Can down and feathers transmit avian influenza?
- The influenza virus needs a living host in order to be able to survive. Down and feathers, however, are no such living host.
- Before down and feathers are used as a filling for bedding, they are thoroughly washed and dried at a temperature of over 100° C or 212° F.
As all influenza viruses, the H5N1-virus belongs to the group of enveloped viruses. It is enclosed by a lipid envelope, or a mantle of fat. If this envelope is damaged, the virus loses its infective power. It is particularly sensitive to dryness and heat. It will neither survive long periods of dryness nor heat. This is why the virus cannot survive any treatment which is applied at temperatures above 100° C or 212° F.
The avian influenza is a highly contagious viral disease, which affects primarily chickens and turkeys, but also wild birds.
Johannes Bhakdi, professor at the Institute of Medical Microbiology and Hygiene at the Johannes Gutenberg University in Mainz considers the import ban on birds to be “still acceptable”, that on feathers, however, “completely crazy and beyond any scientific comprehension”. “The feathers have been washed and dried, and they have furthermore been in transit for several weeks before reaching this country. It is inconceivable, that a virus, which is covered by a lipid envelope – thus a mantle of fat –, will survive all of this“.
Microbiologist Sucharit Bhakdi from Mainz warns of hysteria / vaccination against influenza
It is understandable to put a ban on imports of birds. It is completely crazy and beyond all scientific finding, though, to ban imports of feathers. Leaving out the fact, however, that entire industries would get into economic difficulties, if imports of feathers from Asia were prohibited. These feathers were washed and dried – and moreover on transport for many weeks before they arrive here. It is inconceivable that a virus which is surrounded by a lipids case, i. e. a fat case, might outlive all these procedures.
The viruses get into the body via the respiratory tract.
In fact, it has meanwhile been proved that the virus might pass over to human beings. This is indeed the reason for present hysteria which sometimes conveys the impression, as if the end of mankind was imminent. However, in very rare cases, the virus managed to pass over from one of 100.000 birds which have fallen ill to one human being. Actually, human beings are no appropriate hosts, otherwise there would have been many more infections. For the time being, an infection from man to man is even more improbable. This was only the case with three Thai people who lived together in very cramped surroundings.
The virus would have to modify itself one more time in order to be transmitted efficiently from one human being to another. It just cannot be totally excluded that such a modification might happen. Let me try to explain it in a pictorial way. Influenza viruses have eight different kinds of proteins. Two of them are virtually the hands by means of which the virus docks, the other proteins virtually constitute the body which is partially responsible for specificity of the host (human being – bird). The “hands” of the avian virus are apparently in particular “evil”. If they dock a person, though the “body” does not fit to the human being, the virus is usually not able to propagate, and cannot “jump over” from one person to another. It becomes dangerous, if the human influenza virus and the avian influenza virus meet in the same living being. It might happen then that the viruses exchange their “hands”. A virus provided with avian influenza -“hands” could then propagate within the human body and also spread among human beings.
Usually, two simultaneous infections do not occur in human beings but more likely in pigs. Theoretically, the exchange of “hands” could also take place in human beings under the prerequisite that two infections occurred at the same time. This can be prevented by preventing an infection with the human virus – namely by vaccination against influenza.
No, not at present. It causes problems to cultivate viruses for conventional serum production. From the genetically engineering point of view, however, it should be possible to prepare a serum.
The avian influenza virus has never jumped over to someone who simply “travelled” past. A rather close contact with birds would be necessary, instead. Which tourist would visit a poultry farm? Vaccination against influenza, however, is recommended in any case.
Further information at the internet referring to bird flu