Now that WHO has declared COVID-19 a pandemic, it’s time for a definition.

The word “pandemic” can describe extreme situations like that in 1918, or milder situations that we barely remember, with far fewer deaths. If you look at the definition of the word, you’ll note that it doesn’t really have much to do with number of deaths so much as geography [my emphasis]:

For the sake of clarification, WHO does not use the old system of 6 phases — that ranged from phase 1 (no reports of animal influenza causing human infections) to phase 6 (a pandemic) — that some people may be familiar with from H1N1 in 2009.

In a virtual press conference in May 2009 on the influenza pandemic, Dr Keiji Fukuda, Assistant Director-General ad interim for Health Security and Environment, WHO said “An easy way to think about pandemic … is to say: a pandemic is a global outbreak. Then you might ask yourself: ‘What is a global outbreak’? Global outbreak means that we see both spread of the agent … and then we see disease activities in addition to the spread of the virus.”

In planning for a possible influenza pandemic, the WHO published a document on pandemic preparedness guidance in 1999, revised in 2005 and in February 2009, defining phases and appropriate actions for each phase in an aide memoir titled WHO pandemic phase descriptions and main actions by phase. The 2009 revision, including definitions of a pandemic and the phases leading to its declaration, were finalized in February 2009. The pandemic H1N1 2009 virus was neither on the horizon at that time nor mentioned in the document. All versions of this document refer to influenza. The phases are defined by the spread of the disease; virulence and mortality are not mentioned in the current WHO definition, although these factors have previously been included.

Also, in a March 2 post, I recommended reading an article with a quote I called “fact-based.” It went like this [emphasis mine]:

On the basis of a case definition requiring a diagnosis of pneumonia, the currently reported case fatality rate [for COVID-19] is approximately 2%. In another article in the Journal, Guan et al.5 report mortality of 1.4% among 1099 patients with laboratory-confirmed Covid-19; these patients had a wide spectrum of disease severity. If one assumes that the number of asymptomatic or minimally symptomatic cases is several times as high as the number of reported cases, the case fatality rate may be considerably less than 1%. This suggests that the overall clinical consequences of Covid-19 may ultimately be more akin to those of a severe seasonal influenza (which has a case fatality rate of approximately 0.1%) or a pandemic influenza (similar to those in 1957 and 1968) rather than a disease similar to SARS or MERS, which have had case fatality rates of 9 to 10% and 36%, respectively.

Those pandemic influenzas of 1957 and 1968 were actually pretty bad, especially the one in 1957, which I happen to remember. But as I concluded in that same post, when I describe the 1957 pandemic:

There certainly was newspaper coverage then, and news filtered down to children – including me. But somehow the country didn’t self-destruct.