STORY HIGHLIGHTS
- Social media information like tweets is being used to map the current flu outbreak
- Researchers are working on ways to better filter tweets for accurate real-time predictions
- There are apps and tools from the CDC, Google and startups dedicated to tracking the flu
A new method for filtering tweets, developed by researchers at Johns Hopkins University, could make the real-time data pouring in more accurate.
The United States is in the middle of one of its most severe flu seasons in years.
Tech companies, universities and health organizations are harnessing
the wealth of data from social networks and search engines, in addition
to the usual reports from vital statics offices, hospitals, doctors and
public health departments, to keep the public informed and better
prepare public health workers.
The Centers for Disease Control and Prevention releases a weekly influenza update
for the United States that includes stats on people with flu-like
symptoms, hospitalizations and deaths. But the detailed information is
about two weeks old by the time it comes out.
"There are a lot of gaps
in the system that Twitter can fill," said assistant research professor
Mark Dredze, who headed up the Johns Hopkins project.
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Real-time information
like tweets are becoming a popular source of public health information.
They can be used to do more than just track outbreaks. Dredze's goal is
to get ahead of the curve and actually predict where and when illnesses
will spread. This information could be invaluable for public health
departments, providing them advanced warnings and time to plan with
additional doctors, hospital beds or school closings. Thanks to GPS
information for each tweet, the location information gathered from
Twitter is more finely detailed than the CDC.
Early warnings are good
for regular people as well. They push people to get vaccinated before
they catch the flu, and individuals with health issues who might be more
vulnerable can take extra precautions.
With an average 340
million tweets a day, Twitter is a firehouse of muddled and misleading
information. Taken at face value, keywords would indicate the entire
country is suffering from an ongoing fever epidemic of the Bieber
variety. Much of the running commentary on Twitter is a reaction to news
events, so when a flu epidemic becomes a national news story, the
number of people talking about it spikes, regardless of their own health
status.
"Most people have just
focused on the presence of flu. The very simple thing is you look at
Twitter and look at the number of people using the world flu or sick
everyday," said Dredze. "The problem with that is if you look a little
more closely it doesn't really work."
Dredze's team is using
algorithms to correct for these issues, filtering out the noise to
isolate the useful information. They were already researching using
Twitter to track health issues before this winter's recent outbreak but
quickly changed tracks to focus on the flu. The group plans to share the
information it gathers with public health officials.
Tracking influenza and other illnesses based on social media isn't new. In a 2011 paper, researchers reported being able to accurately track disease
levels for the swine flu outbreak two years earlier by searching for
keywords such as flu, vaccine, illness, Tamiflu and pneumonia.
The University of
Rochester has turned research about predicting the spread of diseases
with social media into a web application called Germ Tracker.
The colorful interactive map pulls up geo-tagged Tweets that contain
keywords related to illness. If you find a tweet that's clearly
mislabeled (like someone bragging that their new car is "sick"), click a
button to let the app know they're not actually sick. It also allows
self reporting with a slider you can set to Awful, Sick, Yuck, Meh or
Good and options to share specific symptoms.
Sick Weather
is a similar project that can pull from Facebook and Twitter to map and
show animations of contagious illnesses such as chicken pox, colds and
whooping cough, as well as other issues like allergies, stress and
depression.
Even as researchers get
better at filtering tweets, the social network presents limitations. It
isn't an accurate representation of the entire population in terms of
age or location. Two of the groups hardest hit by influenza outbreaks,
the elderly and children, are the least likely to be live blogging their
symptoms.
Google's Flu Trends
looks at search terms to create real-time estimates of where the flu is
flaring up. Developed in 2009 in collaboration with the Centers for
Disease Control, the tool digs through massive amounts of search data
(all anonymous) looking for flu-releated searches around the world and
maps out the intensity of outbreaks.
"The advantage of using
these social media tools and Google is they're much faster than the
CDC," said Michael Paul, a doctoral student working on the Johns Hopkins
Twitter research. "As an early warning, they're useful to the
government when it needs to plan."
Armchair influenza
trackers will still get the most detailed information from weekly
reports released by the Centers for Disease Control. The reports dig
deep into the data gathered from doctors, hospitals and other health
officials to outline things like number of deaths, flu-related
hospitalizations and a breakdown of strains. The CDC also has its own simple app called FluView that plots the volume of influenza-like illnesses by state.
"Our job is really to
figure out what viruses are going around and what effect they're
having," said Lynnette Brammer, an influenza epidemiologist at the CDC.
"It's more laboratory based; we try to get as close as we can to the
viruses."
The CDC teams do check
tools like the Google Flu Tracker, and Brammer says that while the
results don't always match up, Google is close to the CDC's own findings
most of the time. The CDC has slightly different goals than tech tools
that track symptoms in real-time. It's drilling down to find out what
strains are being reported, see if they are close to the current vaccine
and if not, determine if the vaccine needs to be changed to include new
virus candidates.
http://www.cnn.com/2013/01/30/tech/social-media/flu-tracking-twitter/index.html