Saturday, August 29, 2015

J.Virol.: Experimental Infectivity Of H3N8 In Swine

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Credit ECDC – 125 years of  Pandemic  History

 

# 10,465

 

The H3N8 subtype of influenza A is of particular interest to influenza researchers for several reasons. 

  • First, as the chart above illustrates, H3N8 is strongly suspected to have sparked human epidemics and a pandemic around the turn of the 20th century.
  • Second, avian H3N8 remains endemic in birds.
  • Third, about 50 years ago H3N8 jumped unexpectedly to horses in Miami, and since the 1970s appears to have supplanted the old equine H7N7  and is now  the only equine-specific influenza circulating the globe.
  • Fourth, in 2004 the equine H3N8 virus mutated enough to jump to canines, and began to spread among greyhounds in Florida (see EID Journal article Influenza A Virus (H3N8) in Dogs with Respiratory Disease, Florida).
  • Fifth, in 2011 avian H3N8 was found in marine mammals (harbor seals), and 2012’s  mBio: A Mammalian Adapted H3N8 In Seals,  provided evidence that this virus had recently adapted to bind to alpha 2,6 receptor cells, the type found in the human upper respiratory tract.
  • Sixth, the mBio findings were further confirmed last year in when Nature Communications: Respiratory Transmission of Avian H3N8 In Ferrets, confirmed that this `virus has an increased affinity for mammalian receptors, transmits via respiratory droplets in ferrets and replicates in human lung cells.

 

Add in that in the short history of studying influenza, only H1, H2, and H3 subtypes have taken hold in the human population (see Are Influenza Pandemic Viruses Members Of An Exclusive Club?), and there are many who believe what went around 110 years ago could possibly come around again.


All of which makes the findings of the following study particularly interesting. 

     

Cross-species infectivity of H3N8 influenza virus in an experimental infection in swine

J Virol. 2015 Aug 26. pii: JVI.01509-15. [Epub ahead of print]

Solórzano A1, Foni E2, Córdoba L3, Baratelli M3, Razzuoli E4, Bilato D5, Martín Del Burgo MÁ6, Perlin DS1, Martínez J7, Martínez-Orellana P3, Fraile L8, Chiapponi C2, Amadori M5, Del Real G6, Montoya M9

Abstract

Avian influenza A viruses have gained increasing attention due to their ability to cross the species barrier and cause severe disease in humans and other mammal species as pigs. H3 and particularly H3N8 viruses, are highly adaptive since they are found in multiple avian and mammal hosts. H3N8 viruses have not been isolated yet from humans; however a recent report showed that equine influenza A viruses (IAV) can be isolated from pigs, although an established infection has not been observed so far in this host.

To gain insight into the possibility of H3N8 avian IAV to cross the species barrier into pigs, in vitro experiments and an experimental infection in pigs with four H3N8 viruses from different origins (equine, canine, avian and seal) were performed. As positive control, a H3N2 swine influenza virus A was used. While equine and canine viruses hardly replicated in the respiratory apparatus of pigs, avian and seal viruses replicated substantially and caused detectable lesions in inoculated pigs without previous adaptation. Interestingly, antibodies against HA could not be detected after infection by hemaglutination inhibition test (HAI) with the avian and seal virus.

This phenomenon was observed not only in pigs but also in mice immunized with the same virus strains. Our data indicated that H3N8 IAV from wild aquatic birds have the potential to cross the species barrier and establish successful infections in pigs that might spread unnoticed using HAI as diagnostic tool.

IMPORTANCE SECTION:

Although natural infection of humans with an avian H3N8 influenza A virus has not yet been reported, this influenza A virus subtype has already crossed the species barrier. Therefore, we have examined the potential of H3N8 from canine, equine, avian and seal origin to productively infect pigs.

Our results demonstrated that avian and seal viruses replicated substantially and caused detectable lesions in inoculated pigs without previous adaptation. Surprisingly, we could not detect specific antibodies against HA in any H3N8-infected pigs. Therefore, special attention should be focused towards viruses of the H3N8 subtype as they could behave as stealth viruses in pigs.

 

 

While H3N8 doesn’t currently appear to be established in swine populations, for much of the world testing of pigs is rarely (if ever) done.  In 2009 we did see evidence of H3N8 detected in Chinese swine in the middle of the last decade (see Isolation and molecular characterization of equine H3N8 influenza viruses from pigs in China).

 

For more background on this increasingly promiscuous virus, you may wish to revisit:

EID Journal: Equine H3N8 In Mongolian Bactrian Camel
Study: Dogs As Potential `Mixing Vessels’ For Influenza

Saudi MOH Announces 2 Additional MERS Cases

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#10,663

 

The number of new MERS cases being reported out of Riyadh has dropped in recent days, which may be an indication that the affected hospitals are starting to get a handle on containing the outbreak.  Today Riyadh only reports 1 new case, while once again we see a sporadic case from Najran.

 

The Najran case had already expired by the time his was announced by the MOH.

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Whether this is a sign that the outbreak in Riyadh is ending – or is just a temporary lull – August 2015 will go down as the third heaviest MERS month for the Saudis, and the most active month since June 2014. .

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Credit ECDC 20th MERS Risk Assessment

This spike is notable also because the hot summer months have not previously been associated with heavy MERS activity on the Arabian peninsula. The seasonality of MERS outbreaks – previously believed to favor spring outbreaks – has proven less predictable during 2015.

Friday, August 28, 2015

CDC FluView: 1 Novel H1N1v Case Reported From Iowa

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# 10,462

 

For the 4th time this year, the CDC is reporting the detection of a novel swine variant virus in a human.  Human infections with these swine-origin viruses are only rarely reported, but presumably happen more often than we know because testing for novel viruses is very limited.


The first two swine variant infections this year were H1N1v (see here and here), while the third case reported just a month ago, was H3N2v.

 

The CDC describes Swine Variant viruses in their Key Facts FAQ.

What is a variant influenza virus?

When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a “variant influenza virus.” For example, if a swine origin influenza A H3N2 virus is detected in a person, that virus will be called an “H3N2 variant” virus or “H3N2v” virus.

 

Up until about six years ago the CDC only received 1 or 2 swine variant infection reports each year.  In 2010, that number jumped to 8, and in 2011 to 12.  In 2012 we saw more than 300 cases – mostly mild - and nearly all associated with exposure to pigs at state and local agricultural fairs. 

 

Of the 376 swine variant infections reported in the United States, that vast majority (350+)  have been of the H3N2v variety. Far behind, in second place, is H1N1v.   A bit surprisingly, of the 4 cases discovered this year, 3 have been of the less common H1N1v variety.


This update from today’s FluView report.

 

Novel Influenza A Viruses:

One human infection with a novel influenza A virus was reported by the state of Iowa. The person was infected with an influenza A (H1N1) variant (H1N1v) virus and was hospitalized as a result of their illness. No human-to-human transmission has been identified and the case reported close contact with swine in the week prior to illness onset.

Early identification and investigation of human infections with novel influenza A viruses are critical so that risk of infection can be more fully appreciated and appropriate public health measures can be taken. Additional information on influenza in swine, variant influenza infection in humans, and strategies to interact safely with swine can be found at http://www.cdc.gov/flu/swineflu/index.htm.

 

While occasional cases are not particularly alarming, we keep an eye on these viruses because they belong to the same subtypes as do human flus (H1, H2 & H3), and presumably would  need less of an evolutionary leap to adapt to humans than avian flu strains. 

 

The CDC’s FAQ states:

Why are human infections with variant viruses of concern?

Influenza viruses that infect pigs may be different from human influenza viruses. Thus, influenza vaccines made against human influenza viruses are generally not expected to protect people from influenza viruses that normally circulate in pigs. In addition, because pigs are susceptible to avian, human and swine influenza viruses, they potentially may be infected with influenza viruses from different species (e.g., ducks and humans) at the same time. If this happens, it is possible for the genes of these viruses to mix and create a new virus that could spread easily from person-to-person. This type of major change in the influenza A viruses is known as antigenic shift. Antigenic shift results when a new influenza A virus to which most people have little or no immune protection infects humans. If this new virus causes illness in people and can be transmitted easily from person-to-person, an influenza pandemic can occur. This is what happened in 2009 when an influenza A H1N1 virus with swine, avian and human genes emerged in the spring of 2009 and caused the first pandemic in more than 40 years.

 

With the fall county and state fair season getting full swing, we’ll be watching to see if more cases are detected this fall. 

 

While infections have been generally mild (with a few exceptions), fairgoers should consider taking a little extra care washing their hands, particularly around the animal exhibits. The CDC’s webpage Take Action to Prevent the Spread of Flu Between People and Pigs at Fairs provides additional advice.

 

For more on swine variant influenza, you may wish to revisit:

Keeping Our Eyes On The Prize Pig

Waiting For The Next Flu To Drop

Fair Biosecurity & H3N2 In North Dakota Show Pigs

ECDC Rapid Risk Assessment On MERS-CoV – August 28th

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# 10,561

 

With the rise in MERS cases in Saudi Arabia over the past month, and now four MERS cases reported in Jordan – the concerns over whether this year’s Hajj will help spread the virus are understandably rising.  

 

Today the ECDC released their 20th Rapid Risk Assessment on the virus, warning that sporadic importations of the virus into EU countries can be expected, along with the risks of  further nosocomial transmission.


As this report indicates, we don’t have a complete picture of what is going on with MERS in Saudi Arabia, or any other countries in the Middle East.   The number, and role of asymptomatic carriers is likewise unknown.

 

The full RRA can be downloaded as a PDF File, and is well worth doing for its detailed epidemiological analysis and graphics.   Below you’ll find the press release/summary.

 

Updated Rapid Risk Assessment on MERS in light of Riyadh hospital outbreak

28 Aug 2015

​A large nosocomial outbreak of MERS in Riyadh, Saudi Arabia has triggered an update of ECDC’s rapid risk assessment, in order to assess whether this event changes the risk of international spread or increases the risk to EU citizens living in or travelling to Saudi Arabia. The update also includes an assessment of the risk of infection and introduction into the EU associated with pilgrims visiting Saudi Arabia during the forthcoming Hajj.


Given the substantial number of people travelling between the Middle East, which continues to report the majority of MERS cases, and EU countries, imported, sporadic cases to Europe can be expected.


Over 110 new cases and 30 deaths have been reported globally so far for August 2015 alone, almost all of them from Saudi Arabia. When compared to previous years, the increase in reported MERS cases in August is unexpected and is mainly explained by a large, ongoing outbreak linked to one Riyadh hospital.

 

The extent to which other healthcare facilities in Riyadh are affected is unknown, as is the number of asymptomatic individuals who may be infected with MERS-CoV.

 

The role of hospitals as amplifiers of MERS-CoV infection is well known, so the strict and timely application of comprehensive infection prevention and control measures is imperative.


Sporadic, imported cases can be expected in EU/EEA Member States, and is associated with a risk of nosocomial spread. This highlights the need for awareness among healthcare workers, early detection through functioning testing algorithms, preparedness planning and stringent infection control precautions.

Media Reports Of Two Additional MERS Cases In Jordan (Updated)

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(See update at bottom)

 

#10,460

 

Earlier this week we learned of two Jordanian MERS cases – reportedly a man in his 60s  and a 38 y.o. male – both with recent travel out of the country.  Yesterday the media reported the death of the 60-something patient. 

 

Today, there are fresh media stories indicating two additional cases have been detected, although I have found no official statement  to that effect.  

 

The ages and conditions are different, and these media reports have incremented the number of Jordanian cases to 16, both of which strongly suggests these represent the 3rd and 4th case reported this week. 

 

The relationship – if any – between any of these patients has not been mentioned. Unlike the first two cases,  today’s report contains no indication of recent travel abroad by these cases.

 

As always, Caveat Lector.   I’ll continue to look for more information, but here is one of the recent reports.

 

 

Registration of two cases of new Pfyrus "Corona" in Jordan

Announced here today for the registration of new HIV Koruna two goals in Jordan, bringing the total number of casualties since the first appearance of the disease in 2012 to 16 injured.

It quoted Jordan News Agency of communicable diseases at the Ministry of Health of Jordan, Dr. Mohammed Abdullat saying that scored the body of a citizens Jordanians of the first of them 78 years old and suffering from cancer and his health is nothing wrong and the second 47-year-old Mkhalt injury installed describing his health as good.

The Jordanian Ministry of Health has registered two goals new virus "Corona" on Monday and Tuesday after the last stop for more than a year for the registration of the disease casualties in Jordan


UPDATED  11:45 EDT 8/28

 

My thanks to Sharon Sanders of FluTrackers for this updated report from the Jordanian News Agency PETRA.   It indicates that these two new cases were detected through epidemiological contact tracking of the original cases.

 

Health Balchorona recorded two goals, bringing the total number to 16 cases

Oman August 28 (PETRA)-the total number of HIV infections in koruna Jordan since the first case of the disease in 2012 to 16 injured after registering new infections on Thursday, according to the Director of communicable diseases at the Health Ministry Dr Mohammad Al-abdallat.

Abdallat said in a statement issued by the Ministry's Information Center said on Friday: "the latest from citizens first reaches 78 years and is suffering from cancer and his condition is critical and 47-year-old is the second contacts for injuring the health status, describing proven good.

He added that the discovery of the injury came as a result of contact follow-up epidemiological survey Directorate teams dates of follow-up and monitoring of contacts were finally discovered.

The Health Ministry has recorded new HIV infections koruna on Monday and Tuesday after more than a year of record casualties in Jordan.

-(PETRA) a t/h a 28/8/2015-02:44 pm

 

Meanwhile the ECDC tweeted the following advice about a half hour ago, with a graphic showing the number of travelers expected to transit between Europe and Saudi Arabia over the next couple of months.

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NEJM: Ebola in the United States — Public Reactions and Implications

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# 10,559

 

Eleven months ago America woke up to learn that the first imported Ebola case had been hospitalized and isolated  - after first seeking treatment in a local emergency room three days earlier – in a Dallas hospital. Ten days later, the first of two nurses to contract the virus – Nina Pham – tested positive.


The first few weeks of October were chaotic, with the 24/7 news cycle pounding the Ebola story for ratings, politicians using the crisis to grab headlines and votes, and internet conspiracy sites speculating in the most lurid way that we would all soon be infected.

 

Understandably, the American public’s concern (and distrust) grew with each passing day. Fighting for their attention was a three-ring circus of media hype, disinformation, and paranoia – one we looked at in A Look Down The Ebola Rabbit Hole  and  All The Ebola News Not Fit To Print.

 

Complicating matters, around the same time that the CDC was releasing `worst-case’ estimates of 550,000 and 1.4 million Ebola cases in Liberia and Sierra Leone by the end of January cases in Africa, they were also trying to minimize the American public’s fear of the virus.

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Except from CDC Infographic

As an example, in August of 2014 the CDC released a reassuring infographic (see above) that - among other things - stated that `You can’t get Ebola through Air’, which immediately set off an internet firestorm of disbelief and derision. While `technically correct’   (Ebola is not an airborne virus) - it overly simplified the threat - which I considered a communications misstep (see The Ebola Sound Bite & The Fury).  

 

In response to the `airborne’ debate  Dr. Ian Mackay produced a series of excellent blogs on how the Ebola virus can be transmitted (see VDU Blog: Droplets vs Airborne - Demystifying Ebola Transmission and Mackay On Ebola: Blood, Sweat & Tears). 

 

But the vast majority of Americans were getting their information from ratings-hungry news organizations, or social media outlets, not from science based blogs.  The public’s trust in official statements took yet another hit when, in late October, the CDC Announced Stricter PPE Recommendations For Ebola - after two Dallas nurses were infected.


Of course, Ebola did not spread in the United States, and after an early false start, hospitals did  figure out how to safely treat patients.  Just as the CDC predicted. Gradually, the public’s level of concern subsided.  

 

But the experience showed how fragile public’s trust of the government can be, and how important it is to get the messaging `right’.  As we’ve discussed so often in the past, overly simplistic or reassuring messaging  can easily backfire (see Sandman & Lanard On Ebola Crisis Communications Lessons).

 

Looking back on all of this, and how things might be handled better the next time a public health crisis like Ebola arrives on our shores, is a perspective article that appeared yesterday in the New England Journal of Medicine.  A good read, and after you return, I’ll have a bit more.

 

Perspective

Ebola in the United States — Public Reactions and Implications

Gillian K. SteelFisher, Ph.D., Robert J. Blendon, Sc.D., and Narayani Lasala-Blanco, Ph.D.

N Engl J Med 2015; 373:789-791August 27, 2015DOI: 10.1056/NEJMp150629

Although there had been only two cases of Ebola transmission inside the United States and both patients had survived, a November 2014 opinion poll revealed that the U.S. public ranked Ebola as the third-most-urgent health problem facing the country — just below cost and access and higher than any other disease, including cancer or heart disease, which together account for nearly half of all U.S. deaths each year (see Table S1 in the Supplementary Appendix, available with the full text of this article at NEJM.org).

(Continue . . . )

 

The timing of Ebola’s arrival in the United States – 2 months before the mid-term elections – undoubtedly added to the public’s level of enmity, but the degree of distrust of science seems to grow worse with each passing year.

 

While many scientists decry this trend as a return to a backwards `flat earth’ mentality, it is sadly at least partially earned.

 

Back in early 2012, in Science at the Crossroads, I wrote about this decline the public’s trust in science. While I cited a number of reasons for this disturbing trend, prime among them has been the abrupt rise in the number of scientific papers that have been retracted sometimes for outright fraud - over the past decade. 

 

In a presentation made in March 2012 (see Dysfunctional Science) before a committee of the National Academy of Sciences, journal editors Arturo Casadevall and Ferric C. Fang warned that the number of retraction notices for scientific journals has increased more than 10-fold over the last decade, while the number of journals articles published has only increased by 44%.

 

Add in the parade of FDA approved drugs that we’ve seen withdrawn for safety reasons after years of use, allegations of biased industry funded clinical trials (see RCTs: All That’s Gold Standard Doesn’t Glitter), and a string of high profile government lab `incidents’ involving Ebola, H5N1, anthrax and smallpox and it’s little wonder that a white lab coat doesn’t engender as much confidence as it once did.

 

These recent lab accidents have led to calls from major journals to improve biosafety, and to even consider blocking certain types of potentially dangerous experiments unless a substantial benefit can be shown that offsets the risks. (see The Laboratory Bio-Safety Backlash Continues and Thebulletin.org: Making Viruses Deadlier – An Accident Waiting To Happen.). 

 

While scientists engaged in this type of work insist that the risks are negligible (see Scientists For Science: GOF Research `Essential’ & Can be Done `Safely’), many others  (see Updating The Cambridge Working Group) are less convinced.

 

Meanwhile a perplexed and increasingly worried public watches on, not knowing which side to believe.

 

As a child of the space age, raised on the science writings of Willy Ley and Isaac Asimov, I am about as `pro-science’ as they come, and will continue to promote it in this blog. But I also realize that science has some serious work to do if hopes to regain its previous high standing with the public.

 

And for everyone’s sake, that’s a change that needs to come sooner rather than later.