Risk in France:

 

It can’t be denied: with the avian flu in Europe and in France, it is no longer an "exotic" disease! It seems the risk will be at its greatest when migrating birds return to our regions or stopover on our shores.

 

Our surveillance networks and epidemic/epizootic monitoring systems are more advanced than those in developing countries, which gives hope of a limited number of outbreaks in our country. Unfortunately, limiting outbreaks involves protective measures and, in some cases, slaughter. Although often viewed poorly by the general population, these measures are essential to limiting the spread of animal diseases. And even more so when the wild and migrant animal population cannot be controlled.

 

Unfortunately, the virus is very sensitive in the environment and can be spread by other less sensitive animals or inert carriers (vehicle wheels, shoe soles, etc.).

 

Everyone is a potential agent: professionals of course, hunters, hikers who find a dead bird, wandering pet owners (with cats and dogs) — and even journalists could be responsible for a passive spread of the virus since the first outbreak in Versailleux in the Ain department.

 

Falling into paranoia would be senseless: it is crucial to act responsibly and to scale up hygienic and disinfecting efforts.

 

H5N1 virus:

 

Flu viruses (human, equine, porcine and avian) constitute a family. They are characterised and differentiated by their surface proteins, including hemagglutinin (H) and neuraminidase (N). Each pathogen subtype therefore has a hemagglutinin -- different and numbered from 1 to 15 -- and a neuraminidase -- different and numbered from 1 to 9. The virus currently responsible for avian flu is the H5N1 subtype. Infectious human influenza viruses are the H1N1 and H3N2 subtypes.

 

The H5N1 virus is very slightly contagious to humans and is not specific enough to the human species for a human-to-human transmission. Yet another feature of these viruses is their instability, which leads to mutations or fusions of genetic material. This is how H5N1, slightly contagious to humans but highly pathogenic, could merge with an ordinary H3N2-type virus that is low pathogenic but highly contagious. Thus a new virus would appear that is highly contagious and highly pathogenic for humans. It is this type of hypothetical scenario that everyone fears and that caused the Spanish flu epidemic of 1918.

 

Fortunately, there are few cases of confirmed human contamination. They affect fragile populations: children or the elderly, weakened by intercurrent or immuno-deficiency diseases and especially those who have had close and prolonged contact with infected poultry.

 

The disease:

 

Symptoms are rough. They vary depending on the affected species. A brutal death with a predominance of nervous and respiratory symptoms confirms the suspicion; but only a laboratory diagnosis with the determination of subtype will allow a firm conclusion.

 

Measures to take:

 

The measures taken (which can change from one day to another depending on the context) aim to limit the number of contaminated birds and therefore the still-weak risk of contamination for humans.

 

The ultimate goal is to limit the virus to the wild in a low pathogenic form. In the present scenario, the pathogenicity of the wild virus has amplified in several mixed species. The wild virus is becoming highly pathogenic and penetrating industrial populations.

 

In practice, the first step is to ban all bird gatherings (markets, exhibitions, competitions, etc.). The second step is to confine birds, when feasible, by:

 

- isolating buildings (air intake grills);

- removing feeders and drinking troughs in outdoor breeding farms and if possible removing all food on the ground;

- installing isolation fences and nets in outdoor breeding farms.

 

These measures are supplemented by total seclusion in at-risk wetlands and French departments with high breeding populations (40, 44 and 85). Vaccination is provided for species that could not be placed in confinement and living in at-risk wetlands in these departments. These measures are also applicable at small breeding farms after a census at town hall (mandatory as of 6 March 2006).

 

Other sanitary measures have been and will be applied in outbreak areas:

 

- protection zone of a 3-km radius around the area;

- complemented by a 10-km surveillance zone;

- associated with a ring-fenced vaccination zone to stop the spread of the virus.

 

Remember that these measures must remain in effect until the return of migratory birds from Africa and the Middle East in spring 2006.

 

And for parrots?

 

Our parrots, even if they are sensitive and can be infected by the virus, have a very low risk of contamination. For the time being, they should remain inside. If not feasible, aviaries should be protected from the droppings of migratory birds (simple sheets acting as a roof). Drinking troughs and feeders should not touch the ground. It is imperative to disinfect outdoor aviaries with city water; the use of water from a natural or artificial reservoir is prohibited.

 

Around an affected area, access to rooms that house birds should be regulated and limited only to people who are essential to their daily care.

 

In such a situation, the use of a foot bath for shoes worn outside or of overshoes is highly recommended.

 

When a large number of birds, especially rare species, is present (in a sanctuary, park, zoo, etc.), preventive vaccination is advised and possible after formal request submitted to the Veterinary Services Department. The terms of this vaccine are still being defined and require denial of contact with domestic poultry or wild birds. 

 

Article written by Veterinary Physician Pascal Perronin