Variant and Novel Influenza at Agricultural Fairs – June 18, 2026 Summary and Action Items

As the agricultural fair season takes off in Illinois with over 50 fairs scheduled between the months of May and August, this health advisory serves to:

1. Provide background on the variant and novel influenza viruses which may occur in birds, cattle, or swine and risk of spread to humans at agricultural fairs.
2. Remind local health departments (LHDs) and providers that influenza testing and subtyping for human specimens is available at IDPH labs if novel or variant influenza is suspected. Testing is encouraged if influenza is occurring outside of the normal influenza season especially if exposure is noted to birds, dairy cattle, or swine.
3. Encourage LHDs to work with directors of fairs and other events where swine, poultry, and dairy cattle will be present to minimize the potential spread of infection to other animals and humans present.
4. Encourage LHDs to work with their local schools and educational institutions to ensure safe visits to dairy farms and agricultural fairs if such visits are deemed necessary.

Background

Novel and variant influenza A viruses do not normally infect humans, but sporadic human infections have occurred. A novel influenza A virus (H5N1, H5N2, H7N3, and H7N9) is a virus that causes human infection but is different from seasonal influenza A viruses (H1N1 and H3N2) that circulate among people each year. Influenza A viruses that normally circulate in pigs are called “variant” viruses when they are found in people (H3N2v, H1N2v, H1N1v).

In 2022, a highly pathogenic avian influenza A(H5N1) outbreak first occurred in wild birds and poultry in the United States. In 2024, the outbreak also spread to dairy cattle. Since 2024, CDC has confirmed 71 total human influenza A(H5N1) infections with most cases being exposed to infected dairy herds or positive poultry farms and culling operations. In the US, there are currently 13 states that have reported positive cases in humans with California and Washington reporting most of those cases. While thought to be rare, these exposures to influenza A(H5N1) bird flu virus with mammal to human transmission cause concern that the virus could result in a pandemic if the virus mutates further. Currently, no dairy herds or humans have tested positive for influenza A (H5N1) in Illinois. Poultry farms in Illinois have tested positive for influenza A (H5N1).

Additionally, variant influenza A viruses have occurred occasionally in humans, often after exposure to pigs at agricultural events. During the 2025-2026 influenza season, two cases of variant influenza were detected in the United States. Illinois has not seen a variant influenza case since 2013.

Transmission

Most commonly, human infections with novel and variant viruses occur in people with exposure to infected cattle, birds, or swine. Transmission is similar to seasonal influenza which primarily occurs when breathing air containing the virus. Transmission may also occur by direct or indirect contact with

Illinois Department of Public Health

milk, oral secretions, or fecal material from infected animals. Most recent human infections with novel and variant influenza viruses have not resulted in person-to-person spread.

Prevention

The best prevention is to avoid sources of exposure. Other measures to prevent spread of infection at agricultural fairs may include:

1. Providing outreach and education to people exhibiting animals (specifically swine, cattle and avian species) at or attending agricultural fairs
2. Minimizing petting zoo experiences at agricultural fairs
3. Encouraging frequent hand hygiene and opportunities for hand hygiene at agricultural fairs

Illinois has developed a public H5N1 toolkit with information and guidance for clinicians, veterinarians, animal control agencies, pet owners, animal exhibitors, and wildlife rehabilitators.

IDPH and LHD Response

LHDs are encouraged to work with their local agricultural fair directors and directors of other events where animals will be present to explore options discussed above and take the following actions:

• Inform and educate exhibitors and visitors on the risks of infection and spread of animal influenza A viruses and how to prevent the spread between people and animals.
• Ensure hand hygiene stations are available throughout, especially near transition areas between animal and non-animal areas and in food concession areas. Hand-washing stations should be accessible for all visitors, including children and persons with disabilities.
• Have available appropriate personal protective equipment (PPE) for staff and exhibitors in the event sick animals are identified during the fair.
• Report to IDPH if a person is believed to have acquired a variant or novel influenza virus from swine, poultry, or cattle so testing can be coordinated and the Illinois Department of Agriculture can follow up on the animals involved.

Contact

Contact the IDPH Communicable Disease Section, Respiratory Surveillance Program at 217-782-2016 or your local health department with questions about novel or variant influenza viruses.

Additional Resources

CDC Highly Pathogenic Avian Influenza A(H5N1) Virus in Animals: Interim Recommendations for Prevention, Monitoring, and Public Health Investigations

CDC About Human Infections with Variant Influenza Viruses CDC What People who Raise Pigs Need to Know about Influenza

CDC Considerations and Information for Fair Organizers to Help Prevent Influenza 2026 Illinois County Fair Schedule

2026 Illinois State Fair Competitive Events IDPH H5N1 Toolkit

IDPH Influenza, Novel (Avian and Variant) SharePoint Page Prevent the Spread of Flu Between Animals and People (poster)

Target Audience

Local Health Departments, Infectious Disease Physicians, Hospital Emergency Departments, Infection Control Preventionists, Health Care Providers, and Laboratories

Date Issued

June 18, 2026