Doctors, scientists, the WHO and all public health organizations keep telling us this. We are on the brink of a devastating global pandemic. The question that no one can answer is that of the source of this expected and almost certain disease. Will it be Ebola, Zika or Nepah? Perhaps it is not these plagues, whose name alone makes us shudder, that we should focus on. A new study that sought to classify the risks of a pandemic reveals that the danger would come from a simple cold. An epidemic spread through the respiratory tract, a priori non-lethal, but caused by an RNA virus, which would spread throughout the world and cause a hecatomb.
Ahe latest data from the World Health Organization (WHO) are conclusive: the probability of a pandemic emergence is increasing. Every day we learn of the existence of a new pathogen, while the world's population continues to grow and the interconnections across the planet are becoming more and more dense. A meeting of parameters that would favour the outbreak and spread of a devastating disease.
According to the World Health Organization, a global pandemic could break out at any time. What disease is it? Could it be a as yet unknown disease that the WHO refers to as "disease X," a mysterious pathogen that has not yet been discovered but whose threat is imminent and seemingly inevitable. It is on the list of the most dangerous epidemics, on a par with Ebola, haemorrhagic fever, respiratory syndrome coronavirus (RSC), severe acute respiratory syndrome (SARS) or the Zika virus.
READ UP : WHO is clear: we are on the brink of a global pandemic.
No one knows where this disease could come from. A multitude of possible sources have been identified. It could be a mutation of an existing virus, a virus that escaped from a laboratory, a terrorist threat. It could also be a zoonosis, an animal-to-human transmission. 70 % of the recently discovered diseases came from animal sources, whether domestic or wild. This is the case of Ebola but also the HIV virus.
"Global Catastrophic Biohazard"
A team of scientists from the Johns Hopkins Center for Health Security has just shed new light on this mystery. They have published a report titled " The Characteristics of Pandemic Pathogens,« which provides a framework for identifying naturally occurring microorganisms that pose a "global catastrophic biohazard" (GCBR in the terminology of public health experts).
GCBRs" are events in which biological agents could lead to a sudden, extraordinary and widespread disaster beyond the collective capacity of national and international governments and the private sector to control it. There is no comprehensive catalogue of GCBR culprits, forcing the health security community to rely only on historical examples (such as the 1918 Spanish Influenza) to guide its preparedness priorities.
Yet Dr. Amesh Adalja, project leader and senior researcher at the Centre warns: " Health security preparedness must be adaptable to new threats and not be based exclusively on historical concepts. ». Another pitfall to be avoided, scientists say, is that of focusing on viruses with a high mortality rate such as Ebola or Zika. As soon as they appear in any part of the world, a general uproar is mobilized to fight them. On the other hand, their high mortality rate works against them. By killing their hosts, these viruses are usually driven to extinction before the pandemic stage. The fight against these terrible diseases should not be neglected, but researchers at the John Hopkins Center fear that this may miss the real danger presented by "secondary" diseases which, with the help of a few mutations, can become potentially pandemic.
Researchers are thus breaking down a preconceived idea: the next pandemic will not come from a virus with a high mortality rate, but from a banal virus, the family of those that assail us in winter, such as rhinoviruses, for example. They are not very deadly, but their pandemic potential is enormous. Indeed, the authors point out that in order to destabilize governments, the economy, societies, and all health organizations, mortality is less important than a very high rate of people who are sick at the same time. There is evidence that a virus that is not very deadly but highly contagious, especially through the airways, can eventually cause a mass death. This was the case with the Spanish flu (H1N1) which occurred between 1918 and 1919. The virus had a mortality rate of only 2.5 %. Yet its transmission in the air allowed the contagion of hundreds of millions of people worldwide, leading to more than fifty million deaths.
Pandemic agent profile
To reach this conclusion, the researchers led by Amesh Adalja reviewed the literature and published reports on the characteristics of emerging infectious diseases, the pathogenic potential of a host of microorganisms: bacteria, fungi, prions, viruses, protozoa, etc.; interviewed more than 120 technical experts from academia, industry and government; and finally convened a meeting of a subset of these experts to discuss the preliminary analysis of the information gathered by the team. The result is a profile of the future pandemic agent.
Its mode of transmission, the team concluded, will most likely be respiratory. It will be contagious during the incubation period, before the onset of symptoms, or when infected individuals show only mild symptoms. Finally, it will require factors specific to the host population (e.g. people not immune to it) and other characteristics of intrinsic microbial pathogenicity (e.g. a low but significant case-fatality rate), all of which together greatly increase the spread of the disease and infection. Among the criteria, the researchers add that this pathogen is distinguished by the fact that no direct treatment or prevention method exists to date against it.
Among all the bestiary of microbes that researchers have analyzed, they distinguish one particular family: RNA viruses. They are the great threat. These viruses, which have no DNA but only RNA, have a high potential for mutation. Most of them are familiar to us, causing our colds, respiratory ailments and other seasonal flues.
The great pandemic that is expected would therefore come from a virus that is apparently benign but mutates easily to acquire maximum nuisance power. In possession of this sketch, the authors of the report call for a different perspective in our strategies to fight epidemics. The mistake that many have made in recent years has been to focus on certain high-profile RNA viruses such as SARS, for example. As a result, no one was interested in viruses that were not being noticed. Researchers therefore recommend that surveillance of human infections caused by RNA viruses of respiratory origin be made a high priority. Clinical research programs aimed at optimizing the treatment of respiratory RNA viruses should be better funded. Finally, the authors of the report call for increased priority to be given to research on vaccines against respiratory RNA viruses, including a universal influenza vaccine.
READ UP : Are we prepared for a major pandemic? Nothing is less certain.
Anything to add? Say it as a comment.
