The Myth of HEPA Filtration

HEPA filters have been on the job protecting environments since the days of the Manhattan Project. HEPA's reputation as an effective filtration measure is well deserved, but some people believe that if they have a HEPA filter, they are completely free from contamination concerns.

From years of utilizing HEPA filters in cleanrooms and hospitals, we know that this notion is false. Please review our White Paper on this topic (The Myth Of HEPA).

If you have any comments on this paper, please post them here.

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Getting a Grip on Hand Sanitizers

A new report in the CDC’s March Edition of Emerging Infectious Disease found that some gel hand sanitizers do not do a good job of killing germs. Researchers found that the alcohol content of some gels in insufficient to kill fungi and bacteria.

The FDA recommends a 60% to 95% formula of ethanol or isopropanol for hand sanitizers. One commercial hand cleaning gel that was tested promised a 99.9% reduction in “germs and harmful bacteria.” Lab experiments showed that this gel, with a 40% ethanol concentration, yielded no significant reduction in microbial load, which makes it as effective as washing your hands with tap water.

While having some effect on fungi, the gel actually increased bacterial load. Results showed that the most common bacteria found on the hands were staphylococci, including those with characteristics of Staphylococcus aureus.

UK Study: MRSA Higher in Crowded Hospital Wards

According to a study in the British Journal of Nursing, patients face a greater risk of contracting MRSA if they are treated in a ward with a high occupancy rate. The study by researchers at the University of Ulster found that more than half of the Northern Irish surgical wards exceed UK overcrowding guidelines.

The UK government recommends that bed occupancy rate of 82%. All 11 Northern Ireland wards tracked in the study had occupancy rates above 85%. Over utilization of the beds equals greater MRSA risk, according to the researchers:

“Their study suggests a relationship between percentage bed occupancy and MRSA rates: the higher the level of occupancy the higher the risk of MRSA infection and they are now investigating these factors in all the English acute and specialist hospital Trusts.
Individual acts, it is argued, such as hand washing, good hygiene, and the use of alcohol gels are important; but there may be structural and systems issues which may contribute to hospital acquired infections. Nurses, managers and Trust boards, they say, must address these macro as well as micro issues in the control of hospital infection.”

Hospitals are finally seeing the mounting evidence that infection issues are environmental and systemic. The chain of transmission has several links. We need to address all of them, including indoor air contamination to find a lasting solution.

(There is no link available to the original study text as the British Journal of Nursing as it does not publish on-line yet)

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The Skinny on Airborne MRSA

The Skinny on Airborne MRSA

In our discussions with infection control professionals, MRSA is a frequent topic. It appears that there is a strongly held belief that MRSA cannot be transmitted via the air. For the doubters, I humbly submit:

1. “Staphylococcus aureus, often referred to simply as "staph," is a bacteria commonly found on the skin and in the nose of healthy people” -CDC.
2. “Normally, skin cells are replaced every 28 to 30 days”-Cleveland Clinic

If MRSA is frequently found on your skin, and you completely shed the top layer of your skin once-a-month, isn’t it reasonable that MRSA is hitching a ride on some of those millions of shed skin cells? You know, those skin cells that form cobwebs hanging from your ceiling?

Finally, If we doctors typically test for MRSA using nasal swabs, how did the MRSA get there? Could it be that people inhaled the MRSA through their noses? Air transmission may not be the largest contributor in the spread of MRSA, but it seems likely that it should be considered as one of the links in the chain of transmission.
(MRSA image-University of Texas)

UPDATE: For more information on MRSA's airborne spread, including a list of peer reviewed studies on the topic, please visit this posting from our blog.

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H2H Avian Flu…Who Knew?

H2H Avian Flu…Who Knew?

‘H2H’ may soon join our lexicon much in the way ‘Y2K’ did at the turn of our last global crisis. If H2H is new to you, it is shorthand for ‘Human to Human’, as in Human to Human transmission of the bird flu. The term H2H is spreading just like the bird flu. In February, the term was searched on Yahoo 471 times; bloggers enter H2H into Technorati’s search engine about eight times a day.

H2H is important because it represents the next big step in the evolution of the H5N1 virus. The question is, when will H5N1 go H2H? The answer is, it already has! With all the hype surrounding bird flu, why don’t more people know about this development? Why aren’t the CDC and WHO telling us?

It turns out that they are, in a muted way. Here’s the alert level posted on WHO’s site:

Note we are in phase 3, “No, or LIMITED H2H transmission”.

From the CDC:

“While H5N1 does not usually infect people, human cases of H5N1 infection associated with these outbreaks have been reported Most of these cases have occurred from direct or close contact with infected poultry or contaminated surfaces; however, a few rare cases of human-to-human spread of H5N1 virus have occurred, though transmission has not continued beyond one person.”

In reality, the medical world has known about H5N1 H2H for awhile. One of medicine’s most prestigious periodicals, The New England Journal of Medicine, featured this study in January of 2005:

Results: The index patient became ill three to four days after her last exposure to dying household chickens. Her mother came from a distant city to care for her in the hospital, had no recognized exposure to poultry, and died from pneumonia after providing 16 to 18 hours of unprotected nursing care. The aunt also provided unprotected nursing care; No additional chains of transmission were identified....
Conclusions: Disease in the mother and aunt probably resulted from person-to-person transmission of this lethal avian influenzavirus during unprotected exposure to the critically ill index patient."

Why aren’t we panicking? The rare cases of documented H2H for H5N1 prove that the chain of transmission is very short. It appears that the virus does not efficiently transfer between humans, leading to the rare H2H infections. As the virus changes, it could acquire the ability to spread easily between humans—or it may not. The only safe prediction is that this virus will change and that the best thing for us to do is to support the researchers who are tracking H5N1.

While there is no cause for panic, there is one fact surrounding H5N1 that is of concern. The most recent great pandemic in 1918 killed upwards of 50 million people worldwide, according to the CDC. Its mortality rate (number of deaths as a percentage of total people who got infected) was under 2.5%.
Today’s H5N1has infected a total of 177 people, killing 98. Its mortality rate is 55%.
Let’s hope that like Y2K, H2H will become a footnote in history, rather than a chapter of global suffering.

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Hoping for the Best, Preparing for the Worst

This month's Health Facilities Management Magazine has an excellent article on how hospitals can prepare for the surge capacity needed should a pandemic or similar infectious outbreak occur. Author Frank Zilm knows the subject matter well and succintly outlines challenges for protecting staff and patients, the hospital building and the Emergency Department.
New ideas in healthcare design, especially the ED, are essential to meet the challenges of infectious disease:

In most scenarios, the emergency service will be a primary entry point into the health care system and other components of the system (inpatient beds,physician offices, and clinics) will also quickly reach saturation.

Of equal importance are the high-risk patients that present on a daily basis. “If you plan for these special-risk situations, it will help with interrupting the chain of transmission,” says Craig Feied, M.D., FACEP, director of the Institute for Medical Informatics, MedStar Health, Washington Hospital Center, Washington, D.C. “Traditional design does nothing to reduce risk.”

Disease can be spread through airborne particles, direct contact with an infected patient and contact with a surface (fomite) that harbors a reservoir of active virus or bacteria. Among these, airborne contamination and fomite contact have clear implications for health care facility design professionals.

Dr. Feied's comment "breaking the chain of transmission" is right on the money. We need to spread awareness that hand washing alone will not prevent the spread of disease. Additional measures of cleaning the environment, especially the airborne route of transmission are important links in the chain.

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