Tuesday, April 22, 2008

Ionic air purifiers' dirty little secret: They don't get rid of dust - Los Angeles Times

Do home air purifiers work?

During a Q and A session following a presentation at an OSHA conference in Harrisburg, PA, a familiar question was asked, "Can VIGILAIR be installed in a home?" While we do not serve the consumer market, there are alternatives such as in-room air purifiers. However, in order to find one that works, you need to find the science and get beyond the marketing of these devices. I found this LA Times article accurate and informative:

"Ionic air purifiers' dirty little secret: They don't get rid of dust

By Chris Woolston, Special to The Times
April 21, 2008

The product: Dust, cigarette smoke, pollen and pet dander: With so many irritants floating around our homes and work places, clean air is a hot commodity. Americans spend hundreds of millions of dollars on furnace filters and air cleaners each year. Though some consumers are simply trying to bring a little extra freshness into their lives, many others hope that their investment will help relieve their asthma or allergies.

If you've ever shopped for an air cleaner -- or if you've ever idly flipped through a SkyMall catalog -- you've undoubtedly seen ads for ionic air purifiers, devices that take an unusual approach to clearing the air. Instead of relying on fans to move air through filters, the machines release a steady stream of negatively charged ions that electrify the bits of dust, dander or other flotsam. The airborne particles pick up the negative charge and become strongly attracted to positively charged collection plates inside the machine. (In many cases, they also become attracted to other charged surfaces such as walls, table tops and TV screens.)

Except for a few models that use fans to help suck in the charged particles, most ionic air purifiers work silently. And, as ads are quick to point out, the devices generally don't have any motors or moving parts, and there are no filters to replace.

There's another thing that separates ionic air purifiers from other technologies: To varying degrees, all ionic air purifiers release ozone, a potential pollutant. A 2006 study by researchers at UC Davis found that one popular brand, the Ionic Breeze Quadra, released about 2.2 milligrams of ozone per hour, or about as much as a constantly running photocopier. (Ionic purifiers shouldn't be confused with ozone generators that are marketed as "air cleaners." By design, these devices can release 50 to 200 milligrams of ozone per hour.)

The claims: According to the Sharper Image web site, the Ionic Breeze is "proven effective at reducing airborne allergens and irritants -- with no fan, no motor and no noise." The Heaven Fresh web site says that its purifiers can provide relief from "asthma, bronchitis, hay fever and other respiratory diseases." Heaven Fresh also claims that the ozone emitted by its machines helps clean the air. According to the site, "ozone is one of the purest and most powerful oxidants and germicides known."

The bottom line: Ionic air purifiers have undeniable appeal, but there's a problem: They don't really improve air quality, says Dr. James Sublett, a clinical professor at the University of Louisville; a fellow at the American College of Allergy, Asthma & Immunology; and co-chair of the 2007 ACAAI Healthy Indoor Environment conference. "We [allergists and immunologists] generally don't recommend them," he says. "This is a windmill that I've been tilting at for a number of years."

According to Sublett, the devices don't effectively remove dust, dander and other irritants from a room. Without fans, he explains, they can't collect airborne particles from more than a few feet away. And when even small amounts of dust enter the device, the plates inside quickly lose much of their power to attract more particles. Meanwhile, the charged particles that stick to walls or TV screens haven't left the room and can always billow up again to cause trouble.

The ozone released from the devices is another deal-breaking shortcoming, Sublett says. "Ozone is a pollutant and an irritant. Even small amounts are too much." People who use several units at a time are especially likely to get an ozone overload, he says. One of Sublett's patients noticed a great improvement in her breathing when she turned off the six ionic purifiers in her home."

Air purification for homes should involve both capture and 'kill'. Filters capture and remove irritants, while technologies such as Ultraviolet light destroy pathogens. FIlters take care of the big airborne contaminants, UV deactivates the microorganisms that elude the filters. The balanced approach is best.

Friday, April 04, 2008

WHO | Avian influenza – situation in Pakistan - update 2

The two best kept secrets in Pakistan

The first secret is, 'Where is Osama bin Laden?'. Secret number two is that there was confirmed Human-to-Human (H2H) spread of Avain flu in Pakistan more than 5 months ago. Here's the complete info release from the WHO:

WHO | Avian influenza – situation in Pakistan - update 2

3 April 2008

Two additional H5N1 cases were confirmed by serological testing, thus providing final H5N1 infection test results on a previously reported family cluster in Peshawar.

These tests were conducted by the WHO H5 Reference Laboratory in Cairo, Egypt and the WHO Collaborating Centre for Reference and Research on Influenza in Atlanta, USA. The table below summarises the testing results of the confirmed/probable cases in the family cluster.

  • The preliminary risk assessment found no evidence of sustained or community human to human transmission.
  • All identified close contacts including the other members of the affected family and involved health care workers remain asymptomatic and have been removed from close medical observation.

These laboratory test results support the epidemiological findings from the outbreak investigation in December 2007, and the final risk assessment that suggested limited human to human transmission likely occurred among some of the family members which is consistent with some human-to-human transmission events reported previously. This outbreak did not extend into the community, and appropriate steps were taken to reduce future risks of human infections.

Relationship Onset Date Outcome Exposure Status
Case 1 (Index case) 29 Oct 07 Fully recovered Direct contact sick/dead poultry Confirmed (serology)
Case 2 12 Nov 07 Dead (19 Nov 07) Close contact with Case 1, no known direct contact with sick/dead poultry Probable
(No sample available)
Case 3 21 Nov 07 Dead (28 Nov 07) Close contact with Case 1 and 2, no known direct contact with sick/dead poultry Confirmed (PCR)
Case 4 21 Nov 07 Fully recovered Close contact with Case 1 and 2, no known direct contact with sick/dead poultry Confirmed (serology)

It is great news that the H2H transmission burned out before it hit the wider community. But many aspects of this news are troubling. First and foremost is the credibility of the WHO reporting. It seems that we hear complete details if a single duck shows up with H5N1 in Eureka-stan; why such a delay for major news such as H2H?

Speaking of credibility, contrast today's news with this Reuters article on December 28, 2007:

No proof of human-to-human bird flu in Pakistan No evidence that bird flu passed between relatives, WHO says

Reutersupdated 1:10 p.m. ET, Fri., Dec. 28, 2007

GENEVA -The World Health Organization said on Thursday it had established a single case of human infection of the H5N1 bird flu virus in a sick family in Pakistan but there was no apparent risk of it spreading further.

A statement from the U.N. agency said tests in its special laboratories in Cairo and London had established the “human infection” through presence of the virus “collected from one case in an affected family.”

But it said a WHO team invited to Pakistan to look into an outbreak involving up to nine people from late October to December 6 had found no evidence of sustained or community human-to-human transmission.

No identified close contacts of the people infected, including health workers and other members of the affected family, had shown any symptoms and they had all been removed from medical observation, the WHO added.

The outbreak followed a culling of infected chickens in the Peshawar region, in which a veterinary doctor was involved. Subsequently he and three of his brothers developed proven or suspected pneumonia.

The brothers cared for one another and had close personal contact both at home and in hospital, a WHO spokesman in Geneva said. One of them, who was not involved in the culling, died on November 23, but the cause of death was not known.

On November 28 another brother who had not been involved in the culling died, and tests on him — in Pakistan as well as in Cairo and London — had established the presence of the H5N1 virus.


The WHO spokesman told Reuters on Thursday all the evidence ”suggests that the outbreak within this family does not pose a broader risk. He added: “But there is already heightened surveillance and there is a need for ongoing vigilance.”

Truth delayed, is none the less the truth. But going forward it is harder to accept what the WHO says is the truth.

Wednesday, April 02, 2008

Doctors Frustrated over Acinetobacter Infections

All the healthcare professionals that I know are good hearted people with a great capacity for compassion and a desire to heal. Doctors are, at heart, 'fixers'. So you can understand the frustration infection control professionals feel when they run out of treatment options. Consider the plight of physicians dealing with drug resistant Acinetobacter, as referenced in this article fron the UK's Telegraph:

"Pandemic fear over resistant superbug

By Stephen Adams
Last Updated: 2:20am BST 02/04/2008

Doctors have warned that if a superbug which is known to be even more resistant to antibiotics than clostridium difficile and MRSA takes hold in hospitals, the country could face a pandemic.

The acinetobacter bug is being treated with older antibiotics because newer ones do not work. There are fears that injured soldiers returning from Iraq and Afghanistan have passed the infection on in civilian hospitals.

Prof Matthew Falagas, an expert in hospital-acquired infections, said: "In some cases, we have simply run out of treatments and we could be facing a pandemic with public health implications."

He warned delegates at the Society for General Microbiology conference in Edinburgh: "Doctors in many countries have gone back to using old antibiotics that were abandoned 20 years ago because their toxic side-effects were so frequent and so bad.

"But superbugs like acinetobacter have challenged doctors all over the world by becoming resistant to these older medicines.

"Even Colistin, an antibiotic discovered 60 years ago, has recently been used. But now it occasionally fails as the bacteria has become resistant."

There are more than 1,000 reports of acinetobacter infections every year in the UK, according to the Health Protection Agency (HPA). Some strains can cause death through blood poisoning and pneumonia."

Acinetobacter is particularly difficult to remove from the environment of care because it is hearty and can survive for nearly a month in dry conditions. Healthcare providers will do their best to fight this bacterium, but turning back the clock to use older antibiotics is not a good long term strategy.

Because Acinetobacter has been proven to be transmitted via the air in several hospital studies, it is prudent to consider that the airborne route of transmission may play a role. While UVGI systems designed by VIGILAIR can help reduce environmental contamination, they are not a silver bullet. Like antibiotics, VIGILAIR is one part of a multi-faceted infection control strategy. VIGILAIR's strength lies in its ability to eliminate environmental reservoirs where microorganisms proliferate.

A VIGILAIR white paper on Acinetobacter is available here.