Vet. Microb.: Analysis Of Korea Lineage Of Avian H9N2 viruses

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While it rarely gets star billing - LPAI H9N2 -  ubiquitous in Asian poultry, yet only rarely found infecting humans, is nonetheless an important player in the avian flu world. 

It is considered to have some pandemic potential of its own, but by far its greatest contribution to date has been to to lend some of its internal genes to recently emerged HPAI & LPAI viruses, including H5N8, H5N6, and H7N9 (see graphic below).

H7N9 Genetic Structure - Credit Eurosurveillance

H9N2's contributions to the creation of these novel HPAI/LPAI strains is not a one shot deal.

In 2014's Eurosurveillance:The Evolving Threat From New, Reassorted H7N9 Viruses, researchers reported finding ongoing and `dynamic reassortments between influenza A(H7N9) and A(H9N2) viruses since the outbreak of A(H7N9) virus infection in March 2013.'

This continual participation in the evolution of H7N9 (and other) avian viruses has led to the creation of new lineages, and dozens of new genotypes, a pattern that makes identifying any changes in H9N2's genetic structure and behavior all the more important. 

In early 2014 The Lancet carried a report entitled Poultry carrying H9N2 act as incubators for novel human avian influenza viruses  where researchers warned that `reassortment between the prevalent poultry H9N2 viruses (providing genetic segments) and the influenza virus from wild birds could make the influenza evolve to adapt to domestic hosts.'

Eighteen months ago, in PLoS Path: Genetics, Receptor Binding, and Transmissibility Of Avian H9N2 researchers found evidence of Chinese H9N2 viruses binding preferentially to alpha 2,6 receptor cells -  the type commonly found in the human upper respiratory tract - rather than to alpha 2,3 receptor cells which are found in the gastrointestinal tract of birds.

As we've seen with other widely distributed avian flu viruses, H9N2 has evolved into many different lineages and/or genotypes.The virus you get in Bangladesh is quite distinct from the version you’ll find in China, the Middle East,  or  . . . in Korea.

All of which serves as prelude to a new study appearing in  Veterinary Microbiology which looks at the genetic evolution, and behavior, of H9N2 viruses collected in South Korea.

Their findings suggest the South Korean lineage of H9N2 may be making strides towards better mammalian adaptation, something which could have serious implications - not only for H9N2 as a standalone pandemic threat - but also conceivably for those viruses it lends its genes to in the future.

First, the link and abstract to the study, then I'll return with a bit more.
      

Genetics and biological property analysis of Korea lineage of influenza A H9N2 viruses

Min Kang, Hyung-Kwan Jang,

https://doi.org/10.1016/j.vetmic.2017.04.014

Highlights

• Little information is available about the biological properties of H9N2 viruses of Y439 lineage in mammals.
• Some Korean H9N2 viruses caused higher than expected mortalities to mice without prior adaptation.
• Korean H9N2 with mammalian host-tropic mutations caused higher than expected mortalities to mice without prior adaptation.
• H9N2 viruses with enhanced pathogenicity to mice might have been established recently from endemic viruses.

Abstract

H9N2 influenza viruses have been detected from wild and domestic avian species including chickens and ducks worldwide. Few studies have compared the biological properties of different H9N2 lineages or determined whether certain lineages might pose a higher risk to mammals, especially H9N2 viruses of Korean lineage.

The objective of this study was to characterize the genetic and biological properties of 22 Korean H9N2 viruses and assess their potential risks to mammals. Their complete genomes were analyzed.

Some Korean H9N2 viruses were found to carry mammalian host-specific mutations.

Based on genomic diversities, these H9N2 viruses were divided into 12 genotypes. All 22 showed preferential binding to human-like receptor. Two of eight H9N2 viruses were highly lethal to mice, causing 90–100% mortality without prior adaptation and severe respiratory syndromes associated with diffuse lung injury, severe pneumonia, and alveolar damage.

These findings suggest that recent Korean H9N2 viruses might have established a stable sublineage with enhanced pathogenicity to mice. Various H9N2 strains pathogenic to mice were endemic in wild bird, poultry farm, and live bird markets, suggesting that Korean H9N2 viruses could evolve to become a threat to humans.

The findings emphasize the necessity of careful, continuous, and thorough surveillance paired with risk-assessment for circulating H9N2 influenza viruses.

In the 16 years between 1998 and the end of 2014, the WHO had been notified of just 18 cases globally (see FluTrackers Global Cumulative H9N2 Partial Case List 1998-2016).  Over the last 28 months, however, the WHO has been notified of 20 new cases (14 in China, 4 in Egypt, and 2 in Bangladesh).

All of which raises the question.  Are we just getting better at detecting human infections, or is the virus getting better at infecting humans?

While this increased surveillance could easily explain this jump in cases, the virus continues to evolve and show signs of becoming a more mammalian adapted virus.

Which means we ignore this meddlesome virus at our own peril.

Are We Prepared to Help Low-Resource Populations Mitigate a Severe Pandemic?

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The 2014 West African Ebola epidemic showed us just how horrific a severe epidemic can be - and how quickly one can grow out of control - particularly in `low resource' settings.

As bad as it was, the toll of death and suffering in West Africa would pale compared to what a severe influenza pandemic would produce globally, particularly across the developing world.

More than a decade ago we looked at a Lancet study that predicted, based on a 1918-like pandemic scenario, could claim as many 62 million lives, and that 96% of those deaths would occur in developing countries. 

Estimation of potential global pandemic influenza mortality on the basis of vital registry data from the 1918—20 pandemic: a quantitative analysis

Prof Christopher JL Murray DPhil , Prof Alan D Lopez PhD, Brian Chin ScB, Dennis Feehan AB , Prof Kenneth H Hill PhD

The authors cited as much as a 30-fold difference in mortality rates around the world in 1918. Countries in Asia, Latin America, and Sub-Saharan African were particularly hard hit. That disparity today, with better access to antivirals, antibiotics, and eventually vaccines for the developed world might even be greater.

In 2012, a  Paper: Are We Prepared For A Pandemic In Low Resource Communities? by Eric Starbuck DrPH, MPH et al., looked at the challenges (and provided some solutions) for helping low resource communities deal with an influenza pandemic.

Those solutions were largely based on NPIs - or Nonpharmaceutical Interventions, such as hand washing, covering coughs, social distancing, and even school closures -  which would be the first line of defense against a severe pandemic everywhere, including in developed nations.

Last weekend, in Community Pandemic Mitigation's Primary Goal : Flattening The Curve, we looked at the freshly minted 2017 Community pandemic mitigation plan by the HHS/CDC, which envision NPIs as our first, and perhaps most effective, response to a pandemic.

While the developed world has an infrastructure, and an (admittedly finite) supply of antivirals, antibiotics, ventilators, and hospital beds to deal with a pandemic, for many low resource populations NPIs may be all they have to rely on.

This week, Eric Starbuck returns with an essay on the NO MORE EPIDEMICS website, which reviews the history of pandemics, the efficacy of NPIs, and how they could be used in low resource settings to mitigate the effects of a severe pandemic.

I've only included the abstract, so you'll want to follow the link to read it in its entirety.  When you return, I'll have a bit more.

Are We Prepared to Help Low-Resource Populations Mitigate a Severe Pandemic?

April 27, 2017
 

By: Eric S. Starbuck, DrPH, MPH 

Abstract: Although the risk of onset in the next year, or in the next decade, cannot be quantified, a severe pandemic involving person-to-person transmission of a novel respiratory virus is considered by leading organizations to be a substantial global threat. The ongoing threat posed by the H5N1 and H7N9 avian influenza viruses, and by the MERS coronavirus, should serve to remind us of the continuing importance of pandemic preparedness.

In a severe pandemic from a rapidly spreading novel respiratory virus, when all countries and all responding organizations will themselves be struck, most low-resource populations will fail to receive adequate medical supplies, and their health services will be more stressed than they are today.

However, these populations could, by employing well-planned, evidence-based measures, reduce disease transmission and care for those not severely ill, without substantial outside resources. Authoritative guidance must be developed, and support provided for country adaptation, planning for rapid roll-out, and testing of these plans.

         (Continue . . . )



The NO MORE EPIDEMICS website describes themselves as:

No More Epidemics is a five year global campaign to encourage governments and key stakeholders to better prevent, prepare and respond to infectious disease epidemics. Established in 2015 by Management Sciences for Health (MSH), International Medical Corps (IMC), Save the Children (SC), and the African Field Epidemiology Network (AFENET) the Campaign was officially launched in November, 2015 in South Africa.

Our 26 current partners include civil society organisations, community-based organisations, private sector companies and academic institutions all working together to hold governments accountable to prioritize epidemic prevention, preparedness and response planning. No More Epidemics goals are to:

• Ensure the development of national preparedness plans that include community protection and mitigation.
• Ensure all States comply with the International Health Regulations (IHR).
• Increase international and national funding levels for epidemic preparedness, prevention and response.

While you are visiting (and perhaps becoming a partner), you'll want to look at some of the other essays available on their Thought Leadership Page.

• Are We Prepared to Help Low-Resource Populations Mitigate a Severe Pandemic?
• Global Priorities to Achieve the Global Health Security Agenda
• The Joint External Evaluation Tool and the Role of Law: Simple Fixes at the One-Year Mark
• Biosafety and the Global Health Security Agenda
• Public Health Emergency Operations Centers: Creating More Resilient Communities
• Measuring and Motivating Global Health Security: Lessons From Taiwan
• Leveraging Synergies to Improve Epidemic Preparedness

Given nearly 10 years of recession and slow economic growth, growing budget deficits, and competing `crisis' issues like nuclear proliferation, climate change, antibiotic resistance, famine, war, and access to clean water - pandemic preparedness can be a tough sell. 

But another pandemic is not just a possibility, it is all but certain. The only real questions are when, and how bad it will be. 

A reality that governments, agencies, businesses, and individuals must all consider carefully as they plan (and hopefully, prepare) for their future.

Macao Bans Import & Sale Of Live Poultry Beginning May 1st

Credit http://portal.gov.mo - Jan 2017

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Macao - like Hong Kong - has been hit repeatedly by H7N9 outbreaks among imported poultry - and last December saw their first locally acquired case from (imported) poultry exposure (see Media Report: Macao Registers 1st Human H7N9 Infection). 

Within weeks a second human case - imported from Guangdong Province  - turned up in Macao, while early February saw the second outbreak in local poultry markets of 2017. Shortly thereafter, we saw a worried  Macao Takes Steps To Protect EMS Crews From H7N9.

With each detection of the virus in local markets, sellers are shut down, poultry is culled, and disinfection of poultry stalls are ordered. Those exposed are placed in hospital isolation, poultry imports are temporarily suspended, and everyone waits to see if the virus has been contained. 

So far, Macao (and Hong Kong) have been lucky.   But the severity of this year's H7N9 outbreak on the Mainland has many concerned that luck may not last.

Not only are live markets strongly linked to human infection with bird flu, by bringing together many different avian species (chickens, ducks, geese, quail, etc.), they provide an ideal environment for the sharing of viruses, viral reassortment, and the creation of new flu subtypes (see The Lancet: Interventions To Reduce Zoonotic & Pandemic Risks From Avian Flu In Asia).

For years there have been calls to shut down live poultry markets - in Hong Kong, Macao, and all of China - but between public resistance to the idea, and a lack of political will, shut downs have been limited, poorly enforced in some regions, and almost always temporary.

Earlier this month, in Hong Kong Releases A Poultry Plan, we looked at a proposed scheme that would allow live poultry sales to continue in Hong Kong, despite the growing risks from H7N9 and H5N6.  A few days later, this plan received strong criticism in the local media (see SCMP Editorial: Enough tiptoeing around the problem of bird flu).

Yesterday Macao - which, admittedly has a fraction of the population of Hong Kong -  announced a complete ban on live poultry sales beginning the 1st of May. Available instead will be chilled or frozen chicken.

The fact that this is being implemented at what is normally the end of China's H7N9 season is a bit surprising. But after last summer's spate of `off season' H7N9 cases, and recent concerns that the virus has become more `heat tolerant',  this summer's respite is not assured.

 
This statement from the Government of Macao.  

Macao to impose sale ban on live poultry, starting from May

2017-04-28 21:45:00

Source : Government Information Bureau

The Government has decided to ban the import and sale of all live poultry in Macao, starting from 1 May 2017.

The measure, to keep the public from having contact with live poultry, aims to protect further the community’s health, prevent diseases and maintain Macao’s stable socio-economic development.

Preventing contact between consumers and live poultry has been proven by experts to be an effective way to prevent transmission to humans of certain infective viruses. It also significantly reduces the risk of outbreaks of disease within a community and the threat that avian influenza in particular could pose to the Macao public.

Macao recorded five outbreaks of avian influenza in poultry between February 2016 and February 2017. With each event, the Government activated contingency plans in order to prevent the relevant virus from spreading further. These included culls of all live birds in the contaminated batches and temporary bans on the sale of live birds in all local markets. During the same period, Macao recorded the city’s first case of human infection from avian influenza A (H7N9) virus.

Following the sale ban on live poultry, the Government will – as always – spare no effort in monitoring the quality of chilled and frozen poultry.

In addition, the Government will remain in close touch with the local poultry industry regarding a reasonable scheme to relieve the impact of its new measure. The Civic and Municipal Affairs Bureau will provide necessary assistance – within its power – to aid the industry.

Following three outbreaks of avian influenza in poultry that occurred between December 2016 and February 2017, the Government plans to provide subsidies to help affected industry participants. The subsidies will include compensation for the cull of contaminated poultry. In addition, each industry participant affected will receive a daily allowance of 200 patacas for the period in which sales were suspended following the outbreaks of avian influenza.

Despite the evidence that it would greatly reduce the transmission of the virus,  closing LMBs (Live Bird Markets) has been a tough sell to the Chinese public. Purchasing live market birds is deeply ingrained in their culture, as it reassures the buyer that the bird is both fresh and healthy.

But until LBMs throughout China follow Macao's lead, their yearly epidemics - and the generation of new strains of avian flu - are likely to continue unabated for the foreseeable future.

Saudi MOH Announces 3 Primary MERS Cases

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After issuing no report for the 27th, the Saudi MOH this morning has announced 3 widely scattered MERS primary MERS cases from around the country.  Two reportedly had camel contact, while the third appears to have had no known risk exposure.

WHO: Press Conference Notes On Cluster Of Unexplained Deaths In Liberia

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The past few days the media has been filled with reports of a cluster of  severe illness and sudden deaths among attendees of a funeral in Liberia - a scenario similar enough to that seen during their  2014 Ebola epidemic to raise concerns that the virus had resurfaced.

Subsequent testing, however, showed that Ebola was not responsible for the outbreak.   The cause remains undetermined.

Today the World Health Organization media team emailed the following set of notes taken by  Fadela Chaib at a press conference held today on the outbreak:

Correction: NINE people died ( and not EIGHT) as previousely sent.

It should read: since Monday, April 24, 17 people have fallen sick. Nine people have died, and eight are still ill and hospitalised

Dear journalists,
Please find below my notes on the unexplained illness and deaths from Sinoe County in Liberia.
On 25 April, WHO received a report from Liberia health authorities about a cluster of unexplained illness and deaths from Francis Grant Hospital in Greenville, Sinoe County. Sinoe Country is 4.5 hours drive South East of Monrovia.
According to the report, since Monday, April 24, 17 people have fallen sick. Eight people have died, and eight are still ill and hospitalised. Most of them are aged below the age of 21 .

• Rapid response teams have been reactivated at District and County level with technical and logistical support from WHO, CDC and other partners.
• Observed symptoms include fever, vomiting, headache, diarrhoea.
• The response team are investigating reports linking the cluster to attendance at the funeral of a religious leader.
• Specimens were collected from seven dead bodies and have been sent to the national laboratory for testing. All came back negative for Ebola.
• Further testing underway to find out the cause of the illness and deaths. The investigation teams will try to find if this could be in relation to the consumption of same food and drinks and if there is an environmental exposure to some chemicals or bacteria.
Response measures include:

Precautionary isolation of the cases
Clinical staff wearing PPEs ( Personal Protective Equipment) at the hospital.
Epidemiological investigations ongoing, active case searching and contact tracing.
Engagement and consultations with community leaders from the affected communities
Social mobilization encouraging encouraging people go to the hospital when sick.
Samples from water sources being collected to test for chemicals and bacteria.
Best regards
WHO Media team

HK CHP Notified Of 17 New H7N9 Cases From The Mainland

Credit FAO - Apr 26th

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While a significant drop from last week's surge of 27 cases, this week's notification by the NHFPC is notable for several reasons. 

• First, the surge in cases in Sichuan province continues with 5 more cases reported (N=23).
• Second, Beijing reports two more cases, bringing their total for the year to 15.
• Third, we get the first report (of 2 cases) from Guangdong province in more than a month.
• And lastly, this report refers to a rare infection in a 4 y.o. child.  While not unheard of, most cases have involved adults over the age of 30. 

These Friday reports provide little in the way of detail, but do give us an idea of the general course and intensity of China's H7N9 activity over the past week.  We'll get more details in next week's Hong Kong Avian Flu Report.

For now, the number of cases in this 5th wave sits just over 640 - notably now twice the size of the largest previous outbreak (wave 2) - which reported 320 cases over a 12 month period.

CHP notified of human cases of avian influenza A(H7N9) in Mainland

         The Centre for Health Protection (CHP) of the Department of Health today (April 28) received notification from the National Health and Family Planning Commission that 17 additional human cases of avian influenza A(H7N9), including two deaths, were recorded from April 21 to 27, and strongly urged the public to maintain strict personal, food and environmental hygiene both locally and during travel.

         The nine male and eight female patients, aged from four to 74, had onset from April 6 to 23. Five of the patients were from Sichuan, two each from Beijing, Guangdong and Shandong, and one each from Chongqing, Fujian, Gansu, Henan, Hunan and Jiangsu. Among them, 16 were known to have had exposure to poultry, poultry markets or mobile stalls.

         Travellers to the Mainland or other affected areas must avoid visiting wet markets, live poultry markets or farms. They should be alert to the presence of backyard poultry when visiting relatives and friends. They should also avoid purchase of live or freshly slaughtered poultry, and avoid touching poultry/birds or their droppings. They should strictly observe personal and hand hygiene if visiting any place with live poultry.

         Travellers returning from affected areas should consult a doctor promptly if symptoms develop, and inform the doctor of their travel history for prompt diagnosis and treatment of potential diseases. It is essential to tell the doctor if they have seen any live poultry during travel, which may imply possible exposure to contaminated environments. This will enable the doctor to assess the possibility of avian influenza and arrange necessary investigations and appropriate treatment in a timely manner.

         While local surveillance, prevention and control measures are in place, the CHP will remain vigilant and work closely with the World Health Organization and relevant health authorities to monitor the latest developments.

         The CHP's Port Health Office conducts health surveillance measures at all boundary control points. Thermal imaging systems are in place for body temperature checks on inbound travellers. Suspected cases will be immediately referred to public hospitals for follow-up.

         The display of posters and broadcasting of health messages in departure and arrival halls as health education for travellers is under way. The travel industry and other stakeholders are regularly updated on the latest information.

         The public should maintain strict personal, hand, food and environmental hygiene and take heed of the advice below if handling poultry:

• Avoid touching poultry, birds, animals or their droppings;
• When buying live chickens, do not touch them and their droppings. Do not blow at their bottoms. Wash eggs with detergent if soiled with faecal matter and cook and consume them immediately. Always wash hands thoroughly with soap and water after handling chickens and eggs;
• Eggs should be cooked well until the white and yolk become firm. Do not eat raw eggs or dip cooked food into any sauce with raw eggs. Poultry should be cooked thoroughly. If there is pinkish juice running from the cooked poultry or the middle part of its bone is still red, the poultry should be cooked again until fully done;
• Wash hands frequently, especially before touching the mouth, nose or eyes, before handling food or eating, and after going to the toilet, touching public installations or equipment such as escalator handrails, elevator control panels or door knobs, or when hands are dirtied by respiratory secretions after coughing or sneezing; and
• Wear a mask if fever or respiratory symptoms develop, when going to a hospital or clinic, or while taking care of patients with fever or respiratory symptoms.

         The public may visit the CHP's pages for more information: the avian influenza page, the weekly Avian Influenza Report, global statistics and affected areas of avian influenza, the Facebook Page and the YouTube Channel.


    Ends/Friday, April 28, 2017

    Issued at HKT 18:50

J. Virology: Molecular Evolution and Emergence of Avian H5N6

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While H7N9 has been the big overachiever this winter, producing the largest and deadliest avian flu outbreak on record, avian H5N6 - despite jumping to South Korea, Japan, and Taiwan - has not been reported as a human infection since November of 2016.

 This respite in human cases, while welcome, is not guaranteed to last.

As with all influenza subtypes, when we talk about H5N6, we're aren't talking about a single viral threat, but rather an expanding array of related viruses sharing similar HA and NA genes. Viruses which can vary considerably in their behavior and the threat they pose (see Differences In Virulence Between Closely Related H5N1 Strains).

Influenza A viruses are broadly categorized by two proteins they carry on their surface; their HA (hemagglutinin) and NA (neuraminidase), producing subtypes like H5N1, H7N9, or H5N6.

Within each subtype there are genetic groupings called clades, and often within each clade - subclades – and within each of these, many genotypes and variants may exist.  Proving that above all else, influenza viruses are both promiscuous and prolific. 

Last December, in Cell Host Microbe: Genesis, Evolution and Prevalence of HPAI H5N6 In China, we saw a report that found that H5N6 had become the dominant HPAI H5 virus in Chinese ducks (replacing H5N1), with 34 distinct H5N6 genotypes, including 4 that have infected people.

The common denominator across all of these genotypes had been that all these H5N6 strains belonged to H5 clade 2.3.4.4.  The same H5 clade that produced the H5N8 outbreaks in Korea in 2014, the North American epizootic of 2015, and this winter's outbreaks across Europe.  

Today we've a new study out of China which confirms the diversity among H5N6 viruses, including one sample that belongs not to clade 2.3.4.4.  -  but is unexpectedly derived from H5N1 clade 2.3.2.

Clade 2.3.2 emerged in central China in 2009 (see 2011 EID Journal New Avian Influenza Virus (H5N1) in Wild Birds, Qinghai, China), and quickly began to appear in migratory birds and poultry from Japan to India, supplanting the old 2.2 clade in many regions.

 It, in turn, has now been largely supplanted by clade 2.3.2.1. (see 2015's Novel H5N1 Reassortment Detected In Migratory Birds - China).

Today's report reaffirms just how diverse the constellation of H5N6 viruses circulating in China really are, and reinforces the need to monitor these viruses closely.  We've the abstract, along with a news release from the Chinese Academy of Sciences to provide additional context.

Molecular Evolution and Emergence of H5N6 Avian Influenza Virus in Central China
Yingying Du1, Mingyue Chen1,Jiayun Yang1,Yane Jia1, Shufang Han1, Edward C. Holmes2 and Jie Cui1⇑ 

ABSTRACT

H5N6 avian influenza virus (AIV) has posed a potential threat to public health since its emergence in China in 2013. To understand the evolution and emergence of H5N6 in the avian population we performed molecular surveillance of live poultry markets (LPMs) in Wugang prefecture, Hunan province, in central China during 2014-2015. Wugang prefecture is located on the Eastern Asian-Australian migratory bird flyway and a human death due to an H5N6 virus was reported in the prefecture on 21th November 2016. 

In total, we sampled and sequenced the complete genomes of 175 H5N6 AIVs. Notably, our analysis revealed that H5N6 contains at least six genotypes arising from segment reassortment, including a rare variant that possesses an HA gene derived from H5N1 clade 2.3.2 and a novel NP gene that has its origins with H7N3 viruses. 

In addition, phylogenetic analysis revealed that genetically similar H5N6 AIVs tended to cluster according to their geographic region of origin. These results help reveal the evolutionary behavior of influenza viruses prior to their emergence in humans. 

  

Researchers Reveal a Complex Pattern of the Evolution and Emergence of H5N6 Avian Influenza Virus in central China

Apr 28, 2017    

Since H5N6 avian influenza virus first emerged in China in 2013, it has caused more than ten human deaths in China, which poses potential risks to human health.

In order to further understand the evolutionary behavior of H5N6 prior to its emergence in humans, the research group led by Prof. CUI Jie from Wuhan Institute of Virology of the Chinese Academy of Sciences developed the studies on the evolution and emergence of H5N6 avian influenza virus in central China. 

To better understand the complex molecular evolution and emergence of H5N6 at the local level, the researchers took surveys in the live poultry markets in Wugang prefecture in Hunan province in central China, and tried to reveal the diversity and genomic origins of H5N6 in birds.

Notably, WHO reported and confirmed a human death caused by H5N6 in these live poultry markets on 21th November 2016 in this prefecture. 

During 2014-2015, cloacal swabs and fecal samples from ducks, geese and environmental samples in the live poultry markets in Wugang prefecture were collected and screened for avian influenza virus by the researchers.

Then the complete genomes of 175 H5N6 avian influenza viruse were sampled and sequenced. Their surveillance of H5N6 revealed that at least six types of reassortant H5N6 have circulated in that region, including a rare variant that possesses an HA gene derived from H5N1 clade 2.3.2 and a novel NP gene that has its origins with H7N3 viruses.

As all currently reported H5N6 avian influenza viruses are members of H5N1 clade 2.3.4.4, their observation that one H5N6 virus seemingly carried an HA gene directly derived from H5N1 clade 2.3.2 is of importance.

They suggest that a careful monitoring of H5N6 viruses in the live poultry markets and wild birds is evidently necessary to help prevent the virus from establishing itself in the human population.

In sum, the researchers have revealed a complex pattern of evolution and emergence of H5N6 in a single locality in central China over a two-year period.

The results have been published in Journal of Virology entitled "Molecular Evolution and Emergence of H5N6 Avian Influenza Virus in Central China". 

This work was supported by funding from the National Key Research and Development Program and the CAS Pioneer Hundred Talents Program. 

WHO MERS-CoV Update - Saudi Arabia & Qatar

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We've been watching a slight increase in the number of MERS cases reported from the Arabian Peninsula over the past couple of months, with 2 recent cases from the UAE, 2 from Qatar, and - in addition to a steady trickle of cases from Saudi Arabia - a cluster of cases in and around Wadi Al Dawasir.

Today the World Health Organization has published their second MERS update of the week, detailing the 2nd case from Qatar, and 13 recent cases from Saudi Arabia. 

Of the Saudi cases, 6 are linked to camel or camel product exposure, 2 had contact with known MERS cases, and the remaining 5 are still under investigation.  The patient from Qatar had recent camel contact as well.

Middle East respiratory syndrome coronavirus (MERS-CoV) – Saudi Arabia and Qatar

Disease outbreak news
27 April 2017

Between 18 March and 20 April 2017 the national IHR Focal Point of Saudi Arabia reported 13 additional cases of Middle East Respiratory Syndrome (MERS) including two fatal cases. On 18 April 2017 the national IHR Focal Point of Qatar reported one additional case of MERS.
Details of the cases

Detailed information concerning the cases reported can be found in a separate document (see link below).

MERS-CoV cases reported between 18 March and 20 April 2017    xlsx, 24kb

 
Between 18 March and 20 April 2017, 13 cases of MERS were reported in Saudi Arabia. Six of these cases had exposure to infected dromedary camels or consumed their raw milk, which is the most likely source of their infection and two cases were detected through contact tracing of previously reported MERS-CoV cases. Investigation into the history of exposure to the known risk factors in the 14 days prior to onset of symptoms is ongoing for the remaining cases. Contact tracing of household and healthcare contacts is ongoing for all 13 cases.

On 18 April 2017, one case of MERS was reported in Qatar. The 25-year-old case has a history of frequent contact with dromedary camels and no history of exposure to other known risk factors in the 14 days prior to the onset of symptoms. He is currently in stable condition admitted to a negative pressure isolation room on a ward. The department of health protection and communicable disease control in the Ministry of Public Health has carried out case investigation and contact tracing. All contacts have tested negative but will continue to be monitored until the end of the monitoring period of 14 days of last exposure to the case.

To date, Qatar has reported 20 laboratory-confirmed cases of MERS. The last case was reported on 21 March 2017 (see Disease Outbreak News published on 4 April 2017).

Globally, since September 2012, WHO has been notified of 1952 laboratory-confirmed cases of infection with MERS-CoV including at least 693 related deaths have been reported.

WHO risk assessment

MERS-CoV causes severe human infections resulting in high mortality and has demonstrated the ability to transmit between humans. So far, the observed human-to-human transmission has occurred mainly in health care settings.

The notification of additional cases does not change the overall risk assessment. WHO expects that additional cases of MERS-CoV infection will be reported from the Middle East, and that cases will continue to be exported to other countries by individuals who might acquire the infection after exposure to animals or animal products (for example, following contact with dromedaries) or human source (for example, in a health care setting). WHO continues to monitor the epidemiological situation and conducts risk assessment based on the latest available information.

         (Continue . . . )

China's CDC Reassures On H7N9's Intrusion Into The North

FAO Apr 26th - Modified With North/South Line

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During its first four years of circulation, H7N9 has been largely a central and southern Chinese problem.  Reports of human infections, or detections in birds or the environment, above the 38th parallel have been rare.  

As of the start of this 5th wave (October 2016), Beijing had only reported 9 cases since the virus emerged in 2013, while Jilin and Liaoning Province had each only reported 1.  Gansu Province, in the northwest of the country, had never detected the virus at all.

As of the latest HK CHP report (Apr 24th), Beijing had jumped to 22 cases,  Liaoning to 4, Jilin to 3, and Gansu had reported 2 cases. These regions have also reported increased bird and environmental detection.  Most of these `northern' cases have come in the past month.

While these numbers still pale compared to the 138 cases reported this year in Jiangsu, the 87 from Zhejiang, or the 63 reported by Guangdong, the late season encroachment of H7N9 into the capital city and surrounding northern provinces has started to raise concerns.

Apart from the public health implications, the entrenchment of the virus in Beijing  - just months before their 19th National Congress of the Communist Party of China - could cause some serious political ramifications this fall.

This recent surge in northern cases, combined with a drop off in reports from the south (noticeably Guangdong province, which hasn't reported a new case in a month), has led to some speculation in the Chinese media that the virus is starting to spread better in the north, than in the south. 

While understandably disconcerting to the millions of northern Chinese who have - until recently - felt relatively separated from these yearly H7N9 epidemics, the numbers this year don't support that assertion.

But speculation in China has apparently grown to the point that their CDC felt compelled to address the issue, and overnight a number of Chinese media outlets are carrying versions of the following (translated) story.

Northern areas are more susceptible to H7N9 bird flu? CDC denies the existence of this trend

2017-04-26 19:16:05

Beijing News News (Reporter Wu) April 26, for the "northern region of human infection with H7N9 influenza cases increased significantly," the media release and reprint of "bird flu this year, the North is more susceptible than the south" and other phrases, Chinese Center for Disease Control and Prevention virus disease control and prevention deputy director, director of the national influenza Center Shu Yuelong to Beijing News reporter said there was no evidence that the northern regions are more susceptible to H7N9 avian influenza.

Some media reports said, "The recent human infection with H7N9 influenza northern region of cases showed an increasing trend, April 24, according to incomplete statistics, in April, Shandong, Hebei, Liaoning, Beijing and other regions reported a total of 17 cases of human infection with the H7N9 flu."

Beijing News reporter combing found that according to public information, since this month, there are indeed more northern Shandong, Henan, Hebei, Liaoning, Jilin, Beijing and other provinces reporting cases of human infection with H7N9. April, Shandong report four cases; Henan, Hebei new cases were reported two cases and four cases; confirmed in Liaoning April 20 Nisshin one case; and Jilin also on April 22 this year the first case was found.

However, public data also show that since 2017, Guangdong, Guangxi, Jiangxi, Zhejiang, Jiangsu, Hunan, Gansu and Anhui and other areas also appear more cases of human infection with the H7N9 flu. According to the National Health and Family Planning Commission recently informed, in 2017, China's mainland has 22 provinces reported cases, 511 cases of H7N9, which killed 188 people.

In this regard, Shu Yuelong, said Nationwide, this year there is no evidence that the northern people more susceptible to H7N9 influenza. "The recent increase in the northern region, due to the wider spread of the virus, reported cases in northern and southern regions has increased." Shu Yuelong said there was no detection of cases of human infection with H7N9 flu a "South", "North" so obvious the regional differences.

Since we've seen some significant genetic changes in the H7N9 virus (more accurately, viruses) this year - along with some subtle changes in behavior - it is impossible to say what this summer and next fall have in store.

There have been concerns raised that the virus is becoming more `heat tolerant', which may increase its presence during the summer months. And the impact of an HPAI version of the virus, reported last January in Guangdong Province, remains to be seen.

As we've seen with H5N1, H5N8, and H5N6, avian flu viruses in China have a habit of eventually expanding their geographic range. While northern China may be at greater risk of seeing cases than in the past, the bigger concern is what happens if, and when, H7N9 hitches a ride on migratory birds into Russia, North Korea, Japan, India, Vietnam, or Laos.