WHO/FAO/OIE: Call It A(H3N2)v

 

 

H3N2 influenza virions –CDC PHIL

# 6029

 

 

When a new flu strain appears there is often some confusion of what to call it, particularly when the HA and NA components are the same as other circulating flu viruses.

 

This is the problem we ran into when a novel H1N1 virus (now officially dubbed  A(H1N1)pdm09) emerged.  The media latched on to `Swine flu’, while scientific publications used a variety of nom de flus, including A/H1N1/09 and pdmH1N1.

 

It took more than two years before a consensus was reached (see WHO: Call It A(H1N1)pdm09).  And while that does not exactly roll off the tongue, it does have the the advantage of being precise.

 

Today we’ve a joint announcement from the World Health Organization, FAO, and OIE on a standardized nomenclature for the recently emergent trH3N2 virus that has been detected in a handful of people across several states since last summer.

 

They’ve decided to go with A(H3N2)v.

 

We’ll have to wait to see if this designation is adopted elsewhere. What will be done if another variant of the A(H3N2) virus should appear is not mentioned.

 

A hat tip to Giuseppe Michieli on FluTrackers for posting the following link.

 

 

Standardization of terminology for the variant A(H3N2) virus recently infecting humans

Joint announcement of FAO, OIE and WHO

23 December 2011

FAO, OIE and WHO continue working closely together to address influenza issues related to public health and animal health.

 

Since July 2011, twelve human cases of infection with a variant influenza A(H3N2) virus have been detected in the United States. To date, no report has been received from elsewhere in the world. This virus has different virological characteristics from current circulating seasonal influenza viruses in humans, and has a new gene constellation: 7 genes from the triple reassortant A(H3N2) viruses known to have been circulating in pigs in the North America and the M gene from an A(H1N1)pdm09 virus, a seasonal virus currently circulating in humans.

 

In order to improve communications and avoid confusion, FAO, OIE and WHO have established a working group of experts to standardize the terminology for variant influenza viruses. The joint recommendation for the above mentioned A(H3N2) virus is: A(H3N2)v , where “v” stands for “variant”.

An example of use of the terminology:

• Sporadic human cases of infection with a variant influenza A(H3N2) virus A(H3N2)v have been reported in the USA. The A(H3N2)v virus is different from seasonal viruses currently circulating in humans.

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WHO: The Inevitability Of Another Pandemic

 

 

# 5968

 

The World Health Organization is holding a 3-day conference this week in Mexico City called Health Risks in Human-Animal Ecosystems, attended by more than 100 experts from 30 countries.

 

Their goal is to coordinate, and improve, the global response to future outbreaks of zoonotic diseases; those that jump between animals and humans.

 

 

At this week’s conference, WHO Assistant Director-General of Health Security and Environment Keiji Fukuda warned on the inevitability of the world seeing another pandemic, calling it was a matter of when, not `if’.

 

He is further quoted by Reuters as saying:

 

"We do face the risk of another pandemic in the future. We know that the viruses which can cause influenza pandemic circulate in animals and then we don't know when one of those viruses then becomes highly infectious for people and then spreads around the world. We also don't know when something like that happens, which we do expect in the future someday, when something like that happens we don't know how severe the effect will be."

 

 

Working as an alliance, the WHO, FAO, and OIE formally joined forces in 2010 with the issuance of a Tripartite Concept Note outlining their collaborative efforts.

 

Their stated goal is to `coordinate global activities to address health risks at the animal-human-ecosystems interface’.

 

The WHO webpage Zoonoses and veterinary public health (VPH)  provides a description of zoonotic pathogens for us:

 

Any disease or infection that is naturally transmissible from vertebrate animals to humans and vice-versa is classified as a zoonosis according to the PAHO publication "Zoonoses and communicable diseases common to man and animals".

Over 200 zoonoses have been described and they have been known for many centuries. They are caused by all types of agents: bacteria, parasites, fungi, viruses and unconventional agents.

 

Twice in the last decade (SARS in 2003, and Swine Flu in 2009) we saw how quickly viruses normally found in non-human hosts can evolve and adapt to humans and spread globally.

 

Which is why efforts such as Global Early Warning System for Major Animal Diseases, including Zoonoses (GLEWS) have been set up to detect, and provide early warning of animal disease threats

 

The WHO lists the criteria by which events are assessed by the GLEWS task force as:

 

Triggers and GLEWS diseases

What triggers GLEWS

A potential event is assessed according to criteria derived from the International Health Regulations (2005) and the Terrestrial Animal Health Code from OIE:

• Is the public health impact of the event serious?
  • High morbidity and/or high mortality in humans and/or animals.
  • Emerging disease with significant mortality and/or morbidity or zoonotic potential.
• Is the event unusual or unexpected?
  • First occurrence or reoccurrence of a disease/strain.
  • Unusual event for the area or season.
  • Event associated with an unknown agent.
• Is there significant risk of international spread or interference with international travel or trade?

 

You’ll find more information, including a priority list of zoonotic pathogens, on this page as well.

 

There are other efforts out there to detect or provide early warning for the next emerging pathogen, including (but not limited to):

 

• Nathan Wolfe’s Global Viral Forecasting Initiative (GVFI) (see Nathan Wolfe On Pandemic Prevention),
• The National Biological Information Infrastructure (NBII)
• Promed Mail
• The volunteer efforts of the newshounds on the flu forums (see Newshounds: They Cover The Pandemic Front).

While the 2009 H1N1 pandemic is ended, it is important to remember that the world remains at pre-pandemic phase III on the H5N1 virus. 

 

 

But as SARS showed us in 2003, sometimes a pathogen can emerge with little or no warning. Hence the need for nations, businesses, and individuals to be prepared for the unexpected.

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FAO-OIE-WHO Bird Flu Technical Update

 

 

# 5862

 

Earlier this month the three international agencies most closely associated with the tracking and control of bird flu (World Health Organization, FAO, OIE) issued a technical report on the current evolution of the H5N1 avian influenza virus.

 

The forward indicated that this report is intended for:

 

. . .  persons generally familiar with influenza viruses and the epidemiology of influenza in humans and animals.

 

Which I suspect describes most of my readers. The document can be downloaded from:

 

 

FAO-OIE-WHO Technical Update: Current evolution of avian influenza H5N1 viruses

7 September 2011

•  Highly pathogenic avian influenza H5N1 viruses continue to circulate in poultry and cause disease, and remain a threat to human and animal health.

 
•  Both animal and public health sectors at the national, regional, and international levels should maintain vigilance in regularly detecting, reporting, and characterizing animal influenza viruses, and in assessing and managing existing and evolving health
risks associated with these viruses. 

 

Although often neglected by the mainstream media (unless they can use the word `mutant’ in a headline), H5N1 avian influenza continues to pose a threat to birds and to other species, including humans.

 

 

As you can see by the chart above, the number of human cases reported has slowly been increasing since their nadir of 2008. Still, they remain far below the numbers we saw in 2003-2006.

 

While that might seem like good news, it isn’t necessarily as comforting as it may appear. 

 

Between budget cuts, pandemic fatigue, and other pressing public health concerns, surveillance and testing for the H5N1 virus remains quite limited in many parts of the world.

 

Best case, only the sickest of the sick - who have had direct contact with poultry - are likely to be tested for the virus. 

 

Meaning that the numbers we see probably do not reflect the full burden of the disease. A fact that is true for practically every illness.

 

Source CDC 

 

Whether we are talking influenza, Lyme Disease, Salmonella poisoning, or bird flu . . . official case counts are usually just the tip of the pyramid.

 

The concern is that if the virus adapts better to human physiology, it could begin to produce less virulent infections in some people, and spread more easily undetected.

 

While solid evidence of that happening is scant, in a recent seroprevalence study of 800 villagers in Thailand (who reported no history of a serious influenza-like illness), (5.6%) had antibodies to A/Thailand/ 676/005H5N1, and (3.5%) were shown to be seropositive to A/Thailand/384/2006 H5N1.

 

Suggestive, at least, that milder or perhaps even subclinical infections with the virus may be occurring outside our view.

 

And in the past couple of years we’ve also seen a trend in Egypt towards less virulent infections along with a mortality rate half that seen elsewhere,  once again suggesting the virus might be adapting better to human physiology (see PLoS: Human-Type H5N1 Receptor Binding In Egypt).

 

 

Despite these recent studies, for now, the H5N1 virus does not appear to be ready for prime time.  Full adaptation to a humanized pathogen could take years, or even decades.

 

Or it might not happen at all.

 

The tripartite report updates the situation in Cambodia, which has seen a resurgence in H5N1 cases this year (see Cambodia: 8th Fatal H5N1 Case Of 2011, stating:

 

Eight human cases of H5N1 infection have been reported from Cambodia in 2011, all of which were in people under 19 years of age and all of which were fatal. This is the highest number of human H5N1 cases reported in one year from Cambodia. The basis for the increased incidence and the high mortality remain unclear.

 

All of these cases represent sporadic infections likely related to exposure to sick poultry, and are not linked to each other, with the exception of a mother and her child. There is no evidence of sustained human-to-human transmission of H5N1 virus in Cambodia or any other country. 

 

The report also addresses the recent announcement of a `mutated’ clade of H5N1 (see FAO Warns On Bird Flu), stating:

 

•  Predictably, the avian influenza H5N1 viruses also continue to evolve, especially in areas where they circulate endemically in poultry. The slowly evolving viruses are periodically regrouped and assigned new clade names. 

•  One clade, recently named H5N1 clade 2.3.2.1 has evolved from clade 2.3.2 viruses previously circulating among poultry in the eastern Asia since 2005. This clade has been increasingly found in poultry in several countries, and in some areas has become predominant over previously circulating clades. Hence, clade 2.3.2.1 viruses are not “new”. 

•  An older clade of H5N1 viruses, named clade 1, is now being reported only from southern Viet Nam and Cambodia. To date (September 2011), only clade 1 viruses  have ever been isolated from humans and animals in Cambodia.

•  The clade “nomenclature” (i.e. method of naming) for H5N1 viruses is regularly addressed by the standing WHO/FAO/OIE H5N1 Evolution Working Group. Maintaining a standard H5N1 clade nomenclature is important for effective communications among scientists working in the animal health and public health sectors, among influenza researchers, and with the public.

 

The report concludes:

 

Virus evolution and nomenclature: Human health

•  There is currently no evidence that any particular clade or strain of the H5N1 virus, including any newly evolved clade, is more transmissible or pathogenic in humans. Although three human cases of H5N1 virus infection have been associated with clade 2.3.2.1 viruses 2, there is no indication that clade 2.3.2.1 viruses pose any greater threat to human health than any of the other H5N1 viruses. 

•  As viruses spread more widely and intensively in poultry and wild birds, the likelihood of human exposures to infected birds increases. However, this does not increase the ability of the viruses to infect and transmit between people.

•  Three clade 2.3.2.1 viruses have already been identified by WHO’s Global Influenza Surveillance and Response System (GISRS; the group of experts that studies animal and human influenza viruses that may impact human health) to be considered for inclusion in future human inter-pandemic H5N1 vaccine viruses if needed.3

 

Although we continue to see isolated human infections around the world, for now H5N1 is primarily a threat to poultry.

 

Despite ongoing evolution and mutation, the virus remains poorly adapted to human physiology, and only causes rare, sporadic human infections.

 

The concern, of course, is that over time that could change.

 

And so the world remains at Pre-pandemic Phase III on the H5N1 virus, and we continue to watch for signs that the virus is adapting better to humans.

 

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OIE Statement On H5N1 Clade 2.3.2.1

 

 

# 5799

 

 

We’ve already seen statements from the FAO (see FAO Warns On Bird Flu) and the World Health Organization (see WHO Statement On New Bird Flu Clade) regarding this week’s big bird flu news.  

 

Now it is the OIE’s (World Organisation For Animal Health) turn.

 

My thanks go to Giuseppe Michieli who posted the link to this OIE statement on FluTrackers today.

 

 

 

Avian influenza H5N1 clade 2.3.2.1

Paris, 31 August 2011 – OIE closely follows the evolution of avian influenza in domestic and wild birds around the world, and acknowledges the recent identification of an H5N1 virus described as clade 2.3.2.1.

 

Small genetic changes are known to routinely occur in influenza A viruses, including those that may affect humans or animals. The emergence of the H5N1 virus, such as clade 2.3.2.1 is one of such genetic mutations taking place as part of the natural evolution of the virus. This is not immediate cause for alert but, as with the emergence of any new strain, reinforces the need for sustained monitoring of viruses in animal populations so that changes in viruses circulating in the field are detected at an earliest stage and that most appropriate disease control strategies are chosen to best protect animal and public health.

 

OIE recommends keeping up with active surveillance in bird populations, encouraging national Veterinary Services to be prepared to quickly report and respond to unusual animal disease events that may represent more serious disease in animals or that may pose increased  risk to humans.

 

As is the case with human influenza vaccines whose composition needs to be reviewed every year, avian influenza vaccines need to be regularly tested to check whether they effectively combat the viruses circulating in the field. OIE Reference Laboratories and other partner laboratories are actively involved in ongoing surveillance and development of good quality vaccines that match the viruses of concern. The OIE Reference Laboratory in Harbin, China, has developed a new vaccine seed strain that experimentally protects poultry from the identified H5N1 virus clade 2.3.2.1. This vaccine, once available for field use, will be used in countries where H5N1 virus clade 2.3.2.1 has been identified. Registration and manufacturing of a poultry vaccine with the new seed strain is in progress.

 

OIE and OFFLU’s guidance on early detection and rapid response to animal disease events prove crucial in the prevention and control of animal influenzas, with positive implications for human health. OFFLU is a joint OIE/FAO worldwide network of expertise on avian influenza. It also provides animal influenza data to the World Health Organization regularly to assist with the selection of candidate influenza vaccines for humans.

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