Influenza Virus Toolbox

Overview site that includes current situation, background, prevention, links to other resources for prevention and monitoring, communication, information for other groups

Outside the United States, more than 950 cases of H5N1 bird flu have been reported to the World Health Organization; about half of those have resulted in death.

Leonard J, Harker EJ, Szablewski CM, et al.
These findings suggest the possible benefit of systematic surveillance for rapid identification of HPAI A(H5) virus in dairy cattle, milk, and humans who are exposed to cattle to ensure appropriate hazard assessments.

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 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 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 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.

This report provides an update to the April 26, 2024, report to include three additional sporadic human cases (1 in Australia and 2 in the United States) and recent activity in wild birds, poultry, and other animals, including the multi-state outbreak in U.S. dairy cattle, and updated information on monitoring for human infections with highly pathogenic avian influenza A(H5N1) virus infections in the United States.

This Health Advisory also includes a summary of interim CDC recommendations for preventing, monitoring, and conducting public health investigations of potential human infections with HPAI A(H5N1) virus.

Describes the case of a person who had exposure to dairy cattle in Texas presumed to be infected with HPAI A(H5N1) viruses.

includes status updates on wild birds, poultry flocks and human infections.

Brown JD, Black A, Haman KH, Diel DG, Ramirez VE, Ziejka RS, et al.
We detected antibodies to H5 and N1 subtype influenza A viruses in 4/194 (2%) dogs from Washington, USA, that hunted or engaged in hunt tests and training with wild birds. Historical data provided by dog owners showed seropositive dogs had high levels of exposure to waterfowl.

Covers the use of personal protective equipment, testing, antiviral treatment, patient investigations, monitoring of exposed persons, and antiviral chemoprophylaxis of exposed persons

Qualls N, Levitt A, Kanade N, et al.

The Influenza Risk Assessment Tool (IRAT) is an evaluation tool conceived by CDC and further developed with assistance from global animal and human health influenza experts. The IRAT is used to assess the potential pandemic risk posed by influenza A viruses that are not currently circulating in people. Input is provided by U.S. government animal and human health influenza experts.

The International Reagent Resource (IRR), formerly named Influenza Reagent Resource (IRR), was established by the Centers for Disease Control and Prevention (CDC)

Naraharisetti R, Weinberg M, Stoddard B, et al.
HPAI A(H5N1) virus was detected in two indoor domestic cats with respiratory and neurologic illness that lived in homes of dairy workers but had no known direct exposure to HPAI A(H5N1)–affected farms.

Leonard J, Harker EJ, Szablewski CM, et al.
These findings suggest the possible benefit of systematic surveillance for rapid identification of HPAI A(H5) virus in dairy cattle, milk, and humans who are exposed to cattle to ensure appropriate hazard assessments.

Outside the United States, more than 950 cases of H5N1 bird flu have been reported to the World Health Organization; about half of those have resulted in death.

This site includes monitoring of Persons Exposed to Infected Animals

Includes data from US Clinical Laboratories, Public Health Laboratories, Outpatient Illness Network, and other sources

Delahoy MJ, Mortenson L, Bauman L, et al.

Covers the use of personal protective equipment, testing, antiviral treatment, patient investigations, monitoring of exposed persons, and antiviral chemoprophylaxis of exposed persons

This page provides information about avian influenza for employers and workers.

Summary of changes
This updated guidance identifies select occupational groups that may be at increased risk of exposure to novel influenza A viruses. Specific recommendations for these groups may be updated as CDC learns more during this evolving situation. Persons in these occupational groups should consult with their supervisor or their employer’s worker safety team to determine how best to apply these recommendations.

Qualls N, Levitt A, Kanade N, et al.

Grohskopf LA, Blanton LH, Ferdinands JM, Chung JR, Broder KR, Talbot HK
Includes recommendations for the use of vaccines for the prevention and control of seasonal influenza during the 2023–24 influenza season (children, adults > 65, pregnant women, immune suppressed, etc.).

McLean HQ, Petrie JG, Hanson KE, et al.
The 2022–23 influenza vaccine provides substantial protection against circulating influenza A viruses and remains the best way to protect against influenza. Influenza vaccination is recommended as long as influenza viruses are circulating.