UK: H1N1 `Swine’ Flu Found In Turkeys

 

 

 

# 5224

 

 

From Defra (Department for Food and Rural Affairs) in the UK this morning, we learn that turkeys on a farm in Cheshire have tested positive for an H1N1 virus `closely similar’  to the 2009 pandemic strain.

 

Although we’ve seen a few instances of turkeys (and cats, dogs, ferrets, and even cheetahs) infected with the 2009 H1N1 swine flu virus, this is the first detection I’ve seen of the swine flu virus among poultry in the UK.

 

A few past blogs on the slightly promiscuous nature of this swine H1N1 influenza strain include:

 

US: Dog Tests Positive For H1N1

US: Turkey Farm Reports H1N1

Study: H1N1 And Birds

Cat Got Your Virus?

 

 

The Defra news release follows:

 

H1N1 found in turkeys

Published on Wednesday 12 January 2011 at 10:56am

A routine disease investigation has ruled out avian notifiable disease but detected H1N1 influenza in turkeys on a farm in Cheshire.

 

The strain is closely similar to the human pandemic H1N1 strain currently circulating.

 

The Health Protection Agency has undertaken a thorough public health risk assessment and can confirm there is no risk to public health.

 

This finding has resulted from a routine notifiable avian disease investigation relating to a small number of turkeys showing mild signs of disease. During the investigation there was clinical improvement in these birds.

 

Results of laboratory tests show that statutory notifiable avian disease – where the government would need to take animal health action – can be ruled out. Restrictions have been lifted on the farm.

 

There is no food safety risk. Pandemic H1N1, in common with avian influenza, has not been shown to be transmissible to people through eating properly handled and cooked poultry meat, products and eggs.

 

Bird keepers should continue to maintain appropriate biosecurity measures and be vigilant for signs of notifiable avian disease and report any suspicion promptly to the Animal Health agency.

Notes

1. Pandemic H1N1 2009 has been confirmed in poultry in other countries around the world including the USA, Canada, Chile and France.
2. Influenza viruses have been shown to infect a great variety of birds. In poultry, influenza causes two distinct clinical forms: highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI). HPAI leads to serious disease in almost all poultry species resulting in large numbers of deaths. It is caused by some viruses of H5 or H7 subtypes. LPAI viruses belong to all H subtypes and only cause mild limited infection.  
3. The UK maintains a programme of surveillance of avian influenza in domestic poultry and wild birds found dead.
4. When statutory notifiable avian disease is confirmed action to confine and stamp out disease includes movement controls on susceptible species in the area around  the premises, enhanced biosecurity, culling of susceptible poultry on the premises  and cleansing and disinfection of the premises.

 

 

Given the tendency for H1N1 to appear as a mild, LPAI infection in gallinaceous poultry (such as  grouse, turkeys, pheasants and quail), poultry infections like this one probably happen more often than we are aware.

»» Read More

OIE Report: Manitoba Bird Flu Identified As H5N2

 

 

 

# 5091

 

 

My thanks to Ironorehopper on FluTrackers for posting the link to this OIE notification detailing the avian flu outbreak at a turkey farm in Rockwood, Manitoba.

 

I’ve excerpted part of the report below.

 

 

Low pathogenic avian influenza (poultry), Canada

Information received on 25/11/2010 from Dr Brian Evans, Chief Food Safety Officer/Chief Veterinary Officer, Office of the President, Canadian Food Inspection Agency, OTTAWA, Canada

New outbreaks

Outbreak 1 (NAI-2010-MB-001)
Rockwood municipality, MANITOBA

Date of start of the outbreak
17/11/2010

Outbreak status
Continuing (or date resolved not provided)

 

Affected Population

Turkey breeders farm, with four barns on site. Barn 1 is empty, barn 2 contains 600 toms (approx.), barn 3 contains 3,000 hens (approx.) and barn 4 contains 3,800 hens (approx.). The hens in both barn 3 and 4 are 44 weeks old and were lethargic with a 45% decrease in egg production but the egg production has improved since the start of the event. No respiratory disease was observed. The mortality in the flock has not increased.

Epidemiology

Source of the outbreak(s) or origin of infection

• Unknown or inconclusive

Epidemiological comments

This is the first outbreak of Notifiable Avian Influenza (NAI) detected in the province of Manitoba.

The farm has been quarantined by the Canadian Food Inspection Agency (CFIA) and investigation will be conducted in compliance with the Canada's Notifiable Avian Influenza Hazard Specific Plan. A stamping out policy will be applied.

Preliminary results from the National Center for Foreign Animal Diseases in Winnipeg indicate the presence of a H5N2 subtype avian influenza virus (PCR).

Sequence analysis of the PCR products indicates that the cleavage site is consistent with low pathogenic avian influenza virus H5. Closest matches (99% identity) in Genbank are to North American H5N2 viruses from wild birds.

Virus isolation is underway and additional testing is to come, including the intravenous pathogenicity index test.

NAI surveillance has been in place in domestic poultry in Canada for many years and this outbreak is limited to the province of Manitoba.

Note by the OIE Animal Health Information Department: H5 and H7 avian influenza in its low pathogenic form in poultry is a notifiable disease as per Chapter 10.4. on avian influenza of the Terrestrial Animal Health Code (2010).

Control measures

Measures applied

• Quarantine
• Movement control inside the country
• Screening
• Vaccination prohibited
• No treatment of affected animals

Measures to be applied

• Stamping out
• Disinfection of infected premises/establishment(s)

»» Read More

CFIA Statement On Manitoba’s Avian Flu Outbreak

 

 

# 5087

 

The CFAI (Canadian Food Inspection Agency) has released the follow statement on the detection of bird flu on a Manitoba turkey farm.

 

As opposed to the earlier news story out of Winnipeg, no mention of the strain is made in this release.

 

 

CANADIAN FOOD INSPECTION AGENCY

Nov 24, 2010 17:00 ET

Canadian Food Inspection Agency: Avian influenza Confirmed in Manitoba

OTTAWA, ONTARIO--(Marketwire - Nov. 24, 2010) - The Canadian Food Inspection Agency (CFIA) has confirmed the presence of an avian influenza virus in a commercial poultry operation in the Rural Municipality of Rockwood, Manitoba.

 

Further testing is underway to determine the precise subtype and pathogenicity of the virus. Pathogenicity refers to the severity of the illness caused in birds. Clinical assessment and laboratory analysis to date suggests this is likely a low pathogenic virus.

 

Avian influenza viruses do not pose risks to food safety when poultry and poultry products are properly handled and cooked. Avian influenza rarely affects humans, unless they are of specific types and there has been close contact with infected birds.

 

All birds on the infected premises will be humanely euthanized and disposed of, in accordance with provincial environmental regulations and internationally accepted disease control guidelines. Once all birds have been removed, the CFIA will oversee the cleaning and disinfecting of the barns, vehicles, equipment and tools to eliminate any infectious material that may remain.

 

The CFIA is conducting a thorough epidemiological investigation, including tracing any recent movement of birds, bird products and equipment onto and off of the infected property. To limit any potential virus spread, the CFIA is also applying restrictions on the movement of poultry and poultry products within three kilometres of the infected premises.

 

Animal health and public health authorities from the Province of Manitoba, local poultry specialists and industry are actively collaborating on the response to avian influenza in the Manitoba poultry operation, and in supporting the producer.

 

All poultry owners are urged to take an active role in protecting their flocks. This includes employing strict biosecurity measures on their property and immediately reporting sick or dead birds to their veterinarian or the nearest CFIA office. Further information on biosecurity is available on the CFIA website at www.inspection.gc.ca/biosecurity.

 

The CFIA is notifying the World Organisation for Animal Health (OIE) and international trading partners of this situation.

 

New information will be provided to the public as it becomes available.

 

For information on safe food handling, please visit: http://www.inspection.gc.ca/english/fssa/concen/concenrol/rolsafe.shtml

 

For more information, please contact

Canadian Food Inspection Agency
Media Relations
613-773-6600

 

»» Read More

CTV Reporting Low Path H5 On Canadian Turkey Farm

 

 

# 5086

 

 

Although first announced several hours ago, details remain sketchy on the type avian flu strain detected in number of turkeys at a farm in the rural municipality of Rockwood, Manitoba.

 

CTV Winnipeg is reporting this as an H5 strain, likely low path, and not the highly pathogenic H5N1.

 

Other media outlets are not specifying a strain, so these details could change or evolve over the next few hours. 

 

A hat tip to Ironorehopper on FluTrackers who posted the following report.   An ongoing thread (started by Shiloh) tracking new developments is available at this link.

 

 

 

Turkeys in RM of Rockwood test positive for form of bird flu, officials believe strain is non-deadly

Officials have not yet said how many of the animals tested positive for an H5 strain of bird flu.

Updated: Wed Nov. 24 2010 14:19:36
ctvwinnipeg.ca

Provincial and federal officials have quarantined a turkey farm in the RM of Rockwood.

 

Some turkeys have tested positive for an H5 strain of bird flu, but there is no evidence it is the deadly form known as the Asian strain of the H5N1 influenza, said provincial officials.

 

There has been no indication of human illness.

(Continue . . .)

 

 

Low path outbreaks of avian influenza have been recorded in North America (and around the globe) in the past, and rarely present a human health threat.

 

CIDRAP’s overview on avian influenza Avian Influenza (Bird Flu): Agricultural and Wildlife Considerations  details many of these outbreaks.

 

Low Pathogenic avian viruses, if left  unchecked, have the potential to mutate into a more highly pathogenic strain. For that reason low path outbreaks of the H5 and H7 variety are taken seriously, and are a reportable disease to the OIE.

 

Culling is generally the recommended response.

»» Read More

US: Turkey Farm Reports H1N1

# 4104

 

 

 

It was only last month that that a study in Eurosurveilance sought to reassure us that Turkeys weren’t particularly susceptible to the H1N1 virus.   

 

Below is just an excerpt.

 

Eurosurveillance, Volume 14, Issue 41, 15 October 2009

Rapid communications

Resistance of turkeys to experimental infection with an early 2009 Italian human influenza A(H1N1)v virus isolate

C Terregino¹, R De Nardi¹, R Nisi¹, F Cilloni¹, A Salviato¹, M Fasolato¹, I Capua ()¹

 

Our findings suggest that in its present form, the pandemic H1N1 influenza virus is not likely to be transmitted to meat turkeys and does therefore not represent an animal health or food safety issue for this species.

 

 

Despite this study (which has an excellent pedigree in Ilaria Capuam, noted virologist for the OIE/FAO in Italy), over the past few months we’ve had reports of infected turkeys in Chile (see FAO: Concerns Novel H1N1 May Spread In Poultry  and   Chile: H1N1 Jumps To Turkeys) and Canada  (see Update On Ontario H1N1 Infected Turkeys).

 

Now, a US turkey farm in the the state of Virginia is reporting an H1N1 infection in a flock.   A hat tip goes to Indigo Girl on Allnurses pandemic forum and celvin11 on FluTrackers for the link.

 

This report from Reuters. 

 

U.S. finds pandemic H1N1 virus in turkey flock

 

Mon Nov 30, 2009 5:53pm EST

WASHINGTON (Reuters) - The pandemic H1N1 flu virus was confirmed in a flock of breeder turkeys in Virginia -- the first U.S. case involving turkeys, the U.S. Agriculture Department said on Monday.

 

The virus also has been found in hogs, three house cats, pet ferrets and a cheetah in California. USDA said infections of turkeys have been reported in Canada and Chile.

 

"This is the first detection of 2009 pandemic H1N1 influenza in turkeys in the United States," said a USDA spokesperson.

(Continue . . . )

 

We’ve chronicled a number of species jumps involving the H1N1 virus, and the Reveres at Effect Measure took on the subject of promiscuous flu viruses in their blog today  (see Dogs, cats and swine flu's promiscuity).

 

I confess I’m unaware of the `cheetah story’ alluded to in the above story, and a quick Google search didn’t turn up anything. 

 

We will no doubt be reminded by the USDA that these infections pose no food safety issues, but the ultimate threat of an ever widening host range for the H1N1 virus is less clear. 

There are a couple of trains of thought here.  

 

One is that when the virus broadens its host range, it has more opportunities to mutate or to reassort with other viruses. 

 

One might, after all, reasonably expect that the H1N1 virus has a better chance to meet up and reassort with an H5 or H7 avian virus in a turkey, than in a human host. 

 

There is another theory, however, that states that viruses don’t tend to mutate as long as they have a large number of susceptible hosts.

 

Virologist John Oxford has suggested that mutations in the H1N1 virus are less likely to occur until a certain amount of herd immunity is achieved. There have been studies that indicate that vaccination pressure may actually drive antigenic drift in flu viruses.

 

Avian influenza: genetic evolution under vaccination pressure

Magdalena Escorcia, Lourdes Vázquez, Sara T Méndez, Andrea Rodríguez-Ropón, Eduardo Lucio and Gerardo M Nava

Virology Journal 2008, 5:15doi:10.1186/1743-422X-5-15

 

As a population gains herd immunity (through vaccines or exposure), the virus must either evolve (mutate) away from the established immunity or die off for a lack of suitable hosts.

 

But, if the virus has a wider host range (say humans, pigs, and birds), or a ready natural reservoir, then there is less evolutionary pressure on it to mutate.  

 

Of course this second theory doesn’t help much with relatively rare, but major antigenic shifts (reassortments), but deals mostly with the far more common antigenic drift (minor mutations).

 

Which theory is correct?

 

It’s entirely possible that both are correct, as they are not mutually exclusive. 

 

As to what happens with this promiscuous pandemic H1N1 virus? 

 

That’s the $64 question, and no one has a good answer yet. 

 

Stay tuned.

»» Read More