The Centers for Disease Control and Prevention (CDC) announced that a person in the United States has tested positive for highly pathogenic avian influenza (HPAI). The person, who had exposure to dairy cattle in Texas presumed to be infected with HPAI, was reported to have mild symptoms and is recovering.
This is the second person to test positive for influenza A(H5N1) viruses in the United States. A previous case was reported in 2022 in Colorado.
Human infections with avian influenza A viruses, including A(H5N1) viruses, are uncommon but have occurred sporadically worldwide. CDC has been monitoring for illness among people exposed to H5 virus-infected birds since outbreaks were first detected in U.S. wild birds and poultry in late 2021.
If you are working directly with cattle that have tested positive or are suspected to be infected and you are experiencing flu-like symptoms, please consult your physician. Human cases of influenza must be confirmed with testing, they cannot be diagnosed based on symptoms alone. The most common symptoms include:
- Fever or feeling feverish
- Cough
- Sore throat
- Runny or stuffy nose
- Muscle or body aches
- Headaches
- Fatigue
- Eye redness (or conjunctivitis)
- Shortness of breath or difficulty breathing
The CDC recommends the following personal protective equipment (PPE) when people must work with sick or dead animals as well as with animal carcasses, raw milk, feces, litter or materials contaminated by birds or other animals with confirmed or suspected HPAI infection:
- Properly fitted unvented or indirectly vented safety goggles
- Disposable gloves
- Boots or boot covers
- NIOSH-Approved particulate respirator (e.g., N95® filtering facepiece respirator, ideally fit-tested),
- Disposable fluid-resistant coveralls
- Disposable head cover or hair cover
USDA confirms HPAI in New Mexico
USDA APHIS has confirmed the presence of HPAI in a New Mexico dairy herd and five additional Texas dairy herds. So far, HPAI has been confirmed in dairy herds in Texas (7) Kansas (2), Michigan (1), and New Mexico (1).
There continues to be no concern that this circumstance poses a risk to consumer health, or that it affects the safety of the commercial milk supply because products are pasteurized before entering the market.
The U.S. Food and Drug Administration’s (FDA) longstanding position is that unpasteurized, raw milk can harbor dangerous microorganisms that can pose serious health risks to consumers.
Federal and state agencies continue to conduct additional testing in swabs from sick animals and in unpasteurized clinical milk samples from sick animals, as well as viral genome sequencing, to assess whether HPAI or another unrelated disease may be underlying any symptoms.
Veterinarians working with potentially impacted farms should consult with state health officials and their diagnostic laboratories to ensure they follow established diagnostic sampling guidelines.
At this time, impacted herds do not appear to be experiencing mortalities associated with this disease syndrome. Approximately 10% of cattle are affected in impacted herds, with most cases being mid to late-lactation mature cows. Impacted herds are experiencing approximately 10% to 20% reduction in milk production for a 14- to 21-day period. At this time, dry cows, fresh cows, heifers and calves do not appear to be affected.
Cattle symptoms
- Symptoms last between 10 and 14 days with the worst of the symptoms peaking in the first 3 to 5 days.
- A sudden drop in milk production, with severe cases producing thicker, more concentrated milk that appears colostrum-like.
- A drop in feed intake and rumination activity.
- Mostly have tacky, dehydrated feces, but a small number have loose feces.
- Can experience secondary infections including pneumonia and mastitis.
If you feel your herd’s symptoms are consistent with the reported illness, consult your herd veterinarian or the Minnesota Board of Animal Health immediately.
Follow biosecurity practices
Based on these cases, cattle (dairy and beef) owners are encouraged to follow recommended biosecurity practices for mitigating livestock and avian interaction including:
- Minimize or eliminate (when possible) poultry and livestock species access to ponds, wetlands and other stagnant water sources frequented by wild waterfowl (ducks, geese, swans).
- Monitor cattle for signs of illness, this includes decreased milk production, decreased feed intake, fever, dry or tacky feces and depression.
- Monitor domestic poultry for illness, this includes reduced appetite, reduced water intake and unexplained deaths.
- Monitor cats, wild waterfowl, and wildlife that are frequently found around livestock facilities for illness or unexplained deaths.
- Consider housing poultry separately from other livestock and minimize poultry access to pasture areas grazed by other livestock.
- Minimize or eliminate (when possible) poultry, waterfowl, and wildlife access to potentially shared water sources and feedstuffs (cover and secure feed piles).
At this time, it is unclear if the illness can be spread from cow to cow or by inanimate objects such as vehicles or equipment. Cattle (dairy and beef) owners are encouraged to follow these biosecurity practices for livestock:
- Limit visitors to your farm and consider having meetings away from the farm when possible.
- Minimize the interaction of on-farm vehicle routes and off-farm vehicle routes.
- Ensure the equipment used to transport animals is clean and washed between uses, this includes your trailers in addition to outside-hired transport. Inspect trailers before use to ensure they have been cleaned.
- Cattle transported to a new location should be quarantined and isolated for 21 days to monitor for clinical signs before joining the herd.
- Deceased animals should be disposed of promptly and appropriately, including composting, deep burial to prevent wildlife interaction with the carcass, or rendering. Minimize the interaction of the rendering truck with on-farm vehicle routes and animals.
- When possible, personnel should have dedicated clothing, boots and other PPE for the farm that stays on the farm.
- Service providers are encouraged to have dedicated equipment, clothing, boots and other PPE for farms they visit regularly. Boot washing and disinfection, equipment washing and disinfection, and changing soiled clothing are recommended when dedicated equipment is not available.
- Milk intended for feeding animals, including calves, from cows that are infected or have potential contact with infected animals, should be pasteurized.
We will share additional information as we learn more. For updates, please continue to check this website, the USDA APHIS website, the Minnesota Board of Animal Health, and the CDC website. You can also listen to The Moos Room podcast for updates.
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