Initially printed April 2022. Up to date April 2024 to replicate additional developments within the outbreak.
Many individuals are involved concerning the outbreak of avian influenza, or hen flu, that started in 2022 and has affected home poultry, waterfowl, raptors, shorebirds, different species of birds, and a few mammals in lots of elements of the world. As a result of the present pressure (H5N1) causes heavy losses to poultry, it’s known as extremely pathogenic avian influenza, or HPAI. Be aware that the Facilities for Illness Management considers transmission of avian influenza from birds to people to be very uncommon. Thus far, two folks within the U.S. have examined constructive for avian influenza: a poultry employee in Colorado in April 2022 and a employee at a dairy farm in March 2024; each confirmed delicate signs and recovered.
Stories of Avian Flu in Birds
This specific pressure of avian influenza virus impacts all kinds of untamed birds, together with hawks, eagles, falcons, owls, crows, vultures, shorebirds, sport birds, seabirds, and particularly waterfowl akin to Canada Geese and Mallards (see checklist of species with HPAI detections, beneath). The virus is shed within the saliva, mucus, and feces of contaminated birds and is transmitted to different birds through ingestion or inhalation.
Due to the period of this outbreak, its current unfold to mammal species, and widespread mortalities in some varieties of wild birds, there was concern about whether or not it’s secure for folks to feed wild birds. In April 2022 and March 2023, we checked in with Dr. Julianna Lenoch, who directs the USDA APHIS Nationwide Wildlife Illness Program, and we’ve compiled the next summaries of key factors concerning HPAI, particularly amongst songbirds and different feeder guests. As of April 2024, there isn’t any official advice for folks to take down hen feeders due to the chance of avian influenza (see subsequent part).
Low Danger of Avian Flu to Songbirds
There was widespread transmission of avian flu to wild hen species together with waterfowl and raptors. The virus has additionally been present in mammals that prey on useless birds. Nevertheless, transmission to songbirds and different typical feeder guests has been low (lower than 2% of all instances reported in wild birds), though this will change with elevated testing or modifications to the virus. Which means there may be at the moment low danger of an outbreak amongst wild songbirds, and no official advice to take down feeders except you additionally hold home poultry, in response to the Nationwide Wildlife Illness Program. We do at all times advocate that you just clear hen feeders and birdbaths commonly as a option to hold many sorts of illnesses at bay.
We additionally at all times advocate that you just observe any suggestions put out by your state authorities, even in instances the place that recommendation conflicts with ours. The CDC’s web page on avian influenza in birds compiles further useful data and assets.
How do we all know songbirds are at low danger?
- USDA APHIS has a powerful, multiyear surveillance program that routinely samples wild birds, together with flocks of songbirds (and different species akin to Rock Pigeons and Mourning Doves which can be usually round people), for the presence of avian influenza. Since January 2022 they’ve detected the HPAI pressure in 8,447 wild birds (plus 849 captive birds), with 153 detections in wild songbirds (see beneath for an inventory of species). Newest information concerning the outbreak.
- Avian influenza doesn’t have an effect on all varieties of birds equally. The “extremely pathogenic” a part of the time period HPAI refers particularly to the severity of the illness in poultry, not essentially in different hen species. For instance, waterfowl usually carry and transmit hen flu, and with the present pressure they generally get sick or die. Raptors are far more delicate to the illness. Home poultry are extraordinarily inclined to HPAI and unfold the illness simply, resulting in as much as 100% mortality of affected flocks.
- Songbirds are a lot much less seemingly than waterfowl to contract avian influenza and fewer prone to shed massive quantities of virus, which means they don’t transmit the illness simply. (See Shriner and Root 2020 for an in depth evaluate within the journal Viruses.)
- Based on a separate research within the Journal of Wildlife Ailments, “…though passerines and terrestrial wild birds could have a restricted function within the epidemiology of IAV [avian influenza A viruses] when related to contaminated home poultry or different aberrant hosts, there isn’t any proof supporting their involvement as pure reservoirs for IAV.” (Slusher et al. 2014)
- For these causes, it’s unlikely that hen feeders will contribute to an outbreak amongst songbirds.
If songbirds are at low danger, why are individuals who hold poultry suggested to take down their hen feeders?
- The primary concern with songbirds is the prospect {that a} uncommon particular person would possibly transmit an an infection to poultry. This can be a concern as a result of poultry are a lot extra susceptible than songbirds to HPAI.
- The important thing intervention is to maintain songbirds away from poultry; it’s much less vital to maintain songbirds away from one another.
- When you have a yard poultry flock, these are a very powerful steps to take:
(click on for full information on these biosecurity measures from USDA APHIS) - As a secondary measure, USDA APHIS recommends for poultry homeowners to take down wild hen feeders or hold them properly away from their captive flock
- In the event you hold chickens or geese, please see additionally newest data from the USDA Animal Plant and Well being Inspection Service.
In the event you hold nest packing containers:
Avian influenza is barely not often transmitted to people, in response to the USDA. The Facilities for Illness Management and Prevention considers most of the people well being danger from avian flu to be low. Nonetheless, our NestWatch challenge at all times advises good hygiene and extremely recommends that individuals put on disposable gloves and/or wash their palms completely after checking nest packing containers. Most birds that use nest packing containers are songbirds, that are at low danger for contracting or transmitting avian influenza. In the event you monitor waterfowl or raptor nests (e.g., Wooden Duck, Frequent Merganser, Canada Goose, American Kestrel, Barred Owl), we recommend you put on gloves, change or wash gloves and disinfect gear between nest packing containers, put on a masks when cleansing out nest packing containers, and alter garments and footwear earlier than visiting any home poultry.
In case you are a wildlife rehabilitator:
Wildlife rehabilitators ought to take precautions when accepting sick birds in order that they don’t inadvertently introduce HPAI to the remainder of their sufferers. Right here’s additional steerage for rehabbers, from USDA APHIS. Rehabbers in New York State are additionally inspired to contact the Cornell Wildlife Well being Lab for extra data.
What to do when you discover a sick or useless hen:
Keep away from dealing with sick or useless birds. As an alternative, name your state wildlife well being company; they will decide reason for loss of life and ship the hen to the suitable lab for testing. Moreover, hold pets (together with pet birds) away from sick or useless wild birds.
- Keep away from contact with birds that seem sick or have died.
- Keep away from contact with surfaces which have hen feces.
- In the event you should contact sick or useless birds:
- Put on gloves and a face masks.
- Place useless birds in a double-bagged rubbish bag.
- Throw away your gloves and facemask after use.
- Wash your palms properly with cleaning soap and heat water.
Hen flu just isn’t a danger to meals security. Poultry and eggs which can be safely dealt with and cooked to an inner temperature of 165°F are suitable for eating.
In the event you really feel sick after having contact with sick or useless birds, contact your well being care supplier.
Has Avian Flu Been Reported in Mammals?
There have additionally been stories of mammals akin to pink foxes, skunks, bobcats, fishers, and bears contaminated with avian influenza, seemingly from consuming contaminated birds. Exterior the U.S. avian flu has contaminated farmed mink and has precipitated losses at marine mammal colonies in South America. In March 2024 the USDA reported that avian flu has been present in cattle in a number of U.S. states. The CDC has further data on avian flu in cattle and related dangers to people.
Further Sources:
Wild hen species with HPAI detections in 2022–2024
Up to date April 26, 2024. Complete variety of detections in wild birds: 8,447 (plus 849 captive birds). Detections in songbirds: 153. See Detections of Extremely Pathogenic Avian Influenza in Wild Birds for up to date detections.
Songbirds (13 species)
American Crow (78 people, plus 9 unidentified crow spp.)
American Robin (1)
Black-billed Magpie (3, plus 4 unidentified magpie spp.)
Boat-tailed Grackle (1)
Frequent Grackle (3)
Frequent Raven (42)
Darkish-eyed Junco (1)
Fish Crow (5)
Grackle spp. (unidentified; 2)
Nice-tailed Grackle (3)
Home Sparrow (2)
Crimson-winged Blackbird (1, plus 1 unidentified blackbird spp.)
Sparrow spp. (unidentified; 1)
Tree Swallow (1)
Non-Songbirds (138 species)
American Black Duck
American Coot
American Kestrel
American White Pelican
American Wigeon
Arctic Tern
Bald Eagle
Barn Owl
Barred Owl
Black Skimmer
Black Turnstone
Black Vulture
Black-bellied Plover
Black-crowned Night time-Heron
Black-legged Kittiwake
Blue-winged Teal
Bonaparte’s Gull
Brandt’s Cormorant
Brant
Broad-winged Hawk
Brown Pelican
Bufflehead
Cackling Goose
California Condor
California Gull
California Quail
Canada Goose
Canvasback
Caspian Tern
Cattle Egret
Cinnamon Teal
Frequent Eider
Frequent Goldeneye
Frequent Loon
Frequent Merganser
Frequent Murre
Frequent Tern
Cooper’s Hawk
Crested Caracara
Double-crested Cormorant
Dunlin
Eared Grebe
Jap Screech-Owl
Forster’s Tern
Fulvous Whistling-Duck
Gadwall
Glaucous Gull
Glaucous-winged Gull
Shiny Ibis
Golden Eagle
Nice Black-backed Gull
Nice Blue Heron
Nice Egret
Nice Horned Owl
Better Sage-Grouse
Better Scaup
Better White-fronted Goose
Inexperienced Heron
Inexperienced-winged Teal
Harris’s Hawk
Herring Gull
Hooded Merganser
Horned Grebe
Iceland Gull (Thayer’s)
Laughing Gull
Lesser Scaup
Lengthy-eared Owl
Mallard
Merlin
Mottled Duck
Muscovy Duck
Mute Swan
Neotropic Cormorant
Northern Fulmar
Northern Gannet
Northern Harrier
Northern Pintail
Northern Shoveler
Osprey
Pacific Loon
Parasitic Jaeger
Peregrine Falcon
Pied-billed Grebe
Prairie Falcon
Crimson-necked Grebe
Crimson-necked Phalarope
Crimson-shouldered Hawk
Crimson-tailed Hawk
Redhead
Ring-billed Gull
Ring-necked Duck
Ring-necked Pheasant
Roseate Spoonbill
Ross’s Goose
Tough-legged Hawk
Royal Tern
Ruddy Duck
Ruddy Turnstone
Ruffed Grouse
Sabine’s Gull
Sanderling
Sandhill Crane
Sandwich Tern
Sharp-shinned Hawk
Quick-billed Gull
Quick-eared Owl
Quick-tailed Shearwater
Snow Goose
Snowy Egret
Snowy Owl
Snowy Plover
Swainson’s Hawk
Trumpeter Swan
Tundra Swan
Turkey Vulture
Western Grebe
Western Gull
Western Sandpiper
Western Screech-Owl
White Ibis
White-winged Scoter
Wild Turkey
Willet
Wooden Duck
Wooden Stork
Avian flu has been detected in an extra 31 species of captive wild birds
