Wednesday, May 07, 2008

Pilot study reinforces use of portable anteroom HEPA filtration

A new study from a leader in airborne disease research indicates that Operating Room HEPA filtration is not a guarantee against nosocomial infection. Dr. Russel Olmstead led a team that looked at airborne contamination inside of the OR environment.

Pilot study reinforces use of portable anteroom HEPA filtration

To prevent perioperative transmission of airborne microorganisms

Washington, DC, May 6, 2008 – Amidst an increase in new tuberculosis cases, researchers have begun investigating the effectiveness of new operating room filtration systems designed to protect staff and patients. According to pilot study findings published in the May issue of the American Journal of Infection Control, a supplemental portable anteroom high-efficiency particulate air (PAS- HEPA) filter unit placed outside operating room suites may prevent secondary transmission of airborne microorganisms like Mycobacterium tuberculosis (M. tuberculosis).

“The rate of decline in newly reported tuberculosis cases in the U.S. has slowed,” said lead study investigator Russell N. Olmsted, MPH, CIC, epidemiologist from Saint Joseph Mercy Hospital in Ann Arbor, MI. “This, coupled with the worldwide emergence of even more drug-resistant tuberculosis, reinforces the need for renewed vigilance and surveillance from healthcare professionals. In particular, study results reinforce the need for measures to optimize air particle removal.”

Olmsted and colleagues compared the efficiency of freestanding HEPA filtration units to a new portable anteroom system (PAS)-HEPA combination unit in removing harmful airborne infectious pathogens. Freestanding HEPA units were evaluated in the operating room, while the PAS-HEPA unit was placed outside over the main operating room door. Both smoke plume and non-infectious particles similar in size to M. tuberculosis were used to mimic movement of airborne pathogens within highly pressured environments.

“We observed interruption of normal patterns of airflow with freestanding HEPA units placed inside the operating room,” said Olmsted, adding that instead of being captured by the air-filtration system, smoke plume traveled upward from the operating room table and into the breathing zone of personnel who might be present during a typical surgical procedure.

“This suggests an increased potential for occupational exposure to airborne microorganisms as well as an unwanted introduction of contaminants into the patient’s open surgical site,” he explained.

In contrast, deployment of the PAS-HEPA combination unit pulled the smoke downward, away from the operating room table and toward the floor and main door. The second phase of the study (which involved simulated microscopic particles) mirrored these observations; within 20 minutes, over 94% of submicron particles were cleared from the operating room.

“The results of Mr. Olmsted’s study reinforce the Centers for Disease Control and Prevention (CDC) 2003 guidelines for environmental infection control as well as 2005 guidelines for preventing the transmission of M. tuberculosis in healthcare settings,” said Janet E. Frain, RN, CIC, CPHQ, CPHRM, APIC 2008 President and Director, Integrated Services, Sutter Medical Center in Sacramento, CA. “These findings should be considered for integration into an overall infection prevention and control program to help ensure both patient and healthcare personnel safety.”

These findings substantiate results we've discovered in our testing of Operating Rooms. Recently we found microbial contamination (including fungi) immediately downstream from HEPA filtration units installed in ORs. The contamination was found one week after the filters were certified for efficiency compliance.
Filters are great for trapping microorganisms, but they do not 'kill'. Eventually filters can become colonized and act as a breeding ground for pathogens. Thinking that you have 100% protection because you have HEPA filtration is a false sense of security.
We suggest a balance between UV and filtration to provide a better strategy for reducing environmental pathogens in critical care areas of your hospital. E-mail us to find out more about a recent study in which VIGILAIR provided better protection than laminar flow for operating suites in a large urban hospital.

A Common Killer

Here's a quick question for our readers:
What is the #1 world wide killer for children five and under?
  1. smallpox
  2. measles
  3. AIDS
  4. malaria
  5. pneumonia
If you chose #5, pneumonia, you're correct. Many of those other disease have a higher profile and get more attention. But a recent report released by the World Health Organization says that Pneumonia kills more than 2 million kids under the age of five each year. It is the #1 killer for that age group, responsible for nearly 1 in 5 deaths for little ones.
I mention it so that we raise awareness on emerging and somewhat exotic disease, we should not forget those common killers who destroy so many young lives, albeit with a low profile.

Hospitals struck by new killer bug |

UK Newspaper continue to examine (and exploit) news on infectious disease. The latest cause for concern is Stenotrophomonas, nick-named 'Steno' for popular consumption.

Hospitals struck by new killer bug |

Tuesday, May 6, 2008

A new hospital superbug resistant to all antibiotics could be killing hundreds of patients, experts have warned.

The infection, known as 'Steno', is on the increase and could be harder to tackle than MRSA and C.difficile.

The bug spreads almost exclusively in hospitals through wet areas such as taps and shower heads, and is thought to kill a third of the people it infects after entering the bloodstream.

Chemotherapy patients, including children, are among those most in danger, because the infection spreads through ventilation tubes and catheters.

There are about 1,000 reports of Steno blood poisoning in Britain each year, according to today's study by the Wellcome Trust Sanger Institute, near Cambridge.

Research leader Dr Matthew Avison said: 'This is the latest in an ever-increasing list of antibiotic-resistant hospital superbugs.

'The degree of resistance it shows is very worrying. Strains are now emerging that are resistant to all available antibiotics.'

MRSA is thought to have caused 1,652 deaths in 2006, up from 51 in 1993. Clostridium difficile was mentioned on 6,480 death certificates in 2006, a 72 per cent rise on 2005.

Steno sticks to catheters or medical tubes and grows into a so-called 'biofilm'. When the catheter is next flushed, the bug enters the patient's bloodstream and can cause septicaemia, especially if their immune system has already been weakened.

The onus is on both patients and healthcare professionals to do more to keep equipment clean, Dr Avison told the Genome Biology journal.

Stenotrophomonas is another pathogen that we've isolated from the hospital environment. In our study, we were able to culture Stenotrophomonas from surfaces in the Heating Ventilation and Air Conditioning (HVAC), surfaces in NICU as well as in the tracheal aspirates of the patients. As mentioned in the article, this bug likes water--and that is where we found it, in the water of the HVAC drain pan.

As we look to decrease Hospital Acquired Infections (HAI), we should consider all the reservoirs for pathogens. Neutralizing the source of an infectious agent is the key to long term success in infection prevention. Is the Stenotrophomonas in the HVAC water making its way into the care areas? It's hard to say and expensive to prove.

So, we focus a lot of attention on 'end of the pipe' solutions such as hand washing. This is a good thing. But at the same time we should eradicate the factories where pathogens are generated and distributed within a health care facility. Our research has shown that one such factory is the HVAC system. We've also shown that VIGILAIR® can eliminate this reservoir as a potential source.