- Maria Blasco Marhuenda
- The Conversation*
A determining milestone in the advancement of human civilization has been to recognize that diseases do not respond to a supernatural origin or are the result of “bad airs”, but rather have a tangible and real origin.
And that only knowing this origin can we prevent and cure them.
A paradigm of this milestone has been infectious diseases, because in this case the first step to combat them has always been know their origin, the pathogen that produces them.
The year 2020 will go down in history by covid-19 pandemic, showing that infectious diseases are not a thing of the past and that they can even help us to be more effective in biomedical research.
Robert Koch, a German physician and father of microbiology, established the scientific methodology to identify which were the agents that caused infectious diseases -also called communicable- and thus be able to combat them.
These are Koch’s postulates, which indicate that in order to find the pathogen that causes a disease, the following facts must be met:
- The pathogenic organism must be in sick people and not in healthy people.
- It must be possible to extract it from a sick person and grow it in a laboratory.
- The isolated pathogen must be capable of reproduce the disease when introduced into healthy people.
- People infected with this pathogen have to develop the same symptoms than the sick people from whom the pathogen was originally isolated.
In the case of the Spanish flu of 1919-1920, the infectious agent was never known that caused the disease despite the efforts of a few scientists in the US, France and Germany.
They applied Koch’s postulates to isolated strains of bacteria of sick patients who thought they could be causing the disease.
It wasn’t a bacteria
However, the isolated bacteria did not comply with Koch’s postulates and, therefore, had to be ruled out as the origin of the Spanish flu.
Not knowing the germ that produced the Spanish flu, no effective treatments could be developed no vaccinations.
The pandemic caused some 40 million deaths all over the world.
We now know that the causative germ was not a bacterium, but a virus, the influenza A virus, subtype H1N1.
The case of HIV
When a little more than half a century later the AIDS as a strange cancer that affected homosexuals, scientists Robert Gallo and Luc Montagnier were the protagonists of a race full of intrigue to be the first to isolate the pathogen that causes the disease.
They knew that the only way to control aids pandemic was to find the pathogen that produced it.
Luc Montagnier and his team did this two years later, isolating the HIV these.
Until then, the life expectancy of an AIDS patient was just over two years and patients developed severe breathing problems and skin tumors called Kaposi’s sarcoma.
No treatment aimed at curing these pathologies was able to stop the fatal course of the disease.
Only when the HIV virus was identified was it possible to find out how the disease was transmitted, how infected people could be detected to avoid transmitting it to other people.
But above all, it allowed for effective treatments that today save the lives of tens of thousands of people.
The identification of SARS-CoV-2
If in the case of AIDS it took two years to find out the infectious agent that caused the disease, in the case of the new pneumonia in Wuhan (the covid-19) was a matter of weeks.
Chinese scientists, including the virologist from the Wuhan Center for Virology Shi Zengli, described that it was a new coronavirus, el SARS-CoV-2.
It was very similar to the one that caused the SARS disease and also discovered by Zengli.
Knowing the pathogen that caused covid-19 made them almost immediately begin to try treatments that could block your entry in cells or their ability to multiply.
Just a few months later they were testing various vaccines and not before the end of the year some countries have already started vaccinating vulnerable groups.
Likewise, dozens of new treatments are being developed to block the entry of the virus into cells, to block its ability to multiply and to treat the effects of the virus in the body.
Undoubtedly, it will be the advances in research that will achieve that let’s overcome the global crisis produced by this new virus.
We are not mistaken if we affirm that the control of infectious diseases has been the greatest revolution of mankind or at least the one that has had the most impact on our lives and, therefore, on the advancement of the 20th century.
The Life expectancy at birth in Europe he was a little over thirty years old.
This was due to a very high infant mortality and the risk of dying was high at any time in life; a simple bacterial infection could make us seriously ill and die.
To what extent can we apply what we have learned from the control and treatment of infectious diseases to the treatment of other types of diseases, many of which are incurable today?
In the 21st century, the increased risk of death in developed countries is concentrated in the last decades of life and is mainly caused by diseases associated with the aging process of the organism.
These diseases include most of the adult cancers, degenerative diseases of different organs (lung, kidney, liver, etc.) and neurodegenerative, as well as cardiovascular diseases, among others.
The incidence of these diseases is increasing in a very significant way due to the demographic aging of the population.
For example, in Spain in 2050 more than a third of the population will be over 65 years old.
Although many of these diseases have been studied for decades, they still it has not been possible to prevent or cure them with effective treatments and this is in contrast to the success achieved with infectious diseases.
Many researchers think that the reason why these diseases have not been controlled is that their origin has been ignored, which in this case is not a virus or bacteria, but the process of molecular aging of the organism.
The situation would be analogous to when the tumors of patients with AIDS were treated, but the disease continued to progress and patients died, since the origin, which was HIV, had not been eliminated.
Therefore, as long as treatments based on prevention and slowing down or elimination of the process of cellular aging, we will not be able to prevent and cure most of humanity’s diseases.
During the last twenty years it has been discovered what some of the molecular origins of aging.
It has also been shown in animal models that delay aging and, with this, delay the appearance of associated diseases, including cancer.
In a similar way to Koch’s postulates to control infectious diseases, demonstrating the molecular origin of a non-infectious disease would be the only way to prevent or cure it.
To some extent this has already happened in the case of cancer.
Cancer patients are currently being treated based on the origin of their tumor, based on the gene or genes altered in that particular tumor.
Thanks to this, it is being achieved decrease mortality in many types of cancer until then incurable.
Preventive treatments to block the harmful effects of mutations could be a way to prevent tumors associated with these alterations.
Half a century later
The next step would be to cure degenerative diseases of aging using therapies aimed at reversing or stopping molecular aging.
If these strategies are successful, it is very likely that we will enter the next great revolution of mankind.
And it would be analogous to the one that occurred in the twentieth century with the control of infectious diseases and that doubled or tripled life expectancy at birth.
On this occasion, the increase in life expectancy in good health could be even more significant.
Richard Feynman -nobel of Physics in 1965- said that we are at the beginning of the evolution of the human species.
That can certainly change if we are able to control all diseases.
* María Blasco Marhuenda is director of the National Center for Oncological Research, National Center for Oncological Research CNIO.
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Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.