PNAS. Flu in kids typically spreads boy to boy and girl to girl

[tetano]

Flu spreads faster in schools than rumors about a pop quiz. But science is revealing more about how germs jump from child to child and strategies that might prevent larger flu outbreaks.

The latest science shows that flu predominantly spreads from boys to other boys and from girls to other girls. The study, conducted by a consortium of researchers that included experts from the U.S. Centers for Disease Control and Prevention, also found that flu transmission is more intensive within students sitting in the same class. But sitting next to someone with the flu doesn't, in itself, increase one's risk.

The scientists examined flu spread among 370 children, ages 6 to 18, during a major H1N1 flu outbreak in a rural Pennsylvania community. The goal was to look at how social networks control flu spread.

Children are about three times more likely to pass the flu to children of the same gender, the researchers found. That's probably because boys tend to mix with boys and girls with girls. Transmission rates were five times higher between classmates compared with children in a different class but in the same grade. Children ages 6 to 10 had the highest infection rate, followed by children age 5 and younger.

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http://www.latimes.com/health/boostershots/la-heb-flu-20110131,0,7561958.story

 

[Laidback Al]

Re: Flu in kids typically spreads boy to boy and girl to girl

Re: Flu in kids typically spreads boy to boy and girl to girl

Published online before print January 31, 2011, doi: 10.1073/pnas.1008895108 <cite> <abbr title="Proceedings of the National Academy of Sciences" class="slug-jnl-abbrev"> PNAS</abbr> January 31, 2011 </cite>

Role of social networks in shaping disease transmission during a community outbreak of 2009 H1N1 pandemic influenza

Simon Cauchemez^a,¹,
Achuyt Bhattarai^b,
Tiffany L. Marchbanks^c,
Ryan P. Fagan^b,
Stephen Ostroff^c,
Neil M. Ferguson^a,
David Swerdlow^b, and
the Pennsylvania H1N1 working group^b,^c,²

Abstract

Evaluating the impact of different social networks on the spread of respiratory diseases has been limited by a lack of detailed data on transmission outside the household setting as well as appropriate statistical methods. Here, from data collected during a H1N1 pandemic (pdm) influenza outbreak that started in an elementary school and spread in a semirural community in Pennsylvania, we quantify how transmission of influenza is affected by social networks. We set up a transmission model for which parameters are estimated from the data via Markov chain Monte Carlo sampling. Sitting next to a case or being the playmate of a case did not significantly increase the risk of infection; but the structuring of the school into classes and grades strongly affected spread. There was evidence that boys were more likely to transmit influenza to other boys than to girls (and vice versa), which mimicked the observed assortative mixing among playmates. We also investigated the presence of abnormally high transmission occurring on specific days of the outbreak. Late closure of the school (i.e., when 27% of students already had symptoms) had no significant impact on spread. School-aged individuals (6?18 y) facilitated the introduction and spread of influenza in households, but only about one in five cases aged >18 y was infected by a school-aged household member. This analysis shows the extent to which clearly defined social networks affect influenza transmission, revealing strong between-place interactions with back-and-forth waves of transmission between the school, the community, and the household.

http://www.pnas.org/content/early/2011/01/28/1008895108.abstract

full article at: http://www.pnas.org/content/early/2011/01/28/1008895108.full.pdf+html