The bird flu in cows was mainly a surprise

How surprised was science when bird flu was discovered in dairy cattle with warnings against raw milk or eating unpasteurized dairy products?

Two researchers from Auburn University offer their expertise on this topic. Dr. Shollie Falkenberg, associate professor and coordinator of animal health research, and Dr. Cris Young, professor of practice at Auburn’s College of Veterinary Medicine, provides the following informed, broad perspective on the issue.

The expertise and opinions of individual faculty members do not necessarily represent an official policy or position of Auburn University. Yet two of the top researchers share their knowledge about the recent discovery of bird flu in dairy cattle.

Was it surprising then that bird flu was recently found in dairy cattle? And if so, why?

Professor Young: Yeah, it wasn’t on our radar. We consider this an emerging disease in cattle. Although HPAI in poultry is reportable, current regulations do not categorize Influenza A (IAV) in cattle in the same way. This means that there are no regulations for testing or movement controls. That’s why the federal order was the first action taken.

Associate Professor Falkenberg:Yes and no. Yes, it was surprising because this went unchecked and was thought to pose a significant threat to the livestock industry, but no, given the number of other mammals that have been shown to be infected with HPAI. Moreover, a link between influenza A virus infection, reduced milk yield and respiratory symptoms in dairy cows was previously reported in the 1990s. However, HPAI infection has not been reported in dairy cattle until recently. Other reports of cattle infected with influenza A virus have also been documented. Given that influenza viruses are single-stranded, negative-signature viruses susceptible to reassortment and spillover, it is not outside the scope of possibility that livestock could become infected with HPAI. It is more generally accepted and believed that cattle become infected with influenza D, not A.

Should people worry about contracting bird flu from food?

Young: People should always handle food safely, regardless of the source. If you develop good food preparation habits and techniques, they will serve you well.

Falkenberg: Food must always be handled properly.

Can you explain the term ‘highly pathogenic avian influenza’ (HPAI)?

Young: HPAI means that the IAV is a highly contagious, multi-organ-systemic disease of poultry that leads to high mortality in poultry.

Falkenberg: HPAI is a highly contagious disease that is often associated with increased mortality in poultry. It is usually caused by influenza A viruses (H5 and sometimes H7). It should be noted that ‘highly pathogenic’ refers to the impact these viruses have on birds, and not necessarily on humans and other mammals that have been shown to become infected.

Should we worry about cows transmitting bird flu to humans?

Young: We should. HPAI has the ability to interbreed with other human-adapted IAV strains, potentially allowing HPAI to incorporate genetic material from the human IAV strain. This could potentially lead to a tension circulating among people and possibly a pandemic.

Falkenberg: As with any pathogenic and diseased animal, proper biosecurity and risk assessment of transmission to humans and other animals should be considered. Furthermore, given that individuals handling infected birds have become infected, it would be assumed that if one species can transmit the virus, then another species would potentially do so as well.

Do we know what consequences bird flu has for dairy cattle?

Young: The virus appears to affect lactating dairy cattle. Milk production is reduced, some milk looks thicker and some cattle are slightly ill.

Falkenberg: It appears that older cows in mid to late lactation are most affected. The clinical picture was accompanied by reduced feed intake, reduced milk production and thickened yellow milk. This peaked four to six days after onset and resolved within 10 to 14 days. 

Now that bird flu has recently spread to dairy cattle, can bird flu be transmitted through milk?

Young: Yes, through raw, unpasteurized milk, but not through the milk or dairy products you would buy in the supermarket. Pasteurization is an essential food safety process.

Falkenberg: It would be assumed that there would be an increased risk of transmission with unpasteurized (raw) milk.

How does the milk pasteurization process work, and why is it so important?

Young: The most common pasteurization method is HTST (High-Temperature Short Time) pasteurization, in which milk is passed between metal plates and hot water is used to raise the temperature of the milk to 161 degrees Fahrenheit for no less than 15 seconds. by rapid cooling.

Falkenberg: The most common pasteurization method usually uses high temperatures. As a follow-up to the previous question and to provide some perspective, influenza viruses have been reported to become inactivated (non-infectious) at the following temperatures: Viral genomic RNA is denatured at temperatures greater than 60 degrees Celsius. Immunoglobin denatures at temperatures higher than 56 degrees Celsius. On the other hand, pasteurization temperatures are typically higher than 100 degrees Celsius.

What are the symptoms of bird flu and what should someone do if they suspect they have been exposed?

Young: There are very few, if any, people who need to worry about “bird flu” at this point. However, if you work with poultry, live birds, or processing, you should consider flu if you have fever, chills, cough, runny or stuffy nose, headache, fatigue, or body aches.

Falkenberg: In general, people don’t have to worry too much about exposure to “bird flu” right now. However, people who work around poultry, live birds or processing may be at greater risk and should seek medical advice if they suspect exposure or if they experience fever, chills, cough, runny or stuffy nose, headache, fatigue or physical have complaints. pain.

How is Auburn helping to tackle the disease-causing strain of bird flu known as H5N1?

Young: Auburn has many phenomenal researchers, and at the College of Veterinary Medicine, our virologists like Dr. Miria Criado, Dr. Falkenberg and Dr. Constantinos Kyriakis groundbreaking programs.

I believe that the BISR project has game-changing potential:

Falkenberg: Auburn continues to monitor information emerging from the current outbreak and is communicating with government agencies and other investigators to assist as needed. Auburn has a robust group of scientists who have ongoing research programs focused on influenza and are involved in ongoing discussions about research needs to address current concerns.

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