Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

[HenryN]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

HIV goes from human to human ... but nevertheless we know today, that the link between SIV and HIV are bush meat hunter ... still today.

Finally it's a fact, that bar headed geese are an industrial factor in china, which are obviously a link to other wild bird species, too.

What happend in Europe, noone doubt here, I don't know,what You want?
I just relate me to the qinghai period, what happend later is almost known.

The homology from the pochard an turkey in france interested me personally, because I'm interested in datas. I have no reason to doubt the impact of wild birds, but finally noone knows details how the virus came to the turkeys in Versailieux in France and in Wermsdorf in Saxon, Germany, both in close buildings. Sorry, that there are people who what to understand the process, and sequences don't answer all questions in toto. Therefore, these people can believe seriously in science nevertheless.

Biosecurity works best when there is no virus. The H5N1 in the region exposes the weaknesses.

Germany is a good example. The outbreak that was confirmed today was in a region that still had restrictions from last year. However, with H5N1 wild bird confimations on the rise, sooner or later the H5N1 gets in (possibly via hay used in bedding).

[Coleman]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

(possibly via hay used in bedding).

That's more probable than the food as speculated from a birder association.

[gsgs]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

there was very much mixing in the Qinghai-lake viruses
through reassortment and recombination.

This indicates more than usual double-infections with
different strains.
Is that consistent with the breeding practices ?

[HenryN]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

That's more probable than the food as speculated from a birder association.

The birder associations will come up with anything that isn't linked to wild birds.

The bird linked sites really lack much of an understainding of infectious diseases in general, and H5N1 in particular. The latest commentary from ProMed suggests that there is some relationship between the one goose that was H5N1 confirmed a couple of months ago in Thuringia, and the latest outbreak in Bavaria.

In Thuringia, the confirmation in domestic birds was literally limited to ONE goose. There was a fair amount of culling and testing in the region, and all other birds were negative. It was clear that the ONE goose, which was a pet, had somehow contact H5N1 wild birds which were reported at MANY locations in Thuringia, as well as the neighboring states of Saxony, Saxony-Anhalt, and Bavaria.

Recently, the confirmed wild bird cases in Bavaria expanded from Nuremberg to Munich, signalling widespread H5N1 in southern Germany. Now H5N1 has made its way to a large commercial farm. amd the Promed commentary focuses on the fact that this outbreak also involves geese.

The groups always focus on the species, and fail to understand that H5N1 can infect MANY species, especially avian speacies.

Qinghai is a good example. Although the initial deaths were bar-headed geese, within days other species of geese, gulls, and cormorants were infected with the same H5N1 sub-clade.

The same thing happened a year later. Sequences from 2006 isolates in Qinghai were published from a goose, a gull, and a swan. All three had virtual idsentical sequences which were Qinghai, but VERY distinct from the 2005 sequences.

The similarities in the sequences are regionally linked, not linked by species, which is a VERY basic fact that the bird watchers and conservation groups can't seem to grasp.

[Coleman]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

Another possibillity than hay could be aerosols of H5N1.
Is it worth to think about?

Box 1: Lessons from Newcastle disease

Oddly, in all the discussion of bird flu there is little reference to parallel experiences with other diseases. Newcastle disease, for example, has already become endemic in most poultry farming areas and vaccination against the disease is now a routine activity for poultry farmers around the world.

Like bird flu, Newcastle comes in mild and highly pathogenic forms. In its endemic form, Newcastle is not a big worry. It typically kills a few baby chicks out of an infected flock and only occasionally results in large die-offs when birds are susceptible.

The virus becomes a major problem when it enters into factory farms. According to researchers Alders and Spradbrow, "In large commercial poultry units, the virus enters flocks through some break in biological security [on food, people, eggs, vehicles], by the introduction of infected birds in multi-age farms, or by aerosol [in the air] from an adjoining property. Once a few birds are infected, spread within the flock will be mainly by aerosol. Large flocks will produce copious quantities of aerosol virus, which can spread with movements of air to other flocks."[20]

It is within this context that the disease can mutate into a highly pathogenic form and wipe out entire flocks. An Australian outbreak in 1998, for instance, killed 10,000 chickens and led to the slaughter of another 100,000. The outbreak took authorities by surprise, as tight quarantine controls had seemingly kept the country free of highly pathogenic strains for 60 years.

"We had assumed it had been brought in from overseas," said Jeff Fairbrother, Executive Director of the Australian Chicken Meat Federation. However, later research by virologists showed that the outbreak occurred when an endemic strain of the virus entered into a factory farm and mutated into a virulent form.[21]

The Australian authorities didn't respond by going after backyard flocks or wild birds potentially carrying the disease and they didn't just accept industry claims about the "biosecurity" of their operations. They made vaccination mandatory for farms with over 500 birds. And what about backyard flocks? Were they also subjected to mandatory vaccination? According to the government's information brochure on the disease outbreak:

"No. A very mild form of Newcastle disease virus is present in all States. Providing that strain does not mutate into something virulent, it poses no threat to birds. The outbreaks we had on the mainland between 1998 and 2002 were caused by a mutation of the endemic mild strain (known as Peats Ridge 1998) into a virulent strain of the virus. All the available evidence indicates that, for such a mutation to occur, it needs a large number of birds in a small area to "generate" the virus mutation process. In simple terms, a small number of birds cannot generate enough virus for the mutation process to occur."[22]Source: Fowlplay www.Grain.org

Another lesson to understand the epidemiological modell ...

The challenge to biosecurity on poultry farms can be discussed using two poultry diseases of global significance, campylobacteriosis and ND, as examples. Inferences are relevant to understand the opportunities for pathogen transfers in and out of confined poultry operations. ND is transmitted among poultry via contaminated faeces and probably via inhalation of aerosols, which is similar to HPAI. The specific mechanisms for spread between farms are also similar to HPAI, i.e. movement of poultry, poultry products, humans, contaminated feed and water. A major difference is the availability of vaccines for ND which can effectively control the disease.

Studies of Campylobacter, an avian commensal and human pathogenic bacteria, are informative as well. Like avian influenzas, wild birds are the natural vertebrate reservoirs of Campylobacter spp, and can serve as vectors for transmission to other vertebrates (eg. Cabrita et al 1992; Fernandez et al 1996; Yogasundram et al 1989). Campylobacter spp move among avian host species, both domesticated (van den Bogaard and Stobberingh 2000) and wild (Broman et al 2004; Petersen et al 2001). The exchange of Campylobacter between broiler flocks and wild avians can occur in both directions (Craven et al 2000). In confinement, broiler poultry are readily colonized by Campylobacter, and the external environment appears to be a major source of colonization. The importance of the environmental reservoir and the inability of conventional biosecurity measures to prevent the movement of microbes in and out of modern broiler facilities were both demonstrated in a recent study of Campylobacter-free broiler flocks, housed in sanitized facilities, using standard biosecurity measures, and fed Campylobacter-free feed and water. Seven out of ten of these flocks became colonized with Campylobacter by the time of slaughter and two flocks were colonized by Campylobacter strains genetically indistinguishable from strains isolated from puddles outside of the facility prior to flock placement (Bull et al 2006). Although the route of entry was not determined, this study clearly showed the capacity for microbes to enter broiler facilities despite the implementation of standard biosecurity measures.

Once a poultry flock is colonized with Campylobacter, the food, water and air within the house quickly becomes contaminated with the bacterium (ibid). Contaminated air exiting the house via ventilation systems is a potential source of Campylobacter to the external environment, and microbes may be carried some distances by wind and surface water transport. Campylobacter strains with identical DNA fingerprints to those colonizing broilers have been measured in air up to 30 m downwind of broiler facilities housing colonized flocks (ibid). There are additional mechanisms by which Campylobacter and other microbes enter and leave 'bio-secure' poultry houses. For example, insects may carry microbes in and out of facilities through ventilation systems and small openings. This was demonstrated in a study in Denmark which found that Campylobacter carriage was common among flies surrounding the broiler facilities and that as many as 30,000 flies may enter a broiler facility during a single flock rotation in the summer months (Hald et al2004). House flies captured within broiler facilities and other food environments can also carry multi-drug resistant bacteria (Macovei and Zurek 2006) as well as avian influenza virus (Bean et al 1985).

Animal house wastes constitute another pathway for pathogens to exit poultry houses. In large scale operations, with few exceptions poultry wastes are managed by land disposal. Some pathogens, including viruses, can survive in poultry wastes for considerable amounts of time (Gerba and Smith 2005). Land-disposed poultry house wastes are attractive to wild birds due to the presence of spilled feed in these wastes. These then may become infected and contaminate water supplies of other poultry operations. In addition, poultry house wastes are used in aquaculture as 'bedding' in many countries around the world. This practice provides an opportunity for direct contact by wild waterfowl. The shipment of poultry wastes for this purpose has been suggested by some as a possible mechanism for the transfer of HPAI from Asia to Central Europe (Butler 2006).

Newcastle disease in Denmark

The 2002 ND epidemic, which has been very well researched and documented by the Danish Veterinary and Food Administration (2003), provides valuable information on the relative risk of introducing epidemic disease agents into commercial vs. backyard poultry operations. Similar to Thailand, the vast majority (app 90%) of poultry in Denmark is raised by commercial enterprises while smallholder backyard poultry keepers constitute the great majority of poultry producers (>95%) (Mortensen, personal communication).

Several incursions of ND have been recorded in Denmark over the past years, which, however, only led to a major epidemic in 2002. Between July and August of 2002, at total of 135 outbreaks (four primary outbreaks and 131 secondary outbreaks) of ND were detected, of which all but one occurred in the central and southern part of Jutland. The majority of outbreaks (126) were observed in backyard flocks while only nine commercial flocks (layers or pullets) were infected. However, the areas affected by the epidemic only contained 270 registered commercial flocks against nearly 23,000 backyard flocks. Thus, the risk of infection was around 50 times higher for commercial than for backyard flocks. Moreover, tracing of outbreaks revealed that all infections in backyard flocks originated from one of the four primary outbreaks (all in commercial flocks), via movement of live birds. The source of infection of the primary outbreaks could not be determined. However, a common feature of these four farms was that they were all located less than 2 km from the coastline, which could be a potential risk factor for infection from wild waterfowl. In one case, a possible path of entry for the ND virus was a ventilator, which had been put on suction instead of exhaustion after repair, and in another case the virus may have been introduced through feed from a feed silo, which had not been covered.

http://www.cipav.org.co/lrrd/lrrd19/7/otte19102.htm

[gsgs]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

http://hosted.ap.org/dynamic/stories/A/AS_SCI_BIRD_FLU_WILD_BIRDS_ASOL-?SITE=AP&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2007-09-03-06-35-16

U.N. says domestic birds mainly to blame for spreading bird flu, not wild birds


Samples from 0.35M healthy wild birds in Europe, Asia, Africa and the Americas
have tested negative for bird flu,
experts at a three-day workshop
survey results taken 2005-2007.

Scott Newman :
"We know now that we haven't found a species that even suggests that it would be a reservoir for this disease,"

------------------------------

where else should the virus evolve ? Maybe .35M just isn't enough...

[HenryN]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

http://hosted.ap.org/dynamic/stories...09-03-06-35-16

U.N. says domestic birds mainly to blame for spreading bird flu, not wild birds


Samples from 0.35M healthy wild birds in Europe, Asia, Africa and the Americas
have tested negative for bird flu,
experts at a three-day workshop
survey results taken 2005-2007.

Scott Newman :
"We know now that we haven't found a species that even suggests that it would be a reservoir for this disease,"

------------------------------

where else should the virus evolve ? Maybe .35M just isn't enough...

The negative data on live birds just shows how bad the testing is. Just more foxes guarding the hen houses.

[HenryN]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

http://hosted.ap.org/dynamic/stories...09-03-06-35-16

U.N. says domestic birds mainly to blame for spreading bird flu, not wild birds


Samples from 0.35M healthy wild birds in Europe, Asia, Africa and the Americas
have tested negative for bird flu,
experts at a three-day workshop
survey results taken 2005-2007.

Scott Newman :
"We know now that we haven't found a species that even suggests that it would be a reservoir for this disease,"

------------------------------

where else should the virus evolve ? Maybe .35M just isn't enough...

How many of the 350,000 live birds had H5 antibodies?

[Coleman]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

Don't they know the sequence data from Europe and Africa?
Sure, in Asia You can blame the poultry industries for the distribution, but ...

[HenryN]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

Don't they know the sequence data from Europe and Africa?
Sure, in Asia You can blame the poultry industries for the distribution, but ...

The sequence data has been quite clear since the summer of 2005. These reports are just propaganda pieces. Scientific studies do NOT focus on negative data, especially when a more reliable test, such as antibody levels, is ACTIVELY avoided.

These studies are WELL into the foxes guarding the henhouse category.

[HenryN]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

<TABLE style="DIRECTION: ltr" width="100%" border=0><TBODY><TR><TD>Scientists Not Sure Whether Wild Birds Are Carrying Avian Influenza Virus</TD></TR><TR><TD vAlign=top>By Luis Ramirez
Bangkok
03 September 2007
</TD><TD vAlign=top align=left></TD></TR></TBODY></TABLE>Ramirez report (mp3) - Download 561k
Listen to Ramirez report (mp3)


Researchers say studies do not confirm whether wild birds are carriers of the H5N1 bird flu virus. VOA's Luis Ramirez reports from Bangkok, where experts are gathering this week to figure out better ways to track how the disease is spreading.
<TABLE class=APIMAGE style="DIRECTION: ltr" width=210 align=left><TBODY><TR><TD></TD></TR><TR><TD class=imagecaption>Scott Newman, the FAO's international wildlife coordinator, Bangkok, 03 Sept. 2007</TD></TR></TBODY></TABLE>Experts meeting in say they have been dealing with data that might be unreliable because there is no uniform system of checking H5N1 infection among wild birds. The Food and Agriculture Organization brought together more than 70 experts from 12 countries.
Scott Newman, the FAO's international wildlife coordinator, says the aim is to identify what countries need what kind of support and training to improve their surveillance of wild birds.
"We are hearing that wild birds have not been found to be positive if they are healthy, free-ranging birds. We are hearing, though, that dead wild birds are being found in various countries and they are confirmed positive for H5N1 avian influenza," said Newman. "So, from a surveillance standpoint, some countries are doing healthy wild-bird surveillance. Others are just collecting dead birds and looking for disease. And so there is a range of surveillance activities and monitoring that are happening."
Bird flu experts say it could be that there is no significant incidence of bird flu among migrating wild birds, or it could be that the virus is simply not being detected. They say the only way to find out is to establish a comprehensive and uniform system of surveillance.
FAO officials last year voiced concerns that bird migration patterns might have spread disease Asia and Europe to Africa. But as elsewhere in the world, very few cases have been found among wild birds in Africa.
The Wildlife Conservation Society Field Veterinary Program Director William Karesh is among those attending the meeting in Bangkok.
"We tested thousands of birds in Africa, in Nigeria, in that area, and we cannot find a wild bird with the disease. [That] Does not mean it cannot occasionally get into them, but it is probably not going to go anywhere. It is a dead end," he said.
Karesh says the illegal trade in wildlife in Africa and other parts of the world makes it especially challenging to track the virus.
Since an outbreak began in 2003, millions of chickens, ducks, and geese around the world have contracted the virus and millions more were culled to prevent its spread.
The World Health Organization says more than 320 people have been infected with bird flu in 12 countries, and about 200 have died. Indonesia and Vietnam account for almost two thirds of the human cases.

http://voanews.com/english/2007-09-03-voa29.cfm

[HenryN]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

<TABLE style="DIRECTION: ltr" width="100%" border=0><TBODY><TR><TD>Scientists Not Sure Whether Wild Birds Are Carrying Avian Influenza Virus</TD></TR><TR><TD vAlign=top>By Luis Ramirez
Bangkok
03 September 2007

</TD><TD vAlign=top align=left></TD></TR></TBODY></TABLE>"We tested thousands of birds in Africa, in Nigeria, in that area, and we cannot find a wild bird with the disease. [That] Does not mean it cannot occasionally get into them, but it is probably not going to go anywhere. It is a dead end," he said.

http://voanews.com/english/2007-09-03-voa29.cfm

Same "dead end" nonsense by same person by same organization which was said in Mongolia in August 2005, just before Qinghai H5N1 spread to 50 countries in Europe, the Middle East, and Africa.

[HenryN]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

Wild birds cleared in tests for flu

<!-- Samples from 350,000 healthy wild birds in Asia, Europe, Africa and the Americas have tested negative for bird flu, offering further proof that spread of the virus is mostly contained in domesticated poultry, United Nations experts revealed yesterday.

//-->Tuesday, September 04, 2007

Samples from 350,000 healthy wild birds in Asia, Europe, Africa and the Americas have tested negative for bird flu, offering further proof that spread of the virus is mostly contained in domesticated poultry, United Nations experts revealed yesterday.

But experts at a workshop in Bangkok said better surveillance of wild birds was necessary given that individual birds from 90 species have been found to carry the H5N1 virus. Most were either sick or dead.
During global wildlife surveillance, 300,000 to 350,000 "healthy, wild birds have been sampled looking for this virus," said Scott Newman, the international wildlife coordinator for the UN Food and Agriculture Organization.
"It hasn't been found."
The results came from surveys taken between 2005 and 2007.
Scientists feared the spread of the virus would pick up speed with the wild birds' winter migration to Africa and the Middle East, and their spring return to Europe. But that has not happened.
Newman and others said the negative tests do not mean that wild birds should be dropped altogether as a transmission source.
Instead, he urged increased surveillance of wild birds, including better testing at sites where domestic and wild birds congregate.
ASSOCIATED PRESS

http://www.thestandard.com.hk/news_detail.asp?we_cat=6&art_id=52725&sid=15216482&con_type=1&d_str=20070904

[HenryN]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

Commentary at

http://www.recombinomics.com/News/09030701/H5N1_WB_Spread.html

[gsgs]

Re: Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

> Which bird species migrates between July and December from
> Novosibirsk to the Caspian Sea

lesser white fronted geese

http://www.piskulka.net/Fennoscandia%202006-2007.htm