And Southeast Asia bore the brunt of the pandemic.
Chinese paramilitary police receive injections of the H1N1 vaccine at a base in Taiyuan. (Stringer Shanghai/Reuters)
How many people did swine flu kill during the H1N1 pandemic a few years back? If you answered 18,500, you'd be -- excuse the pun -- dead wrong. By at least 133,000 deaths.
Researchers from the Centers for Disease Control have upped their estimate of the number of people who died of H1N1 globally between April 2009 and August 2010, according to a new report appearing this week in The Lancet. The study puts the new death toll at a range of 151,700 to 575,500. That means swine flu was somewhere between 8 and 30 times more deadly than previous estimates suggested. Going with the middle ground, the researchers' best guess is that 284,500 were killed by the disease -- with around 201,000 dying for respiratory reasons related to H1N1, and about 83,000 dying for cardiovascular reasons.
Why the discrepancy between the old and new numbers? The previous death toll only took into account laboratory-confirmed swine flu deaths. By contrast, the new study draws in country data on all flu-related deaths as well as reports of flu symptoms, and cross-references them with World Health Organization data on deaths due to respiratory infection and cardiovascular disease for the relevant time period. In all, the researchers looked at 12 different countries of varying levels of development.
Fifty-nine percent of the world's swine flu-related deaths took place in Southeast Asia, and 80 percent were in people younger than 65 -- an unusually high rate of death among young people, for the flu.
The revised report coincides with a separate study on swine flu's effect on high-income and low-income countries. In some wealthy countries, hospitalization among those infected with H1N1 was as high as 87 percent; unfortunately, the disease proved deadly no matter where patients were treated. A quarter of swine flu victims in intensive care wound up dying in the hospital. In lower- and middle-income countries, hospitalization rates reached a high of 45 percent, and about 15 percent of ICU patients ended up dying.