Saturday, March 24, 2007

NPI 101

 

# 585

 

 

Given the scarcity of antivirals, and the nearly non-existence of a vaccine, the primary protection most of us will have during a pandemic will be NPI's, or  Non Pharmaceutical Interventions.

 

All of us would, of course, prefer a shot that would protect us, or a pill that would cure us, but neither are going to be available in any quantity during the first 6 to 12 months of a pandemic.   Here in the United States, our National Strategic Stockpile of Tamiflu currently has enough to treat 6.6% of the population, and that assumes they will respond to the minimum dosage of 10 pills each.

 

And as far as a vaccine is concerned, we have enough poorly matched pre-pandemic vaccine to inoculate less than 2% of the country.  The prospects of having any significant quantity of vaccine during the first year of a pandemic are slim.

 

We are, however, not entirely defenseless.   There are things you can do to help protect yourself, and your family during a pandemic.

 

NPI's should provide some limited protection, and their use will hopefully slow down the progression of a pandemic.  But some of these, too, will be in short supply during a pandemic.  Basically, if you hope to utilize them, you'd better be gathering them up today.

 

The most basic NPI is called social distancing.  Staying away from others who could be infected.   Certainly avoiding crowds during a pandemic is a wise course of action, but avoiding all contact with others may be difficult or impossible.

 

I know some people who plan on locking themselves in their homes, and who plan not to emerge until the pandemic passes. Some people even have set up remote cabins where they intend to isolate themselves.  They are stockpiling a year or more worth of food, water, and medicine and intend to do all that they can to avoid any outside contact.    

 

For a select few, very hardy and lucky individuals, that strategy might work.  But for most of us, it is impractical.

 

A pandemic could last a year, or even two years.  Few of us could afford to stockpile that much food, and successfully remain isolated for that time period.  And there is always the possibility that once the pandemic had `passed', and these people emerge, that they would find the virus still circulating and they would have no immunity.

 

It's a calculated risk, they say.  One they are willing to take to avoid the virus, and the anarchy they fear will arise during a pandemic.  While I have serious reservations as to how well it will work out for them, I wish them luck.   Most of us won't, however, be following that course.

 

Depending on which authority you listen to (and there are many, with conflicting views),  you greatly reduce your odds of contracting the virus if you remain X feet away from others.   X  varies.   Some say 3 feet.  Others say 6 feet.  And still others say 10 feet. 

 

The truth is, no one really knows.  

 

Suffice to say, the closer you get to an infected person, the greater your chance of becoming infected.

 

Government officials seem to have latched onto the 3 foot perimeter idea, since that would allow people to continue to work in many venues.  Whether that is truly a safe distance is in dispute.

 

The problem is, scientists can't even agree on how influenza is transmitted.  Some believe it is primarily spread by large droplets expelled when an infected person coughs or sneezes.  Others believe it is also spread via aerosolized particles, and can remain airborne for minutes and be contagious across significant distances.

 

If the virus is spread by large droplets, then yes, maintaining a 3 foot `exclusion zone' around you might reduce the odds of infection. But even then, a 6 foot zone, or a 10 foot zone would probably further reduce the risk of infection.

 

If the virus is airborne, then 10 feet won't be enough, particularly inside a poorly ventilated room.    I fully expect, in the pandemic-after-next, we'll know more.  Until then, everything is opinion and guesswork.

 

Unless you've locked yourself in a bunker, you are likely going to be in closer contact with others than 10 feet, but all is not lost.   There are other NPI strategies that can further reduce infection.

 

These NPI's could be used if you are out in public, or working, or if you are caring for an infected family member in your home.

 

When doctors and nurses treat patients with the H5N1 virus they wear PPE's,  Personal Protective Equipment, such as gowns, gloves, masks, and goggles.  They do so because the virus is so deadly.   While most of us cannot `suit up' to the extent of medical staff, we can approximate those precautions and hopefully reduce our risks.

 

Taken individually, these precautions may not confer a great deal of protection, but when combined and used religiously, they should reduce your overall risk of contracting the virus.

 

The use of masks is controversial, but most doctors I know believe they will reduce the risk of infection.   There are basically two off-the-shelf choices.  Surgical masks and N95 masks.    Of the two, N95 masks are preferable.

 

But N95 masks are relatively expensive, costing about a dollar apiece.  They are difficult to fit properly, are hard to breathe in, and are only good for a few hours.    And once a pandemic starts, they will be nearly impossible to get.

 

As I expect to be in close contact with infected patients during a pandemic, I have stockpiled some N95 masks for my personal use. But I recognize that the 150 masks I have will be exhausted in a matter of weeks.   Not good when a pandemic could last for months, or even years.

 

Lesser protection, but still better than nothing, are surgical masks.  They are cheap and easier to breathe in.  In quantity, they can be purchased for about 6 cents apiece.    Once again, however, they are expected to be in short supply when a pandemic strikes.

 

Masks of any type also can help stop the dangerous habit of touching your mouth, nose, or eyes with infected hands, an easy route to infection.

 

The advice I would give to everyone is that masks are cheap insurance.  They may not offer complete protection, but they will certainly reduce the risk of infection.  How much?    We really don't know.  

 

In Canada, during the SARS outbreak, at least one report suggested that health care workers who wore surgical masks were 15 times less likely to contract the disease than those who wore no protection at all.

 

But if you want to have the protection masks can afford, you need to buy them now, before a pandemic erupts.

 

Frequent handwashing has been touted as essential in the prevention of the spreading of the influenza virus.   As a former medic, it's a habit I picked up years ago, and I suspect I have suffered fewer colds and flu's because of it. 

 

But most people don't wash their hands properly, nor do they do so often enough.   You touch a door knob, or a telephone receiver, or (worst of all) the handle bar to a shopping cart, and you've transferred entire colonies of pathogens to your hands.  The next time you touch your face, you run a genuine risk of infecting yourself.

 

Alcohol gels are rapidly becoming the preferred method of hand sanitizing in hospitals and clinics, and they should be part of your routine, now, and during a pandemic.  I carry a squeeze bottle of gel in the console of my car, and use it whenever I've been in public.  I also keep a larger bottle in my first aid kit, and one on my desk.   If I'm going to be in a social situation, I even carry a small squeeze bottle in my pocket to `freshen' up my hands after a lot of contact.

 

Name brand gels can be expensive, but generics, as long as they have 62% alcohol content, should be just as effective.  Buy what you need now, all alcohol based products are likely to be hard to find in a pandemic.

 

Latex or vinyl gloves are also part of my arsenal.   Once again, a disposable item that will be in short supply during a pandemic.    You don't need sterile gloves, which are expensive.  Vinyl exam gloves are cheap, at about 6 cents a pair.   Latex gloves give better tactile sense, but some people can develop an allergic reaction to the latex.

 

Masks and gloves can be purchased from drugstores, but medical supply houses will be less expensive, assuming you are buying in quantity.  1000 vinyl gloves and 300 surgical masks can be had for about $60.

 

Since I will be in closer contact with infected people than most, I've also stocked a supply of cheap disposable rain ponchos to put over my clothes.  At 50 cents apiece, I figure they are worth it.   If you are caring for an infected family member, having some of these wouldn't be a bad idea.

 

Lastly, I've bought several pair of safety goggles to wear over my glasses.  The anecdotal evidence out there suggests that the eyes can be a route of infection.   Since they can be had for a dollar or two, I consider them a wise investment.

 

Of course, coughing and sneezing etiquette will be important during a pandemic.  Coughing into your sleeve, or covering your mouth will help limit the spread of the virus (followed immediately by the alcohol gel!).  

 

The key will be having these items on hand before a pandemic starts, and then using them properly when the time comes.  Nothing can guarantee you won't become infected, but these steps will certainly help reduce your odds of contracting the virus.