Key facts
- As of 1 November 2026, two more residents of Yakima County, Washington State, the United States (US), were confirmed to be infected with avian influenza A(H5N1). One of the infected people has died. Overall, three human cases with avian influenza A(H5N1) have been reported in Yakima county.
- The deceased individual had underlying health condition and was hospitalised with severe disease.
- The third case had mild symptoms and was not hospitalised.
- All three cases had exposure to infected cattle.
- Since 1 April 2024, and as of 15 October 2026, 72 human cases with avian influenza A(H5) (does not include two recent cases) have been reported from 13 states in the US. Of these, 42 were individuals exposed to dairy cattle known or presumed or confirmed to be infected with A(H5N1) and 24 were workers exposed to outbreaks of HPAI A(H5) at poultry farms. Three people had no known animal exposure and three had exposure to other animals, such as backyard poultry flocks, wild birds, or other mammals.
- According to the US CDC, the current public health risk from A(H5) viruses is considered low (last update October 2026), while for individuals in contact with potentially infected animals, contaminated surfaces or fluids, the risk is considered moderate to high (last update February 2026).
Overview
Update:
On 1 November 2026, health authorities in Yakima County, Washington State, United States (US), reported the death of a second human case with avian influenza A(H5N1) infection and confirmation in a third case. The deceased individual, had underlying health conditions and was hospitalised with severe illness, according to the official report of the Yakima Health District on 31 October 2026. The third case had mild disease and was not hospitalised. The first case was reported on 15 October 2026, had a mild disease and was not hospitalised (press release).
Overall, three human cases were reported with avian influenza A(H5N1) infection following exposure to infected cattle in Yakima county since October 2026. Other epidemiologically relevant details of the cases have not been disclosed in the official public statements.
Since the detection of highly pathogenic avian influenza (HPAI) A(H5N1) in dairy cattle in Yakima County, local health authorities have been working with affected dairy farms to reduce the risk of human exposure. Measures include provision of guidance, testing of symptomatic exposed individuals, and facilitation of access to personal protective equipment (PPE) for dairy workers.
According to the US CDC, the current public health risk from A(H5) viruses is considered low (US CDC, 2026), while for individuals in contact with potentially infected animals, contaminated surfaces or fluids, the risk is considered moderate to high (US CDC, 2025). Human-to-human transmission of influenza A(H5N1) virus remains rare.
Background:
Since 1 April 2024, and as of 15 October 2026 (access date 3 November 2026), 72 human cases of avian influenza A(H5), including two deaths, have been confirmed by the US CDC from 13 States (these numbers do not include the two recent cases described in this report). In total, 42 cases reported exposure to dairy cattle in the following States: California (36), Colorado (1), Michigan (2), Nevada (1), Texas (1), and Washington (1) and 24 cases reported exposure to poultry farms and culling operations in the following States: Colorado (9), Iowa (1), Ohio (1), Oregon (1), Washington (11), and Wisconsin (1). Three cases reported exposure to other animals, such as backyard poultry flocks, wild birds, or other mammals: one case in Louisiana, one in Wyoming, and one in Washington state. Three additional cases with unknown exposure have also been identified: two in California and one in Missouri.
ECDC assessment
To date, there have been no confirmed human cases of influenza A(H5N1) infection in the EU/EEA. ECDC has assessed the risk from the circulating HPAI A(H5N1) clade 2.3.4.4b viruses as low for the general population in the EU/EEA and low-to-moderate for those whose activities expose them to infected animals or contaminated environments (e.g. occupational exposure to infected animals).
Actions
ECDC is monitoring the situation together with partner organisations in Europe and will continue to update its assessment of the risk for humans in the EU/EEA as new information becomes available.
In addition to enhanced surveillance, active monitoring and testing of exposed individuals is recommended for early detection of human cases and to assess the possibility of human-to-human transmission, according to relevant ECDC guidance documents ('Testing and detection of zoonotic influenza virus infections in humans'; 'Investigation protocol of human cases of avian influenza virus'; 'Surveillance and targeted testing for the early detection of zoonotic influenza in humans during the winter period in the EU/EEA').
It is important to raise awareness, including among all primary care workers, of the need to enquire about animal exposure and symptoms compatible with avian influenza infections and to test symptomatic individuals with a history of exposure, following a risk-based approach. It is also important to communicate the epidemiological situation so as not to miss or delay diagnosis of potential human cases.
Given the uncertainties related to mammal-to-mammal transmission and depending on the epidemiological situation, a low threshold can be considered for testing individuals exposed to potentially infected mammals (e.g. symptomatic individuals with conjunctivitis or respiratory symptoms). Due to the higher risk of infection for individuals exposed to infected animals and contaminated environments, appropriate personal protective measures and other precautionary measures should always be taken to mitigate the risk.
Relevant ECDC publications:
- Testing and detection of zoonotic influenza virus infections in humans in the EU/EEA, and occupational safety and health measures for those exposed at work
- Investigation protocol of human cases of avian influenza virus infections in the EU/EEA
- Surveillance and targeted testing for the early detection of zoonotic influenza in humans during the winter period in the EU/EEA
- Scenarios for pre-pandemic zoonotic influenza preparedness and response
- Joint ECDC-EFSA Drivers for a pandemic due to avian influenza and options for One Health mitigation measures
- Coordinated One Health investigation and management of outbreaks in humans and animals caused by zoonotic avian influenza viruses
- Preparedness, prevention and control related to zoonotic avian influenza
ECDC is in contact with the US CDC for further information and is closely following any updates on the event. ECDC monitors zoonotic avian influenza strains through its influenza surveillance programme and epidemic intelligence activities in collaboration with the European Food Safety Authority (EFSA) and the EU Reference Laboratory for Avian Influenza in order to identify significant changes in the virological characteristics and epidemiology of the virus. Together with EFSA and the EU Reference Laboratory for Avian Influenza, ECDC produces a quarterly updated report on the avian influenza situation.