CDFW News

Avian Influenza Returns this Fall with Migratory Birds

Thu, 14 Dec 2023 09:11:24 GMT

Wildlife disease specialists have confirmed the re-occurrence of the Eurasian strain of Highly Pathogenic Avian Influenza (HPAI) H5N1 in California wild birds.

In late October, Canada geese were found dead in Sacramento County and submitted to the California Department of Fish and Wildlife’s (CDFW) Wildlife Health Laboratory for testing. Preliminary testing was performed at the California Animal Health and Food Safety Laboratory in Davis.

The U.S. Department of Agriculture’s (USDA) National Veterinary Services Laboratories confirmed the detection of HPAI H5N1 in two Canada geese in early November. Subsequent detections have been made in wild birds in several additional counties during mortality surveillance including from Contra Costa, San Diego, Santa Clara, Solano and Yolo. Detections in waterfowl during hunter-harvest surveillance have been reported from Fresno, Glenn, Kern and Yolo counties. Prior to these detections, the last confirmed detection in wild birds occurred in June 2023.

This strain of Eurasian HPAI H5N1 has been circulating in the United States and Canada since the winter of 2021-22, arriving in California in mid-July 2022. In total, 354 confirmed detections of the virus were made in wild birds collected from 44 California counties during mortality surveillance conducted between July 2022 and June 2023. Detections of the virus appeared to subside during spring and summer in California, as well as more broadly in the United States. Now, as waterfowl and other waterbirds are undertaking fall migration, cases again are on the rise.

Avian influenza spreads through direct bird-to-bird contact and may also spread to birds through contaminated surfaces including hands, shoes, clothing and hunting gear. While the Centers for Disease Control considers the transmission risk of avian influenza to people to be low, residents and waterfowl hunters are advised to take precautions to protect themselves, hunting dogs, falconry birds, poultry and pet birds.

Steps that may help reduce the spread of HPAI:

Report dead wild birds, and other wildlife, to CDFW using the mortality reporting form. While it is not possible to test every wild bird for HPAI, all mortality reports are important and help disease specialists monitor the outbreak.
Report sick and dead poultry to the California Department of Food and Agriculture (CDFA) hotline at 1 (866) 922-2473.
Prevent contact between domestic birds and wild birds, especially waterfowl. Exclude wild birds from accessing chicken or other domestic bird feed and water.
Do not feed waterfowl or other waterbirds at park ponds as it may increase the congregation of birds and contribute to disease spread.
Do not bring potentially sick wild birds home or move sick birds to another location.
Before transporting potentially sick wild birds to wildlife rehabilitation centers, veterinary clinics, or other animal facilities, contact the facility for guidance and to determine if the bird should be collected.
If recreating outdoors in areas with large concentrations of waterfowl and other waterbirds, wash clothing and disinfect footwear and equipment before traveling to other areas or interacting with domestic birds.
Where it can be done so safely, consider disposing of dead birds to help reduce exposure to new birds and minimize scavenging by birds and mammals that also may be susceptible to infection. Dead birds may be collected into a plastic bag and placed in the regular trash collection.

Additional safety recommendations for waterfowl hunters:

Harvest only waterfowl that look and behave healthy. Do not handle or eat sick game. Do not handle wild birds that are obviously sick or found dead.
Field dress and prepare game outdoors or in a well-ventilated area. Do not dress wild game in the vicinity of poultry or pet birds.
Wear rubber gloves or other impermeable disposable gloves while handling and cleaning game.
Remove and discard intestines soon after harvesting and avoid direct contact with intestinal contents. Place waste in a plastic bag and dispose in a garbage container that is protected from scavengers.
Do not eat, drink, smoke or vape while handling dead game.
When done handling game, wash hands thoroughly with soap and water (or alcohol-based hand sanitizer if soap and water are unavailable), and clean knives, equipment and surfaces that came in contact with game. Wash hands before and after handling any meat.
Keep harvested waterfowl cool (either with ice or refrigeration), below 45 degrees Fahrenheit, until processed, and then refrigerate or freeze.
Thoroughly cook all game to an internal temperature of 165 degrees Fahrenheit before consuming.
Clean and disinfect clothing, footwear and hunting gear before traveling to other areas. As appropriate, footwear and gear may be washed with soap and water, then disinfected in household bleach diluted 1:10 with water for at least 10 minutes.
Bathe hunting dogs with pet shampoo after hunting, and do not feed dogs raw meat, organs or other tissues from harvested waterfowl.
Falconers should avoid hunting waterfowl, and other waterbirds, during the HPAI outbreak.

For more information on HPAI H5N1, check out CDFW’s informational flyer addressing frequently asked questions and links to additional resources. The USDA maintains the official list of HPAI H5N1 detections on its website. For guidance on keeping domestic birds healthy, please visit the CDFA and USDA websites.

For guidance on orphaned or injured live wild birds, please contact your nearest wildlife rehabilitation center prior to collecting the animal. Be advised that some wildlife rehabilitation centers may have restrictions on the wildlife species they will admit.

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Media Contacts:
Peter Tira, CDFW Communications, (916) 215-3858
Krysta Rogers, CDFW Wildlife Health Lab, (916) 531-7647

Avian Influenza Detected In Deceased Mountain Lions

Tue, 28 Mar 2023 12:31:06 GMT

The Eurasian strain of highly pathogenic avian influenza (HPAI H5N1) was detected in two mountain lions in Mono County in December 2022 and January 2023, according to wildlife health experts with the California Department of Fish and Wildlife (CDFW). While additional disease testing is being conducted to rule out the possibility of co-infections, HPAI H5N1 is suspected to be the cause of the death for both mountain lions.

This is the second species of wild mammal known to have contracted HPAI H5N1 in California since the virus was reported in wild birds in July 2022. In January, the virus was detected in a bobcat found in Butte County.

The new findings also mark the first detection of HPAI H5N1 in Mono County. To date, the virus has been found in 45 counties statewide.

“The Eurasian lineage of avian influenza is primarily a disease impacting birds but is occasionally being detected in wild mammals. We don’t expect this to have a population-level impact for California’s mountain lions or other mammalian carnivores, but it is a disease we will continue to monitor,” said Dr. Jaime Rudd, a pesticide and disease investigations specialist in CDFW’s Wildlife Health Lab.

“The main route of disease transmission for carnivores seems to be through ingestion of infected birds – typically waterfowl such as geese. Biologists following the movements of these mountain lions noted that they had preyed upon wild Canada geese in the past,” Rudd said.

Remains of the two mountain lions, who were related (mother and daughter), were collected from Mono Lake in Mono County on December 23 and January 14. Samples were submitted to the California Animal Health and Food Safety Laboratory in Davis for preliminary testing. Last week, the U.S. Department of Agriculture’s National Veterinary Services Laboratories confirmed the detection of HPAI H5N1.

“The main pathological finding for these two mountain lions was encephalitis, which is inflammation of the brain. Additionally, there were lesions in the lungs causing pulmonary edema. Much of the lesions in the brain and lungs were associated with the virus, but additional disease testing is being performed to rule out the possibility of co-infection,” said Rudd.

Of note is that both mountain lions were wearing GPS collars as part of a CDFW population study. The mortality notification sent from the collar helped biologists track the deceased animals and allowed for their remains to be collected in a timely manner to perform necropsies and determine cause of death.

“HPAI H5N1 is still considered a low-risk zoonotic pathogen,” said CDFW Senior Wildlife Veterinarian Dr. Deana Clifford. “It’s significant that the detections occurred far from the bobcat detection, and in an area where the disease had not yet been detected in wild birds. This means it’s possible that the mountain lions may represent detections of a new foci of infections for wild birds.”

Notwithstanding the mountain lion and bobcat detections, infection of wild mammals with avian influenza viruses appears to be relatively rare. Elsewhere in the U.S. and Canada, periodic detections of HPAI H5N1 have been made in mammalian carnivores including foxes, bobcats, raccoons, skunks and bears. Detections in mountain lions have occurred in five other states. The virus has also been detected in a small number of marine mammals.

The strain of HPAI H5N1 currently circulating in the U.S. and Canada has caused illness and death in a higher diversity of wild bird species than during previous avian influenza outbreaks, affecting raptors and avian scavengers such as turkey vultures and ravens. Mammalian and avian predators and scavengers may be exposed to avian influenza viruses when feeding on infected birds.

An informational flyer addressing frequently asked questions about avian influenza is available on CDFW’s website. Currently, the Centers for Disease Control considers the transmission risk of avian influenza to people to be low, but recommends taking basic protective measures (i.e., wearing gloves and face masks and handwashing) if contact with wildlife cannot be avoided. CDFW does not recommend people handle or house sick wildlife.

Practicing biosecurity is the most effective way to keep people, domestic poultry and pets healthy. Please visit the CDFA and USDA websites for biosecurity information. Please report sick or dead poultry and pet birds to the CDFA hotline at (866) 922-2473.

CDFW’s Wildlife Health Laboratory, in coordination with partners, continues to monitor wildlife for signs of illness and investigate mortality events. The public is encouraged to report dead wildlife using CDFW’s mortality reporting form. For non-urgent questions concerning wildlife, please contact your local CDFW Regional Office or your local animal control service.

Media contact:
Ken Paglia, CDFW Communications, (916) 825-7120

Avian Influenza Detected in Deceased Bobcat

Wed, 15 Feb 2023 12:22:15 GMT

Wildlife disease specialists with the California Department of Fish and Wildlife (CDFW) recently received confirmation that an adult bobcat died from the Eurasian strain of highly pathogenic avian influenza (HPAI) H5N1. This is the first detection of the virus in a wild mammal in the state.

The bobcat’s remains were collected in Butte County by CDFW on December 23, 2022. Samples were submitted to the California Animal Health and Food Safety Laboratory System for preliminary testing. On January 24, the U.S. Department of Agriculture’s (USDA) National Veterinary Services Laboratories confirmed the detection of avian influenza H5N1 in the bobcat. Elsewhere in the U.S. and Canada, periodic detections of Eurasian HPAI H5N1 have been made in mammalian carnivores including foxes, bobcats, raccoons and skunks.

The bobcat was wearing a GPS collar as part of a CDFW population study. The collar was equipped with a sensor that alerted biologists when the animal stopped moving for an abnormal amount of time. CDFW biologists located the remains and began an investigation into the bobcat’s cause of death.

HPAI H5N1 was first detected in wild birds in California in July 2022. To date, HPAI H5N1 has been detected in wild birds from 44 counties. The California Department of Food and Agriculture (CDFA) has also reported detections of HPAI H5N1 in domestic birds from 18 counties. Waterfowl and domestic poultry are especially vulnerable to the disease. The strain of H5N1 currently circulating in the U.S. and Canada has been causing illness and death in a higher diversity of wild bird species than during previous avian influenza outbreaks, affecting raptors and avian scavengers such as turkey vultures and ravens. Mammalian and avian predators and scavengers may be exposed to avian influenza viruses when feeding on infected birds. This bobcat was found in an area where HPAI H5N1 had recently been detected in a turkey vulture. Notwithstanding this detection, infection of wild mammals with avian influenza viruses appears to be relatively rare.

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Media Contacts:
Jordan Traverso, CDFW Communications, (916) 212-7352
Ken Paglia, CDFW Communications, (916) 825-7120

Avian Influenza Virus Activity Continues in California

Fri, 02 Sep 2022 15:58:08 GMT

Photo credit: CDFW Senior Environmental Scientist Krysta Rogers

As the Eurasian strain of Highly Pathogenic Avian Influenza (HPAI) H5N1 continues to impact wild and domestic birds across the state, California Department of Fish and Wildlife (CDFW) wildlife disease specialists are reminding the public of steps they can take to help reduce the spread of infection. To date HPAI H5N1 has been detected in 34 wild birds from 13 counties including Butte, Colusa, Glenn, Mendocino, Placer, Plumas, Sacramento, Santa Clara, Siskiyou, Solano, Sonoma, Stanislaus and Yolo. The California Department of Food and Agriculture (CDFA) has also reported detections of HPAI H5N1 in domestic birds in Butte, Contra Costa, Sacramento, Fresno and Tuolumne counties.

Highly pathogenic avian influenza is contagious among birds, and domestic birds such as chickens are especially vulnerable. The strain of Eurasian HPAI H5N1 currently in circulation in the U.S. and Canada has been causing illness and death in a higher diversity of wild bird species than during previous avian influenza outbreaks. In particular, waterfowl, other waterbirds, raptor predators and avian scavengers such as vultures and gulls have been affected. Unfortunately, infection in these species is nearly always fatal, and no vaccines or treatments are available.

Help reduce the spread of HPAI:

Report dead wild birds to CDFW using the mortality reporting form. While it is not possible to test every wild bird for HPAI, all mortality reports are important and help disease specialists monitor the outbreak.
Report sick and dead poultry to the CDFA hotline at (866) 922-2473.
Prevent contact between domestic birds and wild birds, especially waterfowl.
Exclude wild birds from accessing chicken or other domestic bird feed and water.
Do not bring potentially sick wild birds home or move sick birds to another location.
Before transporting potentially sick wild birds to wildlife rehabilitation centers, veterinary clinics or other animal facilities, contact the facility for guidance and to determine if the bird should be collected.
If recreating outdoors in areas with large concentrations of waterfowl and other waterbirds, wash clothing and disinfect footwear and equipment before traveling to other areas or interacting with domestic birds.
Where it can be done so safely, consider disposing of dead birds to help reduce exposure to new birds and minimize scavenging by birds and mammals that also may be susceptible to infection.

The Centers for Disease Control considers the transmission risk of avian influenza to people to be low, but as a general precaution recommends limiting contact with wild birds and sick or dead poultry. If there is a need to dispose of a dead bird, wear impermeable gloves or a plastic bag turned inside-out to collect the remains into a plastic garbage bag, which may then be placed in the regular trash collection. Afterwards, wash hands with soap and water and change clothing before having contact with domestic poultry or pet birds. If assistance or guidance is needed with the disposal of dead birds on private property, contact your county environmental health department or animal services for options available in your area.

For more information on HPAI H5N1, check out CDFW’s informational flyer addressing frequently asked questions and links to additional resources. The U.S. Department of Agriculture (USDA) maintains the official list of HPAI H5N1 detections on its website. For guidance on keeping domestic birds healthy, please visit the CDFA and USDA websites.

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Media Contacts:
Ken Paglia, CDFW Communications, (916) 825-7120

Avian Influenza Virus Detected in Wild Birds in California

Thu, 14 Jul 2022 17:49:36 GMT

Wildlife disease specialists have confirmed the presence of Highly Pathogenic Eurasian H5N1 Avian Influenza in three wild birds found in Colusa and Glenn counties.

The birds were collected by the U.S. Fish and Wildlife Service on July 5 during a mortality event at the Sacramento National Wildlife Refuge Complex and submitted to the U.S. Geological Survey’s National Wildlife Health Center for preliminary testing. On July 13, the U.S. Department of Agriculture’s (USDA) National Veterinary Services Laboratories confirmed the detection of avian influenza H5N1 in two Canada geese and one American white pelican and notified the California Department of Fish and Wildlife’s (CDFW) Wildlife Health Laboratory.

These are the first detections of avian influenza H5N1 in wild birds in California. Although avian influenza viruses naturally circulate among waterbirds, the strain of H5N1 currently in circulation in the U.S. and Canada has been causing illness and death in a higher diversity of wild bird species than during previous avian influenza outbreaks. The virus also remains highly contagious for domestic poultry. Currently, there are no confirmed cases of avian influenza in domestic poultry in California.

According to data compiled by the USDA, avian influenza H5N1 has been detected in at least 1,825 individual wild birds in 42 states and the District of Columbia since January 2022. Additionally, infection has been confirmed in 386 commercial and backyard domestic poultry and mixed-species flocks in 37 states. Prior to its detection in North America, avian influenza H5N1 activity had been on the rise across Europe since October 2021.

Avian predators and scavengers may be exposed to avian influenza viruses when feeding on infected waterbirds. Infection with avian influenza viruses among songbirds, including many common backyard birds, appears to be rare. However, feeding and providing water to wild birds is discouraged, especially in the vicinity of backyard poultry or other captive birds such as ducks, geese, pigeons, doves and parrots. Increased concentration of wild birds at feeders and bird baths may lead to fecal contamination of the local environment, which may aid in disease transmission. Wild birds should be excluded from entering enclosures for domestic and pet birds, and food and water should not be shared between wild birds and domestic or pet birds.

CDFW’s Wildlife Health Laboratory, in coordination with partners, is continuing to monitor wild bird populations for signs of illness and investigating mortality events. The public may report dead wild birds using CDFW’s mortality reporting form. For guidance on orphaned or injured live wild birds, please contact your nearest wildlife rehabilitation center. Be advised that some wildlife rehabilitation centers may have restrictions on the wildlife species they will admit.

An informational flyer addressing frequently asked questions is available on CDFW’s website. Currently, the Centers for Disease Control considers the transmission risk of avian influenza to people to be low, but recommends taking basic protective measures (i.e., wearing gloves and face masks and handwashing) if contact with wild birds or domestic poultry cannot be avoided.

Practicing biosecurity is the most effective way to keep domestic poultry and pet birds healthy. Please visit the California Department of Food and Agriculture (CDFA) and USDA websites for biosecurity information. Sick and dead poultry may be reported to the CDFA hotline at 1 (866) 922-2473.

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Photo by CDFW Senior Environmental Scientist Krysta Rogers.

Media Contact:
Ken Paglia, CDFW Communications, (916) 825-7120