Tweet
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
Commentary
Commentary
-
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
<TABLE cellSpacing=0 width="100%" border=0><TBODY><TR><TD style="FONT-WEIGHT: bold; FONT-SIZE: 18px; COLOR: #0253b7; FONT-FAMILY: Arial">Fresh bird flu outbreak in N-E to hit poultry exports</TD></TR><TR><TR><TD style="FONT-WEIGHT: bold; FONT-SIZE: 11px; FONT-FAMILY: Arial">Surinder Sud / New Delhi December 01, 2008, 22:49 IST</TD></TR><TR><TD style="BACKGROUND-IMAGE: url(/images/common/gn_005.gif); BACKGROUND-REPEAT: repeat-x"></TD></TR></TBODY></TABLE>
Fresh outbreak of the dreaded bird flu disease of poultry at Hajo in Kamrup (Rural) district of Assam is expected to hit export of poultry products though it may not have much impact on the domestic market, feel poultry experts.
<STYLE> .rightDiv2{float:right;position:relative;width:220 px;BORDER:#787962 1px solid;padding:5px} </STYLE>
The Assam government has confirmed the epidemic of the most hazardous H5N1 virus of the highly pathogenic avian influenza (bird flu) at Hajo, about 45 km from Guwahati, on Friday last and has started culling operations to destroy all poultry birds in and around that area.
The action came after the unnatural death of over 300 birds in that area and the confirmation of the presence of the H5N1 influenza virus in the dead birds by the Bhopal-based High Security Animal Disease Laboratory (HSADL).
This is the fifth major outbreak of this fatal poultry disease in the country since February 2006. The 4 previous epidemics had collectively caused a colossal economic loss, estimated by the poultry industry circles at around Rs 10,000 crore, in terms of loss of production and destruction of poultry birds in areas surrounding the disease epicentres. The organised poultry industry is currently reckoned to be worth over Rs 30,000 crore.
The first outbreak was in Navapur in Maharashtra in February 2006; the second again in Jalgaon, Maharashtra and Burhanpur in Madhya Pradesh in March-April 2006; the third in Chingmeirong (East Imphal district) in Manipur in July 2007; and the fourth in 15 districts of West Bengal and 2 districts of Tripura in May 2008.
Following the successfully containment of the disease in West Bengal, India had formally declared itself bird flu-free country only on November 4. The latest epidemic has occurred just over 3 weeks after this declaration.
A well known poultry expert and India representative of the US Grains Council, Amit Sachdev, told Business Standard that the recurrence of the H5N1 bird flu disease might dash the poultry industry’s hopes of resuming export of poultry products to major destinations in West Asia.
Bhutan, which had lifted the ban on poultry imports from India, notably from the bordering northeastern region, following the declaration of bird flu-free status, was expected to retract the move. The other importers were also likely to stop sourcing their supplies of poultry products from India. The Indian poultry exports have, in any case, been in the doldrums, in the past couple of years due to repeated resurgence of bird flu.
However, Sachdev does not expect fresh disease eruption in Assam to make much difference to the consumption and sale of chicken meat and eggs in the domestic market outside the affected area. Most consumers have realised that well washed and properly cooked poultry products are safe to consume.
According to veterinarians, the H5N1 influenza virus, even if passed on from birds to human beings, does not get transmitted from one person to another unless it gets mutated into another form that is communicable among the human beings. However, in other countries, where the disease epidemics have been relatively more severe and longer lasting, several human beings have died on getting infected with this virus.
The poultry analysts are, however, not surprised at the recurrence of the disease in India and fear that sporadic incidence of bird flu may keep surfacing as the H5N1 viral infection continues to occur in the countries around India. The northeastern region is deemed relatively more vulnerable as Bangladesh, in particular, has been unable to uproot the H5N1 virus in its territory. The movement of birds across the borders cannot be checked.
Some other Intensive poultry producing regions, especially in the states like Punjab and Uttar Pradesh bordering Pakistan and Nepal, respectively, are also vulnerable to this menace as this infection is believed to be present in these countries as well.
Sachdev said joint initiatives between India and neighboring countries were essential to curb the bird flu menace. The neighbouring countries needed to evolve joint-strategies for keeping a vigil on the infection and undertaking bio-safety measures to ward off the build up of the virus.
According to Union animal husbandry department sources, an effective system has been put in place for the prevention and control of avian influenza. Reserves of material needed for the disease control operations have been developed and are gradually been expanded further.
An avian influenza vaccine bank has been created with a capacity of 45 million doses. Besides, the Bhopal diagnostic laboratory has been stocked with required reagents, some of which are now being produced indigenously, these sources maintain.
<SCRIPT>window.google_render_ad();</SCRIPT><IFRAME name=google_ads_frame marginWidth=0 marginHeight=0 src="http://pagead2.googlesyndication.com/pagead/ads?client=undefined&dt=1228160541099&format=undef inedxundefined&output=html&correlator=122816054109 9&ea=0&frm=1&ga_vid=788717388.1228160541&ga_sid=12 28160541&ga_hid=482666588&flash=10.0.12.36&u_h=800 &u_w=1280&u_ah=770&u_aw=1280&u_cd=32&u_tz=-300&u_his=35&u_java=true&dtd=31" frameBorder=0 scrolling=no allowTransparency></IFRAME><SCRIPT>window.google_render_ad();</SCRIPT>
<SCRIPT>window.google_render_ad();</SCRIPT><IFRAME name=google_ads_frame marginWidth=0 marginHeight=0 src="http://pagead2.googlesyndication.com/pagead/ads?client=undefined&dt=1228160588021&format=undef inedxundefined&output=html&correlator=122816058802 1&ea=0&frm=1&ga_vid=1261692860.1228160588&ga_sid=1 228160588&ga_hid=784404141&flash=10.0.12.36&u_h=80 0&u_w=1280&u_ah=770&u_aw=1280&u_cd=32&u_tz=-300&u_his=35&u_java=true&dtd=47" frameBorder=0 scrolling=no allowTransparency></IFRAME><SCRIPT>window.google_render_ad();</SCRIPT>Comment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
INDIA: MINISTRY OF AGRICULTURE, CONFIRMATION OF AVIAN INFLUENZA IN KAMRUP DISTRICT, ASSAM (1/12/2008)
INDIA: MINISTRY OF AGRICULTURE, CONFIRMATION OF AVIAN INFLUENZA IN KAMRUP DISTRICT, ASSAM
Full PDF document at LINK
<table style="width: auto;"><tbody><tr><td>
</td></tr><tr><td style="font-family: arial,sans-serif; font-size: 11px; text-align: right;">From TABLES</td></tr></tbody></table>
<table style="width: auto;"><tbody><tr><td>
</td></tr><tr><td style="font-family: arial,sans-serif; font-size: 11px; text-align: right;">From TABLES</td></tr></tbody></table>
Comment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
CommentaryOriginally posted by niman View Post
H5N1 Spread in Assam India
Recombinomics Commentary 15:35
December 1, 2008
27,000 chicken were culled at Rangiya Circle in Kamrup (Rural) district to prevent spread of the disease to other districts.
3,000 chicks were culled at Gerua and Abhaypur
The above comments suggest that H5N1 has spread in the Kamrup district in Assam, India. Last week confirmed H5N1 positives were at Hajo circle and 20 villages were scheduled for culling. However, there were also unusual poultry deaths in Sapara Village near Paliburi (see satellite map), and the number of villages slated for culling has increased to 50, which is well beyond the initial 3 or 5 km radius of the confirmed cases in Thakuria Chuba of Rajabazar.
The spread of H5N1 in the area is not unexpected. India has recently acknowledged the role of migratory birds in the spread of H5N1, based in part by the sequence relationship between the outbreaks in India and those of migratory birds in Russia and Mongolia (Clade 2.2 Qinghai strain). Moreover, the last major outbreak in India (West Bengal) and adjacent Bangladesh began almost exactly one year ago, when migratory birds began arriving in the region, where they winter.
Bangladesh has also recently reported confirmed H5N1.
."The next major advancement in the health of American people will be determined by what the individual is willing to do for himself"-- John Knowles, Former President of the Rockefeller FoundationComment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
India loses bird flu-free status
Gargi Parsai
NEW DELHI:Barely three weeks after India declared itself to be free from the highly pathogenic Avian Influenza (Bird Flu), the deadly disease showed up in Kamrup district of Assam last week.
Consequently, India has notified the World Organisation for Animal Health(OIE), about the outbreak of the disease and has lost its bird flu-free status.
A country has to be completely free from the disease for at least three months to be notified as such.
Samples from Rajabazar village in Assam tested positive for H5 strain of Avian Influenza at the High Security Animal Disease Laboratory in Bhopal on November 27, according to sources in the Department of Animal Husbandry here.
About 20 Rapid Action Teams were consequently deployed in the State to undertake the culling operations. Teams of Health Ministry officials have also been rushed from New Delhi.
The State government has so far stamped about 40,000 poultry and the culling operation is expected to be completed by Tuesday, the sources said.
Culling
The culling is being done as per the Action Plan of Animal Husbandry for Preparedness, Control and Containment. The plan, which is in consonance with international standards, requires all poultry to be culled within a radius of five kilometres.
Comment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
<TABLE border=0 cellSpacing=1 cellPadding=1 width="100%"><TBODY><TR bgColor=#ffffff><TD bgColor=#ffffff>Avian flu in new areas, sale of poultry banned</TD></TR><TR><TD bgColor=#ffffcc>By our Staff Reporter
GUWAHATI, Dec 1: As a precautionary measure, sale and movement of poultry birds have been banned in Kamrup district from today, as bird flu is suspected to have spread over new areas, including Sarpara (near Mirza), Rangamati and Bongra Kachuniapara villages in the district, said Kamrup Deputy Commissioner RC Jain.
Meanwhile, Kamrup (Metro) district administration has also imposed a ban on the movement of all kinds of birds and eggs from Mirza and Pasashbari areas into the district and Guwahati city. According to sources, unnatural death of the birds has been reported from Rangamati and Sarpara since a few days back. Over 100 hens and cocks were found dead in Bongra Kachuniapara today, sources said.
Jain said samples of dead birds from Bongra have been collected and will be sent to laboratories in Bhopal and Pune. Samples from the other two villages have already been sent for testing. He said the authorities are awaiting for the final test report before starting fresh culling operation in the new areas.
Meanwhile, about 32,000 birds have already been culled in the Hajo area in last three days. The operation is expected to be over by next two days, he added.
http://www.sentinelassam.com/index.htm
</TD></TR></TBODY></TABLE>Comment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
Bird flu spreads to new areas
Guwahati, Dec 2 : Thousands of birds are being culled daily at Hajo near the state capital even as Avian Influenza spread to new areas forcing authorities to ban sale of chicken in some areas.
<SCRIPT type=text/javascript BixAG="2"><!--google_ad_client = "pub-1318167688658577";/* 250x250 Newkerala */google_ad_slot = "8004631634";google_ad_width = 250;google_ad_height = 250;//--></SCRIPT><SCRIPT src="http://pagead2.googlesyndication.com/pagead/show_ads.js" type=text/javascript BixAG="2"></SCRIPT><SCRIPT BixAG="2">window.google_render_ad();</SCRIPT>
''Culling is on, though remoteness of areas and resistance by owners presents some difficulties in further expediting the process,'' state Veterinary department director Dr A K Kotoky said.
He added that about 37,000 [COLOR=blue! important][COLOR=blue! important]ducks[/color][/color] and chickens had been culled so far.
Blood samples were sent to Bhopal and [COLOR=blue! important][COLOR=blue! important]Pune[/color][/color] laboratories after unnatural death of birds was reported since last week and they had tested positive for the H5N1 strain, confirming the first outbreak of [COLOR=blue! important][COLOR=blue! important]bird [COLOR=blue! important]flu[/color][/color][/color] in the state.
The director informed that all district deputy commissioners have been alerted to keep watch on any possible mass death of poultry and report immediately in the wake of such a situation.
Preventive culling was undertaken in the state last year when bird flu was detected in North Bengal.
Dr Kotoky said migratory birds, who arrive in small numbers to roost in water bodies at Hajo, could have been the bearers of the virus.
Kamrup (rural) district authorities have imposed a ban [COLOR=blue! important][COLOR=blue! important]on [COLOR=blue! important]sale[/color][/color][/color] of poultry and sounded a general alert in about 40 villages in a radius of five kms from the area where the deaths were reported.
The country has not reported any human infections so far, though the first outbreak in poultry was reported in 2006 in Maharashtra.
Experts fear the H5N1 strain could mutate into a form easily transmitted from person to person, leading to an epidemic.
After the last outbreak reported in Darjeeling in West Bengal in May, there were no further reports prompting the Centre to declare the country free of avian flu. Between January and May this year, 42 incidents of bird flu were reported from West Bengal and Tripura.
Though the last reported case in Darjeeling was disinfected on June 4, the government could not declare the country flu-free due to a sporadic incident of outbreak in Manipur in July.
<!-- google_ad_section_end -->--- UNI
<SCRIPT type=text/javascript><!--google_ad_client = "pub-1318167688658577";/* 336x280 Newkerala */google_ad_slot = "8389873548";google_ad_width = 336;google_ad_height = 280;//--></SCRIPT><SCRIPT src="http://pagead2.googlesyndication.com/pagead/show_ads.js" type=text/javascript></SCRIPT><SCRIPT>window.google_render_ad();</SCRIPT>
<SCRIPT>window.google_render_ad();</SCRIPT><IFRAME name=google_ads_frame marginWidth=0 marginHeight=0 src="http://pagead2.googlesyndication.com/pagead/ads?client=undefined&dt=1228216680500&format=undef inedxundefined&output=html&correlator=122821668050 0&ea=0&frm=1&ga_vid=1012604715.1228216681&ga_sid=1 228216681&ga_hid=644942651&flash=10.0.12.36&u_h=80 0&u_w=1280&u_ah=770&u_aw=1280&u_cd=32&u_tz=-300&u_his=86&u_java=true&dtd=62" frameBorder=0 scrolling=no allowTransparency></IFRAME><SCRIPT src="http://googleads.g.doubleclick.net/pagead/test_domain.js"></SCRIPT><SCRIPT src="http://pagead2.googlesyndication.com/pagead/render_ads.js"></SCRIPT><SCRIPT>window.google_render_ad();</SCRIPT><IFRAME name=google_ads_frame marginWidth=0 marginHeight=0 src="http://googleads.g.doubleclick.net/pagead/ads?client=undefined&dt=1228216680578&prev_fmts=un definedxundefined&format=undefinedxundefined&outpu t=html&correlator=1228216680500&ea=0&frm=1&ga_vid= 1012604715.1228216681&ga_sid=1228216681&ga_hid=644 942651&flash=10.0.12.36&u_h=800&u_w=1280&u_ah=770& u_aw=1280&u_cd=32&u_tz=-300&u_his=86&u_java=true&dtd=15" frameBorder=0 scrolling=no allowTransparency></IFRAME>Comment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
Commentary
Comment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
Source: http://www.hindu.com/thehindu/holnus...0812021412.htm
Alert in Assam districts following fresh detection of flu
Rangiya, Assam (PTI): An alert has been sounded in two central Assam districts of Kamrup (Metro) and Kamrup (Rural) as avian flu has been detected in fresh areas there amid reports of death of more than 100 birds.
The death of chickens was reported from the Bogri and Kachumara areas, prompting the district administrations to ban purchase and sale of eggs, official sources said.
Over a hundred birds were found dead yesterday at the Bongra and Kachumara areas from where samples had been collected and sent to the laboratories in Bhopal and Pune, Kamrup (rural) deputy commissioner R N Jain said.
As a precautionary measure, an alert has been sounded as the avian disease is suspected to be spreading to fresh areas of Sarpara, Rangamati, Bongra and Kachuniapra villages.
The Karmup (metro) district administration has imposed a ban on movement of birds and eggs from the affected areas as well as from the nearby markets at Mirza and Plashbari in the outskirts of the city.
In the Kamrup (rural) district, nearly 50,000 birds have been culled and another 30,000 will be culled in the next couple of days.
The administration is also probing the reported sale of flu-affected birds at a very low price in the Hajo area.Comment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
Commentary
Comment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
<table style="width: auto;"><tbody><tr><td>
</td></tr><tr><td style="font-family: arial,sans-serif; font-size: 11px; text-align: right;">From TABLES</td></tr></tbody></table>
Comment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
:: News Plus
Alert in Assam as avian flu spreads to new areas
Manoj Anand
If migratory birds were centre attractions for the tourists in Assam, this time they have brought disaster with them. The health ministry has confirmed that it was migratory birds who brought this deadly bird flu to Assam.
The Assam government has not only started culling operations, but also formed teams of experts to keep a close watch on inter-country bird movements.
The Assam health officials said: "We are taking measures to control it, and let me assure that everything is under control. A team from the central health ministry has also arrived and is helping authorities in culling the poultry."
The outbreak of bird flu has come as a big setback to the health ministry also as barely three weeks before India had declared itself to be free from the highly pathogenic Avian Influenza (bird flu).
However, India has re-notified the World Organisation for Animal Health (OIE) about the outbreak of the disease and has lost its bird flu-free status. A country has to be completely free from the disease for at least three months to be notified as such.
Samples from Rajabazar village in Assam tested positive for H5 strain of Avian Influenza at the High Security Animal Disease Laboratory in Bhopal on November 27. Since then more than 20 Rapid Action Teams are deployed in the area to undertake the culling operations.
The health ministry was also extending all possible help to the Assam government in terms of human resource, medicine, masks and other preventive measures.
The culling of ducks and chicken is being carried out in 48 villages within a 5 km radius of village Thakurchuba in Kamrup district, about 40 km west of Assam?s main city of Guwahati.
The Assam health authorities, however, clarified that there was no need to panic. "Winter is a favourable period for the spread of bird flu as these migratory birds come southwards (to India) from other countries. The movement of these migratory birds cannot be stopped completely."
India has witnessed several outbreak of bird flu earlier in states like Maharashtra, West Bengal and a few North-eastern states.
"So far, nearly 40,000 chickens and ducks have been killed and the operation is still on in the district of Kamrup since Friday," said deputy director of the Assam veterinary department Manoranjan Choudhury. Culling is being carried out in as many as 48 villages that lie within the radius of 5 kilometers of village Thakurchuba in Kamrup district.
The outbreak of bird flu was confirmed by the health ministry last week soon after the laboratory tests found strains of the deadly H5N1 avian influenza. A pandemic will be spread if the H5N1 strain mutates in the human beings. World Health Organisation has also expressed its concern over the situation.
The virus has already taken a toll of more than 300 birds in the area. With veterinarians carrying out checks on all poultry farms, Assam?s veterinary and animal husbandry department has announced an alert. The authorities are also maintaining a strict surveillance on all farms in the state.
An alert has also been sounded in some new areas of the districts as avian flu has been detected in fresh areas.
The death of chickens was reported from the Bogri and Kachumara areas, prompting the district administrations to ban purchase and sale of eggs. Over a hundred birds were found dead at the Bongra and Kachumara areas from where samples had been collected and sent to the laboratories in Bhopal and Pune, Kamrup (rural) deputy commissioner R.C. Jain said.
The alert has been sounded as a precautionary measure as the avian disease is suspected to be spreading to fresh areas of Sarpara, Rangamati, Bongra and Kachuniapra villages.
The Karmup (metro) district administration has also imposed a ban on movement of birds and eggs from the affected areas as well as from the nearby markets at Mirza and Plashbari in the outskirts of the city.
In the Kamrup (rural) district, nearly 50,000 birds have been culled and another 30,000 will be culled in the next couple of days.
Comment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
CommentaryOriginally posted by niman View Post
Additional H5N1 Spread in Assam India
Recombinomics Commentary 11:46
December 2, 2008
bird flu is suspected to have spread over new areas, including Sarpara (near Mirza), Rangamati and Bongra Kachuniapara villages in the district, said Kamrup Deputy Commissioner RC Jain.
According to sources, unnatural death of the birds has been reported from Rangamati and Sarpara since a few days back. Over 100 hens and cocks were found dead in Bongra Kachuniapara today, sources said.
The above comments describe likely additional spread of H5N1 into new areas. After confirmation of H5N1 30 km west of Guwahati, culling activities have expanded well beyond the initial radius of 3 km, 5 km, or 10 km (see updated map). The poultry deaths at these additional locations are not a surprise. Large numbers of birds migrate into the area at this time, and H5N1 has also been confirmed recently in Bangladesh.
One year ago both countries experienced massive outbreaks in the region, and poultry deaths were described in Assam. Additional poultry deaths in the region are expected.
."The next major advancement in the health of American people will be determined by what the individual is willing to do for himself"-- John Knowles, Former President of the Rockefeller FoundationComment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
CommentaryOriginally posted by niman View Post
H5N1 Transport and Transmission By Wild Birds
Recombinomics Commentary 13:53
December 2, 2008
While it is not impossible that this outbreak in Assam in northeast
India might be due to migratory birds, there is as yet very little
evidence for them playing a meaningful part in the epidemiology of
this disease, in fact, rather to the contrary, as commercial
movements of poultry and such have been found to be the consistent
cause.
The above remarks on the current outbreak of H5N1 in Assam, India ignore the temporal and spatial data, as well as sequence data, which support a wild bird origin for the spread of H5N1 west of China, including south Asia, since the outbreak at the Qinghai Lake Nature Reserve in the spring of 2005. Prior to that outbreak H5N1 had been reported in wild birds, but the direction of transmission was unclear, due in part to the frequent poultry outbreaks of H5N1 in China and countries to the east of China.
In May, 2005 China reported large scale deaths of long range migratory birds at Qinghai Lake. One hypothesis, which was published in detail on ProMED held that the deaths at Qinghai Lake represented ?wild birds as victims? and the spread from Qinghai Lake was unlikely because ?dead birds don?t fly?. However, the nature reserve at Qinghai Lake is large, with well over 100 species of birds representing 100?s of thousands of birds.
The initial OIE report described five H5N1 infected species of long range migratory birds, including bar-headed geese, which can migrate 1000 miles in 24 hours, allowing for significant spread by birds that were lethally infected. Moreover, low path H5 is present in wild migratory birds offering cross-reactive immunity to H5N1. Therefore, many H5N1 produced mild symptoms or were asymptomatic in waterfowl. The outbreak at Qinghai Lake represented a new sub-clade (2.2 or Qinghai strain), which allowed the spread to be monitored by phylogenetic analysis of the sequences from the isolates. The sequences had many of the hallmarks of highly pathogenic avian influenza from Asia, including a polybasic cleavage site in HA, and 20 aa deletion in NA, a 5 aa deletion in NS. Moreover, clade had a number of distinguishing markers, including a distinctive HA polybasic cleavage site of GERRRKKR, as well as E627K in PB2, which had not been previously reported in H5N1 in birds (prior H5N1 isolates with E627K were mammalian, which was also true for seasonal flu).
Since clade 2.2 was associated with waterfowl deaths, following its spread was relatively straightforward, even in the absence of confirming sequence data. After the May / June outbreak at Qinghai Lake, farms in northwest China reported H5N1 outbreaks in waterfowl in June, suggesting the clade 2.2 at Qinghai Lake did not burn itself out. This was confirmed by a large outbreak of H5N1 in wild bird and poultry near Chany Lake in Russia in July. The H5N1 was sequenced and was clade 2.2. Moreover the isolates included a healthy crested grebe, providing direct evidence for asymptomatic infection of migratory birds. Previously Russia had not reported HPAI H5N1, which was also true of Kazakhstan, which also had H5N1 in adjacent regions in August, 2005.
In addition to the outbreaks in Russia and Kazakhstan in August, 2005, Mongolia reported wild bird deaths at the remote Erhel Lake. Bird conservation groups aided in the investigation and the comments on results linked to Erhel Lake were telling. Initial comments expressed doubts that the dead birds would be H5N1 positive, because the number of dead birds was markedly lower than Qinghai Lake. Even after initial data showed that the dead waterfowl was H5 positives, doubts were expressed that the H5 birds would be H5N1 infected. After the birds were H5N1 confirmed, doubts were expressed that H5N1 would spread, because cloacal swabs from healthy birds were H5N1 negative.
However, H5N1 had clearly migrated into Erhel lake, and the negative data on healthy birds was not compelling because the H5N1 testing was initially designed to detect H5 in dead or dying poultry, which would have a higher viral load and individual tissues with signs of pathology could be assayed. Moreover, although detection of H5N1 in healthy birds was a challenge, H5N1 had been isolate from a asymptomatic crested grebe at Chany Lake.
The ability of the testing procedures to detect H5N1 in infected birds was experimentally tested. Although the birds had been experimentally infected, most H5N1 detection was limited to nasopharyngeal swabs. Cloacal swabs were negative for H5N1 isolates, and generally negative in PCR tests. Virus isolation from nasopharyngeal swabs was limited to a 24 hour period several days post-infection. PCR tests detected H5 for a slightly longer time period, but most daily collections post infection were negative.
Thus, detection of H5N1 in healthy wild birds is rare, especially when cloacal swabs or fecal samples are collected. However, Russia published a Mission report in the 2005 outbreak and found H5N1 in hunter killed birds including over two dozen wild bird species. These data once again demonstrated that H5N1 was widespread in wild birds, but detected under a limit set of circumstances.
Russia reported multiple outbreaks in southern Siberia in the summer of 2005, raising concerns that H5N1 would spread to Europe, the Middle East, and Africa as birds migrated south from Russia and Mongolia via well characterized flyways.
The concerns were realized in the following months. H5N1 was first reported in the Volga Delta in late August, followed by outbreaks in Romania, Turkey, and Ukraine in late 2005.
However, the most compelling data was the detection of H5N1 in a healthy teal in the Nile Delta in December, 2005. Although the level of H5N1 was too low for isolation of the virus, repeated extraction and amplification of the RNA yielded HA and NA sequences which were Qinghai H5N1 and most closely related to H5N1 in Austria. In December, 2005 all countries in western Europe, including Austria, denied H5N1 infection, as did countries in the Middle east and Africa.
In late 2005, family members in eastern Turkey began developing bird flu symptoms. Four siblings were transferred to Van and three were unconscious. Initial throat swabs were negative, but as siblings died, fluid from their lungs were H5N1 positive and sequence analysis showed that these were clade 2.2. Human cases were subsequently confirmed in Iraq, Azerbaijan, Egypt, and Djibouti. All were clade 2.2.
In January, 2005 reports of confirmed H5N1 in wild birds and poultry were submitted by countries in Europe and the Middle East and by the spring of 2005 approximately 50 countries reported confirmed H5N1. All isolates were clade 2.2 and many countries, especially in Europe, reported H5N1 exclusively in wild birds.
This sequence of events was repeated a year later. In the summer of 2006 there was a massive H5N1 outbreak at Uvs Lake in Mongolia and adjacent areas in southern Russia. H5N1 is not a reportable disease in wild birds and neither country filed an OIE report, but media reports indicted the bird deaths were on a par with Qinghai Lake and sequences from Mongolia and Russia (Tyva) were published. The sequences represented one of the clade 2.2 sub-clades circulating in eastern Europe and south Asia in 2006 (clade 2.2.3), but additional changes were found in these isolates, which phylogenetically defined a Uvs Lake strain. These sequences were subsequently reported in South Korea and Japan at the end of 2006, followed by Kuwait in early 2007.
Although the Uvs Lake strain was not reported in Europe at the end of 2006 or beginning of 2007, it appeared in wild birds in the summer of 2007. Following a poultry outbreak in the Czech Republic, H5N1 was reported in wild birds in Germany at multiple location in four states, as well as wild birds in the Czech Republic and France. Although all isolates were the Uvs Lake strain, each location had unique sequences indicating that a common poultry source was not responsible for the multiple outbreaks. Earlier, in 2007 the outbreaks in Bernard Mathew turkeys in England was virtually identical (99.96% identity) with sequences from Hungary, where the same country had operations, demonstrating the level of identity expected for isolates from a common source. This level of identity was not present in the multiple wild bird isolates. Thus although all were the Uvs Lake strain, all were due to independent introductions, which was also reported for multiple outbreaks in Nigeria in 2006, which were initially speculated to be due to trade.
In late 2007 / early 2008 the Uvs Lake strain spread throughout Europe. Recently released sequences from a German wild bird outbreak in Bavaria in the summer of 2007, as well as free range turkeys in England at the end of 2007, and wild swans in England at the beginning of 2008 were all the Uvs Lake strain, but each outbreak represented an independent introduction.
Thus, sequence analysis can easily distinguish between a common source or independent introductions, but this type of analysis is rare for countries like India or Bangladesh. A recent report on the 2007 outbreak in Bangladesh had only one full sequence. Although all HA cleavage sites were clade 2.2, the lack of full sequences precluded determination of whether the multiple outbreaks were due to independent introductions. For the outbreaks that began at the end of 2007 in Bangladesh, no sequences have been made public, but are clade 2.2 and closely related. However, it is unlikely that the level of identity is above 99.9% as was seen in the England / Hungary isolates which were linked by the same company with facilities in both countries.
Thus, which sequence data from the current outbreak in India is unlikely to be forthcoming, sequence analysis of prior outbreaks in Europe, the Middle East, Africa, and south Asia support independent introductions of clade 2.2 by resident or migratory birds.
."The next major advancement in the health of American people will be determined by what the individual is willing to do for himself"-- John Knowles, Former President of the Rockefeller FoundationComment
-
Re: India: Assam, a new confirmed h5n1 poultry epizootic (11/26/2008) [rsoe edis]
Is this true for non-avian species also? Or is it a function of the fact that birds are able to keep the viral load low becase they are so well adapted to influenza?....the negative data on healthy birds was not compelling because the H5N1 testing was initially designed to detect H5 in dead or dying poultry, which would have a higher viral load and individual tissues with signs of pathology could be assayed....
."The next major advancement in the health of American people will be determined by what the individual is willing to do for himself"-- John Knowles, Former President of the Rockefeller FoundationComment
Comment