Preparing for HPAI in Oil Spill Response
Highly Pathogenic Avian Influenza has reached California and is affecting wildlife and domestic poultry. This virus is highly infectious and can cause significant mortality events amongst wild birds and poultry. Because of the serious implications of an HPAI outbreak, the OWCN is implementing additional biosecurity measures across our operations to protect our patients, our responders, and our member organizations.
What is HPAI?
Highly Pathogenic Avian Influenza (HPAI) is caused by an influenza type A virus which typically infects poultry such as chickens, turkeys, geese, ducks, and wild birds (especially waterfowl). The current outbreak affecting California (and other parts of North America) is a strain of HPAI H5N1. While HPAI is a zoonotic disease which can infect humans, the risk to the general public is very low. People working directly with birds should take precautions including donning personal protective equipment—something that we already do while working with birds during oil spills.
Why is this outbreak more serious than other Avian Influenza Viruses?
Low pathogenicity avian influenza (LPAI) virus strains occur naturally in wild migratory waterfowl and shorebirds without causing illness. LPAI can also infect domestic poultry without causing serious illness.
Highly pathogenic avian influenza has proven to be much more infectious and causes higher mortality both in domestic poultry and in some species of wildlife. This strain of HPAI has been infecting and causing significant mortality events in groups of wild birds that are not typically affected by LPAI such as scavengers like bald eagles and vultures.
Additionally, HPAI is a major economic concern for the poultry industry. The virus readily spills over from wild birds to poultry on farms and vice versa. These spillover occurrences make outbreak prevention very difficult. Both the migration of wild birds and the nationwide transport of domestic poultry can perpetuate the geographic spread of the virus.
Which wildlife species are affected?
Waterfowl are the natural reservoirs for avian influenza viruses. Canada geese, mallards, and other waterbirds have been the primary species testing positive for this strain of HPAI H5N1. Somewhat unique to this 2022 outbreak of HPAI H5N1, other bird species such as raptors and vultures have also experienced significant mortality events.
Though HPAI typically infects avian species, it has been detected in mammalian species in some rare cases. HPAI H5N1 has been detected in a dolphin, seals, a bear, raccoons, foxes, and skunks. Transmission is thought to occur when scavenging mammals consume birds infected with HPAI or when they share a contaminated environment such as water.
What are the clinical signs of HPAI?
Birds infected with HPAI tend to exhibit clinical signs such as:
- Sudden death
- Abnormal position of head & neck
- Impaired coordination
- Respiratory (sneezing, coughing, ocular & nasal discharge, periorbital edema)
- Cloudy eyes
- Dermatologic (limb swelling, patchy redness)
- Gastrointestinal (diarrhea, green feces)
- Inappetence, weight loss
- Weakness, lethargy, depression
Infected mammals have exhibited:
- Weakness, lethargy, or depression
- Circling, tremors, & seizures
- Apparent blindness
- Drooling, hypersalivation
- Repeated opening & closing of the mouth
Why does HPAI matter during spill response?
HPAI is a risk for wildlife affected by oil spills. Traditionally, all affected live and dead animals are collected from within the spill zone and brought to a primary care facility for processing and care. Gathering a variety of species, especially waterbirds, together could result in unintended transmission of HPAI amongst our patients. Biosecurity has always been a part of animal care operations at the OWCN, but during outbreaks of wildlife diseases like HPAI, our biosecurity measures are increased to include additional screening, testing, and quarantine precautions. These increased biosecurity measures may complicate what is already a complex wildlife response, so planning ahead is key. Here are some of the steps we are taking:
HPAI Field Screening Sites
For spill responses occurring during HPAI outbreaks, we will implement a new biosecurity precaution, field screening sites. We will utilize our western shelter tent structures for this purpose. These can be set up, disinfected, and broken down as needed. The screening process includes assessment of clinical HPAI signs and risk factors. Animals suspected to have HPAI will be euthanized and submitted for testing. Animals passing this screening check point move on to either the Field Stabilization Site or the Primary Care Facility for continued care and processing.
Dead Animal Processing
Processing, the function of collecting oiling and species data during a response is a crucial component of our work. Both live and dead animals collected during a spill response are processed. To mitigate the potential risk of deceased birds introducing HPAI to our Primary Care Facility, all dead animal processing will occur offsite during HPAI outbreak conditions.
Our usual method of housing waterbirds in conspecific groups could potentially expose more birds to HPAI. To mitigate this risk, birds will only be grouped when it is necessary for the available resources or the birds’ social needs (some species do poorly when housed alone). Groups will be formed based on species and age class.
While cleaning and disinfection has always been a part of our work, HPAI has highlighted the importance of these routine duties. Detailed and specific cleaning and disinfection protocols will be posted throughout the response and communicated to all OWCN responders as it relates to their assignments. Field capture and transport supplies will be cleaned and disinfected more frequently than before. Animal care spaces in Field Stabilization Sites and Primary Care Facilities will be frequently and thoroughly cleaned and disinfected. Gloves and handling towels will be changed between cages of animals.
Our partnerships with California Department of Fish and Wildlife (CDFW), the Office of Spill Prevention and Response (OSPR), and our 40+ member organizations are more important than ever. We will work closely with both the CDFW Wildlife Health Laboratory and OSPR to monitor HPAI impacts near spill events. We have also surveyed our member organizations who are most likely to house wildlife during a spill response to gauge their HPAI concern and risk levels. Outside of spill responses, we have also adapted our training events to accommodate the heightened biosecurity risks associated with utilizing carcasses for training purposes.
Adapting to a new normal
Highly Pathogenic Avian Influenza is likely to have impacts on oiled wildlife events (and wildlife care in general) for the next few years or perhaps even longer. As part of the One Health Institute and Wildlife Health Center, the OWCN has experience navigating the complexities of such wildlife disease outbreaks. As we prepare to face these new challenges, our hearts go out to wildlife organizations across California and beyond. For some, coping with HPAI has become a new way of life and for others, it is still a looming threat. Many animals will be lost during the current outbreak of HPAI and these losses may feel overwhelming at times. Stay strong, wildlife caregivers. Be aware of compassion fatigue and practice self care. OWCN responders are encouraged to view the Trauma Resiliency webinar available in the OWCN Webinar Library accessed through Better Impact.
—Sam, Wildlife Care Specialist