ICAAC Video: How Quickly A Virus Can Spread In A Building

 

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The 54rd Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) runs through September 9th in Washington D.C. , and this morning we’ve an absolutely fascinating video sponsored by the American Society for Microbiology showing just how quickly a single introduction of a virus into an office environment can spread to contaminate an entire building.

 

Of particular interest, this conversation explores how their results relate to this week’s Enterovirus (HEV-D68) outbreak (see Enterovirus D-68 (HEV-D68) Update).

 

First, the press release on the study, then a link to the video on  MicrobeWorld’s Youtube channel.

 

How Quickly Viruses Can Contaminate Buildings and How to Stop Them

EMBARGOED UNTIL: Monday, September 8, 2014, 9:00 a.m. EDT

(Images are courtesy Gerba Lab and are free to use. First image is Gerba and a student working on samples and second is a sampling sponge.)

WASHINGTON, DC – September 8, 2014 – Using tracer viruses, researchers found that contamination of just a single doorknob or table top results in the spread of viruses throughout office buildings, hotels, and health care facilities. Within 2 to 4 hours, the virus could be detected on 40 to 60 percent of workers and visitors in the facilities and commonly touched objects, according to research presented at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), an infectious disease meeting of the American Society for Microbiology.

There is a simple solution, though, says Charles Gerba of the University of Arizona, Tucson, who presented the study.

“Using disinfecting wipes containing quaternary ammonium compounds (QUATS) registered by EPA as effective against viruses like norovirus and flu, along with hand hygiene, reduced virus spread by 80 to 99 percent,” he says.

(Continue . . . )

The video is available on the http://www.microbeworld.org/podcasts/asm-live website right now, but should be moved to the MicrobeWorld’s Youtube channel later today.

 

Monday, September 8

9:00 a.m. -- How Quickly Viruses Can Contaminate a Building
Using tracer viruses, researchers found that contamination of just a single doorknob or table top results in the spread of viruses throughout office buildings, hotels, and health care facilities. Within 2 to 4 hours, the virus could be detected on 40 to 60 percent of workers and visitors in the facilities and commonly touched objects. Simple use of common disinfectant wipes reduced virus spread by 80 to 99 percent.

Charles Gerba, University of Arizona, Tucson

 

 

Sigh.  Based on this, and the viral threats lining up, guess I’m gonna need to lay in a bigger supply of hand sanitizer.

MERS: A Focus On Fomites?

WHO team in Jeddah Investigation MERS - Credit @WHO

 

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This week a team from the World Health Organization is on the ground in Jeddah, where the largest concentration of MERS coronavirus cases has been reported to date. 

 

Although their investigation is on-going and it is too soon to reach any conclusions,  this morning WHO spokesperson Gregory Hartl suggested that fomites – inanimate objects and environmental surfaces –might be a significant player in the transmission of the MERS coronavirus.

 

 

While the role of fomites in the transmission of the virus has yet to be established (and indeed, its relevance may vary by location and/or cluster), it is probably worth taking a closer look at the environmental stability of the MERS virus, and how well it might be transmitted by contaminated surfaces or other inanimate media.

 

We have a pair of studies that address the survivability of the MERS virus outside of an animal host, and both suggest that – under the right environmental conditions – the virus remains viable for extended periods of time.

 

Three weeks ago, in EID Journal: Stability Of MERS-CoV In Milk, we saw a study where researchers inoculated various types of milk products (camel, goat, cow, etc.) and DMEM (a cell culture media) with MERS-CoV strain Jordan-N3/2012, stored multiple samples at 4°C or 22°C, and then tested their infectious disease titers at 0, 8, 24, 48, 72 hours post dilution. 

 

Their results?

 

At 0–72 hpd, virus titers decreased significantly only in goat milk (p = 0.0139, 1-tailed paired t test) and DMEM (p = 0.0311) but not in dromedary camel milk (p = 0.1414) or cow milk (p = 0.2895). Samples stored at 22°C showed a greater loss of infectivity than did samples stored at 4°C.

 

Making unpasteurized milk at least a plausible medium for carriage of the MERS virus or its transmission to humans. Unknown at this time is whether camels shed the virus in their milk, a project that Dr. Ian Lipkin’s group at Columbia University is reportedly going to tackle next.

 

Another study, going back to September of last year, appeared in the journal Eurosurveillance: Environmental Stability Of MERS-CoV.  Here researchers looked at the environmental stability of the MERS coronavirus, both on surfaces (fomites), and as an aerosol.

 

The researchers describe their experiments below (slightly reformatted for readability).

 

In this study, the stability of MERS-CoV (isolate HCoV-EMC/2012) was evaluated under three different environmental conditions:

• high temperature and low humidity, 30°C – 30% relative humidity (RH);
• high temperature and high humidity, 30°C – 80% RH
• and low temperature and low humidity, 20°C – 40% RH

to reflect a wide range of environmental conditions including an indoor environment (20°C – 40% RH).

The stability of MERS-CoV under the three tested environmental conditions was respectively compared with that of influenza A virus A/Mexico/4108/2009 (H1N1) originating from a human isolate obtained during the influenza A(H1N1)pdm09 pandemic in 2009 [9]. The stability of the two viruses in aerosols at 20°C with 40% or 70% RH was also assessed and compared.

 

The results?

 

• While the Influenza A virus became non-viable on steel and plastic surfaces in less than 4 hours for all testing environments, the MERS virus survived 48 hours in the 20°C – 40% RH environment. Survival of the coronavirus at 30°C – 30% RH was 24 hours, and 8 hours at 30°C – 80% RH.
• As an aerosol, the MERS virus remained very stable at 20°C – 40% RH, while its viability decreased  (89% – comparable to the Influenza A virus)  at 20°C – 70% RH.

 

The full study can be found at: Stability of Middle East respiratory syndrome coronavirus (MERS-CoV) under different environmental conditions by  N van Doremalen¹, T Bushmaker¹, V J Munster.

 

The bottom line, under favorable temperature and humidity conditions (such as you might find in an air conditioned hospital), the MERS virus survives quite well on surfaces, and in the air. This may help explain the high rate of nosocomial outbreaks we’ve seen in the Middle East.

 

While the route of infection with this virus has not been determined, this virus shows the kind of environmental hardiness that would be conducive for either fomite or droplet/aerosol  (contact) transmission.

 

When the WHO’s mission in Saudi Arabia is completed, and they’ve had time to look at the data they’ve collected, we should have a better idea of what is going on with this virus.

 

Stay tuned.

 

 

Before You Ask To Borrow Someone’s Cell Phone . . .

 

 

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Just in time for Global Handwashing Day – which is tomorrow, October 15th – we’ve a report from the London School of Hygiene & Tropical Medicine that should give one pause before asking to borrow another person’s cell phone.

 

Contamination of UK mobile phones and hands revealed

One in six mobile phones in the UK is contaminated with fecal bacteria, researchers found

 

One in six mobile phones in Britain is contaminated with faecal matter, according to new research released ahead of Global Handwashing Day.

 

Experts say the most likely reason for the potentially harmful bacteria festering on so many gadgets is people failing to wash their hands properly with soap after going to the toilet.

 

The findings of the UK-wide study by scientists from the London School of Hygiene & Tropical Medicine and Queen Mary, University of London also reveal a tendency among Britons to lie about their hygiene habits.

 

Although 95% of people said they washed their hands with soap where possible, 92% of phones and 82% of hands had bacteria on them. Worryingly, 16% of hands and 16% of phones were found to harbour E. coli – bacteria of a faecal origin. Harmful E. coli (Escherichia coli) is associated with stomach upsets and has been implicated in serious cases of food poisoning such as the fatal O157 outbreak in Germany in June.

 

(Continue . . .)

 

 

BBC News has a short (2 minute) video on this story, showing how the testing of mobile phones was accomplished.

 

 

While cell phones were the subject of this study, in truth anything and everything we touch can harbor bacteria.  Door knobs, computer keyboards, shopping cart handles, elevator buttons, credit cards, cash . . . .

 

And as the movie `Contagion’ pointed out so effectively, we touch our faces 3 to 5 times every waking minute, and in between we are touching hundreds of other (likely contaminated) surfaces every day.

 

The opportunities for introducing pathogens into your body via your eyes, nose or mouth are abundant, and your only real defense is washing your hands as often as possible.

 

And it isn’t just bacteria, like Staph, MRSA, or E. coli that can contaminate surfaces. Viruses can live for hours – and under the right condition, sometimes days – on inanimate surfaces.

 

With cold and flu season upon us, it is all the more reason to carry (and use) a bottle of alcohol sanitizer and to seek out opportunities to wash your hands with soap and water as often as possible.

 

Although better than nothing, hand sanitizers are not always enough. In CMAJ: Hand Sanitizers May Be `Suboptimal’ For Preventing Norovirus we saw how these handy sanitizers are not always effective against C. Diff and Norovirus.

 

In Fomite to Fingers To Face: A Triple Play Combination, we looked at how long some of these pathogens could remain viable on surfaces and act as a vehicle of transmission.

 

The 2007 study Significance of Fomites in the Spread of Respiratory and Enteric Viral Disease by Stephanie A. Boone,& Charles P. Gerba found that most viruses survived longer on nonporous surfaces (metal or plastic), and that respiratory viruses (RSV, HPIV, influenza virus, coronavirus, and rhinovirus) could remain viable for hours or even days.

 

Under the right conditions, enteric viruses - like Rotavirus, Norovirus, and Hepatitis A - have been known to survive on fomites from weeks to months.

 

We live in a germy world. 

 

Which is why public health agencies and organizations push hand washing so vigorously.  They know it literally saves lives.

 

As an inveterate hand washer from way back (I was a paramedic during the 1970s, before wearing latex gloves became de rigueur), I’m certainly a believer.

 

I had my hands in an untold number of unspeakable messes, but washed (well . . actually scrubbed) my hands more than a dozen times each day, and managed to stay healthy.

 

For more on all of this I’d invite you to visit:

 

 http://www.globalhandwashingday.org/

 

And the CDC’s hand hygiene website, where you will find many resources, including a link to a new iPad/iPhone application called iScrub.

 

Fomite to Fingers To Face: A Triple Play Combination

 

 

 

 Photo Credit – CDC 

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Fomites are any surface or object that can become contaminated with viral or bacterial pathogens and that can act as a vehicle of transmission. 

 

Surfaces like the touch screen on your bank’s ATM, the door knob to a public restroom, or the the handle of a shopping cart are touched by scores of people every day.  

 

And some of those people, undoubtedly, are leaving behind bacteria and viruses you really don’t want to get.

 

Last June (see Firefighters & MRSA Revisited) I wrote of a study by researchers from the University of Washington that looked for – and found – MRSA (Methicillin-resistant Staphylococcus aureus) contaminated surfaces at fire houses in Snohomish county.

 

MRSA was detected in 4% of samples taken from places such as kitchens, bathrooms, and rescue vehicles – and researchers also found 30% of firefighters who volunteered to be tested were colonized with either MRSA or S. aureus in their noses.

 

While fomites have long been suspected of playing a significant role in the transmission of diseases, it has only been in recent years that we’ve learned how remarkably resilient many of these pathogens are once they are deposited on an inanimate surface.

 

The 2007 study Significance of Fomites in the Spread of Respiratory and Enteric Viral Disease by Stephanie A. Boone,& Charles P. Gerba found that most viruses survived longer on nonporous surfaces (metal or plastic), and that respiratory viruses (RSV, HPIV, influenza virus, coronavirus, and rhinovirus) could remain viable for hours or even days.

 

Under the right conditions, enteric viruses - like Rotavirus, Norovirus, and Hepatitis A - have been known to survive on fomites from weeks to months

 

It’s a germy world out there, and most people touch their face 10 to 20 times each hour, providing ample opportunities for pathogens to move from fomite to fingers to face.

 

All of which serves as prelude to a study that appears in the August issue of the American Journal of Infection Control that surveyed the hand hygiene knowledge and beliefs of 71 nurses, infection preventionists and hospital environmental services managers.

 

Individual differences in judgments of hand hygiene risk by health care workers

Anne Collins McLaughlin, PhD Fran Walsh, PhD

 

Participants were asked to assess their perceived risk of contracting or spreading an infection in 16 real-life situations. 

 

The authors found that across all levels, healthcare workers perceived surfaces as safer to touch than a patient’s skin, despite studies that have implicated fomites in the chain of disease transmission. 

 

The authors comment:

"Despite the dangers that fomites present, this knowledge may not be common enough among HCWs for them to understand the level of risk when touching surfaces and then touching patients."

 

Studies have shown that although compliance rates are improving, 50% of health care workers in the United States fail to consistently wash their hands between patients (cite).

 

Hospital acquired infections (HAIs) remain a huge problem, and exact a terrible toll on patients and their families.

 

This from the HHS.

 

HHS Action Plan to Prevent Healthcare-Associated Infections: Introduction

Healthcare-associated infections exact a significant toll on human life. They are among the top ten leading causes of death in the United States, accounting for an estimated 1.7 million infections and 99,000 associated deaths in 2002.

 

Of course, this isn’t just a problem in the United States, but also around the world. 

 

So this year the World Health Organization designated May 5th as global  CLEAN YOUR HANDS DAY - to encourage HCWs (Healthcare workers) to improve and sustain hand hygiene practices around the world (see A Movement With Five Moments).

 

 

 

For some earlier blogs on the importance of fomites in the transmission of disease, and the value of hand hygiene you may wish to revisit:

 

CMAJ: Infectious Risks In Family Doctor’s Offices

Hand Hygiene Among Doctors Exposed

MDs Behaving Badly

Suitable For Framing

 

And lastly . . . to start your week off with a smile, a return engagement by that consummate entertainer, one that Maryn McKenna  introduced me to a couple of years ago . . .  the one you all know and  love . . give it up for GERMY, in the award winning all singing, all dancing production of Soapacabana!

Stick around for the outtakes!

Study: Longevity Of Viruses On PPEs

 

 

 

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PPEs – or personal protective equipment – are items worn by Health Care Workers (HCWs) when examining or caring for potentially contagious patients. They include masks, gloves, and gowns.

 

During the opening months of the 2009 pandemic, it became 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. 

 

This, as you might imagine, raised concerns among HCWs that this strategy of reusing masks could expose them, and their patients, to the virus.  That, and the decision to issue surgical masks instead of N95s, 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

 

Unfortunately, there are differing opinions and gaps in our scientific knowledge regarding the relative effectiveness of N95 vs. surgical masks (something I’ve covered often, including here, here, and here) and on how long a virus may remain viable on inanimate objects (like masks & gloves).

 

Inanimate objects that can transfer infectious agents are called fomites, and the CDC’s  (very) short answer on how long viruses can remain viable on these surfaces reads:

 

How long can human influenza viruses remain viable on inanimate items (such as books and doorknobs)?

Studies have shown that human influenza viruses generally can survive on surfaces for between 2 and 8 hours.

 

Today we’ve a new study that looks specifically at how long viruses may remain viable on PPEs. It appears in the Japanese journal Environmental Health and Preventative Medicine  (Hat tip Tetano on FluTrackers).

 

Essentially, researchers inoculated various fomites (masks, gloves, gowns, wooden and steel desktops) with laboratory grown H1N1, and then tested the surfaces after 1, 8, and 24 hrs for the presence of the virus (HA titer & 50% tissue culture infective dose (TCID₅₀)/mL were measured).

 

Environmental Health and Preventive Medicine

Volume 15, Number 6, 344-349, DOI: 10.1007/s12199-010-0149-y

Maintenance of influenza virus infectivity on the surfaces of personal protective equipment and clothing used in healthcare settings

Hiroko Sakaguchi, Koji Wada, Jitsuo Kajioka, Mayumi Watanabe, Ryuichi Nakano, Tatsuko Hirose, Hiroshi Ohta and Yoshiharu Aizawa

ABSTRACT (Excerpt)

Results 

The HA titer of this influenza A virus did not decrease in any of the materials tested even after 24 h. The infectivity of influenza A virus measured by TCID₅₀ was maintained for 8 h on the surface of all materials, with the exception of the rubber glove for which virus infectivity was maintained for 24 h.

Conclusions 

Our results indicate that the replacement/renewal of personal protective equipment and clothing by healthcare professionals in cases of exposure to secretions and droplets containing viruses spread by patients is an appropriate procedure to prevent cross-infection.

 

TCID₅₀ is the  amount of a pathogenic agent (in this case the H1N1 virus) required to infect 50% of cell cultures inoculated.

 

The results indicate that all surfaces tested harbored viable H1N1 viruses for at least 8 hours, with some surfaces infectious for more than 24 hours.

 

These test results extend the window of infectivity from fomites considerably beyond what has previously been reported.

 

The debate over the proper use of PPEs, and just how protective they really are, is a contentious one.

 

During a highly virulent disease outbreak, getting the science right (and applying it) could save a lot of lives.  We were very lucky that the CFR (case fatality ratio) of the 2009 pandemic was as low as it was. 

 

Last January the IOM (Institute of Medicine) released, through the National Academies Press, an extensive, 200+ page update on the use of PPEs (personal protective equipment) for healthcare workers when facing pandemic influenza and other viral respiratory illnesses.

 

The short version is, we need better science upon which to make decisions regarding the right kind of protection for HCWs.

 

While the entire 200 page pre-publication pdf can be downloaded for free, you can also view an executive summary and an abbreviated list of recommendations.

 

 

While this study from the EHPM won’t close the book on fomite transmission - it does add to our knowledge of the subject – and it shows us just how hearty influenza viruses can be, even outside of a host.

 

For more on the debate over PPEs you may wish to review:

 

Why Size Matters

Study: Aerosolized Transmission Of Influenza

NPI’s and Influenza

NEJM Perspective: Respiratory Protection For HCWs