Validation for flu prediction

January 8, 2013 by Angela Herring
Network scientist Alessandro Vespignani’s predictions about the spread of the H1N1 in 2009 were highly accurate, according to new validation studies. Credit: Brooks Canaday

(Medical Xpress)—In 2009, the H1N1 virus slipped into the blood­streams of more than 40 mil­lion people around the world. In just four months, it killed more than 14,000 indi­vid­uals as it trav­eled from Mexico to India on its most favored vehicle: humans. As trav­elers moved about the planet via air­planes and cars, the pathogen fol­lowed, cre­ating an epi­demic the likes of which had not been seen since the 1970s.

At the time, Alessandro Vespig­nani was at the Uni­ver­sity of Indiana, where he began tracking the dis­ease with as much atten­tion as the Cen­ters for Dis­ease Con­trol. Vespignani—now the Stern­berg Family Dis­tin­guished Uni­ver­sity Pro­fessor of physics, com­puter sci­ence, and health sci­ences at North­eastern University—and his research team built a com­pu­ta­tional model called GLEAM, or Global Epi­demic and Mobility Model, which they used to pre­dict the out­breaks as they sur­faced around the globe.

In the last three years, the team has been tire­lessly working to val­i­date its pre­dic­tions. To that end, its recently pub­lished article in the journal BMC Med­i­cine offers defin­i­tive proof of a strong agree­ment between the pre­dic­tions and the real-​​life sur­veil­lance data col­lected in 2009.

"Although we knew the pre­dic­tion of the model were in pretty good agree­ment in sev­eral places of the world," said Vespig­nani, "here we pro­duce a very exten­sive val­i­da­tion on more than 45 countries."

To model dis­ease spreading, GLEAM inte­grates three data "layers." The first uses a pop­u­la­tion data­base, which was devel­oped by a team at Columbia Uni­ver­sity and pro­vides a high-​​resolution pop­u­la­tion den­sity map of the entire planet. The second uses local com­muting flows and air­line trans­porta­tion data­bases to esti­mate within and between coun­tries, respec­tively. Finally, an epi­demic layer accounts for the behavior of the dis­ease itself, including infor­ma­tion such has incu­ba­tion and trans­mis­sion times.

Oper­ating from within the prover­bial eye of the storm in 2009, the team used the model to fore­cast the week of the epidemic's peak in 48 coun­tries in the Northern Hemi­sphere. In 42 of these coun­tries, the fore­casts were directly on target; in the other five, the team's pre­dic­tions were off by only one to two weeks.

Nor­mally, flu season peaks months after H1N1 did, making even the two-​​week vari­a­tion a con­sid­er­ably good result. "This is the first large-​​scale val­i­da­tion of a com­pu­ta­tional model that pulled out pre­dic­tions in real time," said Vespig­nani. "It shows that com­pu­ta­tional models have acquired the matu­rity to pro­vide useful infor­ma­tion and at the same time points out the way on how to improve and develop better models and tools."

More information: www.biomedcentral.com/1741-7015/10/165/abstract

Related Stories

Eating your fruits and veggies

August 31, 2012

(Medical Xpress)—Teenagers in gen­eral are rel­a­tively unhealthy eaters. But minority teens in par­tic­ular have higher rates of obe­sity and eat far fewer fruits and vegetables.

3Qs: Patients' access to doctors' notes examined

November 20, 2012

In a pilot study called Open­Notes, more than 100 primary-​​care physi­cians vol­un­teered to invite more than 20,000 patients to review their doc­tors' notes fol­lowing an office visit to deter­mine the effects ...

Opioid overdose rates 'impossible' to ignore

November 21, 2012

(Medical Xpress)—Opioid over­dose now kills more people than both AIDS and homi­cides in America and has sur­passed auto­mo­bile acci­dents as the leading cause of acci­dental death in many states. According to the ...

Recommended for you

Viruses thrive in big families, in sickness and in health

August 5, 2015

The BIG LoVE (Utah Better Identification of Germs-Longitudinal Viral Epidemiology) study, led by scientists at the University of Utah School of Medicine, finds that each bundle of joy puts the entire household at increased ...

Experimental MERS vaccine shows promise in animal studies

July 28, 2015

A two-step regimen of experimental vaccines against Middle East respiratory syndrome (MERS) prompted immune responses in mice and rhesus macaques, report National Institutes of Health scientists who designed the vaccines. ...

Can social isolation fuel epidemics?

July 21, 2015

Conventional wisdom has it that the more people stay within their own social groups and avoid others, the less likely it is small disease outbreaks turn into full-blown epidemics. But the conventional wisdom is wrong, according ...

Lack of knowledge on animal disease leaves humans at risk

July 20, 2015

Researchers from the University of Sydney have painted the most detailed picture to date of major infectious diseases shared between wildlife and livestock, and found a huge gap in knowledge about diseases which could spread ...

IBD genetically similar in Europeans and non-Europeans

July 20, 2015

The first genetic study of inflammatory bowel disease (IBD) to include individuals from diverse populations has shown that the regions of the genome underlying the disease are consistent around the world. This study, conducted ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.