Concerns are mounting over avian flu and how the virus has shown up in US cattle. Experts have joined forces to voice their unease over the ongoing outbreak, highlighting how more must be done to prevent the spillover of viruses from animals to people.

A host of stakeholders are commenting on the spread of bird flu (H5N1) to cows, and how it has now been detected in milk in the US. They draw parallels to the COVID-19 pandemic.

However, it is important to note that US health officials have stressed that bird flu’s risk to the public is low, and the country’s food supply remains safe and stable. Since then, the topic has garnered more attention from around the world with increasing calls to be “pandemic prepared.”

Dr. Dirk Pfeiffer, professor of One Health at City University of Hong Kong and professor of Veterinary Epidemiology at the Royal Veterinary College, UK, comments: “Sadly, despite all the other warning signs such as climate change, biodiversity loss and the COVID-19 pandemic, we are still not acting with the urgency that is required.”

One key goal has to be the transformation of global food production systems toward sustainability, he highlights. “There is still a widespread philosophy of aiming for maximum profit in meat production when it should be about optimizing food security, food safety, animal welfare and ecological sustainability.”

“In that context, global investors who see opportunities in making money out of meat production should be aware that ‘growing cattle, pigs or chickens’ is not the same as making parts for mobile telephones because we are dealing with biological entities that are capable of amplifying pathogens as well as being sentient beings.”

Dr. Robyn Alders, an honorary professor at the Australian National University, believes experts “know the influenza virus well and understand how easily it can be transmitted, including via mechanical spread.”

She calls for a collaborative approach to data and resource sharing to prevent and control all influenza subtypes across all species. “We must also demonstrate to decision-makers that strategic, systems-based control of influenza in animals will reduce pandemic risk while also contributing to improved food safety and security as well as biodiversity and ecosystem benefits.”

Similar opinions are shared by Dr. Thomas Mettenleiter, former chair of the One Health High-Level Advisory Panel for WHO and previous head of the German Federal Research Institute for Animal Health.

“The panzootic of HPAI H5N1 demonstrates how fast influenza viruses can change and adapt. From a mere sporadic appearance, HPAI has become enzootic in poultry and wild birds with an unprecedented global spread. The repeated spillovers to mammals, including humans, document the continuous evolution of adaptations to new hosts. Influenza viruses have caused major devastating pandemics before, so we have to take this very seriously and do all in our power to reduce the likelihood of spillovers at source.”

USDA actions to protect livestock
The USDA began collecting samples of ground beef from retail stores this week. They will be analyzed with PCR tests that indicate “whether any viral particles are present.”

Officials are targeting the states with avian flu outbreaks in dairy but they remain confident the meat supply is safe.

In addition, the USDA has implemented several steps to get ahead of the virus and limit its spread.

These include mandatory testing for interstate movement of dairy cattle, which means dairy cattle must test negative for the virus prior to any movement. The test must be carried out at an approved National Animal Health Laboratory Network laboratory.

Another safeguard is that laboratories and state veterinarians must report positive Influenza A nucleic acid detection diagnostic results (for example, PCR or genetic sequencing) in livestock to USDA APHIS. They must also report positive Influenza A serology diagnostic results in livestock to USDA APHIS.

Milk safety
Sampling has also been carried out on milk. The FDA and USDA have the first set of results from a limited targeted sample.

“The FDA continues to analyze this information; however, preliminary results of egg inoculation tests on quantitative polymerase chain reaction (qPCR)-positive retail milk samples show that pasteurization is effective in inactivating HPAI,” it states.

This additional testing did not detect any live, infectious virus. “These results reaffirm our assessment that the commercial milk supply is safe.”

Samples of retail powdered infant formula and powdered milk products marketed as toddler formula were also tested, and all qPCR results of formula testing were negative, indicating no detection of viral fragments or virus in powdered formula products.

“The FDA is further assessing retail samples from its study of 297 samples of retail dairy products from 38 states. All samples with a PCR positive result are going through egg inoculation tests, a gold-standard for determining if infectious virus is present. These important efforts are ongoing, and we are committed to sharing additional testing results as soon as possible. Subsequent results will help us to further review our assessment that pasteurization is effective against this virus and the commercial milk supply is safe.”

Colombia’s restrictions on US beef
Despite reassurances that the US beef supply is safe, Colombia has restricted beef and beef products coming from some US states wher dairy cows have tested positive for avian influenza.

But Joe Schuele from the US Meat Export Federation (USMEF) has hit back at Colombia’s beef suspension.

“The restrictions Colombia has imposed on US beef as a result of the recent highly pathogenic avian influenza (HPAI) findings in lactating dairy cows have no scientific basis. Colombia is the only country that has officially restricted imports of US beef. USMEF is encouraged that the vast majority of our trading partners are following the science on this matter,” he says.

“The US is Colombia’s largest supplier of imported beef, and Colombia’s attempt to suspend beef imports from specific US states is unworkable and misguided. It has created uncertainty for Colombian importers and their customers as well as their suppliers, and will greatly disrupt trade. USMEF appreciates the efforts of the US government to address Colombian officials’ concerns and we are hopeful that this matter can be resolved as soon as possible.”