Bird Flu Found in Michigan Dairy Cattle After Herd Moved from Texas


A herd of dairy cattle in Michigan that had recently been relocated from Texas has tested positive for highly pathogenic avian influenza (HPAI) according to the USDA and Michigan Department of Agriculture and Rural Development (MDARD).

The affected farm—which is located in Montcalm County, northeast of Grand Rapids—recently received cattle from an affected premises in Texas before that herd showed any sign of disease. When the cattle were moved from Texas to Michigan, the cattle were not symptomatic and did not appear ill.

In a written statement sent to Hoosier Ag Today by the Indiana State Board of Animal Health (BOAH):

No cases have been identified in Indiana. 
Any cattle owner in Indiana who notices clinical signs consistent with this illness should contact his/her veterinarian for evaluation and diagnostics.
As always, producers are encouraged to practice good biosecurity when moving on/off and between farms.
BOAH will continue to monitor the situation and communicate developments as appropriate.

On Monday, March 25, the agencies confirmed the detection of highly pathogenic avian influenza (HPAI) in two dairy herds in Texas and two dairy herds in Kansas that had cattle exhibiting these symptoms. Presumptive positive test results have also been received for additional herds in New Mexico, Idaho, and Texas.

USDA’s National Veterinary Services Laboratories (NVSL) has also confirmed that the strain of the virus found in Michigan is very similar to the strain confirmed in Texas and Kansas that appears to have been introduced by wild birds (H5N1, Eurasian lineage goose/Guangdong clade  Initial testing has not found changes to the virus that would make it more transmissible to humans. While cases among humans in direct contact with infected animals are possible, this indicates that the current risk to the public remains low.

HPAI is a highly contagious virus that can be spread directly by infected wild birds/animals or indirectly through any item that has been exposed to the virus—such as equipment, feed, or the clothing and shoes of caretakers. The virus has been detected in various species of mammals—presumably after the animals come into contact with infected birds. To limit the spread of the disease, the affected premises voluntarily stopped movement.

Spread of symptoms among the Michigan herd also indicates that HPAI transmission between cattle cannot be ruled out; USDA and partners continue to monitor this closely and have advised veterinarians and producers to practice good biosecurity, test animals before necessary movements, minimize animal movements, and isolate sick cattle from the herd. Among the dairies whose herds are exhibiting symptoms, the affected animals have recovered after isolation with little to no associated mortality reported.

There continues to be no concern about the safety of the commercial milk supply because products are pasteurized before entering the market, or that this circumstance poses a risk to consumer health. Dairies are required to send only milk from healthy animals into processing for human consumption; milk from impacted animals is being diverted or destroyed so that it does not enter the human food supply.

In addition, pasteurization has continually proven to inactivate bacteria and viruses, like influenza, in milk. Pasteurization is required for any milk entering interstate commerce for human consumption. FDA’s longstanding position is that unpasteurized, raw milk can harbor dangerous microorganisms that can pose serious health risks to consumers, and FDA is reminding consumers of the risks associated with raw milk consumption in light of the HPAI detections.

Because of the limited information available about the transmission of HPAI in raw milk, the FDA recommends that industry does not manufacture or sell raw milk or raw/unpasteurized milk cheese products made with milk from cows showing symptoms of illness, including those infected with avian influenza or exposed to those infected with avian influenza.

At this time, the FDA is not aware that any milk or food product from symptomatic cows is entering interstate commerce.  Furthermore, if milk from cows showing symptoms of illness, including those infected with avian influenza or exposed to those infected with avian influenza is intended to be used to feed calves, FDA strongly encourages that it be heat treated to kill harmful bacteria or viruses, such as influenza, before calf feeding.

Milk loss resulting from symptomatic cattle to date is too limited to have a major impact on supply and there should be no impact on the price of milk or other dairy products. Further, the U.S. typically has a more than sufficient milk supply in the spring months due to seasonally higher production.

Federal agencies are also working with state and industry partners to encourage farmers and veterinarians to report cattle illnesses quickly so that we can monitor potential additional cases and minimize the impact and risk to farmers, farmworkers, consumers and other animals. Producers are urged to work with their veterinarian to report cattle illnesses quickly and practice enhanced biosecurity measures.

Sources: USDA Animal and Plant Health Inspection Service, Michigan Department of Agriculture and Rural Development (MDARD)