We've been told, ad naseum , that pandemics are short term events. That the 1918 pandemic lasted 18 months. And that is the model for any future `worst case' pandemic. I believe this to be a faulty assumption.
What follows is speculation on my part.
Looking at the excess mortality rates for P&I (pneumonia/influenza) during the 20th century, I believe I see evidence of continuing outbreaks of Spanish Flu well into the late 1920's. There are reports of islands in the Pacific, that escaped the pandemic of 1918, being hit very hard in the early 1920's by a killer influenza, with mortality rates comparable to 1918.
The assumption is that the H1N1 virus mutated to a less lethal strain. But (and this is speculation on my part), it appears that we just gained herd immunity. Those areas that largely escaped infection during the pandemic years of 1918-1919 simply paid the price later.
The chart below shows the excess death rate for P&I in Massachussetts, from 1987 to 1956.
http://www.history.navy.mil/pics/flu-46.jpg
The 1918-1919 pandemic is clearly off the charts. But the death rate in 1920 was every bit as high, if not as long lived. And you look to the years 1921, 1923,1926, and most significantly 1929, you you find major upswings in the mortality rate.
While no serological typing was available in the 1920's, it is assumed that these all were H1N1 (Spanish flu) outbreaks. It appears that it remained endemic, and deadly , for at least a decade.
I believe the theory that H1N1 mutated away from a virulent strain in 1919 is specious. I suggest we simply gained herd immunity, but the virus remained endemic, and resurfaced repeatedly for 10 years in unexposed, susceptible populations. If it did lose it's virulence, it did so after 1929.
What then, does this mean to us? Well, it appears you can run, but you can't hide. Short of developing, and distributing an effective vaccine, it appears that the threat of contracting and dying from a novel virus outbreak remains in play for quite some time after the `pandemic' is over.
Related Post:
Widget by [ Iptek-4u ]