagues estimated the annual cost of lost lives and damage to the economy caused by these diseases. (While it may seem strange to estimate how much a person’s death “costs,” it is something routinely quantified by economic agencies and governments.)
On the most conservative (that is, less “spending”) account, the cost of these deaths would be $350 billion annually. The average loss of GDP (Bruno Domestic Product, roughly equivalent to the sum of wealth produced by a society) linked to these diseases per year would be US$ 212 billion.
And how much would it cost to tackle the problem at the source, before the arrival of new viruses in the human organism?
In this account, the researchers included investments in tracking wild animals in search of potentially dangerous pathogens, strict control and monitoring of trafficking in these animals (today one of the main sources of income for organized crime) and programs to reduce deforestation, especially in countries tropical countries like Brazil.
Taken together, these actions would cost $20 billion a year — less than one-twentieth of the total costs of zoonotic diseases, or one-tenth of the impact they have on global GDP.
Most important, the team says, is much more careful observation and control of human-wildlife interactions, and of the economic and social forces that are driving the increase in these contacts. That’s why it doesn’t make much sense to think that Covid-19 would have been “created in a lab”.
“The data clearly show that the vast majority of emerging viral diseases did not arise in research laboratories, but from accidental transmission from animals to humans”, says Mariana Vale, a researcher at the Department of Ecology at UFRJ and also a co-author of the study.
“Laboratory accidents can happen, of course, but the probability is very small compared to that associated with the thousands of people who come into contact with wild animals daily in the rainforests because of the commercialization for the pet, bushmeat and traditional medicine markets. In the state of Amazonas alone, 10,700 tons of game meat are sold per year, according to a 2020 study”, she exemplifies.
In fact, the size of this market and the magnitude of deforestation in Brazil leaves a frightening question in the air: why hasn’t a pandemic started here yet? “Raw material”, strictly speaking, is not lacking.
Monkeys, rodents and bats are the main reservoirs of zoonotic viruses. In the case of these three groups of animals, Brazilian biodiversity is among the largest in the world. And the diversity of viruses usually follows that of animals.
“I think that [não aconteceu ainda] because God is Brazilian”, jokes the researcher.
“As the Amazon still has about 80% of its forests, this reduces the probability of emergence and also the spread of new diseases. It is quite possible that viruses passed from wild animals to humans, causing deaths, but never reached spread because the victims lived in isolated places. But as deforestation increases, of course, the likelihood of a new disease emerging also increases.”
Another possible element is the fact that viruses from South American bats appear to be less easily transmitted to humans than those from Old World bats — and, as is well known, viral pathogens in flying mammals are linked to a number of emerging diseases, such as Ebola and Covid-19 itself.
Source: Folha
