Bird flu and man

Although bird flu is an animal illness which affects all species of wild or domestic birds as well as other animal species, in exceptional circumstances the bird flu virus can also be transmitted from animals to humans.

The bird flu virus is transmitted from animals to humans by air, essentially when there are 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. Exposure occurs above all in the slaughtering, plucking, butchering and preparation of poultry prior to cooking.

In the European Union, where contact with animals is generally not as close as in Asia, no case of transmission of the H5N1 virus to humans has yet been diagnosed.

The current subtype H5N1 of the bird flu virus is not very infectious to humans: out of millions of people who have been in close contact with infected birds, especially in Asia, there have been 650 cases of human infection so far, of which 386 have resulted in death. The first documented cases of transmission from animals to humans date back to 1997 in Hong Kong. For updated figures please consult the list of confirmed human cases of bird flu by the World Health Organisation.

(State of knowledge as at 24.1.2014)

The first documented case of human infection by the bird flu virus (subtype H5N1) dates back to 1997, in Hong Kong.

18 people were affected by a severe respiratory ailment, and six of them subsequently died. That infection in humans coincided with a highly pathogenic bird flu epizootic among poultry in Hong Kong.

In-depth surveys revealed that those human infections were due to close, prolonged and repeated contacts with live poultry infected by the bird flu virus.

Since 2003, 650 people have contracted the bird flu virus (subtype H5N1) and 386 of them have died. The World Health Organisation regularly updates the list of confirmed human cases of bird flu.

(State of knowledge as at 24.1.2014)

Cases of disease and death among humans due to bird flu have occurred in a number of countries of Asia and Africa. Among the latter are several popular holiday destinations like China, Thailand, Indonesia, Vietnam and Cambodia, but also Turkey and Egypt.

A world map by the World Health Organisation presents a complete summary of the countries affected by bird flu in humans.

At first, the illness appears to be seasonal flu with clinical signs such as a fever higher than 38°C, sore throat, muscular pains, respiratory difficulties and cough. Infection by the bird flu virus (subtype H5N1) causes a rapid aggravation of the patient’s state of health.

There are tests which enable rapid diagnoses to be made of the presence of the bird flu virus in humans. More comprehensive laboratory analyses are necessary however to specify the type of virus and to know whether the human infection has been transmitted by an animal or another person.

Until now, in very rare cases, it has not been possible to exclude human-to-human transmission of the H5N1 virus, but taking account of the information currently available, there is no proof of lasting human-to-human transmission.

If the body of a bird is found, it should under no circumstance be touched. Any discovery of a dead aquatic bird (swan, goose, duck) or a bird of prey is to be reported by dialling telephone number 112.

The discovery of other dead birds is also to be reported by dialling 112 when

• the number of dead birds found within a radius of 500 metres is significant, namely four or more;

AND

• no clear cause of mortality has been established.

At the present time, there is no immediate risk of infection either to children or to adults.

Nevertheless, the applicable measures are to be observed most particularly by children who, by playing in the open, in parks and in public places, could find the body of a bird. It is important to draw childrens’ attention to the fact that they must under no circumstances touch the bodies of birds or other animals, or their excrement. It is clear that places severely soiled by excrement are not suitable places in which to play.

For reasons of prevention, the authorities recommend avoiding any contact with wild aquatic birds, whether dead or alive, or their excrement. For that reason, it is also ill-advised for children to feed wild aquatic birds.

Children must be reminded of elementary hygiene rules, in particular frequent washing of one’s hands with soap and water.

At the present time, there is no immediate risk of infection either to children or to adults. It is clear however that places severely soiled by excrement are not suitable places in which to play. Here too, washing one’s hands with soap and water is vital in the case of contact. This is all the more true near ponds or lakes and alongside watercourses or where there are aquatic birds like swans, geese, ducks and so on.

Travellers who visit areas affected by bird flu are recommended to take the following precautions:

• Avoid any contact with live or dead poultry and poultry excrement. This also applies to apparently healthy domestic or wild ducks.
• Do not visit poultry farms, bird markets, zoos or farms in regions affected by bird flu.
• Wash their hands frequently with soap and water or disinfectant.
• Only consume thoroughly cooked poultry meat and eggs.
• Heed current import requirements and do not bring any birds, poultry meat, eggs, feathers, hunting trophies or other poultry products back from their journey.

The bird flu virus can be suspected in humans:

• if during the journey in an affected country there has been contact with live or dead poultry

AND

• if within the first ten days after the return the following symptoms show up: fever higher than 38°C, coughing, breathing difficulty, neck and muscle pains.

In such cases a doctor is to be consulted immediately!

Poultry, poultry products and eggs on sale are supervised by the competent veterinary services. Eggs cooked at a temperature of 70°C present no danger when consumed.

Liquid or dried egg-based products (egg yolk, egg white, whole eggs) used for industrial purposes undergo thermal treatment to eliminate all germs.

In accordance with a European exemption, eggs from such farms may still be sold as free-range or organically produced only if the confinement has been ordered by the authorities and for a limited period of time (three months).

Poultry, poultry products and eggs on sale are supervised by the competent veterinary services which undertake anything possible to ensure food safety.

In any circumstance, consumption of poultry meat poses no risk, provided it is well cooked. The inside of the meat must have reached a temperature of at least 70°C throughout (the bird flu virus is destroyed by cooking at this temperature for five minutes).

This does not alter the fact that elementary hygiene standards should still be observed, such as ensuring the cleanliness of cooking utensils and washing one’s hands with soap and water before and after handling the meat.

It is advisable to wash one’s hands carefully with soap and water after handling raw and/or defrosted poultry meat or raw eggs. The same applies to surfaces and cooking utensils.

Feathers used in duvets, pillows and so on do not represent a danger, because they are cleaned during preparation, and this destroys any bird flu virus should it be present.

An antiviral medicine is used in case a person has contracted an illness caused by a virus. The antiviral medicine is administered when the first clinical signs of the illness appear. The medicine has a curative effect, as opposed to a vaccine, which has a prophylactic effect.

The vaccine is a substance prepared in advance and inoculated into people to avoid their contracting an illness caused by microbes, viruses or parasites. That person’s body then develops immunity to the corresponding germ.

At the present time, there are two antiviral medicines which enable the seriousness and length of seasonal flu to be reduced: Tamiflu® and Relenza®.

In the case of infection with the bird flu virus, these medicines could improve the survival chances of an infected person, provided they are administered within a period of 48 hours.

In the absence of a vaccine, antiviral medicines are currently the only means of protection beyond the hygiene measures and precautions to be taken in normal circumstances.

There is no point at present in taking antiviral medicines (Tamiflu®, Relenza®) for prophylactic purposes.

If they are not administered correctly, these medicines can have significant side effects. They can even create resistant strains and thus lose their effectiveness in the event of a flu pandemic.

The current seasonal flu vaccine does not protect against the bird flu virus.