CID Journal: Under Utilization Of Antivirals For At Risk Flu Patients

 

# 8842

 

Between the frequent hyperbolic demonization of  influenza antivirals (see Daily Mail: Ministers blew £650MILLION on useless anti-flu drugs) by media critics of `Big Pharma’,  spurred on by repeated Cochrane group analyses that have found insufficient evidence that the drug reduces influenza complications, it probably comes as little surprise that many doctors – particularly in outpatient settings – tend to underutilize antiviral drugs, even for patients at the greatest risk for complications.

 

While well-respected, the Cochrane Group uses a very narrow (and some would say misguided) criteria for evaluating the effectiveness of antiviral drugs.  One that discards all but a handful of studies.

 

Last April, in Revisiting Tamiflu Efficacy (Again), I wrote at some length on the BMJ –  Cochrane Library review Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children – that examined a subset of the scientific literature and cast doubt on its effectiveness in treating influenza.

 

While I too lamented the lack of solid, well mounted Randomized controlled trials (RCTs) proving the effectiveness of Oseltamivir (particularly in high risk patients, or with novel flu strains), I listed a number observational studies that strongly support the effectiveness of Oseltamivir.

 

A few days later, the CDC issued their own response. I’ve posted the link and some excerpts below.  Follow the link to read their rationale in its entirety.

 

CDC Recommendations for Influenza Antiviral Medications Remain Unchanged

April 10, 2014 -- CDC continues to recommend the use of the neuraminidase inhibitor antiviral drugs (oral oseltamivir and inhaled zanamivir) as an important adjunct to influenza vaccination in the treatment of influenza. CDC’s current influenza antiviral recommendations are available on the CDC website and are based on all available data, including the most recent Cochrane report, about the benefits of antiviral drugs in treating influenza.

(Continue . . .)

 

The CDC considers those a higher risk of influenza complications, and for whom they recommend antiviral treatment for suspected or confirmed influenza , to include:

• children aged younger than 2 years;
• adults aged 65 years and older;
• persons with chronic pulmonary (including asthma), cardiovascular (except hypertension alone), renal, hepatic, hematological (including sickle cell disease), metabolic disorders (including diabetes mellitus) or neurologic and neurodevelopment conditions (including disorders of the brain, spinal cord, peripheral nerve, and muscle such as cerebral palsy, epilepsy [seizure disorders], stroke, intellectual disability [mental retardation], moderate to severe developmental delay, muscular dystrophy, or spinal cord injury);
• persons with immunosuppression, including that caused by medications or by HIV infection;
• women who are pregnant or postpartum (within 2 weeks after delivery);
• persons aged younger than 19 years who are receiving long-term aspirin therapy;
• American Indians/Alaska Natives;
• persons who are morbidly obese (i.e., BMI is 40 or greater); and
• residents of nursing homes and other chronic-care facilities.

But based on a new study, published this week in Clinical Infectious Diseases, antiviral drugs for these cohorts appear to be underutilized. Worse, patients were twice as likely to be prescribed antibiotics than antivirals for influenza.

Use of Influenza Antiviral Agents by Ambulatory Care Clinicians During the 2012–2013 Influenza Season

Fiona Havers1, Swathi Thaker2, Jessie R. Clippard2, Michael Jackson3, Huong Q. McLean4, Manjusha Gaglani5, Arnold S. Monto6, Richard K. Zimmerman7, Lisa Jackson3, Josh G. Petrie6, Mary Patricia Nowalk7, Krissy K. Moehling7, Brendan Flannery2, Mark G. Thompson2, and Alicia M. Fry2

Abstract

Background. Early antiviral treatment (≤2 days since illness onset) of influenza reduces the probability of influenza-associated complications. Early empiric antiviral treatment is recommended for those with suspected influenza at higher risk for influenza complications regardless of their illness severity. We describe antiviral receipt among outpatients with acute respiratory illness (ARI) and antibiotic receipt among patients with influenza.

Methods. We analyzed data from 5 sites in the US Influenza Vaccine Effectiveness Network Study during the 2012–2013 influenza season. Subjects were outpatients aged ≥6 months with ARI defined by cough of ≤7 days’ duration; all were tested for influenza by polymerase chain reaction (PCR). Medical history and prescription information were collected by medical and pharmacy records. Four sites collected prescribing data on 3 common antibiotics (amoxicillin-clavulanate, amoxicillin, and azithromycin).

Results. Of 6766 enrolled ARI patients, 509 (7.5%) received an antiviral prescription. Overall, 2366 (35%) had PCR-confirmed influenza; 355 (15%) of those received an antiviral prescription. Among 1021 ARI patients at high risk for influenza complications (eg, aged <2 years or ≥65 years or with ≥1 chronic medical condition) presenting to care ≤2 days from symptom onset, 195 (19%) were prescribed an antiviral medication. Among participants with PCR-confirmed influenza and antibiotic data, 540 of 1825 (30%) were prescribed 1 of 3 antibiotics; 297 of 1825 (16%) were prescribed antiviral medications.

Conclusions. Antiviral treatment was prescribed infrequently among outpatients with influenza for whom therapy would be most beneficial; in contrast, antibiotic prescribing was more frequent. Continued efforts to educate clinicians on appropriate antibiotic and antiviral use are essential to improve healthcare quality.

 

In an accompanying press release from the Infectious Diseases Society of America we get the following summary:

 

 

Findings suggest antivirals underprescribed for patients at risk for flu complications

Study also shows that antibiotics may have been prescribed unnecessarily

(EXCERPT)

Overall, only 19 percent of the patients at high risk for influenza-associated complications who saw a primary-care provider within two days of the onset of their symptoms received antiviral treatment. Among patients with laboratory-confirmed influenza, just 16 percent were prescribed antivirals. In contrast, 30 percent of these patients received one of the three antibiotics.

"Our results suggest that during 2012-'13, antiviral medications were underprescribed and antibiotics may have been inappropriately prescribed to a large proportion of outpatients with influenza," the authors wrote. "Continuing education on appropriate antibiotic and antiviral use is essential to improve health care quality."

While some of the antibiotics may have been appropriate for bacterial infections secondary to influenza, which is caused by a virus, it is likely most were unnecessary, potentially contributing to the growing problem of antibiotic resistance, the authors noted.

(Continue . . . )

 

IDSA: Pandemic and Seasonal Influenza Preparedness

 

 

# 6556

 

This morning the IDSA (Infectious Disease Society of America) and the AMA held a 2-hour webinar as part of the launch of an updated set of IDSA guidelines designed to educate federal policymakers on the issues of Pandemic and Seasonal Flu preparedness.

 

You’ll find a summary of their recommendations, and the link to download the 24-page PDF file at IDSA webpage below:

 

 

Pandemic and Seasonal Influenza

 

IDSA has published (September 2012) an updated set of Pandemic and Seasonal Influenza Principles for United States Action to educate federal policymakers about how best to prepare for and respond to seasonal and pandemic influenza.

 

IDSA's first set of principles was issued in 2007 (see previous version here).  IDSA's updated principles rely upon the experience of the 2009 H1N1 influenza pandemic and are intended to assist the U.S. Department of Health and Human Services' (HHS) Assistant Secretary for Preparedness and Response (ASPR) and other agency officials as they establish priorities for implementation of the reauthorized Pandemic and All-Hazards Preparedness Act (PAHPA).

What Action Does IDSA Recommend?

IDSA strongly believes that much work remains ahead of us, and overall responses to seasonal influenza and pandemic preparedness must be closely interrelated. The Society calls for:

• coordination between HHS and other U.S. government departments, as well as a need for better coordination within HHS, particularly concerning influenza vaccine efforts
• establishing processes for continual review of critical and rapidly evolving components of influenza preparedness, such as the contents of the Strategic National Stockpile (SNS)
• vigorously supporting the uptake of the annual influenza vaccine by health care workers including through the adoption of a mandatory approach (see IDSA's revised policy statement (PDF) for details)
• significant and sustainable multi-year funding that may be used flexibly particularly by local health departments for "All-Hazards" preparedness

 

(Continue . . . )

 

While many items were discussed during today’s webinar, the take-away message is that while much progress has been made in recent years, the United States remains vulnerable to many pandemic and other biological threats.

Influenza is by far the best known threat, but isn’t the only pandemic possibility.

 

The IDSA Guideline, in its conclusion, sums it up this way:

 

Influenza remains among the greatest infectious disease threats to our nation and the global community.  Despite the investments and progress made in research and preparedness over the past decade, substantial gaps remain. The next influenza pandemic is inevitable, only the timing,  severity,  and point of origin remain unknown.  We cannot be complacent. We cannot afford to be penny-wise and pound-foolish,  eroding the  progress made and leaving our nation and the world vulnerable.  We must be prepared.

Norovirus Sequelae

 

 

# 6404

 

 

Last month I wrote a blog called Norovirus: The Gift That Keeps On Giving, about an outbreak of this nasty gastrointestinal malady among a group of teenage girls at a soccer tournament in 2010.  

 

It now appears that the above title may have been more appropriate than I imagined, as a new study appearing in Clinical Infectious Diseases finds a link between norovirus infection and ongoing gastrointestinal complaints.

 

According to the CDC norovirus sickens more than 20 million Americans every year, hospitalizes up to 70,000, and contribute to 800 deaths.  The CDC maintains an extensive Norovirus webpage where they describe the illness, how it is spread, and how to avoid infection.

 

 

As if enduring 24 to 48 hours of vomiting and diarrhea wasn’t enough, today’s study suggests that those who experience a norovirus infection are at substantially greater risk of developing chronic dyspepsia, constipation and GERD (Gastroesophageal reflux disease).

 

In the following study researchers looked at the records of more than 1700 military personnel who were treated for AGE (acute gastroenteritis) during three known norovirus outbreaks. 

 

By comparing them to controls, they determined that those with a history of AGE were at increased risk of developing chronic gastrointestinal disorders.

 

Since this was a fairly small study, and some variability was detected in outcomes across the three outbreaks studied, more research will be needed to confirm their findings and to determine how long these after effects may persist.

 

 

 

Post-infectious gastrointestinal disorders following norovirus outbreaks

Chad K. Porter1, Dennis J. Faix, Danny Shiau, Jennifer Espiritu, Benjamin J. Espinosa, and Mark S. Riddle

Results. We identified 1,718 subjects from three outbreaks. After controlling for important demographic covariates, the incidence of constipation, dyspepsia and GERD was approximately 1.5 fold higher (p<0.01) in AGE exposed subjects than matched subjects. We also noted variability in outcome incidence across outbreaks.

Conclusions. It appears that the risk of dyspepsia, constipation and GERD are higher among those who have AGE during a confirmed norovirus outbreak. While these findings need confirmation, they suggest that dysmotility may result subsequent to these infections. If confirmed, the costs and morbidity associated with the chronic consequences of norovirus should be considered.

Dysmotility is a generic medical term to describe diseases of the GI tract (esophagus, stomach, small and large intestines) where the muscles do not function properly.

 

The primary route of infection is the fecal-oral route (although there is evidence it can also be airborne), and the best intervention is . . . you guessed it . . .  washing your hands.

 

Unfortunately, unlike with many other bacteria and viruses, alcohol gel doesn’t do a particularly good job of killing the virus, as we discussed last year in  CMAJ: Hand Sanitizers May Be `Suboptimal’ For Preventing Norovirus.

 

For more information, the CDC’s hand hygiene website provides many useful resources, including a link to a new iPad/iPhone application called iScrub.

 

Study: Aerosolized Influenza And PPEs

Photo Credit PHIL (Public Health Image Library)

 

# 6253

 

We’ve a new study, appearing yesterday in the journal Clinical Infectious Diseases, that once again raises questions over the effectiveness of different types of PPEs (Personal Protective Equipment) used by Health Care Workers (HCWs) in an infectious environment.

 

 

Ideally, the well-protected HCW (Health Care Worker) working in an infectious environment would be wearing an N95 mask, gloves, gown and eye protection.

 

But during the opening months of the 2009 pandemic, it became apparent that our world faced a shortage of PPEs, and so strategies were adopted to maximize their use.

 

In some cases nurses were issued only one N95 mask to be used for an entire 8 hour shift, and told to don it only when in direct contact with a potentially infected patient.

 

In other venues, HCWs were issued surgical masks in lieu of N95s, despite the recommendation at the time from the CDC that N95 masks were the preferred level of protection.

 

Fortunately, the virulence of the novel 2009 H1N1 virus was less than originally feared. Had the pandemic carried a higher mortality and morbidity rate, the lack of PPEs would have become a much bigger issue.

 

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

 

N-95 Respirator         Surgical mask

 

But in recent years we’ve seen dueling studies that alternately show surgical masks to be a reasonable protective barrier against respiratory viruses  . . . or pretty much useless.

 

Take your pick.

 

A brief tour of these conflicting reports include:

 

 

In October of 2009 the NEJM published a perspective article (see NEJM Perspective: Respiratory Protection For HCWs) based on a 2009 IOM evaluation of surgical masks vs. respirators, and came out in favor of the N95.

 

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 2010, we saw the following study (see Study: Efficacy of Facemasks Vs. Respirators) in Clinical Infectious Diseases, that suggested that surgical masks are just as effective as respirators in protecting HCWs.

 

In guidance, updated as late as March of 2010, the CDC continued to recommend N95 respirators for HCWs who came in close contact with suspected or confirmed influenza patients.

 

But in June of 2010, the CDC proposed new guidance that relaxed those recommendations to using surgical masks for routine care, and reserving N95 masks for aerosol producing procedures (intubation, suctioning, etc).

 

Still, the controversy remains. 

 

Adding to the confusion, we’ve seen recent studies that give more credence to the notion that influenza may be spread in aerosolized form (see Study: Aerosolized Transmission Of Influenza), as opposed to primarily by large droplets, and may also be contracted via the transocular route.

 

Our knowledge of how influenza spreads, and what barriers work well to protect HCWs, remains limited.

 

All of which serves as prelude to this new study, that simulates the aerosolization of influenza viruses and measured the protective qualities of surgical masks and respirators by constructing a simulated  exam room using `coughing and breathing manikins’.

 

Although the full paper is behind a pay wall, we can get a pretty good idea of the study’s content from the abstract.

 

Detection of Infectious Influenza Virus in Cough Aerosols Generated in a Simulated Patient Examination Room

John D. Noti, William G. Lindsley, Francoise M. Blachere, Gang Cao, Michael L. Kashon, Robert E. Thewlis, Cynthia M. McMillen, William P. King, Jonathan V. Szalajda, and Donald H. Beezhold

ABSTRACT (Excerpts)

Methods. National Institute for Occupational Safety and Health aerosol samplers collected size-fractionated aerosols for 60 minutes at the mouth of the breathing manikin, beside the mouth, and at 3 other locations in the room. Total recovered virus was quantitated by quantitative polymerase chain reaction and infectivity was determined by the viral plaque assay and an enhanced infectivity assay.

Results. Infectious influenza was recovered in all aerosol fractions (5.0% in >4 μm aerodynamic diameter, 75.5% in 1–4 μm, and 19.5% in <1 μm; n = 5). Tightly sealing a mask to the face blocked entry of 94.5% of total virus and 94.8% of infectious virus (n = 3). A tightly sealed respirator blocked 99.8% of total virus and 99.6% of infectious virus (n = 3). A poorly fitted respirator blocked 64.5% of total virus and 66.5% of infectious virus (n = 3). A mask documented to be loosely fitting by a PortaCount fit tester, to simulate how masks are worn by healthcare workers, blocked entry of 68.5% of total virus and 56.6% of infectious virus (n = 2).

Conclusions. These results support a role for aerosol transmission and represent the first reported laboratory study of the efficacy of masks and respirators in blocking inhalation of influenza in aerosols. The results indicate that a poorly fitted respirator performs no better than a loosely fitting mask.

 

The results here are fascinating.

 

First, this study provides more evidence of the role of aerosolized virus particles in the transmission of influenza. Important because these particles can stay aloft and viable for some time, and spread further than large droplets can.

 

From a more practical standpoint, the big revelation is that a surgical mask, as normally worn by HCWs, only blocked 56.6% of infectious virus particles.

 

But . . . if you tightly seal the surgical mask against the face , you can achieve a level of protection approaching that of a well fitted N95 respirator (94.8% versus 99.6%).

 

And a poorly fitted N-95 respirator provided little more protection (66.5%) than a loosely fitted surgical mask.

 

This study will no doubt add further fuel to the debate over what constitutes appropriate PPEs for healthcare workers during a pandemic.

 

For the rest of us, the takeaway message here is that surgical masks (which are much cheaper, and easier to stockpile) appear to provide a reasonable level of protection against aerosolized influenza viruses when tightly sealed against the face.

 

Which means, I suppose, that now I need to think about beefing up my supply of paper surgical tape.

Study: Statins, Influenza, & Mortality

 

 

 

# 6008

 

We’ve a study today that lends additional weight to the argument that statins – a class of cholesterol lowering drugs – may have a role to play in the treatment of influenza.

 

This would be of particular value during a severe pandemic, when the world would need a cheap (preferably generic) medication that is shelf stable, easy to dispense, has a low incidence of side effects, and can reduce influenza morbidity and mortality.

 

That’s a tall order, but there are some researchers who believe that statins might fit the bill.

 

Over the years we’ve seen a number of studies that have suggested that taking statins can improve survival rates among those with influenza and/or pneumonia.

 

The idea of using them in a pandemic has been largely championed by Dr. David Fedson – former Professor of Medicine at the University of Virginia School of Medicine and formerly Director of Medical Affairs, Aventis Pasteur MSD who has urged that scientists look seriously at statins, which he believes may help modulate the immune response.

 

A couple of his papers on the subject include:

 

Pandemic Influenza: A Potential Role for Statins in Treatment and Prophylaxis

David S. Fedson

New Approaches to Confronting an Imminent Influenza Pandemic

Dr. Fedson and Peter Dunnill, DSc,FREng

 

While we’ve seen a number of studies (see here, here, and here) supporting the notion that statins might reduce mortality due to pneumonia and/or influenza, not every study has been positive.

 

In July of 2009 there was a report that found no evidence of benefit among pneumonia patients (see Another Take On Statins And Pneumonia) taking statins.

 

Today, from the IDSA’s Journal of Infectious Disease we have a new study that looked at the 30 day survival rates of hospitalized influenza patients either taking, or not taking, statins. 

 

They found, after adjusting for:

• age;
• race;
• cardiovascular, pulmonary, and renal disease;
• influenza vaccination and antiviral administration

 

Those not already on statins, or placed on statins during their hospital stay, were nearly twice as likely to die within 30 days of hospitalization as those who received statins.

 

A cautionary note: This was an observational study, not a Randomized Controlled Trial – and so there may have been confounding factors not adjusted for by the authors. Additionally, this study did not attempt to track the amount of statins used by patients during their hospitalization.

 

First a link to the study’s abstract, followed by a few excerpts to the press release, and then a link to an accompanying editorial.

 

 

Association Between Use of Statins and Mortality Among Patients Hospitalized With Laboratory-Confirmed Influenza Virus Infections: A Multistate Study

J Infect Dis. jir695 first published online December 13, 2011 doi:10.1093/infdis/jir695

Meredith L. Vandermeer, Ann R. Thomas, Laurie Kamimoto, Arthur Reingold, Ken Gershman, James Meek, Monica M. Farley, Patricia Ryan, Ruth Lynfield, Joan Baumbach, William Schaffner, Nancy Bennett and Shelley Zansky

 

Since the bulk of this study is behind a pay wall, the press release from the IDSA provides some valuable details.

 

Infectious Diseases Society of America

Statins may reduce mortality in patients hospitalized with influenza

[EMBARGOED FOR DEC. 14, 2011] The two main ways to prevent and control influenza today are annual immunization and antiviral drugs. A team of investigators has found that statins, cholesterol-lowering drugs, may offer an additional treatment to complement these approaches and reduce mortality among patients hospitalized with influenza. The findings are published in The Journal of Infectious Diseases and are now available online.

 

In an observational study led by Meredith L. Vandermeer, MPH, then with the Oregon Public Health Division in Portland, researchers used data for hospitalized adults during the 2007-2008 influenza season to evaluate the association between patients prescribed statins and influenza-related deaths. The data were drawn from the Centers for Disease Control and Prevention's Emerging Infections Program, which conducts active surveillance for patients hospitalized with confirmed influenza in 59 counties in 10 states.

 

Among 3,043 hospitalized patients with laboratory-confirmed influenza, 33 percent were given statin medications prior to or during hospitalization. After adjusting for various factors, patients not receiving statins were almost twice as likely to die from influenza as those who did receive the medication.

 

"Our study found that statins were associated with a decrease in odds of dying among cases hospitalized with laboratory-confirmed influenza, when adjusted for age, race, cardiovascular disease, chronic lung disease, renal disease, influenza vaccine receipt, and initiation of antivirals within 48 hours of admission," the study authors wrote.

(Continue . . .)

 

You’ll find an accompanying editorial, also published today, titled:

 

Statins and Influenza: Can We Move Forward?

Edward E. Walsh

 

More than 2 years ago, the Reveres at the now shuttered Effect Measure Blog took an in depth look at the statin controversy, and why we still don’t know if they are effective against influenza.

 

While the Revere’s are greatly missed in Flublogia, that archive is still online, and very much worth revisiting.

 

Statins for influenza. Why don't we know if it works yet?

Category: Infectious disease • Influenza treatment

Statins for influenza are in the news again, this time because of a paper given at the Annual Meeting of the Infectious Disease Society of America (IDSA). We'll get to it in a moment, but first a little background.

Read on »

 

 

For more on the potential utilization of statins during a pandemic, or for seasonal influenza and pneumonia, you may wish to revisit these earlier blogs:

 

Statins & Pneumonia: Revisited

Statins Revisited

First Statins, Now Fibrates

E. Coli: In the Raw (cookie dough)

 

 

 

# 5998

 

Little noticed by the public, since it happened more or less at the same time as the emergence of 2009’s H1N1 virus, was a multistate outbreak of Shiga toxin-producing Escherichia coli (STEC) O157:H7.

 

Although more people were likely infected and experienced only minor symptoms, 77 patients with E. coli related illness were identified across 30 states.

 

Of these, 35 were hospitalized, and 10 developed HUS (Hemolytic Uremic Syndrome), a serious form of kidney failure. The victims were predominantly female (71%), and under the age of 19 (66%)

 

The CDC’s investigation (see archived details) determined:

 

Preliminary results of this investigation indicate a strong association with eating raw prepackaged cookie dough. Most patients reported eating refrigerated prepackaged Nestle Toll House cookie dough products raw.

 

This was the first time that the consumption of raw cookie dough had been associated with E. coli infection.

 

Nestle instituted a voluntary recall, while the FDA and CDC warned consumers not to eat any varieties of prepackaged Nestle Toll House refrigerated cookie dough. They warned that those with products on hand should discard them, rather than cooking them, as consumers might get the bacteria on their hands and on other cooking surfaces.

 

Fast forward 2 1/2 years and we have a study from the IDSA – embargoed until midnight last night – that warns of the dangers of eating raw cookie dough and recommends that manufacturers find ways to make it safer.

 

The 8 page PDF file is available at the link below.

 

A Novel Vehicle for Transmission of Escherichia coli O157:H7 to Humans: Multistate Outbreak of E. coli O157:H7 Infections Associated With Consumption of Ready-to-Bake Commercial Prepackaged Cookie Dough—United States, 2009

 

Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2011.
DOI: 10.1093/cid/cir831

Karen P. Neil,Gwen Biggerstaff, J. Kathryn MacDonald, Eija Trees, Carlota Medus,  Kimberlee A. Musser, Steven G. Stroika, Don Zink, and Mark J. Sotir

 

 

Although the contaminated ingredient in this recalled batch of cookie dough was never conclusively identified, flour – which does not undergo a `kill step’ to rid it of pathogens – was strongly suspected.

 

We’ve a press release on all of this from the IDSA, excerpts of which you’ll find below.

 

Ready-to-bake cookie dough not ready-to-eat, study of E. coli outbreak finds

Consumer education and manufacturing changes may help prevent illness

[EMBARGOED FOR DEC. 9, 2011] The investigation of a 2009 multistate outbreak of Shiga toxin-producing Escherichia coli (STEC), an important cause of bacterial gastrointestinal illness, led to a new culprit: ready-to-bake commercial prepackaged cookie dough. Published in Clinical Infectious Diseases and available online, a new report describing the outbreak offers recommendations for prevention, including a stronger message for consumers: Don't eat prepackaged cookie dough before it's baked.

 

<SNIP>

 

The study authors conclude that "foods containing raw flour should be considered as possible vehicles of infection of future outbreaks of STEC." Manufacturers should consider using heat-treated or pasteurized flour, in ready-to-cook or ready-to-bake foods that may be consumed without cooking or baking, despite label statements about the danger of such risky eating practices, the authors conclude. In addition, manufacturers should consider formulating ready-to-bake prepackaged cookie dough to be as safe as a ready-to-eat food item.

(Continue . . . )

 

 

Eating raw cookie dough is apparently a popular culinary choice, based on the results of a Google search with the terms `eating raw cookie dough’.  

 

You’ll find abundant questionable `advice’ on the safety of this practice, including instructions on how to make `safe to eat’ raw cookie dough by eliminating `raw eggs’.

 

Much of this counsel needs to be taken with a pinch of salt (and a 350 degree oven for 15 minutes), since eggs aren’t the only potential source of contamination.

 

Since the 1980s more than 180 outbreaks of E coli have been reported across the United States from a variety of sources. This past summer, more than 4,000 people across Europe were sickened, and roughly 50 killed, by an E. coli outbreak traced to sprouts.

 

For more on how to avoid E. coli infection, and what to do if you are affected, visit foodsafety.gov’s  E. coli webpage.

 

 

http://www.foodsafety.gov/poisoning/causes/bacteriaviruses/ecoli/

IDSA: Educational Guidelines Lower Antibiotic Use

 

 

 

Photo Credit – CDC

 

# 5715

 

From the IDSA (Infectious Diseases Society of America) today, a major report on the reduction in outpatient antibiotic use in Quebec since an educational campaign, directed primarily at pharmacists and physicians, was begun in 2005.

 

On a per capita basis, outpatient use of antibiotics has declined by 4.2% in Quebec, while increasing by 6.5% across the rest of Canada.

 

The latest version of these guidelines are available at the Le conseil du médicament website.

 

 

 

This study appears in today’s online edition of Clinical Infectious Diseases. The press release (below) provides details.

 

Simple guidelines decreased unnecessary antibiotic use in Quebec, Canada

Infectious Diseases Society of America

[EMBARGOED FOR JULY 26, 2011] Antibiotic overuse and resistance have emerged as major threats during the past two decades. Following an outbreak of Clostridium difficile infections, which often result from antibiotic use, health care professionals in Quebec, Canada targeted physicians and pharmacists with an education campaign that reduced outpatient antibiotic use, according to a study published in Clinical Infectious Diseases and now available online.

 

The Quebec Minister of Health and the Quebec Medication Council collaborated with designated physicians and pharmacists to develop guidelines to improve prescribing practices. First issued in January 2005, the guidelines emphasized proper antibiotic use, including not prescribing antibiotics when viral infections were suspected and selecting the shortest possible duration of treatment. Approximately 30,000 printed copies of the original recommendations were distributed to all physicians and pharmacists in Quebec. An additional 193,500 copies were downloaded from the Medication Council's website. (The current versions of the guidelines are available online: LINK.)

 

During the year after the guidelines were initially distributed, the number of outpatient antibiotic prescriptions in Quebec decreased 4.2 percent. In other Canadian provinces, the number of these prescriptions increased 6.5 percent during the same period.

 

According to study author Karl Weiss, MD, of the University of Montreal, "It is possible to decrease antibiotic consumption when physicians, pharmacists, state governments, etc., are working together for a common goal. This is the key to success: having everybody involved and speaking with a common voice."

 

Dr. Weiss added, "Simple, short, easy-to-use guidelines have an impact on physicians when they are readily available. The web is an increasingly important tool to reach our audience and should now be used as such in the future. With handheld electronic devices available for all health care professionals, these downloadable guidelines can be accessed and used at any time and any circumstance."

 

The paper may be accessed at the following link.

 

Impact of a Multipronged Education Strategy on Antibiotic Prescribing in Quebec, Canada

Karl Weiss, Re´gis Blais, Anne Fortin,  Sonia Lantin, and Michel Gaudet

Department of Infectious Diseases and Microbiology, Faculty of Medicine, University of Montreal, Montreal, Canada;Department of Health Administration, Faculty of Medicine, University of Montreal, Montreal, Canada; and Conseil du Me´dicament du Que´bec, INESSS, Que´bec City,Canada

PPEs & Transocular Influenza Transmission

 

 

 

 

Photo Credit PHIL (Public Health Image Library)

 

 

# 5633

 

Constant readers of this blog are aware that over the past several years we’ve seen many differing studies on the  effectiveness of different types of  PPEs (Personal Protective Equipment) in protecting against influenza.

 

 

Ideally, the well-protected HCW (Health Care Worker) working in an infectious environment would be wearing an N95 mask, gloves, gown and eye protection.

 

But during the opening months of the 2009 pandemic, it became glaringly obvious that our world faced a shortage of PPEs, and so strategies were adopted to maximize their use.

 

In some cases nurses were issued only one N95 mask to be used for an entire 8 hour shift, and told to don it only when in direct contact with a potentially infected patient.

 

In other venues, HCWs were issued surgical masks in lieu of N95s, despite the recommendation at the time from the CDC that N95 masks were the preferred level of protection.

 

This, as you might imagine, raised concerns among health care workers and sparked protests across the country.

 

Nurses Protest Lack Of PPE’s

Report: Nurses File Complaint Over Lack Of PPE

California Nurses Association Statement On Lack Of PPE

 

 

Fortunately, the virulence of the novel 2009 H1N1 virus was less than originally feared. Had the pandemic carried a higher mortality and morbidity rate, the lack of PPEs would have become a much bigger issue.

 

 

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

 

N-95 Respirator         Surgical Facemask

 

But over the past two years we’ve seen dueling studies that alternately show surgical masks to be a reasonable protective barrier against respiratory viruses  . . . or pretty much useless.

 

Take your pick.

 

A few highlights of these conflicting reports include:

 

In October of 2009 the NEJM published a perspective article (see NEJM Perspective: Respiratory Protection For HCWs) based on a 2009 IOM evaluation of surgical masks vs. respirators, and came out in favor of the N95.

 

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 2010, we saw the following study (see Study: Efficacy of Facemasks Vs. Respirators) in Clinical Infectious Diseases, that suggested that surgical masks are just as effective as respirators in protecting HCWs.

 

In guidance, updated as late as March of 2010, the CDC continued to recommend N95 respirators for HCWs who came in close contact with suspected or confirmed influenza patients.

 

But in June of 2010, the CDC proposed new guidance that relaxed those recommendations to using surgical masks for routine care, and reserving N95 masks for aerosol producing procedures (intubation, suctioning, etc).

 

Still, the controversy remains. 

 

Adding to the confusion, we’ve seen recent studies that give more credence to the notion that influenza may be spread in aerosolized form (see Study: Aerosolized Transmission Of Influenza), as opposed to primarily by large droplets. 

 

But the truth is, our knowledge of how influenza spreads, and what barriers work well to protect HCWs, is severely limited.

 

Which is why a few months back the IOM (Institute of Medicine) released, through the National Academies Press, an extensive, 200+ page update on the use of PPEs  that essentially calls for better science on which to base our decisions regarding the right kind of protection for HCWs.

 

While the requisite knowledge won’t come overnight, today we have an ingenious piece of research that appears in the current issue of the IDSA’s  Journal of Infectious Diseases. 

 

Not only does it compare the efficacy of surgical masks verses N95s, it  gives us important new perspectives on the importance of eye protection against the influenza virus.

 

First the link, then I’ll return with a brief summary of what they found.

 

Transocular Entry of Seasonal Influenza–Attenuated Virus Aerosols and the Efficacy of N95 Respirators, Surgical Masks, and Eye Protection in Humans

Werner E. Bischoff, Tanya Reid, Gregory B. Russell and Timothy R. Peters

 

 

Finding safe and ethical ways to test the effectiveness of PPEs against influenza – when exposing test subjects to a virus could endanger their health – has always been a challenge.

Instead, researchers at Wake Forrest chose to expose 28 volunteers (divided into six groups) for 20 minutes to an aerosolized LAIV (Live Attenuated Influenza Vaccine) in a special air-tight chamber.

The six groups were:

 

1. No protective equipment
2. Ocular exposure only
3. Surgical mask only
4. Surgical mask plus eye protection
5. Fit-tested N-95 only
6. Fit-tested N-95 plus eye protection

 

 

While the study size was small, and the type of virus limited to 2 influenza A strains and 1 influenza B strain (MedImmune’s 2009/10 seasonal Flumist), the study yielded some very interesting results.

 

Researchers detected flu virus in all 4 subjects in Group 1 (unprotected), and in 3 of 4 in Group 2 (Ocular Exposure only).

 

Somewhat surprisingly, nasal washes of subjects with ocular exposure only were positive for flu virus within 30 minutes, suggesting the virus made its way rapidly to the nasopharynx by way of the nasolacrimal duct.

 

Flu virus was detected in all 10 volunteers who wore surgical masks (groups 3 & 4), regardless of eye protection.

 

N95 wearers (group 5) fared somewhat better, with 3 of 5 testing positive for the virus.

 

The best result came from the wearing of eye protection and an N95 (group 6). 

 

Only 1 in 5 subjects wearing that combination of protection showed detectable levels of virus.

 

 

The authors conclude:

 

"The eyes could be an entry route for influenza, allowing viral particles easy and fast access to the upper respiratory tract.

The type of surgical mask tested was inferior to a fit-tested N95 respirator in preventing aerosol delivery; however, none of the tested barrier precautions provided complete protection, including a CDC-recommended fit-tested N95 respirator and the addition of eye protection.”

 

This study – like all laboratory research – is subject to certain limitations. The results, while compelling, aren’t definitive.

 

The size of the study – 28 test subjects –was fairly small, and the substitution of a live influenza virus with an LAIV could have potentially skewed the results.

 

More research will be needed to confirm these findings.

 

Meanwhile, conflicting opinions regarding the efficacy of various types of respiratory PPEs will likely continue while we await further studies.

Measles: Forgotten, But Not Gone

 

 

# 5530

 

 

Measles, which was once almost a youth’s `rite of passage’ in the United States, has been all but eliminated in recent years after the introduction of the first measles vaccine in 1963.

 

The chart below (source: CDC) shows the remarkable effectiveness of the vaccination campaign.

 

 

While many parents today think of measles as a relatively benign childhood illness, it actually produced significant morbidity and mortality with respiratory, ocular, and neurological complications - sometimes resulting in death.

 

During the 1950s – before the introduction of the measles vaccine – in the United States the disease infected roughly 4 million, hospitalized nearly 50,000,  and contributed to the deaths of several hundred every year.  

 

Admittedly, a vast improvement over the mortality rates from earlier in the century, when the disease was far deadlier (for reasons that quite frankly, remain hard to explain – Ian York explored this fascinating mystery in Measles week, part I: Introduction ).

 

But in recent years lower uptake of the vaccine – its reputation tainted by (disproven) claims of a possible link to autism (popularized by Dr. Andrew Wakefield and promoted by various anti-vaccination groups) – and the continual importation of the disease from countries where it remains endemic - have allowed the virus to keep a toehold in developed nations.

 

In developing countries, the incidence – and mortality rate – of measles remains high.   These statistics from the World Health Organization:

 

 

Measles

Fact sheet N°286

Key facts

• Measles is one of the leading causes of death among young children even though a safe and cost-effective vaccine is available.
• In 2008, there were 164 000 measles deaths globally – nearly 450 deaths every day or 18 deaths every hour.
• More than 95% of measles deaths occur in low-income countries with weak health infrastructures.
• Measles vaccination resulted in a 78% drop in measles deaths between 2000 and 2008 worldwide.
• In 2008, about 83% of the world's children received one dose of measles vaccine by their first birthday through routine health services – up from 72% in 2000.

 

Today news on measles from several fronts. 

 

First, the WHO’s  WER (Weekly Epidemiological Record) brings us details on an ongoing measles outbreak in Europe, that has infected more than 6,500 people in 33 nations.

 

Measles outbreaks in Europe

As of 18 April 2011, 33 countries in Europe had reported  6500 measles cases. Epidemiological investigations and genotyping have confirmed transmission of measles virus among several countries in the Region and in the Americas.

<SNIP>

In all these outbreaks, except for the second out-
break in Spain and the outbreak in Turkey, the D4
genotype of measles virus has been confirmed.
The B3 genotype of measles virus was isolated
from cases in the second measles outbreak in
Spain, while the D9 genotype, originating from
and common in south-east Asia (e.g. Malaysia and
Indonesia) was confirmed to have caused the out-
break in Istanbul (Turkey) in January 2011.

(Continue . . . )

 

 

As you can see, there are a number of different strains or genotypes of measles.  New ones emerge, or are detected, every so often.  As of mid-2010, the World Health Organization (WHO) maintained reference strains representing 23 recognized genotypes.

 

From Eurosurveillance this week, a report on a novel strain of (an existing genotype:G3) of measles which has spread across Europe over a 2 month period.

 

Eurosurveillance, Volume 16, Issue 17, 28 April 2011

Rapid communications

Appearance of a novel measles G3 strain in multiple European countries within a two month period, 2010

K E Brown, M N Mulders, F Freymuth, S Santibanez, M M Mosquera, S Cordey, J Beirnes, S Shulga, R Myers, D Featherstone

During late 2010, a previously unrecognised strain of measles genotype G3 virus was identified in five different European countries by the World Health Organization Measles and Rubella Laboratory Network. Apart from one, none had a travel history to south-east Asia, the usual source of G3 viruses, although epidemiological links could be established between some of the cases. This case series illustrates the value of genotyping and sequencing in tracking measles infections, and identifying otherwise unrecognised chains of transmission.

(Continue . . . )

 

And next, from the Journal of Infectious Diseases a report on the impact of an outbreak of measles in Tucson, Arizona in 2008 that affected two healthcare facilities. 

 

 

Health Care–Associated Measles Outbreak in the United States After an Importation: Challenges and Economic Impact

 

J Infect Dis. (2011) jir115 first published online April 28, 2011 doi:10.1093/infdis/jir115

Sanny Y. Chen,

Shoana Anderson, Preeta K. Kutty, Francelli Lugo, Michelle McDonald, Paul A. Rota, Ismael R. Ortega-Sanchez, Ken Komatsu, Gregory L. Armstrong, Rebecca Sunenshine, and Jane F. Seward

 

You can follow the above link to read the entire article, or for the short version, you can read the press release from the IDSA.

 

Infectious Diseases Society of America

Measles outbreak underscores need for continued vigilance in health care settings

[EMBARGOED FOR APRIL 29, 2011] The U.S. measles vaccination program has been successful in eliminating endemic measles in the United States; yet this success has provided challenges that require ongoing vigilance for the rapid identification and response to measles cases in health care settings. In 2008, the largest reported health care-associated measles outbreak in the United States since 1989 occurred in Tucson, Arizona, costing approximately $800,000 in response and containment efforts. In a report published in The Journal of Infectious Diseases and available online, researchers identify preventive measures hospitals and health care facilities can implement to reduce the likelihood and decrease the economic impact of a future measles outbreak in these settings.

 

Due to a highly effective vaccine and high vaccine coverage, measles was declared eliminated in the United States in 2000; however, the potential for measles infection still exists in this country. Non-adherence to U.S. vaccination recommendations and infection among unvaccinated travelers coming into the United States continue to pose potential threats to the public and to health care personnel. In the 2008 Tucson outbreak, an unvaccinated, infected Swiss traveler visited a hospital emergency department on February 12. The traveler was admitted to the hospital the next day, but a measles diagnosis was not confirmed until February 20. This ignited an intense and lengthy public health investigation and response to persons with suspected and confirmed measles as well as contacts of those persons.

(Continue . . . )

 

And again from the Journal of Infectious diseases, an editorial comment on the above study by Stephen M. Ostroff.  

The full text of both articles is freely available.

 

EDITORIAL COMMENTARY:

Stephen M. Ostroff

Measles: Going, Going, But Not Gone

J Infect Dis. (2011) jir125 first published online April 28, 2011 doi:10.1093/infdis/jir125

 

 

While not the scourge of the early 20th century in the United States, measles remains a serious public health threat in much of the world, and is only held at bay in developed countries by relatively high vaccination rates.

 

There is a lot more to the measles story, and I highly recommend reading the entire Mystery Rays blog series on the disease by Ian York from 2010.

 

Measles week, part I: Introduction

Measles week, part II: Emerging disease

Measles week, Part III: Not the answers

Measles week, part IV: Some of the answers

Measles week, Part V: What about the vaccine?

 

 

APIC Calls For Mandatory Flu Vaccination For HCWs

 

 

# 5282

 

 

APIC (the Association for Professionals in Infection Control and Epidemiology, Inc.) has joined the chorus of other professional infection control and medical organizations (including SHEA, IDSA, & AAP) who are calling for mandatory yearly flu vaccinations for healthcare workers (HCWs).

 

If this story sounds a bit like Deja Flu, you probably recall that in October of 2008 APIC released a similar statement (see APIC Seeking Mandatory Flu Shot For HCWs), but in that case provided for an informed `opt out clause’ if HCWs signed a declination form saying they understood the risks to patients.

 

The new statement eliminates that escape clause, recommending that that hospitals, nursing homes, and other facilities employing HCWs:

 

“require influenza immunization as a condition of employment unless there are compelling medical contraindications."

 

You can read the entire 4-page position paper, outlining their recommendations and rationale behind them, on the APIC home page.

 

APIC Position Paper:  Influenza Vaccination Should Be a Condition of Employment for Healthcare Personnel, Unless Medically Contraindicated

 

The paper also calls for those who are exempted for medical reasons to:

 

“. . .  be educated on the importance of careful adherence to all of the non-vaccine related HICPAC prevention strategies, including hand hygiene and cough etiquette.

Further, they may be  required to wear a surgical mask when contact with patients or susceptible employees is likely. “ 

 

Over the past year several other professional medical organizations have made similar calls for mandatory vaccinations.

 

AAP: Recommends Mandatory Flu Vaccinations For HCWs

SHEA: Mandatory Vaccination Of Health Care Workers

IDSA Urges Mandatory Flu Vaccinations For Healthcare Workers

 

While strongly advocating HCW influenza vaccination, the CDC has stopped short of mandating them. I blogged on this back on June 23rd, 2010  in  CDC: Proposed Influenza Infection Control Guidance.

 

Similarly, a UK Department of Health report issued in June 2010 called Learning The Lessons From the H1N1 Vaccination Campaign For Healthcare Workers  – while not mandating vaccination – stresses the `professional duty’ of all HCWs to get the vaccine.

 

New York State attempted to require vaccination as a requirement to work as a HCW in 2009, but legal challenges and vaccine shortages forced them to abandon – at least temporarily – that mandate  (see New York Rescinds Mandatory Flu Shots For HCWs).

 

While many infection control experts see this as a long overdue step in patient and co-worker protection, the obstacles that lay before these sorts of policies are substantial.

 

This is a hugely divisive issue, with many HCWs believing that it is an infringement of their rights to decide what will be injected into their bodies.

 

There will almost certainly be legal challenges, and possibly labor disputes as well. I’ve covered HCW’s objections to forced flu shots in the past, including:

 

HCWs: Refusing To Bare Arms

HCWs: Developing a Different Kind Of Resistance

 

 

Only a few large hospitals have thus far managed to implement mandatory flu vaccinations, including Seattle’s Virginia Mason Medical Center and BJC Heathcare of St. Louis, Missouri  which I blogged about here

.

Details on how Virginia Mason Medical Center implemented mandatory HCW vaccinations can be read in the following  PDF.

 

 

Over the past 5 years Virginia Mason MC has maintained a 98% vaccination rate, and has vigorously promoted the uptake of flu shots not only in the workplace, but the greater community as well.

 

An abstract from a study that appeared in the August 2010 Infection Control and Hospital Epidemiology journal concludes that a policy of mandatory HCW vaccination is feasible, sustainable, and effective.

 

DOI: 10.1086/656210

Mandatory Influenza Vaccination of Healthcare Workers: A 5‐Year Study

Robert M. Rakita, MD; Beverly A. Hagar, BSN, COHNS; Patricia Crome, MN; Joyce K. Lammert, MD, PhD

(EXCERPT)

Results.

In the first year of the program, there were a total of 4,703 HCWs, of whom 4,588 (97.6%) were vaccinated, and influenza vaccination rates of more than 98% were sustained over the subsequent 4 years of our study. Less than 0.7% of HCWs were granted an accommodation for medical or religious reasons and were required to wear a mask at work during influenza season, and less than 0.2% of HCWs refused vaccination and left Virginia Mason Medical Center.

 

Impressive results. 

 

And, when combined with increased calls from infection control organizations to adopt similar practices, likely to inspire other facilities to follow suit.

JID: Emerging Influenza Resistance Threats

 

 

 

 

# 5125

 

 

The old adage - `if you make a better mouse trap, nature will begin to work on a better mouse’ - is well illustrated by the continual evolution of bacteria and viruses to evade our arsenal of antibiotic and antiviral agents.

Between MRSA and the growing number of emerging carbapenemases  - antibiotic resistance (rightfully) has most of our attention because it directly impacts tens of thousands of patients every year.   

 

Antiviral resistance – for now – is viewed with somewhat less alarm simply because we are not currently in an influenza pandemic, and it is rare that we encounter an influenza virus that is resistant to our entire arsenal of antiviral drugs.

 

But scientists worry that could change.

 

A few short years ago Amantadine (an M2 ion channel blocker) was the preferred influenza antiviral.  It was cheap, plentiful, and worked pretty well.

 

But by the mid 2000s Amantadine began to lose its effectiveness against the H3N2 seasonal flu virus and some strains of the H5N1 bird flu.

 

It has been suggested that the prophylactic use of Amantadine by Chinese poultry farmers (who supposedly included it in their chicken feed for several years) may have contributed to this sudden resistance.

 

But whatever the cause, by January of 2006 the CDC had issued a warning to doctors not to rely on Amantadine (or Rimantadine) to treat influenza.

 

Oseltamivir (Tamiflu) – a newer neuraminidase (NA) inhibitor drug  introduced in 1999 - while far more expensive, became the new treatment standard.

 

But within two years seasonal H1N1 began to show growing resistance to Oseltamivir as well (although H3N2 remained sensitive).

 

By the spring of 2009, - in the space of just about a  year – seasonal H1N1 had gone from almost 100% sensitive to the drug to nearly 100% resistant.

 

The arrival of a novel H1N1 pandemic virus was a game changer, in that it – unlike seasonal H1N1 – was still sensitive to oseltamivir (but not Amantadine).

 

In short order novel H1N1 supplanted the seasonal strain, breathing new life – at least for now – into the neuraminidase (NA) inhibitor class of antivirals.

 

But over the past 18 months we have seen a small number (less than 2% of samples tested) of Oseltamivir resistant novel H1N1 viruses – along with some evidence of transmissibility. 

 

So the concern lingers.  If seasonal H1N1 could go from nearly completely susceptible to completely resistant to oseltamivir in a year’s time – could it happen again with the new H1N1 strain?

 

And if that happens, what antiviral alternatives do we have in the pipeline?

 

These issues are addressed in the January issue of IDSA’s Journal of Infectious Diseases in a pair of articles and an editorial.

 

First, links to the three JID items, followed by excerpts from the IDSA’s press release.

 

“Dual Resistance to Adamantanes and Oseltamivir Among Seasonal Influenza A (H1N1) Viruses: 2008-2010” 
 

“Evidence of Person to Person Transmission of Oseltamivir Resistant Pandemic Influenza A (H1N1) 2009 Virus in a Hematology Unit”

 

“Emerging Influenza Antiviral Resistance Threats”

 

 

A few excerpts from the accompanying press release:

 

 

Influenza Virus Strains Show Increasing Drug Resistance and Ability to Spread

 

Studies Highlight Need for New Antiviral Treatment Options and Strategies

Two new studies raise public health concerns about increasing antiviral resistance among certain influenza viruses, their ability to spread, and a lack of alternative antiviral treatment options. The findings are published in the January 1 issue of The Journal of Infectious Diseases.

 

(Please see below (above) for links to these articles online.)

 

Influenza viruses are treated with two classes of drugs: M2 blockers (adamantanes) and neuraminidase inhibitors (NAIs), including oseltamivir and zanamivir.  While the spread of influenza strains with resistance to one class of drugs has been well documented in recent years, a new report from Larisa Gubareva, MD, PhD and colleagues at the Centers for Disease Control and Prevention (CDC) and at health agencies in West Virginia, Texas, and Canada, confirms that dual resistance can emerge in several ways and has been on the rise during the past three years.

 

<SNIP>

 

Although dual resistant viruses are still rare, the investigators noted an increase in the number of tested viruses with this resistance, from 0.06 percent (2007-2008) to 1.5 percent (2008-2009) to 28 percent (2009-2010); however, during the 2009-2010 season the number of circulating seasonal H1N1 viruses was low, and only 25 viruses were tested.  “Because only two classes of antiviral agents are approved, the detection of viruses with resistance to drugs in both classes is concerning,” said Dr. Gubareva. “If circulation of viruses with dual resistance becomes more widespread among any of the predominant circulating influenza A viruses, treatment options will be extremely limited. New antiviral agents and strategies for antiviral therapy are likely to be necessary in the future.”

 

(Continue . . . )