An article on Yahoo regarding the most recent strain of bird flu H7N9 has raised some reasons for concerns. The newest strain first arose in China this past March, killing 37 people of the 130 infected. Scientists have declared the death rate to be about 36 percent. Although this is lower than the rate of 70 percent for the H5N1 strain, H7N9 has been shown to spread faster. Since it’s more deadly than swine flu, the cause of a global pandemic in 2009, the risk of a pandemic is very serious.
Although much of the global population focuses on the fatality rate for serious illness, the rate of infection is of paramount importance as well. Although a disease could be 100% fatal, if it doesn’t spread easily, it is more likely to be contained.
Below is a short thought-experiment demonstrating the important of infection rates.
Say that a deadly disease infected 100,000 people who all died as a result. Obviously, there is a casualty rate of 100,000 people. On the other hand, a flu strain that is 36 percent deadly and spreads to 1 million people (10 times more infectious) would leave 360,000 dead in its wake, as well as the 640,000 people requiring medical treatment. The strain that infected 10 times more people, although about 1/3 as fatal, caused massive destruction in comparison to the 100 percent fatal disease. If you total up the costs, the more highly infectious disease is also the most costly.
People should realize that infection rates and fatality rates must be considered in tandem. The risk of a global pandemic is highly dependent on both sets of data. Hopefully, the latest strain of bird flu will be contained as much as possible. However, the risk of a pandemic is always present.