Wednesday, October 24, 2007

More Evidence of MRSA's Airborne Spread

Epidemiologists are like medical detectives. They analyze an outbreak and then use their knowledge and tools to identify the outbreak source. Below is an excellent study from the Medical School in Kitakyushu, Japan. The study took place in a hospital area that housed 37 patients recovering from head and neck surgery. Three patients in single occupancy rooms became infected with MRSA after surgery.
Were all three patients colonized by the same strain of MRSA? If so, what was the source and how could patients in three separate rooms become infected with the same pathogen?
Researchers used air sampling machines and surface swabs to collect MRSA samples. Then the samples were analyzed using polymerase chain reaction and pulsed-field gel electrophoresis. The result?
"An epidemiological study demonstrated that clinical isolates of MRSA in our ward were of one origin and that the isolates from the air and from inanimate environments were identical to the MRSA strains that caused infection or colonization in the inpatients."
The conclusions of this study indicate that disinfecting the air circulated within their ward could help reduce colonization of patients (bold emphasis added by me).

"In this study, we confirmed that MRSA could be acquired by medical staff and patients through airborne transmission. The findings suggest the importance of protecting patients against cross-infectious agents existing in aerosols. Although measures for prevention and control of nosocomial infection with MRSA include handwashing with an antimicrobial agent; wearing a gown, gloves, and a mask; and removing MRSA from the nasal vestibule, few measures have been established to control airborne bacteria. Laminar unidirectional airflow, air ventilation, and air filtration could also be beneficial in hospital environments and should be considered. Further studies will be needed to assess the levels of MRSA contamination of air and to develop more effective means of controlling and removing airborne MRSA."

Once again we see that there is no silver bullet for infection control. Disease transmission is not all contact, nor is it all airborne, rather it is a dynamic combination of many things. In this hospital ward, airborne transmission took on increased importance because the patients in this care unit lack typical host defense mechanisms in their upper respiratory tracts.
VIGILAIR® systems are proven to reduce pathogen load within the air stream by destroying microorganisms with UVGI, and removing the microorganisms with filtration. You may download the research article in its entirety here.

Teruo Shiomori, MD, PhD; Hiroshi Miyamoto, MD, PhD; Kazumi Makishima, MD, PhD. Significance of Airborne Transmission of Methicillin-Resistant Staphylococcus aureus in an Otolaryngology–Head and Neck Surgery Unit. Arch Otolaryngol Head Neck Surg. 2001;127:644-648

Tuesday, October 23, 2007

MRSA Airborne?

Over the past few weeks this blog and its sister site have seen an increase in traffic fueled by the following search terms:
  • MRSA is airborne
  • How is MRSA transmitted
  • MRSA airborne ultraviolet light
  • MRSA airborn
Since there seems to be an interest in our point-of-view on MRSA and airborne transmission, I put together a White Paper that briefly reviews evidence supporting airborne MRSA. The links in the pdf file are active, so please feel free to click through to the supporting documentation.

The truth is that MRSA is on our skin, is in the air and is on surfaces and fomites. Clearly, contact transmission predominates, but we ignore other sources (such as airborne) at our own peril. We view pathogenic microorganisms as opportunistic--they find any avenue to reproduce. When we eliminate one vector of transmission, they find others. We have cultured Staph, Pseudomonas, Klebsiella, Serratia and Acinetobacter from the cooling coils and drain pans of hospitals that we've tested. Our studies have shown that when the cooling coils are irradiated with UV, the pathogens are eradicated in the HVAC. This also corresponds to a lower environmental load for those pathogens in patient care areas.

Airborne's exact contribution to MRSA disease transmission is not known. However, we have seen that when you eliminate the pathogen reservoir inside the HVAC, there are less microorganisms downstream, where patients receive care.
Using VIGILAIR in a hospital complements existing Infection Control strategies; it does not replace them.
If you're interested in MRSA's airborne links, download this pdf for more information.

Friday, October 12, 2007

H5N1 Beautiful and Deadly

New images of the H5N1 virus were released this week. The images are the work of science photographer Lennart Nilsson, who is well known for his imaging of human conception and development of the baby within the womb. These images were first printed in Swedish daily Dagens Nyeter. Nilsson originally asked the US government for H5N1 virus samples but was turned away. He was able to obtain the virus from the World Health Organization and used a scanning electron microscope to make the images. The virus is strangely beautiful in these images, seen as blue orbs attacking healthy pink cells. But keep in mind that it is deadly, as the samples came from a father and daughter in Hong Kong who died after being infected two years ago. I combined the images with a photo of Nilsson (credit Jacob Forsell) and a music bed by Silvermay.

When E. coli, Salmonella or E. sakazakii is on the menu

Food producers are always vigilant to prevent pathogens from contaminating the products that you and I consume. But lately it seems that there have been some high profile recalls of foods that were tainted by harmful microorganisms. What does this have to do with airborne infection? The link is UVGI.
The mechanics of VIGILAIR® reducing contamination in hospitals can be applied to the food production industry. UVGI can inactivate pathogens such as:

VIGILAIR® technology can help keep food production clean by:
  • inactivating microorganisms in the air used in food production
  • inactivating microorganisms on the surfaces of food products
  • inactivating microorganisms on the surfaces of packaging
Our technology is proving effective in keeping food safe and is used in production facilities in the US, Canada, Mexico and Asia. For more information on how VIGILAIR® is used in the food production industry, click here.
A concise primer to the role of UVGI in food production can be found here.

Wednesday, October 10, 2007

HAI-an explanation

Looking for an excellent overview of Hospital Acquired Infections? Than look no further than this video clip from Dr. David Nash of Thomas Jefferson University. Dr. Nash is at the vanguard of medical educators who are examining health care and health care policies.
Dr. Nash is involved in Pennsylvania's aggressive Health Care Cost Containment Council. PHC4 is considered a model for the public reporting of information on hospital acquired infections.