Bird flu is spreading just as Americans are planning their various holiday dinners that for many involve platters of turkey, goose or other poultry, and various pies, puddings and cakes made with eggs.

The Centers for Disease Control and Prevention believes the risk of it infecting humans is low. But its impact on your pocketbook could be high, USC experts say.

Since 2022, bird flu — widespread in wild birds — has infected nearly 7 million commercial and backyard chickens in the United States. In March, the H5N1 virus was detected for the first time in dairy cattle, and it has sickened some dairy farmworkers. The nation’s leading dairy producing state, California, is at the epicenter the dairy cattle outbreak.

“It’s poised to disrupt supply chains, particularly in the poultry industry, leading to higher prices and possible shortages of poultry products,” said Nick Vyas, founding director of the Randall R. Kendrick Global Supply Chain Institute and an associate professor of clinical data sciences and operations at the USC Marshall School of Business. “We’ve seen how these situations can escalate. In 2022, the outbreak led to skyrocketing egg prices and substantial losses as millions of birds were culled.

“What’s particularly worrying this time is that H5N1 isn’t just affecting poultry — it’s hitting dairy cattle, too. This development underscores how interconnected our food supply chains are and how vulnerable they can be to such outbreaks. Controlling the virus must be practical to safeguard public and animal health, prevent further food availability disruptions and keep prices stable.”

How bird flu could affect Thanksgiving and inflation

The CDC is on watch for whether the virus may jump to other species or develop the ability to spread person-to-person — a shift that would trigger worldwide alarm. The CDC is using its flu surveillance systems to monitor for H5 bird flu activity in people.

For now, the most immediate impact could be on the cost of your holiday dinner. Somya Singhvi, an assistant professor of data sciences and operations at USC Marshall, said we might see a shift toward substitutes, such as plant-based proteins, potentially increasing their prices.

“Retailers may also face operational challenges in reallocating shelf space and managing inventory, further impacting pricing and product availability,” Singhvi said. “Overall, the outbreak could create a ripple effect across various food categories, leading to broader inflation in grocery prices.”

Bird flu could mix with human flu

There have been 46 confirmed human cases in the United States during the this year’s outbreak, reported in California, Colorado, Michigan, Missouri, Texas and Washington state, according to the CDC. There’s been no confirmed person-to-person spread.

The case of a critically ill teenager in British Columbia — Canada’s first detected human case of domestically acquired H5N1 — is in the headlines, but genetic tests showed it is a strain found in wild birds and different from the one circulating in cows.

One way to help prevent a human pandemic is to get your flu shot, said Richard Dang, an assistant professor of clinical pharmacy at the USC Alfred E. Mann School of Pharmacy and Pharmaceutical Sciences. That’s because two different influenza viruses can infect the same person, or animal, at the same time, allowing their genes to mix and create a new virus.

“While a human vaccine for bird flu is not currently available, it is important to prevent co-infections with human influenza viruses by receiving the influenza vaccine,” Dang said. “Through careful monitoring, vaccination and other precautionary measures, we can mitigate this emerging health threat before it turns into another pandemic.”

A new study by scientists at USC and California State University, Northridge, reveals that face masks — while important to public health and recommended in many health care settings — can make it harder for people of all ages to recognize emotions when faces are covered.

The research, published in the journal Emotion, found that expressions of sadness were the most difficult to identify for all age groups. Parents reporting high levels of stress and symptoms of depression had to use even more brain power to decode sad emotions behind masks, suggesting stress amplifies these challenges.

Using MRI brain scans, the researchers analyzed brain activity in fathers and their children. They measured the increased effort required to interpret facial expressions and identified the specific brain areas involved in processing emotional cues.

“Masks obscure the key emotional cues that human interaction relies on, making it harder to connect and communicate in the ways we’re accustomed to and requiring us to adapt how we read and respond to others,” said Yael Waizman, a doctoral student in the Department of Psychology at the USC Dornsife College of Letters, Arts and Sciences and the study’s corresponding author.

“For kids, it’s especially important to be mindful of their emotional cues when they’re wearing face masks, as children learn by observing and modeling behaviors,” she said. “This can be particularly challenging for stressed fathers, who may need extra support in helping their children recognize and express emotions effectively.”

Heightened brain activity required to decode masked faces

The study included three racially and ethnically diverse samples. The researchers first recruited families participating in a larger longitudinal study being conducted at the NeuroEndocrinology of Social Ties (NEST) Lab at USC Dornsife. From that group, they selected a sample of 30 children who started school at the beginning of the COVID-19 pandemic, along with 31 fathers of those children. The researchers also recruited 119 undergraduate students via Cal State Northridge’s research management system.

“Fathers make key contributions to parenting, and understanding how they process emotion can tell us more about how they might model empathy for their kids,” said senior author Darby Saxbe, a professor of psychology at USC Dornsife and principal investigator of the NEST Lab.

Participants were shown images of adults and children, both with and without masks, and asked to identify emotions such as sadness, fear or anger based on the facial expressions.

The larger USC study involved one family lab visit and two MRI visits — one for fathers and one for children. Of those, 41 participants (23 fathers and 18 children) took part in a task while having a brain scan, while the remaining 20 participants (eight fathers and 12 children) who were not eligible for scans took part in the task during their lab visit, but without the MRIs. After the lab visits, fathers filled out online surveys about their background and mental health. All 119 college students completed the facial recognition task virtually.

The results showed that masked faces were harder to recognize, both behaviorally and in brain activation patterns, for all age groups. Faces expressing sadness were especially difficult to identify.

“When responding to masked faces, we observed increased activity in brain regions associated with decoding facial expressions, emotion recognition and social cognition compared to unmasked faces,” said Waizman, who works in Saxbe’s NEST Lab.

“Sad faces, in particular, required more brain resources to interpret, with heightened activation in areas like the frontal-parietal gyri and the insula — regions critical for understanding and processing others’ emotions,” she added.

Waizman added that because sadness often prompts us to seek support and connection, it’s crucial to ensure that masks don’t interfere with those meaningful interactions.

Stressed parents face added difficulty

The study also found that fathers reporting higher levels of stress or depressive symptoms had to use more brain resources to recognize sad faces behind masks. These parents showed increased brain activity in regions associated with emotion recognition, indicating that stress may make it more difficult to process emotional cues.

“We know that stress can affect our ability to empathize with others, which is an important part of parenting,” Saxbe said. “Managing stress can help us read each other’s emotions better.”

Adapting to masked communication

“Masks are essential in many settings, including health care, schools and public spaces, to protect public health, but they also complicate how we connect with others,” Waizman said. “This raises important questions about how we can offer the support people need when the emotional cues we depend on are concealed.”

Waizman added that because sadness often prompts us to seek support and connection, it’s crucial to ensure that masks don’t interfere with those meaningful interactions.

“By raising awareness and encouraging attentiveness to other cues, we can protect our social-emotional connections while maintaining the safety masks provide,” she said.

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About the study: Co-authors include Sara R. Berzenski of California State University, Northridge’s College of Social and Behavioral Sciences; Anthony G. Vaccaro, Phillip Newsome, Elizabeth C. Aviv and Gabriel A. León from the Department of Psychology at USC Dornsife. The study was supported by the National Institutes of Health (R01-HD104801).

Could we pack the dementia-fighting benefits of exercise into a pill?

An intriguing mouse study conducted by USC scientists suggests it may be possible.

Exercise boosts blood flow, reduces stress and more. It also prompts muscles to secrete messengers that guard against Alzheimer’s disease by activating a network called the “muscle-brain axis.”

New research, published in the journal GeroScience, suggests this muscle-to-brain conversation can be switched on — without any exercise at all.

Using mouse models of Alzheimer’s disease, researchers “borrowed” one of these muscle messengers and replicated the benefits of exercise on the brain.

“This opens us opportunities to develop ‘exercise-in-a-pill’ treatments for our brain, which we are currently actively testing in our lab,” said senior author Constanza Cortes, an assistant professor at the USC Leonard Davis School of Gerontology.

New treatment could benefit seniors who can’t exercise

Such an “exercise-in-a-pill” treatment could benefit older people, who may have trouble achieving recommended levels of activity due to injuries or other medical conditions.

For this study, researchers compared the behaviors of Alzheimer’s mouse models with Alzheimer’s mice that had been genetically engineered to secrete high levels of a muscle messaging peptide without exercise.

The muscle messenger preserved the mice’s ability to navigate a maze or to nest — both measures of healthy cognition in mice.

“We looked at a bunch of Alzheimer’s-related pathologies — accumulation of plaques in the brain, inflammation in the brain and synapse communication, which is how neurons talk to each other. All of these things are completely awry in Alzheimer’s,” Cortes said. “So, we examined a group of Alzheimer’s mice, and then the same Alzheimer’s mice but with this muscle modification, and we showed that we could ‘rescue’ a lot of these symptoms.”

The researchers also gave healthy mice a dose of the muscle messenger via injection and then observed benefits to the brain — without exercise.

“This is specifically to activate these brain pathways that respond to exercise in the context of populations that can’t exercise,” Cortes said. “It’s for people who cannot get on the treadmill and exercise to the level that they need to.”

In addition to Cortes, other study authors are Hash Brown Taha, Ian Matthews, Karel Aceituno, Jocelyne Leon, Max Thorwald and Jose Godoy-Lugo, all of USC; and Allison Birnbaum of UCLA.

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The work was supported by funds from the National Institutes of Health, including grants R01 AG077536, NIA T32 AG052374 and the Alzheimer’s Association grant AARF-21–851362.