no current transmission between humans
avian flu is a gastrointestinal infection that spreads primarily in poultry (chicken, turkeys), waterfowl (ducks, geese, swans, gulls, terns) and shorebirds (storks, sandpipers) — waterfowl seems to be faring the worst,
npr has reported. the virus can then be transmitted to the birds of prey who eat their bodies.
the virus is also spread through contaminated bird feces — poultry farmers often unknowingly track the virus into birds’ enclosures through their boots. another risk is when wild ducks, for instance, fly inland and roost in poultry farm fields, or defecate in bodies of water.
luckily, though, “the virus that’s causing the current outbreak is not efficient at transmitting between humans. it’s poorly adapted to do that,” miller says.
this is because the avian flu virus attaches to and infects birds’ cells using a sugar on the outside of the cells called sialic acid, he explains. humans have sialic acid too, but not as much of it as birds have, and the virus isn’t as efficient at attaching to the acid in humans. “it’s what has prevented this family of [bird flu] viruses from causing global pandemics in the past,” miller says.
but if more humans end up getting infected, the virus could learn to adapt to human hosts.
“the more infections it causes in humans, the more opportunities it has to acquire that trait,” miller says. “that’s why it’s really important to be vigilant when these outbreaks occur.”
the only human known to have contracted this specific virus is an elderly person living in the u.k.,
npr reportedon april 9. this person lived in close quarters with 125 ducks, some of whom got sick and died. the owner, though, didn’t have any symptoms. some americans who were in contact with infected birds did experience flu-like symptoms, but they all tested negative for the virus.