28 September 2016
Right now it’s flu shot season, soon to be followed by flu season itself from December to March.
Wild birds have been blamed as a source of influenza but new evidence indicates they’re not the cause of bad flu. To understand why here’s a primer on where flu comes from, how it spreads, and why flu season is in the winter.
Where does flu come from?
Other people! It spreads best — and quickly creates new strains — where people are densely crowded. Amazingly, the Spanish Flu Epidemic of 1918 spread quickly because of crowded camps and trenches in World War I. A new study this month from the University of Chicago finds that “surveillance for developing new, seasonal vaccines should be focused on areas of east, south and southeast Asia where population size and community dynamics can increase transmission of endemic strains of the flu.” Click here to read why flu does so well in that part of the world.
How does flu spread? In the air. We breathe it in. Airborne transmission actually explains …
Why is flu season in the winter?
Not too long ago we were told that it’s in the winter because migratory waterfowl pass avian flu to domestic birds during fall migration. Wrong!!
Recent studies of avian flu transmission show that it spreads in poultry factory farms (crowded conditions!) and along our poultry trade routes. It follows our poultry, not wild birds’ migratory paths.
And the timing has nothing to do with migration. Flu season is in the winter because the pathogen stays airborne longer in dry winter air. It falls to the ground in summer humidity.
So why are waterfowl off the hook?
Wild birds aren’t spreading the worst strains of avian flu because they don’t have it.
After the H5 avian influenza A virus hit U.S. poultry farms in 2014-15, officials worried that avian flu would return when waterfowl migrated south again … but it didn’t. The reason was found by researchers from St.Jude Children’s Research Hospital who “analyzed throat swabs and biological samples taken from 22,892 wild ducks and other aquatic birds collected before, during and after a 2014-15 H5 flu outbreak in poultry.”(*) None of the birds had the highly pathogenic influenza A virus.
“Bad flu is not our fault,” say the ducks.
Read more here at: Evidence suggests migratory birds are not a reservoir for highly pathogenic flu viruses.
p.s. Remember to get a flu shot! However, if you’re over 65 immunologist Laura Haynes says you should get it after Halloween if you can. Click here to read her advice on NPR.
(photo by Brian Herman)
Did we make the the wild ducks pay for their check-ups on the spot or did the charges just go on their bill? ?
It was a preventative exam so it was paid by their universal health care 😉
hilarious!
But what did the jays and crows die of in such great numbers a few years ago? Was it a bird flu specific to those species?
On another note, I cannot seem to get an answer to this question, can you ask Laura Haynes if an individual over 65 got the high dose flu shot two weeks ago, should that individual get a booster in January? (sorry to turn this column into an “ask abbey,” but no one else seems able to answer the question). Thanks for your help.
anne, the crows and jays died of West Nile Virus, a virus that harms them more than us humans and more than other birds. Regarding the high dose flu shot, I don’t know. Please check with your doctor.
Only as they fly across those states that have universal care! Those of you lucky enough to live in the states that do have health coverage seem to forget that there are still 19 states out there that did not accept the health insurance expansion, leaving many of us with no insurance still! Maybe I need to find a flock of migrating birds to hang out with, maybe the ‘flock’ immunity will keep me safe too?
Sue, I feel for you. My husband and I are on Obamacare and it’s great! I shudder to think what would happen if we lost it.
Living in the Pacific flyway and a major tourist destination, we here in Southern California can tell you when the flu cases skyrocket. When all those *people* come out for Winter holidays, Rose parade, Rose Bowl, etc. I bet it’s the same in Florida. Got my shot yesterday.