Wednesday, November 28, 2007

Study: NPI's Work

 

# 1297

 

 

Playing in tandem with the previous blog, we have another NPI related story making waves on the newswires. 

 

A study printed today in the BMJ (British Medical Journal) that gives support to the idea that handwashing, social distancing, and the use of barriers such as masks and gloves can be effective in reducing the transmission of respiratory infections.

 

The science behind the use of handwashing, masks, and gloves to protect against influenza has always been weak.  It has long been suspected that these measures provide some degree of protection, but few studies have actually been done. 

 

In this case, researchers have gone back through existing studies looking for data that would give some indication as to the efficacy of taking such precautions, and the authors believe they have found some.

 

In Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review  (entire article available online), the authors combed through scores of past scientific studies, including those surrounding the outbreak of SARS in 2003, and present evidence that NPI's do work to reduce the spread of infection.

 

In an excerpt from a report by the BBC, the lead researcher on this project had this to say:

 

 

Researcher Dr Tom Jefferson said: "Worried about the flu? Then we have some good news for you.

 

"Wash your hands, and if it is a really bad epidemic avoid contact with people and keep your distance. You may even consider wearing paper masks and disposable gloves. They work.

 

In the study, they give this general assessment:

 

In this systematic review we found that physical barriers such as handwashing, wearing a mask, and isolation of potentially infected patients were effective in preventing the spread of respiratory virus infections.

 

 

All of this is likely to add fuel to the debate whether to recommend the use of masks and gloves to the general public.   Up until now, their use has been either discouraged, or only weakly recommended.  

 

We've been told that masks could offer the wearer a false sense of security, that you must know how to properly fit and wear a mask for it to be effective, and that we don’t know how protective they would really be in any event.  That the value of masks in a pandemic is unproven.

 

Governments rightly understand that there won't be enough masks or disposable gloves to go around during a prolonged pandemic, and that some segments of society probably won't have access to them at all. 

 

Endorsing the use of masks, without providing them to the general public, engenders a certain amount of political risk and could open up a Pandora's box of problems.   Better, some feel, not to go there at all.

 

Exactly how protective masks, gloves, handwashing and other NPI's will be on an individual basis is impossible to quantify.  There are simply too many variables, including proper use and diligence by the user, to make any blanket assurances.  

 

On a societal level, however, implementing their use could make a big difference.

 

I've long supported the idea of using masks and gloves by the general public in a pandemic, and have suggested that it is prudent to have our own stockpile of N95 masks, latex or vinyl gloves, and surgical masks. 

 

However imperfect they might be, I believe some barrier to the virus beats no barrier at all.

 

Simplistic, perhaps. 

 

But now, backed up, at least a little bit, by this study.