A patient in Louisiana has been hospitalized with a severe case of bird flu (H5N1). This is the first instance of serious illness from this virus in the United States. Although health officials emphasize that the risk to the general public remains low and the virus still isn’t transmitted from human to human, this as a stark reminder that avian influenza remains a persistent and pervase threat, especially to those in close contact with birds and other animals.

The Centers for Disease Control and Prevention (CDC) first confirmed the case on December 13, 2024, after the patient, an individual over 65 with underlying health conditions, was exposed to sick and dead birds in a backyard flock. A few days later, this patient developed severe respiratory symptoms and is now in critical condition.

This is the latest episode in a concerning series of bird flu outbreaks.

Since April 2024, there have been 61 confirmed human cases of H5N1 bird flu in the United States. But this is the first case to result in severe illness. Most previous cases involved farmworkers who came into contact with infected poultry or dairy cows. Yes, cows are also getting bird flu.

Partial genetic analysis of the virus from this patient shows it belongs to the D1.1 genotype. This strain has also been detected in wild birds and human cases in Canada and Washington state. The strain differs from the B3.13 genotype, which has been primarily linked to infections in dairy cows and some poultry flocks.

An investigation into the infection is still ongoing, but it appears the patient was exposed to backyard flocks, which many people keep for eggs or hobby farming.

Bird flu has been making the rounds

Since 2020, outbreaks of avian influenza have been constantly happening.

Avian influenza, commonly known as bird flu, has been a concern for decades. The H5N1 subtype first emerged in 1997 in Hong Kong and has since spread globally, causing outbreaks in birds and occasional spillover into humans. In 2024 alone, countries like Canada, China, and parts of Europe reported human cases, some of which resulted in fatalities.

The virus primarily spreads among birds but can occasionally infect mammals, including humans, cats, and even cheetahs and mountain lions. While the virus does not currently spread easily between humans, each new infection provides the virus with an opportunity to mutate. As we’ve seen with COVID-19, all it takes is one unfortunate mutation to turn this into a public health crisis. This is why health experts closely monitor every human case.

Bird flu viruses like H5N1 primarily circulate among wild birds, especially waterfowl. These birds can carry the virus without appearing sick, spreading it through their saliva, mucus, and feces. Domestic poultry, including chickens and turkeys, can become infected when they come into contact with contaminated wild birds or their droppings.

How contagious is it?

People can contract the virus through direct contact with infected birds or contaminated surfaces. Handling sick or dead birds, cleaning coops, or even touching contaminated soil or water can expose individuals to the virus.

In recent months, dairy cows in several states have also tested positive for H5N1, and their milk has been identified as another potential source of the virus. Consuming unpasteurized (“raw”) milk or milk products from infected cows poses a risk of infection.

These outbreaks also threaten food supplies. When poultry farms are hit by H5N1, millions of birds often need to be culled to contain the spread, leading to economic losses and supply chain disruptions.

Avian flu has been detected everywhere from Antarctica to India and from the United States to Cambodia. Despite the alarming nature of this severe case, however, the CDC reiterates that the overall risk to the general public remains low.

So far, there is no evidence of person-to-person transmission of H5N1 bird flu. This means that while the virus can jump from animals to humans, it has not adapted to spread efficiently between people.

For now just be cautious

A sporadic case of severe H5N1 bird flu in humans is not unexpected. This has happened before, but as long as the disease doesn’t isn’t transmitted from human to human, the risk remains relatively low. However, the risk is higher for those who work closely with birds or livestock, including farmworkers, hunters, and veterinarians.

People in these groups are urged to follow CDC guidelines for protective measures. Wearing personal protective equipment (PPE), such as gloves and masks, can significantly reduce the risk of infection. It’s also important to avoid touching sick or dead birds and to practice good hygiene after handling animals.

In the meantime, researchers continue analyzing the genotypes of the avian flu, working with health officials to identify patterns and assess whether certain strains pose greater risks.