Bird flu has been a growing North American issue since late 2021, but it has taken an even higher leap for health officials to concern themselves with. In January 2025, the US experienced its first human death from bird flu, with two February hospitalizations and troubling signs of the virus spreading over to livestock, like cattle. As the H5N1 strain continues to sweep through wild and domesticated animals, egg prices have gone wild as a result of infection in egg-laying hens, showing the outbreak is far from contained.
“Last few weeks, it’s all new developments in the H5N1 drama,” said Meghan Davis, associate professor of environmental health at Johns Hopkins Bloomberg School of Public Health. While the general public may be “alert, not alarmed,” as Davis put it, the situation does warrant caution since the virus is giving no indication of being entirely contained.
What is Bird Flu?
Bird flu or avian influenza is a flu that has birds as its primary victims but can be transmitted to other animals and, very rarely, humans. It is the H5N1 virus, which is a highly pathogenic virus, that is responsible for the current outbreak in North America, taking wild birds, chickens, and even mammals like cows as its victims. Though rare, human infections are a cause for growing concern due to the potential of the virus to mutate.
Human Symptoms of Bird Flu
In humans, avian flu generally replicates seasonal flu symptoms, which are:
- Cough
- Fever
- Fatigue
- Musculoskeletal aches
- Headaches
They also have reported runny or stuffy noses, sore throat, or abdominal pain in the form of diarrhea, nausea, or vomiting. But this outbreak has been reported following unusual symptoms, including conjunctivitis (pink eye), which is not normal with seasonal flu.
Severe symptoms may cause difficulty in breathing, convulsions, or altered states of consciousness—alarming signs that require emergency medical attention, the US Centers for Disease Control and Prevention (CDC) reported.
How Deadly is Bird Flu?
Globally, since 2003, over 950 people have been infected with H5N1 with an alarming 49% death rate. Deaths, however, have been fewer in the current US outbreak. Over the past year, 70 confirmed (and some suspected) cases have emerged, with only one death and three hospitalizations. Scientists speculate that infections are more likely to be mild in this outbreak, but that severe infections are a very real threat.
“The virus is evil in some people,” said Megan Ranney, an emergency physician and dean of the Yale School of Public Health. Nobody knows what makes it severe, and if H5N1 begins to spread from person to person—a scenario that has not yet occurred—it can mutate, potentially altering its deadliness.
In areas where healthcare access is poor, mortality rates could be even greater because the patients cannot get early treatment, says Davis.
How is Bird Flu Transmitted to Humans?
Bird flu is spread by direct contact with infected animals or raw animal products. Individuals at greatest risk are:
- Farm workers handling chickens or milk cows
- Individuals in contact with wild animals or birds
- People who consume raw milk or undercooked meat
Two confounding US cases, one from Missouri and one from California, were patients with no known animal exposure, calling into question the potential for a lack of surveillance transmission pathways. Human-to-human transmission was never confirmed until now, but the recent lack of transparency on the part of healthcare officials has enraged experts.
“We’re missing opportunities to learn more about this virus and the danger it poses,” said Jennifer Nuzzo, director of the Brown University School of Public Health’s Pandemic Center.
For individuals working with animals, habits such as hand washing, wearing masks while working with diseased poultry, and symptom surveillance are important.
Treatment and Vaccines
Antivirals like Tamiflu can reduce the severity and spread of bird flu if administered early, though resistant strains are a concern. “We need more therapeutics,” Nuzzo emphasized.
There are both human and animal vaccines for H5N1. America has stored 4.8 million doses of human vaccines but they’re not yet made public, given the low rate of hospitalizations, absence of person-to-person spread, and vaccine hesitancy fears, reports Nirav Shah of the CDC. Experts find that veterinarians and agricultural workers should be provided on the occupational exposure basis. Chicken and bovine vaccines are also produced but not yet applied.
The flu vaccine does not protect against H5N1, but Davis recommends it to prevent co-infection that could intensify the pandemic through viral reassortment—a process where the influenza viruses cross-breed, potentially creating a more dangerous strain.
Is Bird Flu Here to Stay?
Hopes of the outbreak running out of steam have been “shattered,” Nuzzo stated. With spillover to animals and ongoing transmission in birds, the virus appears to be settled in. If it adapts to transmit readily in people, a global pandemic may occur in a few weeks, specialists warn.
Although H5N1 won’t necessarily spark the next pandemic, another flu outbreak is an all-too-real inevitability. Building healthcare infrastructure, advance vaccination, and test development continue to be at the top of the list.
Food Safety and Testing
Doctors can order H5N1 tests when risk factors like animal exposure or raw milk consumption are reported by the patients. Milk pasteurization and thorough cooking of eggs and meat in the kitchen inactivate the virus. Raw milk, which is linked to animal infection, is strongly discouraged, and meat should be cooked to an internal temperature of at least 145°F (63°C) to kill pathogens.
“Good hygiene principles writ large in the kitchen” are the key, Davis suggested, with hazards from other microbes like E. coli and salmonella found in raw ingredients.
