Is it the end of the nervous breakdown on avian influenza?

The nervous breakdown on avian influenza that has affected the WHO, the different governments and the largest journals in the world may perhaps end with two articles published in the Journal of Infectious Diseases in May 2015 [1], [2].

Both avian influenza H5N1 and H9N2 have triggered a catastrophic tornado of information like never before [1]. In France, a plan to fight bird flu with vaccine orders and the description of an apocalyptic vision of the next flu epidemic was observed. Indeed, Marseille was supposed to reserve 700 beds in case of a flu epidemic! This terror was justified by the memory of the Spanish flu, although we now know that most of the patients died as a result of bacterial infections [3] and the fact that, as with any infectious disease, from the beginning the first detected cases are only the severe and fatal cases. With regards to H5N1, which is one of the infectious poultry agents that cause large epidemics—despite its discovery in 1997, of only 650 cases diagnosed in humans, 60% died [1]. This led to a dramatization, with vaccine orders and the creation of experimental models to try to predict when a mutant may become transmissible between humans and transform this zoonotic disease into a human disease [4].

The echoes of this in scientific journals were huge and disproportionate [5]. This current work [2] has just confirmed what was noted for several years but had been denied, which is the high occurrence of asymptomatic infection in people who are in contact with infected poultry. This prospective survey in Egypt over 3 years on 1000 people showed that when H5N1 was endemic, 2% of the exposed population had antibodies compared with 0% of controls, and when the epidemic H9N2 appeared in poultry, seroprevalence increased from 0 to 5.6% and 7.5%, all asymptomatic infections. In total the zoonotic variant of H5N1 avian flu and H9N2 is very common in people in contact with poultry; it is banal and most of the time, asymptomatic.

These are not the viruses that will destroy humanity! As I have had several opportunities to say, we do not predict future outbreaks [4]. Experimental models may well confirm certain elements but cannot predict the severity, as seen with H1N1 and as we still see with H5N1 [5]. Transmissibility in the ferret probably has no relationship to transmissibility in humans, in which the virus is probably passed mainly through inanimate objects and hands. It is necessary to regain some common sense for respiratory viruses. It is plausible that the Mers (Middle East respiratory syndrome) coronavirus problem is of the same nature and that only a subpart of the population respond with a clinical infection, perhaps because of genetic characteristics or environmental parameters.

A lesson is to be learned from this episode—it is not necessary to set fire to the planet due to some zoonotic infection, nor to spend billions of euros, nor to create a governmental crisis; ultimately it is ‘much ado about nothing’ [6].