return to ICG Spaces home    ICG Risk Blog    discussions    newsletters    login    

State of H5N1 Avian flu (Un)preparedness

  #

A recent off the record conversation with a city public health official on flu pandemic preparedness after three years of "preparation":

  • Insufficient vaccine stocks
  • Little discussion of who gets priority access to vaccine
  • Volunteers exist for assisting positions and for law enforcement, yet most do not yet have an N95 mask and, his words, not mine, it is not clear if an N95 mask is effective against H5N1
  • Vaccine distribution plans pivot about airlift distribution from six regional depositories to adjacent states
  • Population urged to store three days of emergency supplies although most avian flu scenarios require some two weeks of supplies in order for flu to transit the available vectors (vulnerable population sectors)

If only the situation were this bright:

  1. Not only is there insufficient vaccine in the abstract, insufficient regional supplies will further suffer from predation on the supply/distribution chain as have-nots realize what is passing by them, hijacking the supply. Stocks not immediately consumed or destroyed will go to black market auction.
  2. There have been discussions as prioritizing vaccine receipt, nominally first responders and hospital staffs and an ill-defined 'command and control' structure but is expected to break down quickly. Human nature predicts a Dr. Strangelove effect to retain key stocks for senior command and control. I would expect attacks on presumed storage sites.
  3. First responders and support staff will dwindle as they know that their chance of infection is greater, some will come in for vaccine, trying to get more for family members and then depart. There are some recent studies that predict a failure of the first responder hospital staffs begged by their families not to go in. Expect to see infrastructure breakdown.
  4. Standard masks, including simple commercial N95 masks, are insufficient. Worse, most individuals are not taught to put one properly and test it for leaks. People with good masks, or with something better than those who have none, will become assault and battery targets.
  5. Most untrained individuals do not function well in the constrictive environment of a mask, e.g., if a mask is easy to breathe in, it is not adjusted correctly. It is a bit like SCUBA; you have to work to draw a breath. In full masks, vision is constrained, etc. By comparison, SARS was actually difficult to contract. A higher H5N1 contagion rate would have made a mockery of common mask strategies employed by the Chinese.
  6. As to airlift distribution from federal depositories, I suspect that infrastructure faults already alluded to will include airports, often starting with the underpaid and the unnoticed. Think hospital orderlies and janatorials for a start.
  7. People will think too late of the needed two week plus stocks of water and food, so resorting raids on supply points, groceries, et al.

Given the kinds of gaming scenarios with which I am familiar, it is not so great a leap to envision a worst case use of bioweapons to create a firebreak in an exceptional epidemic, i.e., there is no transmission if there are no vectors.

See related background items:

Intractable nature of achieving preparedness

Flu preparedness presents few solutions - where solutions are defined as combinations of money, assets, personnel and attention - to solve what is a massive infrastructure and societal issue that has been unable to breach government and public awareness for what might be a "then, maybe" event in the face of immediate and serious problems for which voters are demanding a solution now. It is a signal to me that federal authorities do not have a viable solution if they are still grappling with the concerns that opened this post.

While one might wonder why flu preparedness presents so intractable a problem after three years of thought, there is a prior example at our feet - earthquake preparedness. Flu preparedness is analogous to earthquake preparedness in that both present the possibility of enormous costs, serious disruption and commercial impact for a "maybe event, but maybe not my city or region" event. Earthquake preparedness has been in the public consciousness far longer than flu and we are not appreciably better prepared for it. Stanford University, for example, is slowly working its way to a comprehensive response posture, propelled by a series of quakes.

One of the few 'solutions' that I can see rises from studies of the emergence of Influenza A H1N1 in the 1918-1919 Influenza epidemic which showed that isolation was a significant factor in reducing infection transmissions. Given today's transportation venues, one wonders if isolation still offers a viable solution.

Much about masks

There are many kinds of masks: Non-powered Air-Purifying Respirators (filtering facepiece, half mask, full facepiece), PAPR (Powered Air-Purifying Respirators), and supplied air (Supplied-Air Respirators (SARs), (Self-Contained Breathing Apparatuses (SCBA)). OSHA's Assigned Protection Factors is the best single source that I have found for mask characteristics, applications and effectiveness.

When I see comments from the infrastructure community such as "The N-95 / N95 mask is the mask recommended by CDC and Health care experts," they neglect to say, or are unaware, that a cost benefit analysis has been done, the upshot of which is that this '95%' class of non-powered air-purifying respirator is the most that responder agencies can reasonably be expected to be purchased in volume, is one of the few classes that is even available in any volume yet still will be insufficient for all in the event of an epidemic. I sum it as, anything more and they don't buy; anything more and there aren't remotely enough.

The H5N1 investigative community properly describes N95 as the minimal protection:

Disposable particulate respirators, such a NIOSH approved N-95, are the minimum level of respiratory protection that should be worn. However, wearing respirators that offer a higher level of protection, including full-face piece, hood, helmet or loose fitting face piece respirators also will serve to protect the eyes.

One of nine NIOSH classifications (National Institute for Occupational Safety and Health) for certified particulate respirators, N95 is described as:

N95 rated filters have a filtration efficiency of at least 95% filtration against solid and liquid particles that do not contain oil. In the NIOSH classification system, particulate respirators are given an N, R, or P rating. N stands for Not Resistant to oil. R stands for Resistant to oil. P stands for oil Proof. Each particulate respirator is also given a filter efficiency rating of 95, 99, or 100 when tested against particles approximately 0.3 microns in size (mass median aerodynamic diameter) according to the criteria stated in 42 Code of Federal Regulations Part 84.

While N95 respirators have a 95% filtration efficiency, the key is the Assigned protection factor (APF):

Respirators are designed to help reduce, not eliminate, workplace exposures to airborne hazards... [The] efficiency of the filter material alone does not determine the overall reduction in airborne hazards provided by a respirator. The other determinant in reducing exposure is fit. If a respirator does not seal properly to the face, airborne hazards can penetrate or enter underneath the face piece seal and into the breathing zone. The term that incorporates the overall expected reduction in exposure is called an "assigned protection factor" (APF). NIOSH defines APF as the "minimum anticipated protection provided by a properly functioning respirator or class of respirators to a given percentage of properly fitted and trained users." The APF tells you the factor by which the respirator will reduce your exposure. The APF takes into account all expected sources of facepiece leakage, such as leakage around the edges, valve leakage, and filter penetration. The APF of a NIOSH-certified half facepiece respirator is 10. This means that a properly used NIOSH-certified half facepiece respirator (one that covers your nose and mouth only, such as an N95 particulate respirator) will reduce your exposure to airborne contaminants by a factor of 10. Note, the APF is not intended to take into account factors that may reduce respirator performance such as poor maintenance, failure to follow manufacturer's instructions, and failure to wear the respirator during the entire exposure period. It is important that the respirator is correctly worn and used as part of a comprehensive respirator program...

It gets worse:

I agree that fit-testing is important and an N-95 respirator is much better than a boulder-catching surgical mask. A full-face respirator with HEPA filters would be even better, but my bet is that hospitals are using half-faced respirators. When I did respirator fit-testing in one USEPA course, none of the three half-faced respirators that I tried worked when I talked or moved my head from side-to-side. The movement broke the seal. Needless to say, hospital staff do talk and move their heads.

When I did that respirator fit testing, only a properly fitted full-faced respirator worked, and only 2 out of 3 full-faced respirators that I tried passed the fit test. People with glasses (like me) can get eyeglass inserts. Also, a beard will prevent an adequate fit. Don't ask me how many times I've seen people with beards wearing respirators that they bought at a hardware store. Between not being properly fit-tested and the bypass created by the beard, they're worthless. Personally, I wouldn't trust a respirator that isn't fit-tested, period, with absolutely no exceptions whatsoever (am I perfectly clear?). The U.S. representative who is trying to stop fit-testing for hospital workers is totally ignoring the science, and if passed, I predict increased infections of all sorts. Also, God help us if this passes and some terrorist releases large quantities of Anthrax or the like. They'll take out the hospitals along with everything else...

And of course, wearers must clean appropriate respirators after use:

Disposable respirators should not be cleaned; dispose of the respirator immediately after use according to facility policy. In addition, the CDC and WHO suggest not touching the front of particulate respirators during removal and to follow with hand hygiene procedures. Reusable respirators may be disinfected using a mild bleach and water solution (0.1% sodium hypochlorite).

P100 HEPA as the standard

HEPA is High Efficiency Particulate Air. HEPA filtration is already in common industrial usage as well as by those afflicted by allergies. While HEPA is good for dusts and molds, it only traps particulates, allowing any contaminant in non-particulate form to pass through the filter. For my general purpose usage, I employ combination cartridges designed for pesticides as well as dusts, fumes and mists (Organic Vapor plus P100 HEPA). I have both half face and full face masks, all with Organic Vapor/P100 HEPA cartridges. Both permit use of glasses w/o breaching mask seal.

Compare P100 filtration to the lesser N95 or N99 filters:

Passes NIOSH's most rigorous testing criteria and is approved for minimum 99.97% efficient protection against oil & non-oil particulates.
Typical applications: battery plants, nuclear power facilities, asbestos abatement [and] remediation, lead, cadmium, silver, cobalt fume & dust, radionuclides and radon daughters. Also used for dusts, fumes, & mists with a PEL [Permissible Exposure Limit] less than 0.5mg per cubic meter.

Even that does not guarantee freedom from infection but it is vastly superior to N95 masks, especially the disposables which are intended to be discarded (properly) after a single use.

I find the advisory through DHS (personal email) that, "Doctors, first responders and air traffic controllers can use N 95 masks in work settings as long as they are properly fitted and some training occurs," to be disingenuous. To be frank, a key problem with these N95 "office work" masks is that masks in which you can talk, can be heard and be understood will not seal, yet those employees (physicians should know better) will still take them home with them, using them in the community, unaware of their risk.

Where is the discussion on home or office decontamination?

Seemingly absent from the discussion of mask use by the public is the issue of decontamination. Assume that you have an acceptable mask, properly fitted with active filtration cartridges, and are exposed to H5N1 flu variants. What happens when you remove the mask, possibly touching mucous membranes or mouth? Where is the guidance for disposable or non-disposable gloves, protective clothing, shoe covers or boots, and safety goggles?

How do you prevent tracking the agent into your home? Again, the procedures are simple but rarely addressed in literature for the public. An Expedient Semi-Permanent Decontamination Shower is described in this post 11 September guide to NBC warfare survival.

Conclusion

With the Katrina recovery debacle as yet unresolved, I am not sanguine with the ability of DHS and FEMA to respond to a pandemic. The valiant at CDC and WHO are not enough. See:

I consider a commercial P100 HEPA cartridge in concert with good practice as the baseline. You can get a good half face HEPA cartridge respirator that can be fit properly along with a box of six cartridges for what I consider a modest price but still a price that neither states or Congress is willing to fund. We cannot recommend what we are unwilling to fund so we all collectively blink and admire the Emperor's new clothes. In our business that is called accepting risk by default, which is not a useful survival strategy. I may still not survive infection, or I may be bludgeoned for my respirator, or I may succumb to some other systemic failure, but my odds are better.

'Supermap' Of Avian Flu Yields New Info On Source And Spread
Source: Ohio State University
Science Daily
April 30, 2007

Google Earth files for avian flu virus
By
Roderic Page at 2007-04-28 10:27
Systematic Biology
VIDEO Clip
The Google Earth file that accompanies the paper "Genomic Analysis and Geographic Visualization of the Spread of Avian Influenza (H5N1)" (Janies et al., doi:10.1080/10635150701266848, or OpenURL) is available here (aiTrees.kmz).

Respiratory Protection and Avian Influenza Viruses Frequently Asked Questions
3M Occupational Health and Environmental Safety Division
9/6/2006

Assigned Protection Factors; Final Rule - 71:50121-50192
U.S. Department of Labor
Publication Date: 08/24/2006
Publication Type: Final Rules
Fed Register #: 71:50121-50192
Standard Number: 1910; 1915; 1926
[Federal Register: August 24, 2006 (Volume 71, Number 164)]
[Rules and Regulations]
[Page 50121-50192]

Faculty Senate hears report on emergency-preparedness plan
Earthquakes, disease outbreaks, acts of terrorism weighed in plan
BY RAY DELGADO
Stanford Report, February 1, 2006

Disease Forecasting
By Jim Duffy
Johns Hopkins Public Health
Fall 2005

OSHA BEST PRACTICES for HOSPITAL-BASED FIRST RECEIVERS OF VICTIMS
from Mass Casualty Incidents Involving the Release of Hazardous Substances
OSHA
January 2005

Avian Influenza Symposium
Moderator: Nina Marano
Centers for Disease Control and Prevention Symposium on Avian Influenza
November 3, 2004

Mail: Respirators and China
Posted 11:55 PM by Jordan
Confined Space
Wednesday, September 15, 2004

The ABC's of NBC Warfare Survival: A Public Guide to Surviving Nuclear, Biological, and Chemical Terrorist Attacks
Fred H. Lane
2002

Gordon Housworth



InfoT Public  Risk Containment and Pricing Public  Strategic Risk Public  
 
In order to post a message, you must be logged in
Login
message date / author


There are no comments available.

In order to post a message, you must be logged in
Login