Shiloh
Editor, Senior Moderator
Source: http://www.ihealthbeat.org/Articles...l-Predictions-of-H1N1-Flu-Spread-Way-Off.aspx
Wednesday, June 03, 2009
Computer Model Predictions of H1N1 Flu Spread Way Off
Two rival supercomputer teams significantly underestimated the spread of H1N1 influenza when they predicted there would be only 2,000 to 2,500 cases in the United States by the end of May, the New York Times reports.
On May 15, CDC estimated that there were "upwards of 100,000" U.S. cases, although only 7,415 had been confirmed at that point. CDC has not yet updated its estimate.
Tim Germann -- a computational scientist who worked on a 2006 flu forecast model at Los Alamos National Laboratory -- said he believed there are now "a few hundred thousand" cases (McNeil, New York Times, 6/2).
Computer Model Predictions
An Indiana University team used air traffic and commuter traffic patterns for the entire U.S. to make its projections. Meanwhile, a team at Northwestern University used a Web site -- called Where's George? -- that tracks how far and how fast $1 bills travel to make its predictions (iHealthBeat, 5/4).
Dirk Brockmann, an engineering professor who led the Northwestern team, said, "The number of reported cases in Mexico that we plugged in at the beginning of our model were orders of magnitude lower."
He added the computer model still was fairly accurate in predicting the geographical spread of the H1N1 flu and identifying California, Texas, Illinois and Florida as hot spots.
Alessandro Vespignani, an informatics professor who led Indiana's team, said he was misquoted or misunderstood when he was reported as estimating that there would be about 2,500 cases by the end of May. He said that his first model predicted that there would be 9,500 cases by May 24.
Vespignani said he believed CDC's estimate of 100,000 cases or more was "a bit of an overshooting."
However, he said that his adjusted predictions on May 17 included an upper estimate of 100,000 cases by the end of May. He added that if one assumed CDC counted asymptotic cases that he did not, then the estimate could increase to 150,000.
Both Brockmann and Vespignani said they would use the H1N1 flu experience to update and refine their computer models (New York Times, 6/2).
Wednesday, June 03, 2009
Computer Model Predictions of H1N1 Flu Spread Way Off
Two rival supercomputer teams significantly underestimated the spread of H1N1 influenza when they predicted there would be only 2,000 to 2,500 cases in the United States by the end of May, the New York Times reports.
On May 15, CDC estimated that there were "upwards of 100,000" U.S. cases, although only 7,415 had been confirmed at that point. CDC has not yet updated its estimate.
Tim Germann -- a computational scientist who worked on a 2006 flu forecast model at Los Alamos National Laboratory -- said he believed there are now "a few hundred thousand" cases (McNeil, New York Times, 6/2).
Computer Model Predictions
An Indiana University team used air traffic and commuter traffic patterns for the entire U.S. to make its projections. Meanwhile, a team at Northwestern University used a Web site -- called Where's George? -- that tracks how far and how fast $1 bills travel to make its predictions (iHealthBeat, 5/4).
Dirk Brockmann, an engineering professor who led the Northwestern team, said, "The number of reported cases in Mexico that we plugged in at the beginning of our model were orders of magnitude lower."
He added the computer model still was fairly accurate in predicting the geographical spread of the H1N1 flu and identifying California, Texas, Illinois and Florida as hot spots.
Alessandro Vespignani, an informatics professor who led Indiana's team, said he was misquoted or misunderstood when he was reported as estimating that there would be about 2,500 cases by the end of May. He said that his first model predicted that there would be 9,500 cases by May 24.
Vespignani said he believed CDC's estimate of 100,000 cases or more was "a bit of an overshooting."
However, he said that his adjusted predictions on May 17 included an upper estimate of 100,000 cases by the end of May. He added that if one assumed CDC counted asymptotic cases that he did not, then the estimate could increase to 150,000.
Both Brockmann and Vespignani said they would use the H1N1 flu experience to update and refine their computer models (New York Times, 6/2).