Viral Creep In Second Decade Of The 21st Century

Photo Credit- CDC

 

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Eleven years ago the Report of the WHO/FAO/OIE Joint Consultation on Emerging Zoonotic Diseases, convened in Geneva, defined an emerging zoonosis as ‘a zoonosis that is newly recognised or newly evolved, or that has occurred previously but shows an increase in incidence or expansion in geographical, host or vector range’

 

Last year, in Emerging zoonotic viral diseases  L.-F. Wang (1, 2) * & G. Crameri wrote:

 

The last 30 years have seen a rise in emerging infectious diseases in humans and of these over 70% are zoonotic (2, 3). Zoonotic infections are not new. They have always featured among the wide range of human diseases and most, e.g. anthrax, tuberculosis, plague, yellow fever and influenza, have come from domestic animals, poultry and livestock. However, with changes in the environment, human behaviour and habitat, increasingly these infections are emerging from wildlife species.

 

Patterns that were predicted nearly two decades ago by well respected anthropologist and researcher George Armelagos (May 22, 1936 - May 15, 2014) - of Emory University - who wrote Disease in human evolution: the re-emergence of infectious disease in the third epidemiological transition. National Museum of Natural History Bulletin for Teachers 18(3)

I wrote at some length back in 2011 on The Third Epidemiological Transition, which Dr. Armelagos called the age of re-emerging infectious diseases, a concept he expanded upon in 2010 in The Changing Disease-Scape in the Third Epidemiological Transition, where he wrote:

 

It is characterized by the continued prominence of chronic, non-infectious disease now augmented by the re-emergence of infectious diseases. Many of these infections were once thought to be under control but are now antibiotic resistant, while a number of “new” diseases are also rapidly emerging. The existence of pathogens that are resistant to multiple antibiotics, some of which are virtually untreatable, portends the possibility that we are living in the dusk of the antibiotic era. During our lifetime, it is possible that many pathogens that are resistant to all antibiotics will appear. Finally, the third epidemiological transition is characterized by a transportation system that results in rapid and extensive pathogen transmission.

 

In other words, the emergence of MERS-CoV, H5N1, Nipah, Hendra, Lyme Disease, H7N9, H5N6, H10N8, NDM-1, CRE, etc. are not temporary aberrations. They are the new norm, and we should get used to seeing more pathogens like these appear in the coming years.

 

The emerging infectious diseases are considered such an important threat that the CDC maintains as special division – NCEZID (National Center for Emerging and Zoonotic Infectious Diseases) – to deal with them. According to the NCEZID:

Emerging means infections that have increased recently or are threatening to increase in the near future. These infections could be

• completely new (like Bourbon virus, which was recently discovered in Kansas or MERS, Middle East Respiratory Syndrome).
• completely new to an area (like chikungunya in Florida).
• reappearing in an area (like dengue in south Florida and Texas).
• caused by bacteria  that have become resistant to antibiotics, like MRSA (methicillin-resistant Staphylococcus aureus), C. difficile, or drug-resistant TB.

 

Over the past 36 months we’ve seen:

• A novel Coronavirus (MERS-CoV) emerge in the Middle East
• Several new avian flu strains have emerged and jumped to humans, including H7N9, H5N6, H10N8, and H6N1. 
• Chikungunya arrived in the Americas, and has already infected well over 1 million people. 
• Several new tickborne diseases have emerged (Heartland Virus, Bourbon Virus, SFTS) in the United States and around the world. 
• Last summer a new variant of a rarely seen EV-D68 virus swept across the United States, sickening hundreds of thousands of kids and leaving more than 100 paralyzed.

 

And in the wings we have a number of epizootic diseases – like HPAI H5N2, H5N8, canine H3N2, H10N7 and H3N8 in seals – that while they haven’t jumped to humans, have at least some potential to do so in the future.

Although our awareness of some of these threats is no doubt enhanced by our improved surveillance and testing capabilities, there are reasons to believe the number of zoonotic threats facing us are increasing faster today than we’ve seen in the past.

 

Additionally, some zoonotic threats – like Lyme disease – are now recognized as being far more prevalent than previously appreciated.  In 2013, the CDC revised their Estimate Of Yearly Lyme Disease Diagnoses In The United States, indicating that the number of Lyme Disease diagnoses in the country is probably closer to 300,000 than the 30,000 that are officially reported each year to the CDC.

While exotic diseases have always existed and plagued mankind, never before has mankind been so able to aid and abet their global spread, via our increasingly mobile society.  

 

Chikungunya was undoubtedly introduced by viremic travelers to the Caribbean in the fall of 2013, who inadvertently `seeded’ the virus into the local mosquito population.  Since then there have been well over 1.3 million infections in the Americas – spanning more than 3 dozen nations - and millions more will undoubtedly be infected in the years to come.  

 

Presumably Dengue arrived in South Florida in 2009 in a similar fashion, as did West Nile Virus to NYC in the late 1990s. Earlier this year we learned of two travelers who returned to Vancouver infected with the H7N9 virus.  A year previously, a nurse died in Alberta, Canada after contracting H5N1 while on a visit to China. 

 

And we’ve seen a handful of Ebola and MERS cases travel via aircraft to the United States, Europe, and the Philippines over the past year.

 

While vector-borne illnesses like West Nile, Dengue, and Chikungunya have done the best so far, there is really no way to know what the `next big thing’ in global infectious disease spread will be.  As the CDC’s Global Health Website puts it:

 

Why Global Health Security Matters

Disease Threats Can Spread Faster and More Unpredictably Than Ever Before

(Excerpt)

A disease threat anywhere can mean a threat everywhere. It is defined by

• the emergence and spread of new microbes;
• globalization of travel and trade;
• rise of drug resistance; and
• potential use of laboratories to make and release—intentionally or not—dangerous microbes.

(Continue . . .)

 

A recent Assessment by the Director of National Security (see DNI: An Influenza Pandemic As A National Security Threat) found the global spread of infectious diseases – along with cyber attacks, terrorism, extreme weather events, WMDs, food and water insecurity, and global economic concerns.- constitutes a genuine threat to national security.

 

As we discussed last year,  in The New Normal: The Age Of Emerging Disease Threats, the reality of life in this second decade of the 21st century is that disease threats that once were local, can now spread globally in a matter of hours or days.

 

We’ve been lulled into a false sense of security since the last pandemic was relatively mild, and the feeling is they only come around every 30 or 40 years.  But viruses don’t read calendars, or play by `mostly likely worst-case scenario rules’  that are adopted by most planning committees.

 

The time has come to take pandemic planning seriously again, not because of one specific threat like MERS or H5N1, but because there’s a growing list of pathogens with pandemic potential queuing up around the globe.

 

All of which makes this a good  time for agencies, organizations, businesses, communities, and families to dust off their pandemic plans, review them, and make any needed refinements.  

 

You do have a pandemic plan, don’t you?

 

For some recent pandemic preparedness blogs, you may wish to revisit:

 

Do You Still Have A CPO?

Pandemic Planning For Business

NPM13: Pandemic Planning Assumptions

The Pandemic Preparedness Messaging Dilemma

The Year Of Spreading Dangerously

 

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In addition to providing the usual scourges of malaria, dengue, seasonal influenza, antibiotic resistant bacteria and pneumonia, 2014 has provided us with a number of new, or sometimes simply transplanted, disease threats around the world.  

 

A reminder that in our highly mobile and interconnected world, a disease threat anywhere can easily become a disease threat everywhere. 

 

The tone for the new year was set during the opening days of January when we saw North America’s first imported case of H5N1 ex-China (see Alberta Canada Reports Fatal (Imported) H5N1 Infection).  During that same week, Hong Kong was dealing with imported cases of H9N2 (link) and H7N9 (link) while Taiwan was dealing with an imported H7N9 infection (see  A Bit More On Taiwan’s Imported H7N9 Case).

Although  these cases were contained they served to remind us how easily a novel flu virus can hop a plane and travel from one country to the next.

The first cases (2 confirmed, 4 probable, 20 suspected) of Chikungunya on the French part of St. Martins were reported in early December of last year, likely imported by a viremic tourist, but by early January it was apparent that the virus was thriving, and spreading across the Caribbean courtesy of a highly competent local mosquito vector.

The ECDC reported as of 9 January 2014:

• 201 probable or confirmed cases in Saint Martin (FR);
• 2 confirmed cases in Saint Martin (NL);
• 48 probable or confirmed cases in Martinique;
• 25 probable or confirmed cases in Saint Barthélemy;
• 10 probable or confirmed cases including one imported case from Saint Martin in Guadeloupe;
• 1 confirmed case imported from Martinique in French Guiana.

 

Within weeks there would be thousands of cases, and within months hundreds of thousands. From these humble beginnings, in less than a year, the latest PAHO surveillance report (December 5th, 2014) puts the number who have been infected in the Americas now at just under 1 million people – although that is likely an undercount.

Of some solace, while painful and sometimes debilitating, Chikungunya has a fairly low mortality rate.  Still hundreds have died, and thousands have suffered long-term disability due to the virus. 

 

Although there have only been 11 locally acquired cases in the continental United States (all in Florida), this year more than 1,900 visitors have tested positive for the virus, increasing the odds that CHKV will eventually take up residence in North America.  

 

We’ve seen similar expansion of Dengue this year, with major new outbreaks in China and Japan.

 

While we were watching  the second wave of H7N9 accelerate in China, on January 17th we learned of the first outbreak of a new subtype of avian flu; H5N8 (see Media Reporting Korean Poultry Outbreak Due To H5N8) – which over the next several months would result in the culling of more than 13 million birds.

 

Currently only a threat to poultry, this virus has – over the first 11 months – spread as far east as Japan and as far west as the UK, likely carried by migratory birds.  Where it shows up next is anyone’s guess.

H5N8 Branching Out To Europe & Japan

 

Adding complexity to last winter’s bird flu season, we also saw three human infections with a new H10N8 virus (see Jiangxi Province Reports Second H10N8 Infection), and later in the spring, with a never-before-seen HPAI H5N6 virus (see Sichuan China: 1st Known Human Infection With H5N6 Avian Flu).

Both are wild cards for the upcoming winter season, but will have to be watched carefully for further spread.  H5N6, in particular, has been widely reported in poultry across both China and Vietnam in recent months.

And while H7N9 set worrisome new records for human infections during its second wave (n=322 cases vs 134 cases) last winter and spring, on the Arabian Peninsula MERS was also setting new records, and expanding its geographic range as well. 

 

The United States saw two imported cases last May, but it wasn’t alone, as more than a dozen nations have seen imported cases from the Middle East. With a distinct seasonal pattern, we can probably expect another surge in MERS cases after the new year.

Credit BCCDC

 

And while bird flu and MERS kept us busy during the first half of 2014, since the summer the first regional epidemic of Ebola – and in an area (West Africa) where it had never previously sparked an outbreak – became the big infectious disease threat of the year. 

 

With at least 17,000 infected (estimates range up to 2.5x’s official counts) and more than 6,000 dead, this Ebola outbreak continues to re-write the rules of how Ebola is expected to behave. 

Credit WHO Roadmap Dec 3rd.

While the effect of this epidemic on nations in western Africa has been nothing less than devastating, so far the impact from exported cases to the United States and Europe has been fairly limited.  It has, however, necessitated the creation of an extensive and expensive surveillance and reporting system here in the U.S., and around the globe.

A far lesser threat, here is the United States we saw an outbreak of a rarely-seen non-polio enterovirus (EV-D68) starting last August -first reported in Kansas City - but quickly spreading across the nation.  While most only saw mild illness, at the same time we saw  a few dozen children experience a rare form of paralysis thought to be linked to the virus (see CIDRAP: Likely That Polio-like Illness & EV-D68 Are Linked).

 

There were others, of course.  One off’s like the imported case of Lassa Fever in Minneapolis, MN and an imported case of CCHF (ex-Bulgaria) to the UK. 

 

Like embers drifting from a distant fire, most of the time these disease introductions burn out without harm, but they nonetheless harbor some potential to ignite where ever they land.

 

The reality of life in this second decade of this new century is that disease threats that once were local, can now spread globally in a matter of hours or days, thanks to our highly mobile society. 

 

And as our population and mobility have grown, so have the number of emerging infectious disease threats.  Something that was foretold two decades ago by anthropologist and researcher George Armelagos of Emory University, which I described in considerable detail in The Third Epidemiological Transition.

 

Earlier this year, we looked at an assessment by the Director Of National Intelligence who includes emerging infectious diseases and  Influenza Pandemic As A National Security Threat. 

From that report:

Worldwide Threats Assessment – published January 29th, 2014,

(Excerpt)

Health security threats arise unpredictably from at least five sources: 

• the emergence and spread of new or reemerging microbes;
• the globalization of travel and the food supply;
• the rise of drug-resistant pathogens;
• the acceleration of biological science capabilities and the risk that these capabilities might cause inadvertent or intentional release of pathogens; and
• adversaries’ acquisition, development, and use of weaponized agents. 

Infectious diseases, whether naturally caused, intentionally produced, or accidentally released, are still among the foremost health security threats.  A more crowded and interconnected world is increasing the opportunities for human, animal, or zoonotic diseases to emerge and spread globally.  Antibiotic drug resistance is an increasing threat to global health security.  Seventy percent of known bacteria have now acquired resistance to at least one antibiotic, threatening a return to the pre-antibiotic era.

While we’ve heard the warnings for years, 2014 seems to have accented the message; global health security is truly a national security issue.

 

The obvious hotspots to watch right now center around China, Africa and the Middle East, but the 2009 H1N1 pandemic and this year’s EV-D68 outbreak show that our own backyard can be a fertile viral proving ground as well.

 

The rise or emergence of disease threats like  MERS-CoV, H5N1, Nipah, Hendra, Lyme Disease, Ebola, H7N9, H10N8, H5N8, H5N6, NDM-1, CRE, etc. doesn’t appear to be a temporary aberration – but rather an ongoing trend - and so we need to be thinking about our local and global response to these threats.

 

And while you and I may not be able to do much personally about the international health response, we can ensure our families, friends, and businesses are better prepared to deal with whatever comes down the pike next.

 

Some earlier blogs on pandemic preparedness you may find worth re-visiting include:

 

MMWR: Updated Preparedness and Response Framework for Influenza Pandemics

It’s Not Just Ebola

NPM14: Because Pandemics Happen

Pandemic Planning For Business

 

Because,  if what’s past is prologue, then 2015 could prove to be an even more challenging year when it comes to the emergence and expansion of infectious disease threats around the world.  

The New Normal: The Age Of Emerging Disease Threats

Photo Credit- CDC

 

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The reality of life in this second decade of the 21st century is that disease threats that once were local, can now spread globally in a matter of hours or days.  Vast oceans and prolonged travel times no longer protect us against infected travelers crossing borders. 

 

And despite the media hype over airport screening, we have no technology that can realistically, or reliably detect infected individuals and prevent them from entering a country (see  Head ‘Em Off At The Passenger Gate?).

 

As our ability to transport diseases rapidly to any corner of the globe has increased, so has the number and variety of emerging infectious diseases.  Something that was foretold two decades ago by anthropologist and researcher George Armelagos of Emory University, which I described in considerable detail in The Third Epidemiological Transition.

 

According to Dr. Armelagos, the Third Epidemiological Transition began in the late 1970s or early 1980s, and is hallmarked by newly emerging infectious diseases, re-emerging diseases carried over from the 2nd transition, and a rise in antimicrobial resistant pathogens.

 

When you combine those factors with an increasingly mobile global population of about 7 billion people, and huge increases in the number of animals being raised for food consumption (often in environments conducive to the spread of diseases), and you have a recipe for explosive growth in diseases.

 

In a 2010 paper, Armelagos along with Kristin Harper, updated his original paper.  Both papers are well worth reading.

 

Int J Environ Res Public Health. 2010 February; 7(2): 675–697.

Published online 2010 February 24. doi: 10.3390/ijerph7020675.

The Changing Disease-Scape in the Third Epidemiological Transition

Kristin Harper and George Armelagos

 

We are, quite simply, living in an age of emerging infectious diseases. 

 

Over the past three decades, dozens of new – mostly zoonotic – diseases have been identified.   Some of these new, or re-emerging disease threats, include:

 

• HIV
• SARS
• The re-emergence and spread of H5N1 bird flu in 2003
• An H1N1 `Swine Flu’  pandemic in 2009
• Swine Variant Influenza viruses (H1N1v, H1N2v, H3N2v)
• MERS-CoV and other `bat borne’ viruses like Nipah and Hendra
• H7N9, H10N8, H5N2 and other emerging avian flu viruses
• Lyme Disease, CCHF, Heartland Virus, SFTS, and other tickborne diseases
• The global spread of MRSA, along with the recent arrival of of NDM-1 and other Carbapenemases that threaten the viability of our antibiotic arsenal. 
• An explosion and spread of mosquito-borne diseases like  dengue, chikungunya & malaria
• Even old scourges, once thought on the way out, are showing new signs of life . . . like Pertussis, measles, and polio.
• Perhaps most troubling of all has been the emergence of increasingly drug resistant strains of tuberculosis.
• And the one that has everyone’s attention right now;  Ebola.

 

If you consider the toll they take each year in terms of lives lost, misery, and dollars – the most effective terrorists in this world are not humans, they are microbial.  

 

And in a lot of places around the globe, they not only have the upper hand, they are gaining territory. .

 

Yet, it wasn’t until the mid-1990s that interest in these emerging pathogens really took off. The CDC only began publishing the EID Journal, a highly respected peer-reviewed journal on emerging pathogenic threats, in 1995.   Today emerging disease threats, and neglected tropical diseases, are a hot topic in scores of respected journals.

 

Currently there is a lot of public concern over the Ebola virus, and while it is a fearsome disease, it has far less potential to wreak global havoc than many of the pathogens on the list above.   

 

Viruses that spread via respiratory routes, like MERS-CoV, the ever expanding flock of avian flu viruses, reassortant swine flu viruses, and other respiratory pathogens are all better equipped to start a global epidemic than is Ebola.

 

None of which is to suggest that Ebola isn’t a serious threat, only that if it manages to spread beyond Africa, it is more likely to manifest in the form of very small, sporadic, localized outbreaks, rather than as a global epidemic.

 

Alas, the same can not be said for many other emerging viruses, should any of them adapt well enough to humans to transmit easily.  Which is why, early this year, we looked at an assessment by the Director Of National Intelligence who includes emerging infectious diseases and  Influenza Pandemic As A National Security Threat. 

From that report:

 

Worldwide Threats Assessment – published January 29th, 2014,

(Excerpt)

Health security threats arise unpredictably from at least five sources: 

• the emergence and spread of new or reemerging microbes;
• the globalization of travel and the food supply;
• the rise of drug-resistant pathogens;
• the acceleration of biological science capabilities and the risk that these capabilities might cause inadvertent or intentional release of pathogens; and
• adversaries’ acquisition, development, and use of weaponized agents. 

Infectious diseases, whether naturally caused, intentionally produced, or accidentally released, are still among the foremost health security threats.  A more crowded and interconnected world is increasing the opportunities for human, animal, or zoonotic diseases to emerge and spread globally.  Antibiotic drug resistance is an increasing threat to global health security.  Seventy percent of known bacteria have now acquired resistance to at least one antibiotic, threatening a return to the pre-antibiotic era.

This was, admittedly, just one of many threats discussed in this 27 page threat assessment.  Others include cyber attacks, terrorism, extreme weather events, WMDs, food and water insecurity, and global economic concerns.

 

A week before that report was issued, Dr. Thomas Frieden – Director of the CDC – penned an opinion piece for CNN called How to Prevent the Next pandemic ( see CDC Director Frieden: On Preventing A Pandemic).  Many of these themes are carried forward on the CDC’s Global Health Website at:

Why Global Health Security Matters

Disease Threats Can Spread Faster and More Unpredictably Than Ever Before

(Excerpt)

A disease threat anywhere can mean a threat everywhere. It is defined by

• the emergence and spread of new microbes;
• globalization of travel and trade;
• rise of drug resistance; and
• potential use of laboratories to make and release—intentionally or not—dangerous microbes.

(Continue . . .)

 

In 2014 alone, in addition to the spread of Ebola, we’ve seen the importation of H5N1 into Canada, imported MERS-CoV cases in the United States (along with 20+ other countries), imported H7N9 to Taiwan and Hong Kong, imported CCHF in the UK, and Lassa fever in a traveler in Minneapolis, and Chikungunya has infected 500,000 people in the Caribbean over the past nine months.

 

And frankly, these are just the highlights.

 

The simple truth is, while Ebola isn’t likely to rise to the level of a global epidemic, nature’s lab is open 24/7, and it is continually producing new candidates (or refining old ones) to spark the next pandemic.  

 

Viruses like H7N9, H5N1, and H3N2v continue to mix and match genes, looking to hit the right combination to spread easily in humans.  Old influenza nemeses, to which we have limited community immunity (like H2N2) still lurk in avian populations, and upstart coronaviruses like SARS and MERS-CoV are still testing the waters, as they try to `figure us out’.

 

All of which means that if and when Ebola is contained (and I believe it will be), the greater threat won’t have gone away.  Whether the `next pandemic threat’ comes in six weeks, six months, or six years – or from what location or source - is unknowable. 

 

But few scientists would argue that another pandemic won’t emerge at some point.

 

Which is why, when the media hype and public concerns over Ebola dies down –  we should not let our resolve to strengthen public health – both here, and around the globe -  die with it. 

 

We live in an age where these threats aren’t going to go away, and we can ill afford to let our guard down.

 

For more on pandemic preparedness, you may wish to revisit:

 

The Global Reach Of Infectious Disease

HSPH Video: The Next Pandemic: Are We Ready? 

Pandemic Preparedness: Taking Our Cue From The Experts

Novel Coronavirus: More Questions Than Answers

 

Coronavirus – Credit CDC PHIL

 

 

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While we wait for more information on the novel coronavirus that continues to pop up in the Middle East (see WHO Announces Additional Coronavirus Cases), it isn’t lost on most infectious disease geeks that this month (November) marks the 10th anniversary of the initial outbreak of SARS in Guangdong Province, China. 

 

Over the next eight months SARS (Severe Acute Respiratory Syndrome) infected more than 8,000 people, killing roughly 10%.  China, Hong Kong, and Taiwan were the hardest hit, but a handful of cases made it into Canada, the United States, and across Europe.

 

Source World Health Organization

 

By mid-April of 2003 we learned the illness was due to a novel coronavirus (SARS-CoV). A bit of a surprise really, since human coronaviruses had previously only been linked to mild respiratory illnesses.

 

Although eventually contained, SARS was the first genuine pandemic threat of the 21st century. It also served to remind us that influenza isn’t the only virus with pandemic potential.

 

One of the most authoritative accounts of the SARS outbreak, and how it appears to have been linked to the practice of consuming bushmeat in China, comes from Karl Taro Greenfeld’s book The China Syndrome: The True Story of the 21st Century's First Great Epidemic.

 

While civet cats, which were served in `wild flavor’ restaurants in China, were first implicated in this outbreak (see A Civets Lesson), bats have also been shown to carry this Coronavirus, and may be the primary host.

 

The jury is out on whether the virus was transmitted directly to man from bats, or perhaps from bats to civits to humans.

 

Now the world is watching another coronavirus – definitely not SARS – but of the same general family, and capable of producing serious, even fatal illness in humans.

 

And like SARS, this new virus may be of bat-origin.

 

What we don’t know (yet) is the source of this virus, how it has managed to jump to at least 6 people in two countries, and whether – once contracted – it can be passed on to other humans.

 

Up until this week, the reassuring mantra has been that the virus does not transmit from human-to-human (H2H). The reason for that assumption has been the lack of nosocomial infection in hospitals where the first couple of cases were treated.

 

But this week we’ve learned of two family members in Saudi Arabia who tested positive for the virus, and that there were two other family members with similar symptoms, one of whom died.   

 

One of the two additional family members tested negative, but we’ve little actual experience with the recently developed tests for this virus, and so its sensitivity isn’t well established. Tests are pending on the fourth family member who died.

 

Although a common environmental exposure is always possible, these latest revelations put H2H transmission back on the table.

 

The lack of human-to-human transmission in the earlier cases doesn’t rule out H2H transmission now, or in the future. When a virus jumps to a new species, it isn’t necessarily completely optimized for its new environment.

 

So one of the things we watch for are signs of further adaptation as the virus `figures out’ its new host. 

 

Influenza viruses are the absolute master at this type of evolutionary adaptation, but are by no means the only virus with this ability.

 

One of the ways researchers test viruses is via a serial passage experiment.  It is essentially how Ron Fouchier created a `mammalian-adapted’ H5N1 virus in the laboratory last year, and it mimics what viruses do in the wild.

 

Last year, in H5N1: A Rite Of Passage, I described how serial passage studies are conducted, but briefly, an experimental animal is infected with a virus, and that virus is then collected and used to inoculate another lab animal. 

 

Simplified Illustration of a Serial Passage Experiment. 

 

The process is repeated, and after 10 or so iterations, the virus is then examined for `adaptive changes’. Sometimes, after multiple passes through a series of hosts, the virus picks up mutations that favor its survival in the new species.

 

This process happens outside of the laboratory as well, which is why – when a virus jumps to a new species – we watch it carefully to see if it develops `legs’; the ability to spread efficiently.

 

Over the summer we watched as swine-variant H3N2v viruses tried – and for the time being, failed – to make a sustained jump to humans (see MMWR: H3N2v Related Hospitalizations In Ohio – Summer 2012). But past performance is no guarantee of future results.

There’s always next year.

 

And so it is with this new coronavirus. It could recede back into the woodwork, or it could sputter ineffectually for years, threatening occasionally - but never quite succeeding -  as a major public health threat.

 

Or it could develop `legs’ and become the next big global health threat.  At this point, no one knows.

 

For those looking for comfort, pandemics are a fairly rare occurrence. Many viruses emerge and threaten, but few are truly ready for prime time.

 

Like with H5N1, H3N2v, Nipah, and a handful of other emerging viruses that continue to make the occasional foray into the human population, we remain in a watchful waiting mode with this new coronavirus. 

 

 

 

For more coverage of this developing story, I’d recommend Maryn McKenna’s blog from last night:

 

WHO Announces Family Cluster of Cases of New Coronavirus

 

Any article or report from Helen Branswell is worth reading, but specifically this one from yesterday, and this one from today.

 

And finally, Crofsblog for the best news round up on the coronavirus, and many other EIDs.

 

Study: Intra-Continental Spread of Invasive Non-Typhoidal Salmonella

 

 Salmonella typhimurium bacteria – Credit CDC PHIL

 

 

# 6599

 

You might not think there’d be much of a connection between an emergent serotype of Salmonella and the HIV epidemic in Sub-Saharan Africa - but if researchers from the Wellcome Trust Sanger Institute have it right - this highly pathogenic bacterial strain may have had a powerful viral ally.

 

There are more than 2500 serovars of Non-Typhoidal Salmonella (NTS) that can produce gastroenteritis or other infections in humans. Taken together, these Gram negative, anaerobic bacteria are believed to be the second most common source of food poisoning in the United States.

 

Those infected often develop diarrhea, fever, vomiting, and abdominal cramps that may persist for several days.

 

In the western world most recover without treatment, although the CDC estimates that nearly 400 people infected die each year in the United States (Cite  CDC Food borne Illness Estimates).

 

In developing countries, Non-typhoidal Salmonella can (and does) exact a much higher toll, particularly among those who may be malnourished or suffer from chronic ailments such as malaria and HIV.

 

In recent years researchers have also noted a much more virulent form of NTS, spreading across sub-Saharan Africa, that they’ve dubbed  Invasive Non-Typhoidal Salmonella (iNTS). 

 

Not only is it a multi-drug resistant strain, it is fatal in about 25% of those who contract it.

 

Today, we’ve a study that appears in Nature Genetics that links the Intracontinental spread and evolution of this invasive and severe form of Salmonella to the emergence and spread of HIV.

 

Intracontinental spread of human invasive Salmonella Typhimurium pathovariants in sub-Saharan Africa

Chinyere K Okoro,Robert A Kingsley,Thomas R Connor,Simon R Harris,Christopher M Parry,Manar N Al-Mashhadani,Samuel Kariuki,Chisomo L Msefula,Melita A Gordon,Elizabeth de Pinna,John Wain,Robert S Heyderman,Stephen Obaro,Pedro L Alonso,Inacio Mandomando,Calman A MacLennan, Milagritos D Tapia,Myron M Levine,Sharon M Tennant,Julian Parkhill & Gordon Dougan

Published online 30 September 2012

 

While the bulk of the study is behind a pay wall, the Abstract is available, as is this press release from the Wellcome Trust Sanger Institute.

 

New pathogen epidemic identified in sub-Saharan Africa

Researchers track the spread of human invasive non-Typhoidal Salmonella in sub-Saharan Africa

A new study out today (Sunday 30 September) reveals that the emergence and spread of a rapidly evolving invasive intestinal disease, that has a significant mortality rate (up to 45%) in infected people in sub-Saharan Africa, seems to have been potentiated by the HIV epidemic in Africa.

 

The team found that invasive non-Typhoidal Salmonella (iNTS) disease is caused by a new form of the bacteria Salmonella Typhimurium that has spread from two different focal hubs in Southern and Central Africa beginning 52 and 35 years ago, respectively. They also found that one of the major contributing factors for the successful spread of iNTS was the acquisition of genes that afford resistance to several front line drugs used to treat blood-borne infection such as iNTS.

 

iNTS is a blood-borne infection that kills approximately one of four people in sub-Saharan Africa who catch it. Yet, in the rest of the world, NTS is a leading cause of acute inflammatory diarrhoea that is self-limiting and tends to be fatal in less than 1 per cent of people infected. The disease is more severe in sub-Saharan Africa than the rest of the world because of factors such as malnutrition, co-infection with malaria or HIV and potentially the novel genotype of the Salmonella bacteria.

 

"The immune system susceptibility provided by HIV, malaria and malnutrition at a young age, may provide a population in sub-Saharan Africa that is large enough for this detrimental pathogen to enter, adapt, circulate and thrive," says Chinyere Okoro, joint first author from the Wellcome Trust Sanger Institute. "We used whole genome sequencing to define a novel lineage of Salmonella Typhimurium that is causing a previously unrecognised epidemic across the region. Its genetic makeup is evolving into a more typhoid like bacteria, able to efficiently spread around the human body"

 

<SNIP>

 

"There has been some evidence that this disease can be passed from human to human. Now the race is on to discover how NTS is actually transmitted in sub-Saharan Africa so that effective intervention strategies can be implemented."

 

(Continue . . . )

 

 

And for more on all of this, here’s Debra McKenzie’s article for New Scientist.

 

 

HIV could be turning salmonella nastier

 

18:00 30 September 2012 by Debora MacKenzie

 

A nastier kind of salmonella infection has emerged alongside the HIV epidemic in Africa. The finding is the first evidence that HIV might be allowing new human pathogens to evolve in immunosuppressed people.

 

(Continue . . . )

 

WHO: Coronavirus Not SARS

 

Coronavirus – Credit CDC PHIL

 

 

 

# 6578

 

We are just three days into the emerging coronavirus story (see here, here, and here) , and the short message above, tweeted this morning by the World Health Organization, deserves repeating.

Despite coming from the same family of viruses as SARS (as do many other, far less pathogenic viruses), this new coronavirus is not SARS - and until more testing can be completed - we don’t know how much of a danger it actually presents.

 

The WHO continued to tweet:

 

 

Kidney failure, while not unheard of in SARS, was not a common presenting symptom back in 2002-2003.  And SARS transmitted readily from human to human. Thus far, we haven’t seen signs of that sort of transmission with this new virus.

 

None of which is to say this virus couldn’t prove to be a bigger public health threat down the road, only that it is premature to think of this virus as the next global health crisis.

 

The media has been quick to refer to this virus as SARS-like, but it remains to be seen just how much the two viruses really have in common.

 

The discovery of new - even deadly - viruses that can afflict humans or other mammals is not uncommon. And most of the time, after an initial flurry of breathless news reports, the threat is found to be less than of pandemic proportion.

 

To provide a little perspective, a few viral discoveries in recent years that sparked initial hyperbolic headlines, but have (so far, anyway) failed to present a major public health threat:

 

• We’ve watched a number of triple-reassortant swine flu (Variant) viruses (H1N1v, H1N2v, H3N2v) make tentative jumps into human hosts (see An Increasingly Complex Flu Field), and so far they’ve failed to spread efficiently, or to produce substantial levels of morbidity.
• In August of this year (see New Phlebovirus Discovered In Missouri) the CDC announced the detection of a novel tick-borne virus in America’s heartland.  Despite being detected in 2009, only two cases have been reported.
• In March of this year, we learned of a new H17 flu subtype, carried by bats in an unusual host: bats (see A New Flu Comes Up To Bat).
• In November of 2011 we saw a major die-off of seals in New England, that was eventually traced to a new mammalian adapted influenza virus mBio: A Mammalian Adapted H3N8 In Seals.  
• In October of 2008  doctors in Zambia and South Africa ran across a mysterious, previously unclassified virus that caused hemorrhagic symptoms in its victims similar to Ebola (see Lujo Virus: Newly Identified Arenavirus) While highly contagious, and fatal in 4 of the 5 identified victims, it has not reappeared since 2008.

 

And if you want to go back a few more years, you can add Nipah, Hendra, H5N1, Ebola, Marburg . . . .

 

The truth is, scientists – with better tools available today – are indentifying `new’ viruses all of the time. A few well distributed viruses that until recently, were unknown, include:

 

• The human metapneumovirus (HMPV) was identified in Dutch children with bronchiolitis about a decade ago.  Since then, it has been found to be ubiquitous around the world, and responsible for a significant percentage of childhood respiratory infections . . . yet until 2001, no one knew it existed.
• Human Bocavirus-infection (HBoV) wasn’t identified until 2005, when it was detected in 48 (9.1%) of 527 children with gastroenteritis in Spain (cite).  It has since been found around the globe using PCR testing.

 

And the list grows longer every year.

 

While most will prove to be less than devastating in impact, we need only look at HIV, the 1918 H1N1 pandemic, and the pandemic viruses of 1957 and 1968 to realize that novel viruses can sometimes emerge and cause incredible morbidity and death.

 

According to well respected anthropologist and researcher George Armelagos of Emory University, we are entering the Third Epidemiological Transition.

This third transition began in the late 1970s or early 1980s, and is hallmarked by newly emerging infectious diseases, re-emerging diseases carried over from the 2nd transition (which began with the industrial revolution, and added chronic, non-infectious, degenerative diseases), and a rise in antimicrobial resistant pathogens.

 

When you combine those factors with an increasingly mobile global population of about 7 billion people, and huge increases in the number of animals being raised for food consumption (often in environments conducive to the spread of diseases), and you have a recipe for explosive growth in diseases.

 

Hence the need for continual surveillance, which will help us spot – and if we are lucky, even contain – the next pandemic before it can spread widely.

Novel Viruses & Chekhov’s Gun

 

 

# 6475

 

 

Although the attribution is suspect, there is an old adage in literary circles – credited most often to Russian playwright Anton Chekhov – that if you show a gun hanging on the wall in the first act, it absolutely must go off by the third.

 

It is such a well used device, that I suspect it leads many people to believe we are on the brink of a pandemic every time a novel influenza virus is reported in humans.

 

Fortunately, emerging infectious diseases are not compelled to follow the dictums of modern literary convention. New flu viruses are constantly cropping up in humans, but only rarely do they portend a pandemic.

With headlines last month on a novel H3N8 `Seal flu’ with supposed pandemic potential, and several small clusters of H3N2v swine flu infections in the Midwest over the past few weeks, today seemed like a good day take a historical look at a few viral contenders that tried, and failed, to spark a pandemic.

Novel flu viruses are most likely to be zoonotic; jumping from another animal species to man, either directly, or through an intermediary host, or via reassortment. 

Over the past 100 years, we’ve seen four of these viral jumps spark a pandemic. The H1N1 pandemic of 1918, the H2N2 pandemic of 1957, H3N2 in 1968, and novel H1N1 in 2009.

But interspersed among these global pandemics have been numerous novel viruses that have infected humans and yet ultimately failed to produce a pandemic.

 

The most obvious example is the H5N1 virus, which first appeared 15 years ago in Hong Kong - and after a 5 year hiatus - returned in 2003.

 

Since that time has infected more than 600 people.

 

Yet despite morphing into more than 20 distinct clades, and spreading from Asia to Europe and the Middle East, this virus remains poorly adapted to human physiology and has (thus far) proved incapable of sparking a pandemic.

 

The caveat being, that this could change.

 

H5N1, like all flu viruses, is constantly evolving.  As long as it is out there, it poses a potential pandemic threat.

Similarly, we’ve seen scattered human infections by the H9N2 avian virus, and sporadic attempts by various strains of the H7 avian virus to jump to man.

 

• In 2003 an outbreak of H7N7 at a poultry farm in the Netherlands went on to infect at least 89 people. Most of the victims were only mildly affected, but one person died.
• In 2004 two people in British Columbia tested positive for H7N3 (see Health Canada Report) during an outbreak that resulted in the culling of 19 million birds.
• In 2006 and 2007 there were a small number of human infections in Great Britain caused by H7N3 (n=1)  and H7N2 (n=4), again producing mild symptoms.

 

But beyond these avian strains, we’ve seen human adapted flu viruses that have threatened – but ultimately failed – to spark a pandemic.

 

The first example comes from shortly after the end of WWII with what would become known as the `pseudo-pandemic’ or vaccine failure of 1947.

 

Fearing that crowded ships and barracks could give rise to a reprise of the 1918 pandemic, the United States Military  commissioned Dr. Thomas Francis of the University of Michigan and his protégé Jonas Salk to come up with a viable influenza vaccine in 1943.

 

Within a year a vaccine based on the 1934 and 1943 flu strains was in wide use in the military, and for several years the Francis/Salk vaccine worked well.

 

But in 1947, a new variant of the H1N1 virus appeared on military bases in Japan,and quickly spread from there infecting hundreds of millions around the globe (see 2002 PNAS article).

 

While it produced a generally mild illness, and few excess deaths, this new strain apparently had drifted enough antigenically to evade both the vaccine and community immunity acquired from earlier strains.

 

Had it been more virulent, the 1947 flu virus might well have been considered a pandemic.  Today it is barely remembered, except by virologists.

 

Four years later, a far more ominous flu strain made a brief appearance during the 1950-51 flu season.

 

For about six weeks, a highly virulent influenza erupted in Liverpool, England and then spread across the UK and to Eastern Canada.

 

For a time, it was as deadly as the 1918 pandemic.

This startling graphic comes from the March 16th, 1951 Proceedings of The Royal Society of Medicine – page 19 – and shows in detail the tremendous spike in influenza deaths in early 1951 over the (admittedly, unusually mild) 1948 flu season. 

 

The CDC's EID Journal  has a stellar account of this 1951 event, and is very much worth reading.

 

Viboud C, Tam T, Fleming D, Miller MA, Simonsen L. 1951 influenza epidemic, England and Wales, Canada, and the United States. Emerg Infect Dis [serial on the Internet]. 2006 Apr [date cited].

 

Despite its virulence, and obvious ability to spread efficiently from human-to-human, this virus died out as suddenly and mysteriously as it appeared.  

 

It remains a medical mystery.

 

Fast forward to  February 1976, and a young recruit at Ft. Dix, New Jersey fell ill and died from a virus that was later isolated and dubbed A/New Jersey/76 (Hsw1N1).

 

This swine-flu virus went on to infect more than 200 soldiers on the base, and caused severe respiratory disease in 13 of them. How and why it appeared in New Jersey remains unknown.

 

While the death rate was very low, this virus appeared to easily transmissible among humans. This led to the swine flu pandemic scare of 1976, which I chronicled several years ago in Deja Flu, All Over Again. 

 

The feared swine flu pandemic never materialized, and for reasons we cannot explain, the virus simply disappeared.

 

In the `close but no cigar’ category,  a year later we did see an epidemic - at least among children - with the return of the H1N1 virus after a 20 year absence. It was dubbed the `Russian Flu’, as it was believed to have escaped from a Russian research laboratory.

 

Given the limits of testing and surveillance, there have most certainly been other failed viruses – of which we are unaware – that simply `flu beneath our radar’. 

 

In recent years we’ve also seen a number of  non-flu viruses, such as the 2003 SARS outbreak, Clusters Of HEV68 Respiratory Infections, and various adenovirus outbreaks, that have produced illness and concerns, but no pandemic.

 

None of this tells us what will become of the H3N2v swine flu virus, or any of the other novel strains that are currently out there. Another pandemic will occur.  We just don’t know when, or from what source.

 

But it does provide some perspective.

 

While all pandemics are caused by novel viruses, not all novel viruses produce pandemics.

 

Emerging viruses deserve our attention and respect, and H3N2v is certainly no exception. In time, this variant virus may prove to be a significant public health threat.

 

But as we watch these myriad novel viruses crop up around the globe, it should provide some solace to remember: history shows us that in the world of emerging infectious diseases . . .

 

. . .  by the time act III comes along – we often find that Chekhov’s gun is loaded with blanks.

HFMD: An Old Illness With A New Cause

 

 

 

Vesicular eruptions in A) hand, B) foot, and C) mouth of a 6.5-year-old boy from Turku, Finland, with coxsackievirus (CV) A6 infection.  Credit - CDC EID Journal 

 

# 6138

 

Since late in January the newshounds on FluTrackers  have been following a story out of Alabama, where public health authorities have been dealing with an offseason outbreak of Hand Foot and Mouth Disease (HFMD).

 

Hand Foot and Mouth Disease is often confused by the public with Foot and Mouth Disease (FMD) seen in cattle, swine, and sheep.  Despite the similar name, the diseases are in no way related.

 

HFMD is a very common viral infection, usually peaking late summer or early fall, and mainly seen among children under the age of 10 (although adults may be vulnerable as well).

 

It is caused by several of the non-polio enteroviruses.

 

While this virus classification may be unfamiliar to a lot of people, the 60+ viruses that fall into this category are among the most prevalent viral infections in the world, probably only second to the myriad and ubiquitous variants of Rhinovirus (`common cold’) that circulate every year.

 

 

The two most common causes of HFMD have been the Coxsackie A16 virus, and the Enterovirus-71 (EV-71), and rarely, the Coxsackie A10 virus.

 

The disease in the United States is commonly caused by the Coxsackie A16 virus and is generally mild. Outbreaks are not uncommon in schools and childcare facilities.

 

Over the past decade we've seen outbreaks - particularly in the Far East  - caused by the more pathogenic EV-71 virus, and this version of the HFMD can occasionally be quite serious.

 

Last year, Vietnam reported more than 90,000 cases of HFMD and reported more than 150 deaths, mostly among young children.

 

And two years ago , the Virology Journal, published an analysis of an EV-71 HFMD virus that caused a major disease outbreak in Fuyang City, China in 2008 that showed it was due to an emerging recombinant virus (see China: A Recombinant EV-71).

 

In 2008, the CDC’s EID Journal carried a dispatch describing an outbreak of HFMD in Finland due to an unusual, and apparently emerging, viral cause; the Coxsackie A6 virus.

 

Dispatch

Coxsackievirus A6 and Hand, Foot, and Mouth Disease, Finland

Riikka Österback, Tytti Vuorinen, Mervi Linna, Petri Susi, Timo Hyypiä, and Matti Waris

Abstract

During fall 2008, an outbreak of hand, foot, and mouth disease (HFMD) with onychomadesis (nail shedding) as a common feature occurred in Finland. We identified an unusual enterovirus type, coxsackievirus A6 (CVA6), as the causative agent. CVA6 infections may be emerging as a new and major cause of epidemic HFMD.

 

This dispatch describe a prolonged nationwide outbreak of HFMD starting in 2008, in Finland:

 

During fall 2008, a nationwide outbreak of HFMD occurred in daycare centers and schools in Finland, starting in August and continuing at least until the end of the year and possibly into the following year. From vesicle fluid specimens of hospitalized children, we identified the etiologic agent as coxsackievirus A6.

 

Since then, we’ve seen a growing number of reports of HFMD outbreaks around the world due to this particular coxsackievirus, including:

 

 

An outbreak of coxsackievirus A6 hand, foot, and mouth disease associated with onychomadesis in Taiwan, 2010

Sung-Hsi Wei, Yuan-Pin Huang, Ming-Chih Liu, Tsung-Pei Tsou, Hui-Chen Lin, Tsuey-Li Lin, Chen-Yen Tsai, Yen-Nan Chao, Luan-Yin Chang and Chun-Ming Hsu

BMC Infectious Diseases 2011, 11:346 doi:10.1186/1471-2334-11-346

Published: 14 December 2011

Hand, Foot, and Mouth Disease Caused by Coxsackievirus A6, Japan, 2011

Fujimoto T, Iizuka S, Enomoto M, Abe K, Yamashita K, Hanaoka N, et al.

Emerg Infect Dis [serial on the Internet]. 2012 Feb

 

 

Until now, this A6 virus has not been associated with HFMD outbreaks in the United States. This from the Alabama Health Department’s website:

 

 

Alabama Department of Public Health monitors new cases of hand, foot and mouth disease

FOR IMMEDIATE RELEASE 
CONTACT:  Mary McIntyre, M.D.
(334) 206-5325

The Alabama Department of Public Health asks the public to be aware that cases of the contagious viral illness called hand, foot and mouth disease are more numerous and severe than normal in Alabama this winter. No known deaths have resulted from the virus, although there have been hospitalizations and there can be some rare, severe complications.

 

As of Feb. 10, the ADPH has interviewed patients and collected and submitted specimens to the Centers for Disease Control and Prevention for individuals with febrile illnesses and rash. Based on the results of testing done by the CDC, the Coxsackie A6 virus has been identified.

 

This  specific type of virus has been identified in other countries but has not previously been
associated with an outbreak in the U.S. There is no specific treatment for hand, foot and mouth
disease.

 

“As this is a new virus for our population, we can expect more cases and are monitoring for any change in the clinical presentation,” Dr. Donald Williamson, state health officer, said. “We will continue statewide surveillance on severe cases of this emerging disease and ask physicians and infection control specialists to make notifications to us.”

The public should not be unduly alarmed at this time; however, individuals diagnosed with hand, foot and mouth disease need to follow the recommendations of their health care provider to remain at home until they have no fever, all lesions have scabbed over, and no lesions have appeared for two days.  

The viral disease affects the hands, feet and mouth and usually infects infants and children younger than 5 years old in summer and early autumn. There is no vaccine to protect against it, but learning about the disease and following these recommendations can reduce the risk of illness.

Hand, foot and mouth disease spreads: 

• Person-to-person: Direct contact with saliva, sputum or nasal mucus from the infected person’s nose and throat or with fluid in blisters, or with stool.
• Surface-to-person: Touching objects and surfaces touched by infected persons.
• Infected persons are most contagious during the first week of the illness, but can still pass the virus for weeks after symptoms have gone away.

These are the symptoms:

 

• Fever, rash, sores, poor appetite, a vague feeling of illness and sore throat.
• Painful sores in the mouth may blister and become ulcers.
• Skin rash, flat or raised red spots, develops over 1 to 2 days.
• Rash usually on the palms of the hands and soles of the feet and may appear on the knees, elbows, bottom or genital area.
• Dehydration may occur because of painful mouth sores.

 

Recommendations to protect yourself and prevent its spread:

• Wash hands with soap and water carefully and frequently, especially after going to the bathroom, after changing diapers, and before preparing foods or beverages.
• Disinfect surfaces and items, including toys. First wash the items with soap and water; then disinfect them with a solution of 1 tablespoon of bleach and 4 cups of water.
• Avoid close contact such as kissing, hugging or sharing eating utensils or cups with infected people.

Health care providers are being asked to notify the Alabama Department of Public Health if higher than normal numbers of cases are being hospitalized with hand, foot and mouth disease symptoms. Please call (800) 338-8374 immediately for hospitalized cases.

     -30-

2/10/12

 

 

While apparently a bit more serious than the garden variety of HFMD we are used to seeing in the United States, this A6 virus doesn’t appear to be as pathogenic as the EV-71 virus seen in Asia.

 

But its arrival in the United States serves as a reminder that well adapted emerging viruses are very good at spreading, and that with today’s highly mobile society, oceans and borders provide little in the way of protection.