Credit CDC
#18,179
Since 2010 we've seen over 500 swine-variant influenza (H1N1v, H1N2v & H3N2v) infections in humans reported to the CDC - most linked to direct or indirect contact with pigs - with exposures often occurring at agricultural exhibits at county and state fairs.
Already this year we've seen 3 H1N2v infections reported in people living in Pennsylvania. Not quite a month ago, in Nature Comms: Potential Pandemic Risk of Circulating Swine H1N2 Influenza Viruses, we looked at growing concerns over this subtype.
Swine variant influenza infections are indistinguishable from seasonal flu without highly specialized testing, which few countries tend to do. Even here in the United States it is assumed we only detect a small percentage of cases (see CID Journal: Estimates Of Human Infection From H3N2v (Jul 2011-Apr 2012)).
Summer and fall - when the many state and county fairs are held around the country - is when we usually expect to see the most spillover events.
The CDC has long advised those who are at higher risk of serious flu complications (including children under 5, adults over 65, pregnant women, and those with certain chronic medical conditions), to avoid pigs and the swine barn altogether.
This year, the spillover of HPAI H5N1 into dairy cattle, goats, and even alpacas raises new concerns over the potential exposure to - and spread - of these novel flu viruses at these agricultural exhibits (see CDC Issues Broader Influenza A Guidance For Agricultural Exhibits).
While the risks to the public are currently believed low, next week the CDC will hold a COCA Call for clinicians and Healthcare centers which will provide information on testing, using antivirals, and infection prevention and control recommendations.
Late yesterday the CDC updated their previous guidance on swine influenza risks to include HPAI H5N1. I'll have a bit more after the break.
CDC Issues Updated Guidance to Help Prevent Spread of Flu at Agricultural Fairs
WHAT TO KNOWSummary
- In March 2024, highly pathogenic avian influenza A(H5N1) virus, also known as “H5N1 bird flu,” was reported in cows in the United States.
- CDC has issued updated guidance to help prevent the spread of flu between animals and between animals and people at fairs.
- Taking preventive actions at fairs can help protect exhibitors, visitors, and livestock from flu.
What CDC knows
An outbreak of H5N1 bird flu among poultry and dairy cows continues to spread in the United States. Four human cases with exposures to sick cows have been reported.
What CDC is doing
CDC has issued updated guidance to help prevent the spread of flu, including from cattle to people, at livestock fairs or exhibitions across the country. CDC continues to respond to the public health challenge posed by the multistate outbreak of H5N1 bird flu in cows and other animals in the United States.
With agricultural and livestock fairs happening all around the country this summer and fall, the chances for people to be in close contact with pigs, poultry (e.g., chickens, turkeys, ducks, geese), and cattle increase. Livestock fairs and shows are an important learning opportunity for people of all ages interested in agriculture.
At the same time, animals exhibited at agricultural fairs and shows can carry and spread influenza A viruses that are different from the seasonal influenza A viruses that commonly spread among people.
As the multistate H5N1 bird flu outbreak in poultry, cows and other animals continues to spread, CDC is recommending that fair exhibitors take actions to help prevent the spread of influenza A viruses between animals and between animals and people.
Multistate bird flu outbreak is ongoing
Since the first report of H5N1 bird flu in U.S. dairy cows this March, four associated human cases have been detected. All four people had direct contact with sick cows before they got sick, had mild illness, and have recovered. These are the first reported instances of cow-to-human spread of H5N1 bird flu.
The number of dairy cow herds infected with H5N1 bird flu continues to grow. As of July 11, 146 dairy cow herds in 12 states have confirmed cases of A(H5N1) virus infections. CDC is working with the U.S. Department of Agriculture, the Food and Drug Administration, and state and local public health and animal health officials to respond to this public health challenge.
The risk of H5N1 bird flu to the general public is low at this time. People with close, prolonged, or unprotected exposures to infected birds or other animals (including livestock), or to environments contaminated by infected birds or other animals, are at greater risk of infection. Farm workers on affected farms, for instance, are at higher risk of infection than others in the population.
Influenza viruses can spread in livestock fairs
While rare, influenza A viruses can spread from animals (including pigs, poultry, and cattle) to people and also from people to animals. For example, swine influenza viruses spread commonly in pigs and avian influenza viruses spread commonly in wild birds and cause outbreaks in poultry and now cows. People can be infected by swine and avian influenza viruses and vice versa. People most often get infected with animal influenza A viruses after being in close contact with infected animals.
It is rare for people to get sick from these viruses, but when they do, the sickness has varied from mild to severe. In some cases, it has led to hospitalization or death.
Animals commonly exhibited at agricultural fairs and shows, including pigs, poultry (e.g., chickens, turkeys, ducks, geese), and cattle, can carry and spread influenza A viruses.
CDC offers guidance to fair exhibitors
Livestock exhibitors can take the following actions to help protect themselves, friends and family, other visitors, and livestock and prevent the spread of flu:
Protect your animals
- If you are sick with flu-like illness, stay home to avoid spreading illness to other people or animals.
- Plan to keep pigs, poultry, and cattle at the fair or exhibition for shorter periods of time to prevent or interrupt the spread of flu between animals (72 hours or less is ideal).
- Don’t take toys, pacifiers, cups, bottles, strollers, or similar items into the animal areas.
- Don’t eat, drink, or touch, or put anything in your mouth or touch your eyes while in animal areas (barns, show arenas).
- Wash your hands often with soap and running water after touching animals, animal associated equipment, or their environments (like a barn or enclosure). If soap and water are not available, use an alcohol-based hand sanitizer.
- Where possible, avoid direct contact with pigs, poultry, cattle, and other animals that look or act ill. (Direct physical contact with the animal includes touching, holding, kissing, being bitten, licked, and scratched.)
- If you must come in contact with animals that may be ill, wear personal protective equipment (PPE), which includes protective clothing, gloves, goggles, and a respirator or well-fitting mask that covers your mouth and nose. Parents and caregivers should review considerations for specific groups of people when selecting a respirator or mask for children.
Other resources
- If your animals are sick or are from herds with a recent history of respiratory disease, keep them at home to prevent further spread of illness.
- Watch animals for illness before and during the fair. In dairy cows, decreased milk production can be a sign of influenza virus infection. Other signs of illness include loss of appetite, fever, tiredness, eye redness, signs of discomfort, cough, or runny nose.Call the fair veterinarian and/or the fair manager right away if you suspect illness.
- Remove sick animals from the exhibition area right away.
- If possible, avoid close contact with sick animals.
- Clean and disinfect all tack, feeders, waterers, equipment, and show supplies before and after bringing them to the fair or show. Do not share equipment used for other animals.
CDC has issued interim recommendations for preventing, monitoring and public health investigations of H5N1 bird flu in animals and people.
An appendix to CDC’s interim H5N1 bird flu guidance categorizes the degree of risk by exposure.
In addition, USDA also has fair guidance that focuses on reducing the risk of influenza spread between animals.
Many states have already issued their own guidance and/or regulations for these livestock exhibitions, but they vary widely from one state to another.
Some have prohibited poultry exhibitions entirely, while others still appear to be on the schedule. Conspicuously, some jurisdictions are apparently mandating enhanced livestock biosecurity, while others only appear to be `urging' farmers to take precautions.
While the HPAI H5 could easily spillover into swine - or humans - without the assistance of agricultural exhibitions - by putting people and multiple livestock species into close quarters with each other - they provide a potential shortcut for the virus.
But the reality is, with more than 3,000 state and county fairs of varying sizes across the nation, there are practical limits to what can be done to prevent that.
Hopefully, we stay lucky and the virus continues to fall short.
Stay tuned.
