Wednesday, July 27, 2016

Denmark: Ducks Infected With LPAI H7 Avian Influenza

Funen - Credit Wikipedia














#11,588


From the DVFA (The Danish Veterinary and Food Administration) we are informed of an LPAI H7 outbreak in a flock of ducks on the island of Funen.

Although LPAI H5 and H7 viruses are common in birds - and pose little threat to poultry or to humans - they are taken seriously due to their ability to mutate into HPAI strains (see You Say You Want An Evolution?)
 
Two reports from the DVFA.

Avian flu in Funen gråandebesætning

A herd of mallard ducks on Funen in Brenderup affected by the less severe avian flu H7N7. The crew consists of 3,000 ducklings. To prevent infection and to prevent the virus evolves, the infected ducklings be killed. DVFA create a 1km restricted zone around the farm.

Press release , Published: July 27, 2016

The movement of birds within and to and from the restricted zone are done with DVFA permission. Backyard poultry within the zone must be registered with the Food Authority. See restricted zone here . The killing is carried out in collaboration between the Food Authority and the Emergency Management Agency. There will be a thorough cleaning and disinfection of the property.

Discovered by routine surveillance samples Smitten crew members are discovered during routine surveillance samples are being taken as part of the Danish action plan against bird flu. - 


We consider always low pathogenic bird flu seriously because it can evolve into a highly pathogenic type. I can reassure that the low-pathogenic avian flu is not contagious to humans. Killing and security is done to prevent further problems, says deputy head of the Food Administration, veterinarian Stig Mellergaard.

Backyard poultry within 1km zone must be registered owners of hobby poultry flocks in the restricted zone must let their herd register with the Food Agency to the Board by the crews, located in zone. the registration of the name, address, poultry type and number must be registered with the Food Authority's customer advice on 7227 6900 or via mail

Note: Although machine translators don't handle the term gråandebesætning very well, it roughly translates to  `mallard herd'. 

A second report from the DVFA follows:

On July 27, 2016: Low pathogenic avian influenza in routine samples taken in Funen gråandebesætning

A fynsk gråandebesætning affected by low pathogenic avian influenza type H7N7, which is a less severe type. There implemented the necessary control measures on detection of low pathogenic avian influenza H7N7 including culling of the infected herd. Furthermore creates DVFA one 1 km restricted zone around the farm. The movement of birds within and to and from the restricted zone are done with DVFA permission. The infection in the herd is discovered during routine surveillance samples are being taken as part of the Danish action plan against bird flu. It is important that poultry owners comply with the restrictions within the restricted zone.

In the restricted zone are not allowed to:
  • Moving poultry, other captive birds lay poultry, day-old chicks and eggs within, into and from the restricted zone,
  • Hold fairs, exhibitions, markets, auctions, kapflyvninger or any other collection of poultry or other birds in the restricted zone
  • Expose feathered to reconstruction of wildlife in the restricted zone
  • Remove or spreading used litter, manure or slurry within the restricted zone.
The ban on movement of poultry, other captive birds lay poultry, day-old chicks and eggs do not apply for direct transit through the restricted zone on road or rail.
Authorize the movement can be given of Veterinary Unit under special conditions.

Have you backyard poultry within the zone?
Owners of backyard poultry within the restricted zone must let their poultry register with the Food & Drug Administration to help the Agency to gain knowledge of the crews that are in the zone.

DEFRA: Update On HPAI Outbreaks In France
















#11,587


Although posted today, this UK DEFRA (Department for Environment, Food & Rural Affairs) report is current through the 22nd of July, and therefore does not include the 80th outbreak I reported on yesterday. 
Department for Environment, Food and Rural Affairs
Animal & Plant Health Agency
Veterinary & Science Policy Advice Team - International Disease Monitoring


Updated Outbreak Assessment


Avian Influenza of high pathogenicity (H5N1 & H5N2)in poultry in France
22 July 2016
Ref: VITT/1200 HPAI in France
Disease Report
Since the last update on the 18 th February, several new outbreaks in poultry have been reported as a result of increased surveillance in South West France (see map – only recent outbreaks shown).
To date there are 79 outbreaks of HPAI H5 (N1, N2 and N9) and sixteen outbreaks of LPAI H5 (N2 and N3) which have been reported to the EU Animal Disease Notification System. The most recent outbreaks have been reported this week, one in the Dordogne and one in Aveyron (OIE, 2016).
In Dordogne, a broiler flock was exhibiting increased mortality over a period of two days, and has tested positive for H5N1 HPAI. In Aveyron, a flock of fattening, free range ducks tested positive for H5N2 HPAI in the framework of national surveillance.
Disease control measures have been put in place around each infected premises including culling all  poultry present. The restriction zone (under an amendment to Implementing Decision 2015/2460/EU) has remained in place and not changed as a result of these outbreaks. The French eradication plan which was put in place earlier in the year has finished and farms are being restocked, so these new cases suggest that disease is still circulating or that viral contamination is still present in certain areas. The exports and trade of live poultry, hatching eggs and day-old chicks are carefully controlled from the restriction zone.
Situation Assessment
The eradication plan put in place by the French Authorities two months ago was designed to allow production of poultry (particularly fattening ducks and geese) to continue under strict control until the point of slaughter and then for restocking to take place after a period of the premises lying fallow and following a programme of C&D, particularly for those farms with free range birds. The monitoring programme on the repopulated farms has been carried out on 100 farms and 99 have tested negative, with just the one positive
result in Aveyron.
It will be of interest to understand whether the HPAI viruses in these recent outbreaks are closely related to those found in 2015 or if they are new introductions, which seems unlikely, but should not be dismissed until the sequences are known.
Conclusion
These recent outbreaks are a setback for the poultry industry in this region, but the French Ministry has confirmed that these results justify the strict biosecurity measures they have put in place in the last eight months because of the high infection pressure present.
The risk to the UK has not increased as a result of the new outbreaks reported. We will continue to monitor the situation closely. We would like to remind all poultry keepers to maintain high standards of biosecurity, remain vigilant and report any suspect clinical signs promptly and in addition using the testing to exclude scheme for avian notifiable disease where appropriate for early safeguard.
For more information, please see
www.defra.gov.uk/ahvla-en/disease-control/nad
The risk level for the UK remains at low, but heightened.

Saudi MOH: KKUH Hospital Outbreak As A `Superspreading' Event

Credit Saudi CCC
















#11,586




For much of the month of June we followed the outbreak at  Riyadh's KKUH (King Khalid University Hospital) which spiraled to more than 2 dozen cases (see Saudi MOH On KKUH MERS Outbreak & Increased Asymptomatic Detections).

Of the 28 cases from the KKUH outbreak, 21 were listed as being either very mild or asymptomatic.  An unusually high ratio by any standard.

Today the Saudi National Command & Control Center (CCC) is back with another review of that outbreak, this time focusing on what they describe as a `super-spreading' event.
We've seen other large hospital outbreaks attributed to `super spreading' events (see The Lancet: Mapping The Korean MERS-CoV Superspreading Event).  

While some infected patients do shed more virus than others (see Influenza Transmission, PPEs & `Super Emitters’), it generally takes more than a highly infectious patient to spark an event.  According to Stein’s excellent 2011 review Super-spreaders in infectious diseases:


Super-spreading events are shaped by host, pathogen, and environmental factors. Often, more than one factor may be implicated in the same outbreak.

Although today's Weekly Monitor Report from the Saudis places the KKUH outbreak in the `superspreading' category, it provides relatively few details. Hopefully a more detailed epidemiological report is in the works.


Weekly Monitor

MERS-CoV

Volume 2 Issue 29 Tuesday 26 July 2016
Current Event


MERS Super-Spreading events

The recent outbreak of MERS reported from a university hospital raised the possibility of having a super-spreading events resulting in a larger outbreak.

Super-spreading events were strongly suspected considered in some MERS outbreaks. Certain MERS infected individual may transmits an infection disproportionately to more susceptible contacts, possibly because of increased viral load, heavy respiratory secretions, than the average infected individual.

Super-spreading events constitute the presence of those “highly infectious” individuals in crowded areas like emergency rooms in contact with other patients, healthcare workers and environment. Such events can cause large outbreaks similar to the outbreak in South Korea last year.

During the outbreak of Korea, majority of MERS transmission were linked to super-spreading events. Similarly, the recent nosocomial MERS outbreak in Riyadh (2016) was probably related to a super-spreading event (Figure 1). 


This was also observed in the outbreak of 2013 in Al-Ahsa. Mis-diagnosis or late diagnosis due to co-infection with another pathogen and/or immunosuppression are one of the facets in super-spreading incidents along with individual variation in infectivity and the number of contacts.

It is self-evident, however, that other factors played a role in these incidents. Super-spreading events tied to nosocomial outbreaks of MERS have been attributed in part to suboptimal infection prevention and control (IPC) measures, overcrowded emergency departments (ED), limited isolation rooms in EDs and inadequate ventilation, delayed hospital admission, interhospital transfers, and/or poor communication between healthcare facilities (HCFs).

Super-spreader events are key to amplify nosocomial transmission of MERS and support the Region adoption of IPC precautions particularly in treatment rooms.

It is important to identify such highly infectious individuals and super spreading events through full investigation of the transmission pathways from a single index case to secondary cases in HCFs. 


Rapid case detection and strict adherence to IPC Eastern Region measures, which can rapidly reduce the risk of super-spreading events and therefore the size of the nosocomial outbreaks.

Predicting and identifying super-spreaders open significant medical and public health challenges, and represent important aspects of infectious disease management and emergency preparedness plans. 
Generally, the key to prevent large outbreaks of emerging infectious diseases is through complete preparedness in HCFs and proper collaboration between health and other governmental agencies.



Super spreading events aren’t limited to SARS and MERS, as they have also been documented with measles, HIV, TB, S. aureus, Ebola, and various STDs . . .among others (cite).


While the host and the pathogen are important parts to the equation, the lesson in South Korea is environment and opportunity play huge roles in exacerbating these super spreader events.  

Beyond exposure to a highly infectious host, just last April the Saudi MOH identified a number of other factors behind many of these large hospital outbreaks.



Many of MERS outbreaks originated in the Emergency Department (ED). Almost all MERS outbreaks in HCFs stemmed from one or more of the following factors:
  • Inadequate awareness of physicians to the case definition of MERS; 
  • insufficient adherence to Infection Prevention and Control (IPC) practices and procedures especially during Aerosol Generating Procedures (AGP), by not wearing proper Personal Protective Equipment (PPE), or performing AGP in rooms with no negative pressure; inadequate implementation of respiratory triaging of cases;
  • discharge against medical advice and inadequate communication of such incidents;
  • gaps and flaws in the referral mechanism of MERS cases;
  •  overcrowded ED and irregular control of entrances;
  •  and inadequate control of visitation.


A reminder that - while we can't control the infectivity of patients walking into the emergency room - we can reduce a hospital's ability to spread the virus once they arrive.


For more on what that may take, you may wish to revisit TFAH Issue Brief: Preparing The United States For MERS-CoV & Other Emerging Infections.

 

Two Out-Of-Season H7N9 Cases - Beijing & Henan Province

 Credit WHO


#11,585


Over its 4 year history, mid-summer (epi weeks 24-36) has been a dead zone for H7N9 reports coming out of China, with just 5 cases falling within that time span since 2013. Most years, the H7N9 season ends on or around week 20 (mid May).

Although the numbers remain low, the summer of 2016 is proving to be a bit different, as we've continued to see reports of H7N9 activity throughout June and now into late July.

This unseasonable H7N9 activity - including outbreaks in Hong Kong and Macao Live Bird Markets -  last month prompted Hong Kong's CHP to publicly warn:

"In view of additional human cases reported in the Mainland with detections of human cases in previously unaffected areas in warmer months, as well as the recent local positive sample of faecal droppings of live poultry, the public should remain vigilant."

Today we've reports of two recent H7N9 cases, both very much out of season, and one in a province (Henan) that hasn't reported a case since the first wave (April of 2013).



In an epidemiology report for the month of June, they reveal a new case, with an apparent onset on June 9th.  This report is dated July 20th.

June 2016 before the outbreak of notifiable infectious diseases in Henan Province
 
Published: 2016-07-20 

2016 Nian . 6 months (2016 Nian . 6 Yue 1 RiMidnight to. 6 Yue 30 Ri24 ), the province reported a total of notifiable infectious diseases 49366 cases of death 131 cases. 


(SNIP)
 

On June 9, the second people's hospital reported the province, Fuyang city people infected H7N9 avian influenza 1, Zhang, female, 54 years old, farmer, xincai, and as confirmed cases.


In response, today Taiwan's CDC issued the following statement:




County, Henan province, health and family planning Committee in the province first H7N9 flu cases this year, based on local environmental exposure risk, CDC Department announced that promote tourism in the province outbreak Taipei proposed to the second-level alert (Alert), and has notified the Mainland Affairs Council. Frequent cross-strait exchanges and falls during the summer, calls on travel plans to the region and local Taiwanese, be sure to pay attention to personal hygiene and diet, and avoiding contact with poultry and live bird markets in order to reduce the risk of infection.


CDC says the case for 54 years old female farmer, xincai, poultry or live poultry market exposure is not known. China city since to (2015) years autumn yilai cumulative at least 116 cases H7N9 flu cases, this popular quarter outbreak obviously below Qian three quarter, only June announced cases number more Shang quarter slightly increased, and in past no outbreak of provinces found cases; existing evidence displayed H7N9 flu still is limitations people descendants, case more for 50 age above, and with poultry class or live poultry market exposed history.

Hospitalized in Beijing (h/t Sharon Sanders for the Beijing CDC link), we have a new case that has been making headlines in the Chinese media for the past couple of hours.


The city has found a case of human infection with the H7N9 avian influenza
Published: 2016-07-27

July 26, 2016, the city found a case of human infection with H7N9 avian influenza. Accounting for some patients, male, 36 years old, current address Langfang City, Hebei Province Yanjiao a district. In the provinces before the onset of suspicious live poultry exposure history. July 26, the Beijing Municipal Center for Disease Control reviewed detected as H7N9 avian influenza virus nucleic acid positive. Currently, patients are being treated in isolation in a hospital in Beijing, a critical condition.

Up to now, the city has reported 2016 3 H7N9 bird flu cases confirmed cases of human infection. This case is only sporadic cases in the city causing widespread risk of transmission is very low. Although our country there have been cases of avian influenza reported, but now that people are not susceptible to avian influenza virus. Poultry, sale, slaughter, Wildfowl and other people exposed to the virus because the probability of a large increase in the risk of infection.

Currently, etiology characterized H7N9 avian influenza virus transmission and propagation mode currently did not change significantly, China's urban and rural areas live poultry market transactions ubiquitous phenomenon backyard poultry in the short term it is difficult to eliminate. Therefore, it is expected there will still be human infection of H7N9 bird flu epidemic still on distributing state, there will be a small number of clusters of disease.

The city remains the illegal small-scale trading of live poultry and live birds enter the presence of other provinces the situation. Therefore, do not rule out the possibility the city residents infected with H7N9 avian influenza virus. In addition, many medical institutions in the city, a large number of foreign patients to seek treatment for the city, does not exclude foreign imported cases to the city medical institution may be diagnosed.
       (continue . . . )


Hong Kong's CHP hasn't taken notice of either of these cases yet, although I suspect when they do they will reiterate their warning about this uptick in warm weather H7N9 reports.

Tuesday, July 26, 2016

PNAS: The Enigma Of Disappearing HPAI H5 In North American Migratory Waterfowl


















#11,584


One of the great unresolved avian flu mysteries is why - after the largest epizootic outbreak in U.S. history over the winter-spring of 2015 - did the virus fail to return the following fall?
The virus arrived in the Pacific Northwest via migratory birds in November of 2014, and ultimately spread to poultry in 15 states, resulting in billions of dollars in losses. 

The expectation was it would appear again last fall with the return of migratory birds, but that didn't happen.  And wild bird detections of HPAI since last summer have been practically nil.


To try explain this unexpected turn of events, we've a study appearing in PNAS (alas, behind a pay wall) - with Robert G. Webster of St. Jude Children's Research Hospital as the corresponding author - that concludes that migratory waterfowl are not a reservoir for highly pathogenic avian flu viruses. 
  
This has significance beyond just further defining the ecology of HPAI, as it validates the choice to employ traditional eradication methods - quarantine, culling and disinfection - rather than rushing to use a poultry vaccine. 

As we've discussed often over the years (see PLoS Bio: Imperfect Poultry Vaccines, Unintended Results & The HPAI Poultry Vaccine Dilemma), despite more than a decade of heavy use, poultry AI vaccines have not proven to be a panacea for avian flu around the world. 

The problem being that poultry vaccines aren’t always 100% effective; sometimes they only mask the symptoms of infection.
That can allow viruses to spread silently among flocks, to continue to reassort and evolve, and potentially lead to new subtypes of avian flu to emerge (see Subclinical Highly Pathogenic Avian Influenza Virus Infection among Vaccinated Chickens, China).


First the link and the abstract from of the study, then some snippets from a press release from St. Jude Children's Research Hospital to fill in the blanks.

The enigma of the apparent disappearance of Eurasian highly pathogenic H5 clade 2.3.4.4 influenza A viruses in North American waterfowl

Scott Kraussa, David E. Stallknechtb, Richard D. Slemonsc, Andrew S. Bowmanc, Rebecca L. Poulsonb, Jacqueline M. Noltingc, James P. Knowlesa, and Robert G. Webstera,1
   
Abstract

One of the major unresolved questions in influenza A virus (IAV) ecology is exemplified by the apparent disappearance of highly pathogenic (HP) H5N1, H5N2, and H5N8 (H5Nx) viruses containing the Eurasian hemagglutinin 2.3.4.4 clade from wild bird populations in North America. 


The introduction of Eurasian lineage HP H5 clade 2.3.4.4 H5N8 IAV and subsequent reassortment with low-pathogenic H?N2 and H?N1 North American wild bird-origin IAVs in late 2014 resulted in widespread HP H5Nx IAV infections and outbreaks in poultry and wild birds across two-thirds of North America starting in November 2014 and continuing through June 2015.

Although the stamping out strategies adopted by the poultry industry and animal health authorities in Canada and the United States—which included culling, quarantining, increased biosecurity, and abstention from vaccine use—were successful in eradicating the HP H5Nx viruses from poultry, these activities do not explain the apparent disappearance of these viruses from migratory waterfowl. 

Here we examine current and historical aquatic bird IAV surveillance and outbreaks of HP H5Nx in poultry in the United States and Canada, providing additional evidence of unresolved mechanisms that restrict the emergence and perpetuation of HP avian influenza viruses in these natural reservoirs.



Public Release: 25-Jul-2016

Evidence suggests migratory birds are not a reservoir for highly pathogenic flu viruses

St. Jude Children's Research Hospital
 

The H5 avian influenza A virus that devastated North American poultry farms in 2014-15 was initially spread by migratory waterfowl, but evidence suggests such highly pathogenic flu viruses do not persist in wild birds. St. Jude Children's Research Hospital led the research, which appears online this week in the Proceedings of the National Academy of Sciences.

While wild ducks and other aquatic birds are known to be natural hosts for low pathogenic flu viruses associated with milder symptoms, the results of this study indicate that is not the case with the highly pathogenic flu viruses that are associated with more severe illness. The research suggests that wild ducks and other aquatic birds are not an ongoing source of highly pathogenic flu infection in domestic poultry.

"The findings provide a scientific basis for the decision by officials to use culling and quarantines to stop the 2014-15 outbreak in domestic poultry," said corresponding author Robert Webster, Ph.D., an emeritus member of the St. Jude Department of Infectious Diseases. "Now, research is needed to identify the mechanism that has evolved in these wild birds to disrupt the perpetuation of highly pathogenic influenza."

In this study, researchers analyzed throat swabs and other biological samples taken from 22,892 wild ducks and other aquatic birds collected before, during and after a 2014-15 H5 flu outbreak in poultry. The outbreak has been linked to a highly pathogenic H5N8 influenza A virus spread from Asia to North America by migratory waterfowl. The H5N8 virus reasserted, or mixed genes, with other influenza viruses in North American waterfowl and went on to trigger 248 flu outbreaks in commercial and backyard turkey and chicken farms in the U.S. and Canada at a cost of nearly $5 billion.

Officials worked to end the outbreaks by quarantining and eliminating infected poultry. The last confirmed case occurred in June 2015. Officials worried that the highly pathogenic virus would be re-introduced into poultry farms by migratory aquatic birds carrying the virus. But none of the migratory birds included in this analysis were infected with a highly pathogenic flu virus. The sampling was conducted in Canada, the Mississippi flyway and along the U.S. Atlantic coast by David Stallknecht and Rebecca Poulson of The University of Georgia and Richard Slemons, Andrew Bowman and Jacqueline Nolting from the The Ohio State University in conjunction with Scott Krauss and James Knowles of St. Jude. The sampling was done as part of the federally funded Centers of Excellence for Influenza Research and Surveillance.

Such viruses have not been identified in any of the more than 100,000 wild birds tested since the flu surveillance sampling began 43 years ago, Webster said. "Existing immunity in wild birds is one of the possible explanations that may explain why highly pathogenic influenza A viruses do not become established in wild bird populations," he said. "But a more complete understanding of the mechanisms at work would aid efforts to prevent, control and eradicate these dangerous viruses in poultry in other areas of the world."

Webster added that while there were no reported human cases of influenza caused by the highly pathogenic flu viruses involved in this outbreak, other related H5 viruses have spread to humans with deadly results.

France: MOA Reports Another H5N1 Outbreak in Dordogne















#11,583


After going roughly three months without a new outbreak, last week France reported 2 fresh HPAI detections in  Dordogne & Aveyron. Overnight they reported a third new outbreak,  once again in Dordogne. 

These outbreaks, which began in November of last year, have produced no fewer than 5 new strains of avian flu, including HPAI H5N1, H5N2, and H5N9, along with LPAI H5N2 and H5N3.  

All of these new subtypes are described as being of `European lineage' - have not infected humans - and not descended from the more dangerous Asian H5N1 virus.

That said, we've not seen much analysis published on these new viruses. The update appended to the MOA's status site reads:

The current situation in France (updated on 07/26/2016)

In total, to date, 80 of highly pathogenic avian influenza (HPAI) in poultry were detected in 10 southwestern departments of France.

As part of the monitoring strategy accompanied by increased vigilance of the actors in the poultry sector, three other outbreaks were detected, one in Aveyron, the other two in the Dordogne.

The set of management measures has been implemented.


DORDOGNE

- Another highly pathogenic avian influenza (H5N1) was reported July 25, 2016 on a farm of 24,000 ducks ready to stuff in this town, 400 m from the home of breeding chickens outdoors.