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Table: Human cases of H5N1 bird flu

Last updated: December 10, 2024

On this page you’ll find detailed information about each human case of H5N1 bird flu since 2020, when a new variant (clade 2.3.4.4b) emerged in birds and spread around the world, eventually reaching every continent except Oceania. This page is updated regularly and as soon as possible when a human case is reported.

The current variant of concern has affected a growing number of mammals since it was first discovered. The first human case with clade 2.3.4.4b was reported in the UK in January 2022. Older variants are also capable of causing human cases, including clade 2.3.2.1c, which is endemic in Cambodia.

Summary (1997-present)

CasesDeathsCFR
New variant7811%
All variants98047048%

U.S. cases in 2024

CasesUnknown source
California342
Washington140
Colorado100
Arizona20
Michigan20
Missouri11
Oregon10
Texas10
Total653

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Clade 2.3.4.4b (new variant)

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NOTE: The most recent case in California has not yet been confirmed by CDC.

ReportedLocationPatientSymptomsOutcomePoultry/
cattle link
Source
2024-12California1MildRecoveredNoLink
2024-12ArizonaN/AMildRecoveredYesLink
2024-12ArizonaN/AMildRecoveredYesLink
2024-12CaliforniaAdultMildN/AYesLink
2024-12CaliforniaAdultMildN/AYesLink
2024-12CaliforniaAdultMildN/AYesLink
2024-11CaliforniaAdultMildN/AYesLink
2024-11CaliforniaChildMildRecoveredNoLink
2024-11CaliforniaAdultMildN/AN/ALink
2024-11OregonAdultMildRecoveredYesLink
2024-11CaliforniaAdultMildN/AN/ALink
2024-11CaliforniaAdultMildN/AN/ALink
2024-11CaliforniaAdultMildN/AYesLink
2024-11CaliforniaAdultMildN/AYesLink
2024-11CaliforniaAdultMildN/AYesLink
2024-11CanadaTeenSevereN/ANoLink
2024-11WashingtonAdultMildRecoveredYesLink
2024-11WashingtonAdultMildRecoveredYesLink
2024-11CaliforniaAdultMildN/AYesLink
2024-11CaliforniaAdultMildN/AYesLink
2024-11CaliforniaAdultMildN/AYesLink
2024-11CaliforniaAdultMildN/AYesLink
2024-11CaliforniaAdultMildN/AYesLink
2024-11WashingtonAdultMildRecoveredYesLink
2024-11WashingtonAdultMildRecoveredYesLink
2024-11WashingtonAdultMildRecoveredYesLink
2024-11CaliforniaAdultMildRecoveredYesLink
2024-10WashingtonAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10WashingtonAdultMildRecoveredYesLink
2024-10WashingtonAdultMildRecoveredYesLink
2024-10WashingtonAdultMildRecoveredYesLink
2024-10WashingtonAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10WashingtonAdultMildRecoveredYesLink
2024-10WashingtonAdultMildRecoveredYesLink
2024-10WashingtonAdultMildRecoveredYesLink
2024-10WashingtonAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-10CaliforniaAdultMildRecoveredYesLink
2024-09MissouriAdultMildRecoveredNoLink
2024-07ColoradoAdultMildRecoveredYesLink
2024-07ColoradoAdultMildRecoveredYesLink
2024-07ColoradoAdultMildRecoveredYesLink
2024-07ColoradoAdultMildRecoveredYesLink
2024-07ColoradoAdultMildRecoveredYesLink
2024-07ColoradoAdultMildRecoveredYesLink
2024-07ColoradoAdultMildRecoveredYesLink
2024-07ColoradoAdultMildRecoveredYesLink
2024-07ColoradoAdultMildRecoveredYesLink
2024-07ColoradoAdult/MMildRecoveredYesLink
2024-05MichiganAdultMildRecoveredYesLink
2024-05MichiganAdultMildRecoveredYesLink
2024-04TexasAdultMildRecoveredYesLink
2023-07UKN/ANoneRecoveredYesLink
2023-07UKN/AMildRecoveredYesLink
2023-05UKN/ANoneRecoveredYesLink
2023-05UKN/ANoneRecoveredYesLink
2023-03Chile53/MSevereRecoveredNoLink
2023-03China52/FSevereRecoveredYes
2023-01Ecuador9/FSevereRecoveredYesLink
2022-10Spain19/MNoneRecoveredYesLink
2022-10Spain27/MNoneRecoveredYesLink
2022-09China38/FSevereDiedYes
2022-04ColoradoAdultMildRecoveredYesLink
2022-01UK80sNoneRecoveredYesLink

NOTE: This table includes 4 probable cases (1 in California and 3 in Washington) which tested positive at a local lab but negative at the CDC.

Other variants or unknown (2020-present)

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ReportedCladeLocationPatientSymptomsOutcomePoultry/
cattle link
Source
2024-12UnknownVietnam18/MMildN/AYesLink
2024-082.3.2.1cCambodia15/FSevereDiedYesLink
2024-082.3.2.1cCambodia16/FSevereUnknownYesLink
2024-082.3.2.1cCambodia4/MSevereUnknownYesLink
2024-072.3.2.1cCambodia5/FMildUnknownYesLink
2024-072.3.2.1cCambodia3/MSevereUnknownYesLink
2024-052.3.2.1aAustralia2/FSevereRecoveredNoLink
2024-05UnknownChina33/FMildRecoveredYesLink
2024-032.3.2.1cVietnam21/MSevereDiedYesLink
2024-022.3.2.1cCambodia17/FSevereUnknownYesLink
2024-022.3.2.1cCambodia16/MNoneRecoveredYesLink
2024-022.3.2.1cCambodia10/MSevereDiedYesLink
2024-012.3.2.1cCambodia69/MSevereRecoveredYesLink
2024-012.3.2.1cCambodia3/MSevereRecoveredYesLink
2023-112.3.2.1cCambodia4/FSevereRecoveredYesLink
2023-112.3.2.1cCambodia21/FSevereDiedYesLink
2023-102.3.2.1cCambodia2/FSevereDiedYesLink
2023-102.3.2.1cCambodia50/MSevereDiedYesLink
2023-022.3.2.1cCambodia49/MMildRecoveredYesLink
2023-022.3.2.1cCambodia11/FSevereDiedYesLink
2022-10UnknownVietnam4-5/FSevereRecoveredYesLink
2021-072.3.2.1aIndia11/MSevereDiedYesLink
2020-10UnknownLaos1/FSevereRecoveredYesLink

Prior to 2020, a total of 879 laboratory-confirmed cases were reported across the world, causing 462 deaths. Most of those cases occurred between 2004 and 2011.

Definitions

  • Reported: The month in which a case was publicly reported. The actual infection or the onset of symptoms may have occurred weeks earlier. In China, it takes anywhere from days to weeks to publicly report a case.

Symptoms/Outcome

  • None: The patient did not report any symptoms (asymptomatic).
  • Mild: The patient experienced symptoms which did not require hospitalization or they were hospitalized but only for observation.
  • Severe: More serious symptoms requiring hospitalization, especially ICU treatment.
  • Recovered: The patient survived the active infection of H5N1 bird flu. Some survivors have long-term or permanent health issues caused by the illness.
  • Died: The patient died while undergoing treatment for H5N1.
  • Unknown: No reliable information is available about the outcome of the case, which often happens when the patient is still hospitalized at the time of the announcement and no further updates are released.

Other data notes

  • Because we can only display one source in the table, the cited link may not include all available or up-to-date information.
  • Some cases may be assigned to a specific clade before laboratory studies are complete. For example, a person testing positive for H5 bird flu may be listed as H5N1 if they worked on a farm where animals were infected with H5N1.