Staying Away from the Flu This YearPosted: October 5, 2011 | |
Little kids sure can be cute, but when they’re all sneezy and drippy, who can blame us for not wanting to get too close — imagine the germs! And when flu season hits, the thought of being sidelined with a hacking cough, fever and chills is enough to make us want to step back just a bit further from those sweet little faces. Hold on though — it turns out that small children may be getting a bad rap when it comes to spreading the flu. Dena Schanzer, MSc, PStat, a senior statistical analyst with the Public Health Agency in Ontario, Canada, published research recently in the American Journal of Epidemiology that suggests that, in fact, teenagers and young adults may be the real drivers of seasonal and pandemic flu outbreaks… not young children.
Curious, I called Schanzer, who told me that she had looked at data from influenza lab tests compiled by the Canadian government between 1995 and 2006. She and her colleagues found that seasonal flu peaked in two of the groups studied, those ages 10 to 19 and those 20 to 29, one week earlier than it did in kids under 10 and older adults. During the much-buzzed-about H1N1 flu pandemic in 2009, cases involving that strain peaked in preteens and teens four days before it did in younger and older groups. And teens ages 15 to 19 were the one group most often associated with the earliest infections (including seasonal flu, swine flu and H1N1).
Schanzer and her team said they could only speculate why these groups would be the Typhoid Marys of the flu, but it’s pretty clear that the social habits of teens and young adults — who tend to frequently gather at malls, parties, concerts and other communal events — makes them particularly vulnerable to the flu virus. These age groups have mobility on their side as well, she surmised — they have fewer responsibilities to tie them down than older people and, unlike little kids, they can move around at will in cars and by public transportation — no mom or dad needed!
The results agree, she said, with a prior study of social contacts that showed that high school students and young adults are likely to be the “transmission backbone” for the next pandemic because of the nature of their social networks. So despite the “high attack rate” (susceptibility to infection) of younger school-aged children between five and nine years old, these kids aren’t in the lead group spreading the flu. There’s no question that if exposed, they have the greater potential to catch it, but they’re not the main culprits when it comes to passing it on.
Schanzer would like to see this study design repeated in other countries to see if age patterns are similar. Her instincts tell her that they will be — and that the findings of this study should be considered in the age-specific recommendations for vaccination — in other words, if we want to reduce the spread of flu throughout every age group, the most effective place to focus would be with our preteens, teens and young adults.
Source: Dena Schanzer, MSc, PStat, researcher, senior statistical analyst, Public Health Agency of Canada, Ottawa, Ontario, Canada.