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The Lancet Infectious Diseases, Volume 13, Issue 3, Page 193, March 2013
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doi:10.1016/S1473-3099(12)70342-0Cite or Link Using DOI
The 2009 influenza pandemic
Peter Doshi aEmail Address
To count deaths is one of epidemiology's oldest pursuits. However, accurate counting of the number of deaths caused by influenza remains an elusive goal, partly because the infection is short-lived, manifests in non-specific ways that only laboratory tests can confirm, and is often treated no differently to the many other clinically indistinguishable influenza-like illnesses. The problem is compounded by the absence of surveillance systems, even in the highest-income countries, that can accurately quantify the proportion of influenza-like illness that is due to influenza viruses?an essential number to ascertain if the impact of influenza is to ever be measured accurately. These knowledge gaps are the context in which Fatimah Dawood and colleagues' estimate1 of 151 700?575 400 H1N1 deaths worldwide in 2009?10 must be understood. This numerical result was obtained after the adoption of a set of assumptions that cannot be validated, but can only be compared with other estimates in the hope that similar numbers are more reliable than dissimilar values. Perhaps such high uncertainty is tolerated because of the pervasive belief that some number is always better than no number.
What is the use of such a number? If the goal is to inform future planning, perhaps the best question to ask, if Dawood and colleagues' estimate is correct, is why public health officials' predictions were so far off the mark?or, in other words, did a pandemic really occur in 2009? The notion of pandemic influenza lacks a formal definition,2 but the massive effort known as pandemic preparedness was certainly justified by officials' assertions that the next pandemic would kill huge numbers of people. ?Even in the best case scenarios of the next pandemic, 2 to 7 million people would die?, WHO declared in 2004.3 However, Dawood and colleagues' result falls well short of these predictions, and largely overlaps with WHO's estimate of normal (seasonal) influenza. The same is true for individual countries (table). The 1957?58 and 1968?69 so-called pandemics were no different: overall mortality was similar to that in non-pandemic seasons.4 The only real anomaly is the 1918?19 influenza pandemic, which was, by all accounts, extraordinary.
<Previous Article|Next Article>
doi:10.1016/S1473-3099(12)70342-0Cite or Link Using DOI
The 2009 influenza pandemic
Peter Doshi aEmail Address
To count deaths is one of epidemiology's oldest pursuits. However, accurate counting of the number of deaths caused by influenza remains an elusive goal, partly because the infection is short-lived, manifests in non-specific ways that only laboratory tests can confirm, and is often treated no differently to the many other clinically indistinguishable influenza-like illnesses. The problem is compounded by the absence of surveillance systems, even in the highest-income countries, that can accurately quantify the proportion of influenza-like illness that is due to influenza viruses?an essential number to ascertain if the impact of influenza is to ever be measured accurately. These knowledge gaps are the context in which Fatimah Dawood and colleagues' estimate1 of 151 700?575 400 H1N1 deaths worldwide in 2009?10 must be understood. This numerical result was obtained after the adoption of a set of assumptions that cannot be validated, but can only be compared with other estimates in the hope that similar numbers are more reliable than dissimilar values. Perhaps such high uncertainty is tolerated because of the pervasive belief that some number is always better than no number.
What is the use of such a number? If the goal is to inform future planning, perhaps the best question to ask, if Dawood and colleagues' estimate is correct, is why public health officials' predictions were so far off the mark?or, in other words, did a pandemic really occur in 2009? The notion of pandemic influenza lacks a formal definition,2 but the massive effort known as pandemic preparedness was certainly justified by officials' assertions that the next pandemic would kill huge numbers of people. ?Even in the best case scenarios of the next pandemic, 2 to 7 million people would die?, WHO declared in 2004.3 However, Dawood and colleagues' result falls well short of these predictions, and largely overlaps with WHO's estimate of normal (seasonal) influenza. The same is true for individual countries (table). The 1957?58 and 1968?69 so-called pandemics were no different: overall mortality was similar to that in non-pandemic seasons.4 The only real anomaly is the 1918?19 influenza pandemic, which was, by all accounts, extraordinary.
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