The outbreak of highly pathogenic avian influenza (HPAI) that has moved from poultry to cattle and, in a rare case, to a human in Texas has raised significant concerns within the agricultural and public health communities.  

The Virginia Tech Animal Laboratory Services (ViTALS) lab at the Virginia-Maryland College of Veterinary Medicine, as part of the National Animal Health Laboratory Network (NAHLN), along with veterinary alumni at federal and state organizations have been monitoring the situation. A meeting to update Virginia producers is planned for later this month.

Overview of the outbreak  

The current avian influenza outbreak began with the detection of the virus in dairy cattle in Texas that exhibited unusual symptoms such as producing less milk, low appetite, and changes in milk quality.  

Investigations linked these symptoms to avian influenza and marked a concerning development in the virus' transmission capabilities. Notably, this is one of the first instances where the virus has been confirmed in cattle. Previous cases predominantly were observed in poultry and wild birds.

The strain of the virus identified in the cattle (H5N1, Eurasian lineage goose/Guangdong clade 2.3.4.4b) has not shown changes that would increase its transmissibility to humans, yet the infection of one person in Texas underscores the unpredictable nature of this virus and the need for vigilance. 

According to the American Veterinary Medical Association, the current avian influenza outbreak “has been confirmed in dairy cattle in eight states: 11 herds in Texas, six in New Mexico, four in Michigan, three in Kansas, and one each in Idaho, Ohio, North Carolina, and South Dakota."

Another twist includes confirmation that three cats on an affected farm in Texas also tested positive for the virus. 

ViTALS lab involvement

"Our ViTALS lab at the veterinary college is part of the National Animal Health Laboratory Network. Initial testing for avian influenza was done by labs within the NAHLN, with confirmation tests conducted by the National Veterinary Services Lab,” said Tanya LeRoith, clinical professor in the Department of Biomedical Sciences and Pathobiology and director of the ViTALS lab.

The National Veterinary Services Lab also handles sequencing. "This confirmed that the strain affecting livestock was identical to that found in birds and had not mutated to increase transmissibility to humans. Such insights are crucial for our ongoing surveillance and response strategies," LeRoith said.

“We are working in close collaboration with state and federal animal health officials to monitor the situation and prepare for any potential spread to other states,” LeRoith said. "All HPAI testing is conducted through labs within our network, ensuring coordinated efforts and rapid response across states.”

Carrie Bissett DVM ’04, director of veterinary services for the Virginia Department of Agriculture and Consumer Service said, “This really has been going on for a couple of months ... a strange sort of confluence of signs with dairy cows.”  

Bissett said it highlighted the unexpected nature of the outbreak. "We also know that this virus has some propensity for mammals. ... How they're getting it is a little bit of a mystery." 

Imports and travel restrictions

In an April 9 news release, the American Veterinary Medical Association stated: “In an effort to prevent domestic cattle from being exposed to highly pathogenic avian influenza virus, 17 states have restricted cattle importations from states where the virus is known to have infected dairy cows: Alabama, Arizona, Arkansas, California, Delaware, Florida, Hawaii, Idaho, Kentucky, Louisiana, Mississippi, Nebraska, North Carolina, Pennsylvania, Tennessee, Utah, and West Virginia."

The U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) has not issued federal quarantine orders at this time, nor is the agency recommending any state quarantines or official hold orders on cattle, the agency announced April 2.

Virginia's response and preparedness 

In Virginia, the situation is being closely monitored with no reported cases in cattle as of the latest updates. The state's veterinary services, under the guidance of the Virginia Department of Agriculture and Consumer Service, are on high alert, prepared to implement containment and management strategies should the virus be detected.  

"So far, minimal to none," was how Bissett described the impact on Virginia, signaling cautious optimism while affirming readiness. "We're sort of all sitting up straight, paying attention and looking around waiting. ... We are preparing just in case, which is what my job is pretty much – and then hoping that it doesn't happen."  

Virginia's approach emphasizes surveillance, biosecurity, and cooperation among agricultural stakeholders to prevent the spread of avian influenza. Key recommendations include practicing good biosecurity, isolating sick cattle from healthy ones, and rigorous monitoring of livestock health by farmers and veterinarians. The collaboration between state and federal agencies, including the Department of Agriculture, the Centers for Disease Control and Prevention, and the Food and Drug Administraiton, plays a critical role in the coordinated response to this outbreak. 

Advice for Virginia residents 

"I think the biggest concerns that we might have are those farms that have dairy cattle and poultry on the same farm," said Bissett, underlining the importance of stringent biosecurity measures to prevent cross-species transmission of the virus. "Making sure that you are changing clothes, changing your personal protective equipment, boots, those sort of things before then go in and work on your poultry, making sure that separation is there is more important than ever right now."  

For residents, particularly those involved in dairy farming and cattle rearing, the advice centers on heightened awareness and proactive health management of livestock: 

  • Monitor livestock closely: Look for symptoms such as decreased milk production, changes in milk quality, low appetite, and general signs of illness among cattle.
  • Maintain stringent biosecurity measures: Ensure that biosecurity protocols are strictly followed to prevent the introduction and spread of the virus within farms. This includes proper sanitation, the use of personal protective equipment, and avoiding cross-contamination between different types of livestock. 
  • Immediate reporting and isolation: Any suspected cases of avian influenza in cattle should be immediately reported to the Virginia Department of Agriculture and Consumer Service or local veterinary services. Infected or suspected animals should be isolated to prevent spread. 
  • Stay informed: Keep abreast of updates from the U.S. Department of Agriculture, Virginia Department of Agriculture and Consumer Service, and health authorities regarding the outbreak and follow their guidance diligently. 

"Certainly, if you see dairy cattle that are off feed, perhaps febrile, perhaps not, with changes in milk production, decreased milk production, changes in milk property and quality, and you've ruled out some of your other common diseases, this is something to think about," said Bissett.  

The Virginia Beef Center of Excellence has produced a guide for local producers and will hold a virtual meeting for Virginia producers on Thursday, April 25, in conjunction with other Virginia agencies. Interested producers should contact the center for details. 

Testing policy amid the outbreak 

"While there's a natural concern among producers to test for HPAI, either for peace of mind or for movement purposes, we will test only if requested by state veterinarians to manage the availability of tests and supplies effectively," LeRoith said.  

"It's important for producers to understand that they should not independently seek testing for HPAI. Instead, if there's a concern, they need to promptly contact their veterinarian or state animal health officials," LeRoith said. "This ensures that the response is measured and within the guidelines set forth by health authorities."

Public health implications 

While the risk to the public remains low, the detection of avian influenza in a human case linked to this outbreak serves as a reminder of the potential for zoonotic transmission. 

Consumers can rest assured that the milk supply is safe, as milk from affected animals is not entering the food chain and pasteurization effectively inactivates the virus. Nonetheless, individuals, especially those in close contact with livestock, should exercise caution and follow public health guidance to mitigate any potential risk. 

The evolution of the avian influenza outbreak, with its spread to cattle and a human case, underscores the interconnectedness of animal health and public health. Vigilance, rapid response, and collaborative efforts across sectors are paramount to managing this situation effectively. Virginia's preparedness and response strategies, anchored in surveillance, biosecurity, and public awareness, are crucial steps in safeguarding both animal and human health against avian influenza.     

Further links and information 

For updates on this developing situation, it's advisable to frequently check the provided links and resources.

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