Monday, August 24, 2009

HK: Smoking Cited As Swine Flu Risk Factor




# 3663



A little over a year ago I wrote a blog entitled PAMP and Circumstance which looked at a Yale study published in the Journal of Clinical Investigation, suggesting why cigarette smokers are more apt to suffer greater ill effects, or even die, from viral respiratory infections.


The study:


Cigarette smoke selectively enhances viral PAMP– and virus-induced pulmonary innate immune and remodeling responses in mice

Min-Jong Kang1, Chun Geun Lee1, Jae-Young Lee1, Charles S. Dela Cruz1, Zhijian J. Chen2, Richard Enelow1 and Jack A. Elias1,3


. . .  was conducted on mice, since it wouldn't be ethical to infect humans with potentially lethal viruses.  


The H1N1 swine flu virus operates under no such ethical limitations, and so doctors around the world are getting a first hand look at how the virus acts in various groups of people, including smokers.


First this article by Jason Gale of Bloomberg News, where doctors in Hong Kong are seeing a much higher incidence of smokers suffering severe pneumonia from the H1N1 virus, and then a little discussion.


A hat tip to GennieF on Flutrackers for this link.



Smokers Risk Swine Flu Complications Like Pneumonia, Data Show

By Jason Gale

Aug. 24 (Bloomberg) -- Smokers may be prone to developing life-threatening complications from swine flu, according to patient data from Hong Kong, where tobacco use was noted in almost half of severe cases.


Twelve of 27 swine flu patients who developed pneumonia and other serious illnesses were either current or former smokers and some had no other known risk factors, Thomas Tsang, acting controller of Hong Kong’s Centre for Health Protection, told a medical meeting in Beijing yesterday.


“The proportion of smokers among the serious cases is pretty high,” Tsang said in an interview. “So far this is just one observation that stands out and we need to investigate it.”


Tsang’s findings may shed more light on a mystery that doctors are grappling with: why the new flu remains mild for a majority of people and is severe enough to kill in others. Worldwide, about 1,800 people infected with H1N1 have died since the virus was discovered in April.


In Hong Kong, about 1 in 200 people who tested positive for swine flu developed severe disease, with some needing weeks of intensive-care treatment. About 13 percent of adults in the city smoke, Tsang said at a meeting on influenza over the weekend organized by the Lancet medical journal, China’s health ministry and the World Health Organization.

(Continue . . . )


Smoking in the United States has been on the decline for years, with now only about 20% of adults stating that they are smokers.   When I was a kid growing up, everybody smoked.


Actors smoked in the movies, talk show hosts smoked as they interviewed their guests, people smoked in movie theatres, and even some schools set aside smoking areas for students!


Smokers are now, as they say . . . a dying breed.  As an ex-smoker, I’m allowed the macabre reference.


While the percentage of adult smokers in the US has been cut in half in the past 20 years (down from about 42% to just over 20%), smoking in developing countries around the world is on the rise.



 MSN Encarta Data



It would appear - if this smoking-pneumonia connection holds true – that the countries least able to provide care to those with severe pneumonia are likely to see a higher incidence of that complication due to their high tobacco consumption.

Another factor that may cause this H1N1 pandemic to have greater impact on some societies than it does others as it wends its way around the world.


h1n1_watcher said...

Twelve of 27 swine flu patients who developed pneumonia and other serious illnesses were either current or former smokers and some had no other known risk factors,

It's always the same with those alleged "underlying health factors": Those percentages of severe caseses having factor X are absolutely meaningless unless the percentage of people with X in the general population is reported too for comparison.

Of course you would expect 20% of the fatal flu cases to be, for example "obese", if about 20% of the population are obese (the same with such common conditions like Asthma (15% prevalence in the western population etc. etc.)

Twelve of 27 swine flu patients who developed pneumonia and other serious illnesses were either current or former smokers and some

So how many out of 27 normal population are either current or former smokers ?

It is my impression that people deserately cling to these "underlying conditions" stories because the truth (i.e. that we unfortunately simply do not know what factor causes the sudden flu death in the young and healthy) is too freightening.

Over at flutrackes, the question was posed why there are not much more medical/scientific efforts underway to find out the true risk factors behind this very disturbing disease pattern.

A very good question IMO.

This is not 1918. We have all the data (thousads of patients, virus sequences ...) live and right at our hands ...

FLA_MEDIC said...

H1N1 Watcher,

According to the article `About 13 percent of adults in the city smoke'

Without that little gem of information you are right, the story wouldn't tell us much.

But if 45% of the patients in ICU were current or former smokers - 3 times higher than the % of smokers in the society - then it does seem significant.

Where we get into a `grey area' is in former smokers. What % of pts were former, not current smokers?

And How far back do you have to go, and does someone who is a former smoker have to have COPD in order to be compromised?

Hopefully we'll get better answers to these, and other questions, as we go along.

h1n1_watcher said...

According to the article `About 13 percent of adults in the city smoke'

Thanks, I must have overlooked this one.

I remember one of the CDC's PPT slides that showed hospitalized cases' underlying conditions percentages and actually listed the percentages of prevalence of the conditions among the general population in a seperate column.
(unfortunately I do not have the link anymore)