How quickly will health authorities detect the next pandemic? How will we measure the effectiveness of preventative anti-virus medications? A new report from researchers at the University of Warwick provides the math for a statistical method to help estimate the answers to these questions.
A Math Study on How Quickly Swine Flu may Spread in Households
“Estimation of outbreak severity and transmissibility…” explains how a research team tracked the transmission of the H1N1 swine flu in Birmingham, England during the first seven weeks of the 2009 pandemic.
One key question concerned “transmissibility”: how readily did this H1N1 strain infect a healthy person who lived in the same household with someone already suffering from an active case of influenza?
After patients with symptoms were confirmed by laboratory tests as infected with the H1N1 flu, their housemates were “swabbed” for further tests. Once the pandemic was well established, however, doctors began to treat everyone as having H1N1 flu, without waiting for lab results, which limited the statistical survey period.
The survey included 424 initial cases from 424 different households, and then an additional 1612 participants from those households.
At the outset of an H1N1 epidemic, doctors generally require patients who have symptoms to undergo laboratory tests to confirm that the cause truly is swine flu, rather than seasonal influenza. Leaping to the “swine flu” conclusion without tests could lead to reporting inflated infection rates and using excessive doses of prescription medication. In Birmingham, the H1N1 influenza was mild enough that the researchers believed many cases went unreported; so an H1N1 pandemic might not be recognized in time to protect the vulnerable.