final program.qxd - Parallels Plesk Panel

Knowing that waterfowl and live poultry markets are most likely the primary source of
infection to the industrial poultry flocks, the question is how to prevent those introductions.
Prevention of introductions
Actually there is one word that covers the prevention measure and that is bio-security.
However, that word is still kind of vague, so it should be made clear what is meant by this
word.
The basic means for the prevention of primary introductions of influenza viruses into
poultry flocks is to minimize the direct and indirect contacts between birds in these flocks
on the one side and wild water fowl, live bird markets and pet birds on the other side.
Consequently, bio-security is the way to minimize the risk of the initial introduction of Avian
Influenza viruses into commercial poultry flocks.
ABSTRACTS
The most important bio-security measures are: 1) poultry kept indoors, 2) only one
species of poultry on the premises, 3) no pet birds on the same premises as commercial
poultry, 4) all in - all out production system (reduces the risk of an endemic infection with
LPAI viruses), 5) no items (such as ponds) that attract wild birds to the premises, 6) feed
and drinking water for poultry is not accessible for wild birds, 7) poultry workers do not
have access to other birds, 8) fence around the poultry house 9) only those persons that
really need to be there are admitted to the poultry house, 10) persons change clothes and
boots before entering the poultry house.
In addition to preventing the introduction of AI viruses it is desirable to impose surveillance
for antibodies or clinical signs of AI. Such a program may detect LPAI virus infection in
commercial poultry before mutation to HPAI has taken place or can detect an introduction
of HPAI as soon as possible, before it has spread to (many) other flocks. When adequate
measures are taken in such a situation, an epidemic of HPAI may be prevented or at least
minimized.
Keeping poultry indoors in a way that wild birds cannot reach them and they cannot come
into contact with feces of wild birds may be very difficult to achieve in traditional housing
systems. Next it is important to keep no other birds on the premises, because they may
serve as a source of infection, either directly or through contact with wild waterfowl.
In addition an all-in all out production system is important. Actually this is not a measure
to reduce the probability of introduction of the virus, but to stop the circulation of lowpathogenicity
virus. Items, such as ponds, that attract wild birds increase the risk of virus
introduction. The same is true for feed and drinking water if wild birds can access it.
Moreover, poultry workers may introduce the virus by feces on their boots our clothing, or
they may be infected themselves. Finally, it is wise to have stringent regulations for the
admission of persons. Only those persons that really need to be there should have permission
to enter the shed, and they should change clothes and boots before they enter
the poultry houses.
Control of secondary transmission
The amount of virus produced by an infected flock can be reduced by the killing and removal
of these flocks (culling). This approach is followed in most countries, for instance during
the epidemics in Italy, the Netherlands (2003), countries in Asia and the US (e.g. 2003-
2004). As farmers should be compensated financially, which is not always, feasible culling
infected poultry is not always possible.
“ Focusing FIRST on PEOPLE “ 67 w w w . i s h e i d . c o m