Influenza Virus Mashup

(Tue, 31 Aug 2010 17:07:00 +0000)

 

 

 

# 4855

 

 

The vaccination rate among health care workers (HCWs) against seasonal influenza runs abysmally under 50%, and in recent years there have been multiple calls to make yearly vaccination a requirement of employment.

 

For infection control professionals, the advantages are obvious.  Influenza exacts a heavy burden on patients, their families, and co-workers.  Requiring vaccination would undoubtedly save lives, and reduce costs.

 

But for many HCWs, the issues are more about personal rights to decide what they will inject into their bodies. And that has left this hot-potato issue in the wings.

 

Earlier this summer the CDC released their proposed infection control guidelines, where they strongly urged – but did not mandate – flu vaccinations for HCWs.

 

Here is the passage from the proposed guidance:

 

Strategies to improve HCP vaccination rates include providing incentives, providing vaccine at no cost to HCP, improving access (e.g., offering vaccination at work and during work hours), and requiring personnel to sign declination forms to acknowledge that they have been educated about the benefits and risks of vaccination.

 

While some have mandated influenza vaccination for all HCP who do not have a Contraindication, it should be noted that mandatory vaccination of HCP remains a controversial issue.

 

In response to what many felt was a tepid policy, Richard Whitley, MD president of the Infectious Diseases Society of America (IDSA), wrote an open letter to CDC  director Thomas Frieden urging that these guidelines include mandatory influenza vaccination.

 

You can read the letter off the IDSA website from the link below.  

 

IDSA Letter to CDC Director Tom Frieden on Draft Guidance “Prevention Strategies for Seasonal Influenza in Healthcare Settings”  07/15/2010

 

 

As you can imagine, this is a hot button issue.
 

Last year New York State attempted to require vaccination as a requirement to work as a HCW, but legal challenges and vaccine shortages forced them to abandon – at least temporarily – that mandate  (see New York Rescinds Mandatory Flu Shots For HCWs).

 

• Some hospitals around the nation have adopted mandatory vaccination – or require the wearing of masks by unvaccinated workers during flu season.
• APIC (Association for Professionals in Infection Control and Epidemiology) has been promoting the idea of mandatory flu shots for HCWs for two years (see APIC Seeking Mandatory Flu Shot For HCWs)
• In the UK, the Department of Health  – while not mandating vaccination – stresses the `professional duty’ of all HCWs to get the vaccine.

 

 

Which brings us to a press release and a positions paper from SHEA (Society for Healthcare Epidemiology of America), – endorsed by the IDSA -  that calls for the mandatory vaccination of all HCWs against seasonal flu each year.

 

First an excerpt from the press release, followed by a link to the position paper.

 

NATION’S LEADING INFECTIOUS DISEASES EXPERTS CALL FOR MANDATORY FLU VACCINE FOR ALL HEALTHCARE PERSONNEL

Vaccination Should Be Requirement for Continued Employment for Healthcare Personnel, Epidemiologists and Infectious Disease Physicians Say

(Arlington, VA)— Influenza vaccination of healthcare personnel is a professional and ethical responsibility and non-compliance with healthcare facility policies regarding vaccination should not be tolerated, according to a position paper released today by the Society for Healthcare Epidemiology of America (SHEA). The paper, published in this month’s Infection Control and Healthcare Epidemiology journal and endorsed by the Infectious Diseases Society of America (IDSA), stresses influenza vaccination of healthcare personnel as a core patient safety practice that should be a condition of both initial and continued employment in healthcare facilities.

 

According to SHEA, their recommendations apply to all healthcare professionals in all healthcare settings, regardless of whether the professional has direct patient contact or whether he or she is directly employed by the facility. The policy also applies to students, volunteers, and contract workers. The only exemptions, say the epidemiologists and infectious disease physicians, should be in cases of medical contraindications.

(Continue . . . )

 

 

SHEA Position Paper: Influenza Vaccination of Healthcare Personnel

An update of an original SHEA statement issued in 2005, this paper states that influenza vaccination is the professional and ethical responsibility of healthcare professionals and that non-compliance with healthcare facility policies regarding vaccination should not be tolerated. It is endorsed by IDSA.

 

SHEA Position Paper

 

 

 

Hospitals are looking at this as both a liability and an economic issue, on top of their concerns for patient welfare.  So this movement has `legs’.

 

Of course, legal challenges still lie ahead, but the momentum is clearly moving in the direction of mandatory vaccinations for Health Care Workers.

(Tue, 31 Aug 2010 16:00:00 +0000)

 

# 4854

 

 

Title Quote, a variation of several refreshingly informal and candid tweets from FEMA Director Craig Fugate on Twitter  over the past few days.

Photograph by NOAA.

 

 

 

For some terrific coverage of how FEMA, and other preparedness agencies are using social media to get people informed (and hopefully prepared) for a hurricane I would heartily recommend John Solomon’s In Case of Emergency Blog.

 

For advice on how to prepare for an approaching hurricane – or any other disaster – go to Ready.gov.

 

 

‘Nuff said.

WHO has published Pandemrix® vaccine and cases of narcolepsy.

WHO’s attention has been drawn to reports of narcolepsy in Sweden and Finland allegedly related to vaccinations with Pandemrix®, an adjuvanted 2009 influenza A (H1N1) vaccine produced by GSK. 

WHO notes that the European Medicines Agency (EMA) has launched a review to look carefully at all of the available data and determine whether there is sufficient evidence to establish a causal association between the vaccine and narcolepsy. WHO, through its Global Advisory Committee on Vaccine Safety, is monitoring the situation closely. 

Pending the outcome of the ongoing reviews, Pandemrix® remains licensed for use by the EMA and prequalified by WHO. Given that the benefits of 2009 influenza A (H1N1) vaccines are established, WHO recommendations to immunize vulnerable populations remain unchanged.

(Tue, 31 Aug 2010 13:31:00 +0000)

 

 

# 4853

 

 

Long-time readers of this blog are aware of a number of conflicting studies that have come out in recent years regarding the relative efficacy of surgical masks and N95 respirators in protecting HCWs (Health Care Workers) against airborne infections.

 

 

For decades, the assumption was that only properly fitted N95 masks protected the wearer, and that surgical masks were worn by HCWs to protect the patient during invasive procedures.

N-95 Respirator         Surgical Facemask

 

Last year, during the summer outbreak of pandemic H1N1, many hospitals citing shortages of N95 masks, opted to equip their nurses with surgical masks instead. 

 

This went against the recommended infection control guidelines issued by the CDC at the time, but was supported by several major infectious disease professional organizations.

 

This resulted in numerous protests last fall by nurses and other care givers, as I reported in:

 

CNA/NNOC Plan Protest Over Inadequate H1N1 Protection

 

(Photo from CNA/NNOC Webpage)

 

Since then, we’ve seen several `semi-reassuring’ studies that suggested that surgical masks are acceptable protection.

 

In October the NEJM published a perspective article (see NEJM Perspective: Respiratory Protection For HCWs) based on the recent IOM evaluation of surgical masks vs. respirators, and reiterated the advice:

 

Until more data are available, the committee recommends that clinicians reach for the N95 respirator when confronting patients with influenza-like illnesses, particularly in enclosed spaces.

 

A few days later JAMA (Journal of the American Medical Association) published a study which reported that HCWs using surgical masks experienced `noninferior rates of laboratory-confirmed influenza’.

In March of this year, we saw the following study (see Study: Efficacy of Facemasks Vs. Respirators).

 

 

Study finds surgical masks provided effective protection of health-care workers against H1N1

The effectiveness of ordinary surgical masks as opposed to respirators in protecting health care workers against the 2009 H1N1 influenza virus has been the subject of debate. An observational study published in the April 1, 2010 issue of Clinical Infectious Diseases, available online, suggests that surgical masks are just as effective as respirators in this regard.

 

 

The evidence over the winter, it seemed, was largely supportive of the notion that surgical masks were adequate protection against influenza viruses.

 

So in June of this year, the CDC released revised infection control guidance proposals which relaxed their previous recommendations to the allowing of surgical masks for routine care, and reserving N95 masks for aerosol producing procedures (intubation, suctioning, etc).

 

CDC: Proposed Influenza Infection Control Guidance

 

To complicate matters, however - after these studies suggested that surgical masks are reasonably protective against influenza - we now get a new study that questions whether surgical masks or N95 respirators provide any substantial protection to the wearer at all.

 

No . . .  I don’t make these things up.  I just report on them.

 

The study appears in the September issue of the AJIC (American Journal of Infection Control), and is titled:

 

Quantifying exposure risk: Surgical masks and respirators

Keith T. Diaz, MD, Gerald C. Smaldone, MD, PhD

 

These researchers (using mannequins fitted with a variety of masks, and using radiolabeled wet aerosols) determined that wearing surgical masks and N95 masks without an airtight (Vaseline) seal provided little more protection than wearing no mask at all.

 

They did find that placing a surgical mask on an infected source (patient) could significantly reduce the spread of a virus to the environment.

 

Since only the abstract is freely available, it is helpful that the SurgiStrategies website has posted a summary of these findings.  

 

A hat tip to Tetano on FluTrackers for passing along this link.

 

 

AJIC Releases New Study on Face Masks and H1N1

 

The authors of this review quote the researchers as stating the type of mask (N95 vs Surgical) “does not play a significant role in reducing exposure to the recipient unless a respirator is physically sealed to the face of the source.”

 

 

While obviously not the last word on the subject, the issue of just how protective various types of masks are to the wearer has just gotten a bit more murky.

 

Obviously, we will await the next mask efficacy study with considerable interest. In the meantime, I guess I’d better check my supply of Vaseline.

Via Wales Online: Avian flu still likely to strike in humans, says Welsh expert. Excerpt:

The threat of bird flu crossing over to humans and igniting a pandemic remains real, one of Wales’ leading experts on health and disaster management has claimed. 

Alan Hawley, who until recently was the UK’s Director General of Army Medical Services, said climate change and international food scarcity has the potential to spread social and economic chaos across the globe. 

His comments follow the decision of the Assembly Government to reduce the surveillance of live wild birds for avian influenza. Instead, attention will be focused on dead birds. 

However, Prof Hawley said bird flu is not the greatest threat to Wales and the world. 

The former major general, who is now the University of Glamorgan’s professor of disaster studies, described the Assembly Government’s decision to narrow the field of monitoring as “quite sensible”. 

He said: “I think, scientifically, you have to constantly re-prioritise what you are doing. We have got a resource issue and hard decisions have to be made; I’m really glad I’m not a politician.” 

But he said the threat of avian flu mutating into a form which could be passed between people “absolutely” remained on the radar. 

He said: “The one we worry about is the avian epidemic where it moves from birds to the human species. I think that’s likely to happen, just being dispassionate about it. 

“It will be bad enough to give us a jolt, but the technology and the modern public health techniques will allow us to cope with it.”

Ida at Bird Flu Information Corner has a report from Antara: Bengkulu ::: Bird flu H5N1 prefers backyard chickens. Excerpt:

Bird flu H5N1 preferably attacks native or backyard chickens, so broiler chicken meat consumption is relatively safe, said Head of Animal Health Division of Bengkulu Livestock Service (Disnakwan), Varisna Bahar. 

Until now Disnakwan Bengkulu is still prohibiting chicken transport incoming and outgoing of Bengkulu. However, broiler chickens can be sold out of Bengkulu after the farms have passed certain examinations done by Disnakwan, and received transporting permit. 

This action is done to prevent overstock of broiler chicken inside Bengkulu. 

Varisna said bird flu H5N1 had killed hundreds of chicken in two municipals (Kabupaten) and a city; Kabupaten Central Bengkulu and Kepahiang, and Bengkulu city.

This is the first I’ve heard about “backyard” chickens being more vulnerable to H5N1. I’d like more evidence than the opinion of one local official.

(Tue, 31 Aug 2010 11:21:00 +0000)

 

 

# 4853

 

 

During the opening months of the pandemic there were widely varying policies and opinions around the world as to how antivirals would be used. 

 

In the UK, fearing that patient loads would overwhelm their medical system, just about anyone who exhibited flu-like symptoms could call a hotline and get a packet of Tamiflu prescribed without testing or seeing a doctor.

 

In the United States, and many other countries, antivirals were used more conservatively, partially out of concerns over fostering antiviral resistance.

 

Now that the pandemic is over, we are getting studies looking at how these varying strategies worked.  

 

Today the ECDC’s web portal has summaries, and a comparison, of two recent journal articles that looked at the therapeutic and prophylactic use of antivirals during the pandemic.

 

Differing effectiveness of the therapeutic and prophylactic use of antivirals and other measures for public health purposes during the 2009 influenza A(H1N1) pandemic

31 Aug 2010

 

 

The two studies in question are:

Lee VJ, Yap J, Cook AR, et al.
Oseltamivir Ring Prophylaxis for Containment of 2009 H1N1 Influenza Outbreaks
New England Journal of Medicine; Volume 362:2166-2174; 10 June 2010; Number 23

and

Health Protection Agency UK The role of the Health Protection Agency in the ‘containment’ phase during the first wave of pandemic influenza in England in 2009
Health Protection Agency, March 2010

 

At first glance, these two studies appear to come up with different conclusions. 

 

In the first study, which I profiled back in June (see CIDRAP On Two NEJM Pandemic H1N1 Studies), ring prophylaxis (or PEP) was shown to slow down or contain an influenza outbreak in a closed or semi-closed setting.

 

The second study, conducted by the UK’s HPA, found that chemo-prophylaxis could be effective in the home, and somewhat effective in schools, but proved less effective when scaled up to a larger community.

 

The ECDC’s comment (slightly reformatted for readabilty) follows:

 

ECDC Comment (19/08/10)

On the surface these two evaluations suggest different outcomes while in reality they are compatible.

 

Both found that if antivirals are used intensively in small defined populations in combination with personal health measures even pandemic influenza can be halted at least for a while. That is consistent with other observations of the effectiveness of oseltamivir against the pandemic strain.(1)

 

However when scaling up to the macro-level such containment is simply impossible as well as being very resource intensive and exhausting.  That is what was suggested by WHO in April and the UK experience was reported to the Swedish Presidency meetings in July 2009 which led to the abandonment of containment policies in Europe.(2,3)

 

It had been pointed out in the UK by their official evaluation that containment was never part of the original plan.(4)

 

Whether or not to use antivirals in a pandemic remains a controversial area. In some EU countries it was policy to offer them to all people when they developed symptoms, in others only to those at higher risk of severe disease and in yet others to confine their use to those ill enough to require hospital treatment.

 

Dilemmas for clinicians were that it is generally agreed that to be effective antivirals had to be given early, hence waiting for someone to become very ill was risky. Equally the policy of giving treatment to only those in the risk group was confronted with the fact that around 30% of those who eventually died from the pandemic infection were outside any risk group.(5) 

 

 

Of course, limiting the spread of the virus isn’t the only measure of the effectiveness of chemoprophylaxis. 

 

The aggressive use of antivirals in some communities may have reduced pandemic morbidity or mortality, but without a uniform surveillance and reporting system (and definition of `flu-related fatality’), it is exceedingly difficult to judge.

 

No doubt, some group of researchers is working on that weighty problem, and in time we may have a better idea of how antiviral use affected these numbers.

 

The pandemic of 2009 will no doubt end up being the most studied pandemic in history (up to now). 

 

Over time we should end up with a better understanding of what mitigation strategies worked best under which circumstances.

 

It is unlikely, however, that we will find a `one-size-fits-all’ solution.

(Tue, 31 Aug 2010 10:13:00 +0000)

 

 

 

# 4952

 

 

Last night CIDRAP posted a summary of a PLoS Pathogens study in their nightly newsscan that has the potential, at some point, to become a significant story.

 

A brief excerpt, followed by some comments on my part.

 

Study: Tamiflu-resistant 2009 H1N1 passes fitness tests

Trials to assess the pathogenicity and transmissibility of oseltamivir-resistant 2009 H1N1 viruses in mice and ferrets suggest that the resistant strain is as fit as counterparts that are sensitive to the drug, according to Japanese researchers. The group, which includes Dr Yoshihiro Kawaoka, a virologist from the University of Wisconsin at Madison, reported their findings in PLoS Pathogens . .  .  .

Aug 26 PLoS Pathogens abstract

 

 

The entire study is titled:

 

Characterization of Oseltamivir-Resistant 2009 H1N1 Pandemic Influenza A Viruses

Kiso M, Shinya K, Shimojima M, Takano R, Takahashi K, et al. (2010) Characterization of Oseltamivir-Resistant 2009 H1N1 Pandemic Influenza A Viruses. PLoS Pathog 6(8): e1001079. doi:10.1371/journal.ppat.1001079

 

And as the CIDRAP piece explained, the authors looked a the fitness (ability to replicate, compete, and transmit) of oseltamivir (Tamiflu) resistant novel H1N1 viruses compared to non-resistant strains.

 

For now, the good news is that the 2009 H1N1 virus remains overwhelmingly sensitive to Tamiflu.

 

But of course, the same could have been said about the old seasonal H1N1 virus back in 2006-2007, when 99% of isolates tested showed good sensitivity to oseltamivir.

 

Resistance is generally caused by a mutation, known as H274Y, where a single amino acid substitution (histidine (H) to tyrosine (Y)) occurs at the neuraminidase position 274.

 

Back in 2007, the belief was that the mutation that made the virus resistant to Tamiflu (H274Y), also reduced its biological fitness – suggesting that mutated versions of the viruses were unlikely to spread widely.

 

But those hoped dimmed when, by the end of the 2007-2008 flu season,  nearly 13% of H1N1 isolates tested the United States were resistant to the drug.

 

Jump ahead to December of 2008, and nearly all seasonal H1N1 isolates tested around the world carried the H274Y mutation that conferred Tamiflu resistance.

 

The CDC was forced to issue major new guidance for the use of antivirals for the second time in just three years (see CIDRAP article With H1N1 resistance, CDC changes advice on flu drugs).   

 

The `replacement’ 2009 pandemic virus, that supplanted the largely resistant seasonal strain, was fortunately both relatively mild and sensitive to Tamiflu. 

 

But over the past 16 months, several hundred scattered cases of Tamiflu resistance have been detected, including in a couple of clusters, raising the specter that someday this new strain of H1N1 could become resistant as well.

 

Earlier this summer, part of the mystery of how the old seasonal H1N1 developed resistance and still managed to transmit efficiently was revealed when researchers identified two “pre-adaptive mutations” that helped pave the way for the H274Y strains to spread (see Caltech: How Seasonal Flu Gained Tamiflu Resistance).

 

Today’s study shows that while still limited in the wild, the mutated 2009 H1N1 virus demonstrates biological fitness, and replicates and spreads efficiently in mice and ferrets.

Post mortem exams of ferrets used in this study also show no reduction in pathogenicity of the mutated virus.

 

Leading the authors to state:

 

Our findings highlight the possibility that NA H274Y-possessing oseltamivir-resistant 2009 H1N1 pandemic viruses could supersede oseltamivir-sensitive viruses, as occurred with seasonal H1N1 viruses.

 

Since novel H1N1 is already resistant to the older amantadine-class (M2 ion channel blockers) antivirals, the loss of these newer neuraminidase (NA) inhibitors (oseltamivir and zanamivir) would be a serious blow.

But not as serious as it would have been before a vaccine was available. Today, unlike a year ago, we have the ability to substantially (not 100%, of course) protect against this virus. 

 

And it is almost always better to prevent a disease than to try to treat one.

 

Antibiotics and antivirals are fleeting victories against rapidly evolving pathogens at best, since from the minute they are introduced, nature begin to work on ways to defeat them.

 

Once again, from the study’s text:

 

The widespread administration of oseltamivir, and to a lesser extent zanamivir, will clearly contribute to the emergence of NA inhibitor-resistant viruses that retain optimal replication fitness and transmissibility in humans. 

 

The authors note that in vitro and in vivo experiments on two experimental drugs- CS-8958 and favipiravir – suggest these may be candidates to deal with 2009 H1N1 line of viruses in the future.

 

For some earlier essays on the H274Y mutation, you might wish to check out:

 

NIH: Rapid Development Of Antiviral Resistance In Two Cases

WER Review: Oseltamivir Resistance In Pandemic H1N1

NEJM: Community Cluster Of Tamiflu Resistant H1N1

Via Antara: Bird flu-infected chickens sold in E Java. Excerpt:

A local chicken seller admitted that he sold 30 of 60 dead chickens to a wet market in Pamekasan district, East Java Province, recently. 

About 60 chickens of Sofiullah, a resident of Bugih village, East Java, died of bird flu on August 24 but he did not immediately report this to local veterinary authorities.
  

Speaking to newsmen here Sunday, Sofiullah said he did that because he thought that they died of normal sickness. “I had even sold thirty or sixty dead chickens to the market,” he said. 

The attack of bird flu on the chickens of Sofiullah who lived in Bugih village, Kota sub-district, East Java district of Pamekasan, had been positively confirmed by the district`s veterinary officials. 

“The results of our rapid test to the dead chicken samples have shown that they are positively infected by bird flu viruses,” Head of the animal disease prevention of Pamekasan district`s veterinary office Ulung Promono said. 

A part from this bird flu case, some local chicken sellers said that the case did not affect the market prices. The selling prices of chickens remained relatively stable, they said. 

According to Rahimah, a chicken trader at Kolpajung wet market in Pamekasan district, the chicken prices were expected to rise up during the third week of fasting month of Ramadan.

Mike Coston at Avian Flu Diary has some good commentary on this report.

(Mon, 30 Aug 2010 23:01:00 +0000)

 

 

# 4951

 

 

Back in the late 1920s my grandfather kept chickens in the backyard.   Every Sunday morning he’d tell my Dad (who was a young boy at the time) to go out back and grab the sickliest looking bird for their Sunday meal.

 

It was a pragmatic decision back then, given the lack of refrigeration.  And, of course, bird flu wasn’t a concern. 

 

But today, sickly chickens are viewed somewhat more suspiciously, at least in regions where bird flu is endemic. 

 

At least, that’s what we expect to happen.

 

But a story today from ANTARA news tells us that there are exceptions to that practice.  A poultry vendor in East Java, Indonesia who had 60 chickens die suddenly last week, admits he sold the fresh carcasses to a wet market.

 

He claims he thought the birds died of a `normal sickness’, and so he didn’t report it to the authorities.  Later his dead birds were tested and found positive for H5N1 bird flu virus.

 

 

Bird flu-infected chickens sold in E Java

Monday, August 30, 2010 20:44 

Pamekasan, Ewat Java, Aug 30 (ANTARA) - A local chicken seller admitted that he sold 30 of 60 dead chickens to a wet market in Pamekasan district, East Java Province, recently.

 

About 60 chickens of Sofiullah, a resident of Bugih village, East Java, died of bird flu on August 24 but he did not immediately report this to local veterinary authorities.

 

Speaking to newsmen here Sunday, Sofiullah said he did that because he thought that they died of normal sickness. “I had even sold thirty or sixty dead chickens to the market,” he said.

(Continue . . . )

 

 

The matter-of-fact reporting of this case, and the focus of the reporter on the stability of poultry prices in the region, suggests that this sort of thing may be more commonplace than we might suspect.

 

Alerting the authorities that your chickens are sick or dying is undoubtedly bad for business, even if some form of compensation is offered. So it isn’t unusual to hear of a certain amount of reluctance on the part of bird owners to cooperate.

 

The good news is, just because infected birds entered the food chain, that doesn’t necessarily mean that anyone will get sick.

 

Given the wide geographic spread of the bird flu virus, it is likely that Infected chickens are sold, prepared, and eaten in countries around the world every day.

 

It is a testament to how difficult it is for people to contract H5N1 that we don’t have more human cases than we do.

 

Still, handling and consuming infected birds is not without risk, and public health officials will no doubt be keeping an eye on local clinics and hospitals in the area in case human cases show up.