Avian Influenza (H5N1) in Finland: Current U.S. Strategies and Future Preparations
Executive Summary
Finland has recently reported several cases of avian influenza (H5N1) within the farmed animal population. Avian influenza (H5N1), commonly known as Bird Flu, is a highly pathogenic avian influenza virus that has been responsible for a number of outbreaks since 1996. Since 2022, there have been 22 human infections and 1 death attributed to the H5N1 virus across eight countries. The United States has reported 1 human infection in April 2022 in Colorado. The current U.S response has been managed by the USDA, U.S Department of the Interior, and the CDC. Future preparations should include active communication with the Finnish government, strengthened surveillance networks, and scaled-up medical countermeasures.
Background
Finland Outbreak
Since July 2023, several cases of avian influenza (H5N1) have been reported among farmed animals in South and Central Ostrobothnia, Finland (Figure 1).(1) This outbreak has included infections in foxes, American minks, and raccoon dogs across 20 farms.(1) Initial cases were investigated by the Finnish Food Authority and Finnish Institute for Health and Welfare which confirmed H5N1 via genetic testing.(1) The virus is predominately spread through animals and recent reports have detected several infections in humans. The Finnish health authorities have ordered the culling of all farmed animals at outbreak facilities to reduce the spread of the virus.(2)
Figure 1. Map of Finland Municipalities with Detected Avian Influenza Cases in Fur Farms in 2023 (10)
History of H5N1
Avian influenza (H5N1), commonly known as Bird Flu, is a highly pathogenic avian influenza virus that was first identified in Southern China in 1996.(3) Since then, there have been a number of widespread bird and poultry outbreaks across Asia, Africa, Europe, and the Middle East.(3) In recent years, the United States has experienced two major avian influenza outbreaks, including H5N2 in 2014 and H7N8 in 2016.(4) These outbreaks were well contained and did not result in any human infections or transmission.
There have been a total of 22 human infections and 1 death attributed to the H5N1 virus across eight countries since 2022.(5) The United States reported its only human infection in April 2022 in Colorado and sporadic H5N1 infections in mammals have been identified in 29 U.S states (Figure 2).(6) The CDC currently designates H5N1 as a low threat to public health given the absence of human-to-human transmission of the virus.(6)
Figure 2. Detections of Highly Pathogenic Avian Influenza in Mammals in the U.S from 2022-2023 (6)
Current Strategies
Responsible Agencies
The U.S. Department of Agriculture (USDA) and The U.S. Department of the Interior are the lead departments for avian influenza outbreak investigation and control in wild birds.(7) The USDA Animal and Plant Health Inspection Service is the lead agency for control of domestic birds, such as poultry.(7) The U.S. Department of Health and Human Services and CDC are responsible for monitoring the public health concerns of the virus.(7)
Preventative Strategies
The CDC recommends avoiding direct contact with birds and to wash hands with soap and water following any contact.(8) Individuals working with sick or dead poultry are recommended to wear respiratory protection as well as gloves.(8) Sick birds are required to be reported directly to the USDA Animal and Plant Health Inspection Service.(8)
Medical Countermeasures
The current medical countermeasures are aimed at preventing transmission and providing treatment to infected individuals. All persons greater than 6 months are recommended to receive the annual flu vaccine to reduce symptoms of the virus.(8) Current influenza antiviral therapeutics have been shown to be effective against the H5N1 virus. The U.S Food and Drug Administration maintains a national stockpile of H5N1 vaccines in preparation for future outbreaks.(9)
Recommendations
The recent outbreak of H5N1 among farmed animals in Finland heightens concern for a potential spread of the virus. The United States should remain vigilant and proactive to prevent any major outbreaks within our borders. The following recommendations have been developed to monitor and control the spread of the virus.
Recommendation 1: Maintain active communication with the Finnish Institute for Health and Welfare regarding H5N1. It is essential to maintain a strong line of communication between the Finnish Institute for Health and Welfare and the U.S CDC to ensure up-to-date information on the transmission of the virus is available. This open dialogue will provide insight into the current surveillance and control measures in place to restrict the spread of the virus.
Recommendation 2: Strengthen the H5N1 national surveillance network through coordination with the U.S Department of Agriculture and the CDC. The USDA currently administers a robust surveillance program to test large numbers of birds for highly pathogenic avian influenza. This program should collaborate with the CDC to identify humans potentially exposed to avian influenza and administer diagnostic tests. This would provide increased source control and exposure management.
Recommendation 3: Scale-up medical countermeasures to prepare for a potential H5N1 outbreak. Quantities of medical countermeasures including, gloves, masks, antivirals, and vaccines, should be assessed and scaled-up to ensure the nation is prepared for a potential H5N1 outbreak. These preparations will enable the nation to combat not only the spread of H5N1, but also other infections that may arise in the future.
References
Lindh, Erika, Hanna Lounela, Niina Ikonen, Tuija Kantala, Carita Savolainen-Kopra, Ari Kauppinen, Pamela Österlund, et al. “Highly Pathogenic Avian Influenza A(H5N1) Virus Infection on Multiple Fur Farms in the South and Central Ostrobothnia Regions of Finland, July 2023.” Eurosurveillance 28, no. 31 (August 3, 2023): 2300400. https://doi.org/10.2807/1560-7917.ES.2023.28.31.2300400.
Schnirring, Lisa. “H5N1 Avian Flu Strikes Another Finnish Fur Farm | CIDRAP,” September 28, 2023. https://www.cidrap.umn.edu/avian-influenza-bird-flu/h5n1-avian-flu-strikes- another-finnish-fur-farm.
“Emergence and Evolution of H5N1 Bird Flu | Avian Influenza (Flu),” June 6, 2023. https://www.cdc.gov/flu/avianflu/communication-resources/bird-flu-origin- infographic.html.
“Past Outbreaks | Avian Influenza (Flu),” November 21, 2023. https://www.cdc.gov/flu/avianflu/past-outbreaks.htm.
“Past Reported Global Human Cases with Highly Pathogenic Avian Influenza A(H5N1) (HPAI H5N1) by Country, 1997-2024 | Avian Influenza (Flu),” February 14, 2024. https://www.cdc.gov/flu/avianflu/chart-epi-curve-ah5n1.html.
CDC. “Technical Report: Highly Pathogenic Avian Influenza A(H5N1) Viruses.” Centers for Disease Control and Prevention, October 27, 2023. https://www.cdc.gov/bird-flu/php/technical-report/h5n1-102723.html
CDC. “CDC Newsroom,” January 1, 2016. https://www.cdc.gov/media/releases/2022/s0428-
avian-flu.html.
“Prevention and Antiviral Treatment of Bird Flu Viruses in People | Avian Influenza (Flu),” February 1, 2023. https://www.cdc.gov/flu/avianflu/prevention.htm.
Research, Center for Biologics Evaluation and. “Influenza Virus Vaccine, H5N1 (for National Stockpile).” FDA, February 24, 2023. https://www.fda.gov/vaccines-blood- biologics/vaccines/influenza-virus-vaccine-h5n1-national-stockpile.
Finnish Food Authority. “Avian Influenza Cases in Finland 2016-2023.” Accessed July 21, 2024. https://www.ruokavirasto.fi/en/animals/animal-health-and-diseases/animal-diseases/poultry/avian-influenza/avian-influenza-in-finland/olderavian-influenza-cases-in-finland/.