Bird flu and animals

Poultry is extremely sensitive to the virus, in particular chickens and turkeys. Quail, pheasant and partridge are also sensitive to it.

The role of vector of the illness may be played by wild and migratory birds, more particularly ducks, geese, swans, storks, cormorants, birds of prey and so on.

Web-footed birds, such as ducks and geese, are less sensitive to bird flu, but can play the role of healthy carrier and disseminator of the virus. The same applies to pigeons.

Cage and pet birds, like psittacidae and canaries, are not very sensitive to the illness.

Among mammals, it is above all the pig which can be a carrier of the virus without presenting any signs of the illness. Sensitive to various subtypes of the bird flu virus, the pig could at worst play the role of genetic "mixer" and consequently represent a risk of transmission of the illness to a human.

It cannot be excluded that in exceptional cases, cats could also be infected by the subtype H5N1, as shown by certain instances of cats carrying the virus. However, even in the case of infection, it has still not been proved that a cat could transmit the virus to a human.

The bird flu virus is essentially transmitted

• by air;
• by direct contact with the respiratory secretions or excrement of infected animals;
• by exposure to contaminated material (food, water, equipment and clothes).

Among birds, there are more than one hundred identified subtypes of the bird flu virus. Bird flu is caused by the type A flu virus (Influenzavirus) which has 16 subtypes H and 9 subtypes N. Bird flu viruses which are slightly pathogenic may belong to each of the 16 subtypes H, whilst highly pathogenic viruses can only belong to subtypes H5 or H7. Subtype H5N1, which is particularly virulent, is responsible for the current epizootics and casualties.

The continents affected by bird flu in animals are Asia, Europe and Africa, Asia being the first affected on a massive scale.

Four principal ways are to be taken into account:

• there could be a risk of introduction by migratory birds if they come from contaminated regions;
• illegal imports of birds living in countries infected by bird flu;
• bird products originating from countries where the virus is rife, such as:
  • poultry meat, eggs;
  • basic poultry meat products;
  • bird trophies, bird feathers, etc.
• material and objects which have been in contact with infected animals.

In order to avoid illegal imports, checks have become stricter at the international airport (Findel) for passengers arriving from bird flu risk zones.

It is now the responsibility of everyone to ensure that the bird flu virus is not introduced into the Grand Duchy of Luxembourg.

The bird flu virus has a life span which differs according to meteorological conditions. It is more active in a cold and damp environment than in a warm and dry one. At a temperature of 4 °C, the resistance of the virus is 35 days, and at 20 °C its resistance is seven days.

The activity of the virus is at a maximum from November to March. (Source: World Organisation for Animal Health [OIE])

The life span of the bird flu virus depends upon meteorological conditions. In a cold and damp environment it is more active than in a warm and dry one.

Among poultry

The illness may be instant in that death occurs without any apparent clinical signs.

The clinical signs most frequently observed are:

• loss of appetite,
• exhaustion,
• decline of egg laying,
• swollen head and sinus,
• watering of the eyes,
• swelling of the comb and caruncle,
• respiratory difficulties.

The subtype H5N1 of the bird flu virus is extremely aggressive and may cause mortality of almost 100% in the space of 48 hours among poultry.

Among web-footed birds

The signs are less constant and slower to appear, and in general nervous signs are predominant.

In a flock of poultry or web-footed birds, there is a risk of bird flu being present if there is:

• a more than 20% reduction of food consumption;
• a mortality rate of more than 3% a week;
• a decline in egg laying of more than 20%.

However, as the clinical signs and the evolution of the illness are variable, a laboratory diagnosis is essential.

In general, the advice at present is not to feed wild aquatic birds, the aim being to limit to a maximum any direct contact with birds and their excrement.

Where it proves vital to feed these birds, the food should be thrown onto the surface of the water and not on the banks, so as to avoid fouling those sites already soiled by bird excrement.

Winter feeding should be limited to periods of intense cold. If food is too abundant, there is a risk that wild aquatic birds will lose their ability to feed themselves.

In general, there are some basic arguments against feeding ducks and swans:

• on the one hand, shallow water is fouled more rapidly by the introduction of food and, on the other hand, birds lose the aptitude to search for food themselves.
• badly maintained feeders are a source of all sorts of contamination for birds.
• birds are constantly excreting all sorts of germs.

After any contact with wild birds or their excrement, it is highly advisable to observe elementary hygiene rules and to wash one’s hands with soap and water.

Migration season takes place twice a year, from South to North in spring and from North to South in autumn.

In spring, the season usually begins at the end of February and ends for the great majority of migratory birds around mid-May. In automn, it starts about mid-September and normally ends about mid-December.

Ornithologists are of the opinion that Luxembourg is not on a principal migration route. There could however be a risk of the virus being introduced by migratory birds which cross our country if they originate from contaminated regions.

France and the Netherlands have been the first two countries to participate in a pilot project to vaccinate certain species of poultry, on the basis of recommendations from the European Commission and the agreement of veterinary experts from the European Union dated 22 February 2006 authorising preventive vaccination. Since then, the European Commission has authorised other countries, on request, to proceed to vaccination campaigns against bird flu. A later scientific assessment will enable conclusions to be drawn on the advantages/disadvantages of such a campaign of preventive vaccination.

In the case where vaccinated poultry is infected by the bird flu virus, it would present fewer or no clinical signs at all of the illness. It would continue however to excrete the bird flu virus, thus representing a source of infection for animals and humans.

The bird flu situation has calmed down in Europe these last months. In South-East Asia, in Egypt and in some other African countries, this highly pathogen illness in poultry is still responsible for a high mortality rate in the poultry breeding sector. It has also caused on rare occasions the death of human beings having been in direct and intense contact with infected poultry.

The important bird migrations taking place at the approach of the warmer season may possibly spread the bird flu virus. The Administration des services vétérinaires (Veterinary Services) and the Lëtzebuerger Natur- a Vulleschutzliga (Luxembourg League for the Protection of Nature and Birds) monitor, in close collaboration, the health state of these migratory birds by means of laboratory tests. The migrations of wild birds generally last until the end of April.

During this period, the following precaution measures regarding domestic poultry should be respected:

• avoid any contact between domestic poultry and wild birds, especially aquatic birds.
• always dispense food and drinking water inside the poultry shed, and if outside, it should at least be sheltered from wild birds.
• purchase poultry only from recognised breeders, who can produce an official health certificate.
• monitor the health of poultry very closely and contact a vet in the event of signs of illness.
• gatherings of birds and bird shows can only take place under the medical supervision of a vet.

Any discovery of several dead wild birds in a restricted area is to be reported to the Administration des services de secours (Emergency Services) by dialling telephone number 112.

It is to be noted that there has not been any case of bird flu in Luxembourg and that the laboratory tests carried out until this day have not revealed any presence of the bird flu virus.

For any further information, the Veterinary Services can be contacted at the following telephone numbers: 247-82539 and 247-83533.

Generally, good operational hygiene is the first measure to be put in place to avoid introduction of the virus.

The following measures are to be applied at a minimum:

• place disinfection facilities for footwear at the entries and exits to poultry houses;
• use hygiene screens and clothes belonging to the farm;
• forbid any outside person entering poultry houses;
• keep a register of all people entering poultry houses.

Confinement measures generally apply only to poultry, geese and ducks.

Until now no case of infection of a dog by the bird flu virus has been documented. This does not however alter the fact that in the event of bird flu appearing it will be necessary to keep dogs under control in risk areas. Furthermore, it is helpful to recall that dogs are to be kept on their leash in order to avoid any unnecessary contact with dead birds.

Despite the fact that cats have been infected by the bird flu virus, it is not known whether they are very susceptible to infection. In general cats catch passerine birds which are not very susceptible to the bird flu virus, like songbirds in general. Furthermore, in principle domestic cats do not eat dead birds.

Until now no case of bird flu has been detected in Luxembourg. At present, therefore, there is no immediate danger either to pets or to humans.

In general, it should be recalled that dogs should be kept on their leash to avoid any unnecessary contact with dead birds.

In the event of an outbreak of bird flu on Luxembourg territory, it is vital that in risk areas cats and other pets are kept indoors, under the owner’s control.

There are tests which enable rapid diagnosis of the presence of the bird flu virus in animals. More comprehensive laboratory analyses are necessary however to specify the type of virus.

Bird flu is an animal illness found throughout the entire world and known for more than a century. It is caused by the type A flu virus which affects all species of birds and in addition some other animal species.

Since 1997, when human cases of bird flu were diagnosed in Hong Kong, it has been known that the bird flu virus can also infect humans under exceptional circumstances.

The bird flu virus is transmitted from animals to humans by air, essentially through close, prolonged and repeated contacts in confined spaces with the respiratory secretions or excrement of infected animals, or by exposure to contaminated surfaces or materials.

After discovery of the bird flu virus on Luxembourg territory, the competent authorities will at once take all measures necessary to curb the spread of bird flu.

The emergency measures provided by the European Community for the case of a wild bird being infected by the H5N1 virus are as follows:

• a reinforced "protection zone" will be implemented 3 kilometres around the place where the body of the bird was found, for a period of 21 days;
• this will itself be surrounded by a "surveillance zone" 10 kilometres around the place where the body of the bird was found (including the protection zone), for a period of 30 days.

In principle, the following measures will be applied (for a minimum period of 21 days):

• Identification and inventory of all poultry farms;
• Regular visits by a veterinary inspector to all commercial establishments;
• Obligatory confinement of poultry and other captive birds, unless there is an exemption;
• Confinement of cats;
• Surveillance of dogs;
• Ban on feeding wild aquatic birds;
• Collection of dead birds by the Emergency Services;
• Laboratory analysis of all wild birds found dead;
• Limitation of traffic in the protection zone;
• Residents in and visitors to the protection zone must pass through disinfection installations in order to leave with their vehicles;
• Ban on fairs, markets and exhibitions;
• Ban on hunting wild birds.

The following measures will be applied for a minimum period of 21 days:

Poultry owners:

• must take measures of confinement of their poultry as far as possible;
• must avoid any contact between poultry and wild birds;
• cannot take poultry out of the protection zone, unless the Veterinary Services so authorises;
• will be obliged to provide means of disinfection at entries and exits to poultry houses;
• cannot spread the manure and slurry from poultry houses on the fields, unless the Veterinary Services so authorises;
• can only take eggs out of the protection zone after authorisation by the Veterinary Services;
• must have poultry examined by a veterinary official prior to any slaughtering of non-confined poultry;
• must ensure the hygienic handling of poultry eggs and meat originating from within the protection zone.

In principle, the following measures will be applied (for a minimum period of 30 days):

• Identification of all poultry farms;
• Ban on feeding wild birds;
• Collection and laboratory analysis of all wild birds found dead and collected by the persons responsible at the Emergency Services;
• Ban on fairs, markets and exhibitions;
• Ban on hunting wild birds.

The following measures will apply for a minimum period of 30 days.

Poultry owners:

• must take measures of confinement of their poultry as far as possible;
• must avoid any contact between poultry and wild birds;
• can only take poultry out of the surveillance zone after the official veterinary inspector so authorises;
• can only take poultry meat out of the surveillance zone after the official veterinary inspector so authorises;
• will be obliged to provide means of disinfection at entries and exits to poultry houses;
• cannot spread the manure and slurry from poultry houses on the fields, unless the Veterinary Services so authorises;
• must have poultry examined by the official veterinary inspector prior to any slaughtering of non-confined poultry.