Wednesday, March 23, 2011

You too can catch Panedemic Flu

The New York Times is putting limits on how many times you can connect to them in one month.  I believe the current one month charge is $15 dollars:  a lot for a non-print subscription to my mind.   So I will be limiting my trips there.  But I picked up this one a while ago, so I thought I would make use of it.  I will have some flu related posts coming up and it is relevant.

Close Look at a Flu Outbreak Upends Some Common Wisdom, by Nicholas Bakalar, link at New York Times, February 8, 2011.

 A new study of a 2009 epidemic at a school in Pennsylvania has found that children most likely did not catch it by sitting near an infected classmate, and that adults who got sick were probably not infected by their own children…
   
Transmission was 25 times as intensive among classmates as between children in different grades. And yet sitting next to a student who was infected did not increase the chances of catching flu…

Social networks were apparently a more significant means of transmission than seating arrangements. Students were four times as likely to play with children of the same sex as with those of the opposite sex, and following this pattern, boys were more likely to catch the flu from other boys, and girls from other girls…
  
Only 1 in 5 adults caught the illness from their own children….

“Here we find that most of the infected adults were not infected by one of the children in their household,” said Dr. Cauchemez, a research fellow at Imperial College London….

The study, Role of Social Networks in Shaping Disease Transmission During a Community Outbreak of 2009 H1N1 Pandemic Flu by Cauchemez, et al, notes that adults are only half as likely to catch this particular variety of flue as children.  But when they did, they were just as infectious as children.  The generation time for the illness at home was 2.3 days, but 1.1 for schools.  Likely the lower times in schools is because the kid stays home when sick.  In any case a generation time of only 1.1 days shows that it can spread pretty quickly.

In the case of this study, the school they were at was eventually closed for a time period.  But by then it was likely too late as there was no reduction in transmission rates.

One side note, the flu shot they give you is helpful in stopping all sorts of known flu viruses.  However, it is not usually going to be helpful against the unique types that no one has resistance to.  They are unique after all.  For myself, I did get the H1N1 so if it was like the bird flu (H1N5 I think) I would have had a 50/50 chance of surviving.

Lessons:

I can think of only two:

1.      The flu spreads so quickly, that if you ponder isolating yourself from others when you first hear of a deadly pandemic, you will likely wait too long to act.  The authorities are likely to be to slow in shutting down schools.

2.      On the plus side, casual contact is not as important as involved contact (your peer group) in transmitting the disease.  Elementary precautions against exposure to strangers/casual acquaintances may be helpful.

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