Now we are
well into the flu season, things still seem quiet. The rumored bird flu
comeback doesn’t appear to have appeared. Colds, of course, abound and we are
often poor at wrapping up warm in case (like our Mom’s told us.) But then the
weather seems to be so unpredictable. One of the problems that we keep hearing
about is the Southern Oscillation in the Pacific.
These
weather fluctuations, cold for La Niña and warm for El Niño,
pop up every few years and douse our expectation. Now it seems that things
might be more worrying than we thought.
The suggestion by Shaman and Lipsitch from Columbia and Harvard U's
respectively, is that the change in weather patterns can change bird migratory
patterns (1,2). Before you say that only the birds would worry about that, the suggestion
is that the changes cause mixing of species and that in turn can be a driving
factor in nasty flu pandemics.
Shock horror and we have to ask show us the evidence. Well, the
bad flu years were 1918, 1957, 1968 and 2009 and all correspond to El Niño
years, although some strong and some weak oscillation years. The subtlety we
have to note though is not that we may have a flu epidemic, bad though that may
be, But that the bird mixing may be a vector for the viral reassortment which
gives us a variety which we have less resistance to and then a pandemic rages.
If it is a particularly virulent viral type, we could have a 1918.
None of us want that, of course. We’d better watch where those birds are
heading as the weather changes.
- http://www.bbc.co.uk/news/science-environment-16577612
- http://www.pnas.org/content/early/2012/01/11/1107485109.full.pdf+html?sid=5da526b5-5753-4b96-9ee4-16c0e43a5fce
