CDC researchers used key flu indicator data to develop intensity thresholds (ITs) to classify the severity of flu seasons.

In this week's update, CDC shares an update on the investigation in Missouri; information about updated guidance on the use of personal protective equipment for people working with or exposed to infected animals; and information about a new standardized protocol for subtyping of wastewater samples that test positive for influenza A.

CDC reported one new flu-related death in a child last week, bringing the total number of U.S. pediatric deaths for the 2023-2024 season to 200.

Experts discussed the importance of protecting people this fall with recommended vaccines against flu.

Today, the U.S. Food and Drug Administration approved FluMist for self- or caregiver-administration.

In this week's update, CDC shares information on a new MMWR report summarizing data from the first 9 weeks of monitoring influenza A viruses, including avian influenza A(H5), in wastewater across the United States; an update on an H5 serosurvey of bovine practitioners; an update on the investigation in Missouri; and an update on the implementation of guidance around CDC's influenza surveillance activities for the 2024-2025 season.

CDC provides an update on its response activities related to the multistate outbreak of avian influenza A(H5N1) virus, or "H5N1 bird flu," in dairy cows and other animals in the United States.

CDC reported two new flu-related deaths in children last week, bringing the total for the 2023-2024 season to 199.

CDC has confirmed a human case of avian influenza A(H5) ("H5 bird flu") reported by the state of Missouri.

A new CDC study suggests that starting antiviral treatment early reduces the risk of death in adults hospitalized with flu.

As the 2024 Southern Hemisphere flu season draws to a close, data reveal that the 2024 flu season was similar to previous flu seasons in the Southern Hemisphere, underscoring that seasonal flu continues to have a significant public health impact in terms of illnesses, hospitalizations, and deaths globally.

As the 2024 Southern Hemisphere flu season draws to a close, data reveal that the 2024 flu season was similar to previous flu seasons in the Southern Hemisphere, underscoring that seasonal flu continues to have a significant public health impact in terms of illnesses, hospitalizations, and deaths globally.

In this week's update, CDC shares information about ongoing serology studies in Colorado and Michigan, genetic characterization of viruses from recent human cases in Colorado poultry workers, and how CDC's National Syndromic Surveillance Program is supporting this response.

CDC's National Syndromic Surveillance Program (NSSP) captures electronic health record data reported automatically from more than 6,500 U.S. healthcare facilities, representing nearly 80% of emergency departments (ED) in all 50 states, the District of Columbia, and Guam.

In this week's update, CDC shares information about a new report summarizing the results of an Influenza Risk Assessment Tool (IRAT) of an avian influenza A(H5N1) virus from a human case in Texas. This update also provides key findings from a new CDC laboratory study of the effects of the avian influenza A(H5N1) virus from a human case in Michigan on ferrets, a model used to assess potential impact on people.

In this week's update, CDC shares information about two new investments the agency announced this week to protect and improve farmworker health. This update also provides a summary of new genetic sequencing data from the viruses that caused three human cases in Colorado poultry workers that were confirmed on July 25, 2024. Also included is an update on seroprevalence studies in Colorado and Michigan.

In this week's Spotlight, we confirm three additional cases of H5 bird flu in poultry farm workers at a second poultry farm in Colorado, for a total of 13 human cases since April 2024. All three people were working to depopulate infected poultry as part of a culling at a commercial egg layer operation that had reported an outbreak of H5 bird flu among poultry. All three people have mild illness and have been offered antiviral medication.

In this week's Spotlight, we include the key findings from the recent Michigan-led study that tested the blood of farmworkers from two dairy farms that experienced an outbreak of highly pathogenic avian influenza A(H5N1) virus among cattle.

Four human cases of highly pathogenic avian influenza (HPAI) A(H5) ("H5 bird flu") virus infection in the state of Colorado have been confirmed by the Centers for Disease Control and Prevention (CDC). This includes all three presumptive-positive cases reported by that state on Friday, July 12 and a fourth specimen that was later found to be presumptive-positive by the state on Friday.

The state of Colorado has announced that three people have tested presumptive positive for highly pathogenic avian influenza (HPAI) A(H5) ("H5 bird flu") virus infection.