Avian influenza strains that began circulating in 2020 continue to evolve around the world and locally in the United States. If you're wondering what this means, it helps to understand the basics, including what bird flu is, how it spreads, is the food safe, and tips for prevention. More information will come as scientists learn more, so stay tuned.
1. What is bird flu and how does it spread?
Bird flu is a naturally occurring disease. Just as certain influenza viruses spread among humans, influenza A viruses often spread among wild birds. The current viral strain is H5N1, named for the two proteins on its surface.
Bird flu infection is highly contagious. Infection often spreads first among wild waterfowl such as ducks, geese, and gulls, and shorebirds such as plovers and sandpipers. The virus is carried to the intestines and respiratory tract and is excreted in saliva, mucus, and feces. Wild birds can easily infect poultry such as chickens, turkeys, and ducks.
Some birds, such as ducks, can carry and spread infectious diseases even if they don't appear to be sick. Herds of livestock are more likely to get sick and die from avian influenza. However, not all avian influenza viruses are equally harmful.
- Low pathogenic avian influenza (LPAI) It may cause no signs of disease, or it may cause mild signs of disease, such as fewer eggs or ruffled feathers in poultry.
- Highly pathogenic avian influenza (HPAI) Infected poultry causes more severe disease and higher mortality. Her current H5N1 virus is thought to be HPAI.
2. Can humans also get infected with bird flu?
Yes, this usually doesn't happen.
When an influenza virus mutates, it can move from its original host (in this case, a bird) to humans or other animals. As of this writing, two human cases of avian influenza have been reported in the United States since 2022.
Viruses can enter the body through the eyes, nose, and mouth. For example, people can inhale airborne virus particles (in droplets, small aerosolized particles, and even dust). Or you may touch a surface contaminated with the virus and then touch your eyes or nose.
3. Which animals are affected by avian influenza?
The surprisingly long list of animals affected by current H5NI avian influenza infections includes:
- Wild birds, chickens, ducks, geese, and other poultry and commercial poultry from 48 states and more than 500 countries.
- Dairy cattle and other farm animals in nine states at the time of writing.
- Marine animals such as seals, sea lions, and even dolphins
- This includes wild animals such as foxes, skunks, and raccoons, as well as domestic animals such as domestic cats.
4. Why are experts concerned about this bird flu outbreak?
It may seem strange that there has been so much concern and news coverage about bird flu lately. After all, bird flu has been around for years. We have long known that this virus can infect non-avian animal species, including humans.
However, the current outbreak is unique and alarming for several reasons.
- It spreads quickly and widely. The virus has been found in the United States, Europe, the Middle East, Southeast Asia, multiple countries in sub-Saharan Africa, and even Antarctica.
- Many species are infected. Previously uninfected species are being affected, including animals in our food supply.
- Economic impact. If large numbers of beef cattle, dairy cattle, or chickens become sick or have to be culled (culled) to limit the spread of infection, there will be significant economic costs to farmers, agricultural operations, and the economies of affected countries. may have an impact. This could also mean higher prices at grocery stores.
- Exposure opportunities. In recent years, only two human infections have been reported in the U.S., both in people who worked with animals, but the more people are exposed to bird flu, the more the virus mutates. This increases the possibility that the virus can easily spread to humans.
- Possibility of death. Since 2003, severe forms of avian influenza have infected approximately 900 people in 23 countries with H5N1. More than half of the reported cases resulted in death. Please note that the calculation is not simple. There are probably many more cases of bird flu in humans, but the fatality rate may be overestimated because people with few or no symptoms or who were not tested are not counted. There may be.
- new mutation. It's rare, but possible. If this H5N1 bird flu develops mutations that allow it to spread efficiently from person to person, bird flu could become the next human pandemic.
5. Are milk, beef, chicken, and other foods safe?
Public health officials stress that the food supply is safe.
However, concerns have understandably increased since this outbreak was first discovered to have spread from birds to dairy cows. What's even more worrying? One study found fragments of avian influenza DNA, distinct from the live virus, in 20% of milk sold commercially in the United States.
So far, there is no indication that avian influenza in pasteurized milk, beef, or other common foods can cause illness in humans. Studies have shown that even if live avian influenza virus gets into the milk supply, regular pasteurization kills the virus. Initial tests did not detect the virus in the ground beef.
Of course, if you're particularly concerned, you can also avoid food and drinks made from animals infected with bird flu. For example, you can switch to oat milk or almond milk, even though there is currently no convincing scientific evidence.
6. What if I work with animals or have pets?
Avian influenza is rarely transmitted to pets. That's good news, but your pet can be exposed to an animal infected with bird flu by eating or playing with dead birds. Therefore, it is safest to limit your pet's exposure to potentially infected animals.
If you work with animals, especially birds or livestock, or if you hunt, the Centers for Disease Control and Prevention (CDC) recommends precautions to minimize your exposure to avian influenza. .
7. What else can I do to stay safe?
The CDC recommends that everyone take the following steps to avoid exposure to avian influenza:
- Avoid contact with sick or dead animals, and keep pets away.
- As is often the case on farms, avoid birds and animal faeces that may be contaminated by bird droppings.
- Do not cook or eat raw or undercooked foods.
- Avoid drinking raw (unpasteurized) milk, eating raw milk cheese, and raw or undercooked foods from animals suspected of having avian influenza.
- When working near sick or dead animals or their feces, wear personal protective equipment (PPE) such as safety glasses, gloves, and an N95 face mask.
At this time, the available evidence does not support more drastic preventive measures, such as switching to a whole plant diet.
8. Is there any good news about bird flu?
Despite all the alarming news about bird flu, this recent outbreak may pose little threat to human health. Viral strains can mutate to make them less efficient at spreading or less lethal. Efforts are underway to stop the spread of avian influenza to humans, including removing sick and infected animals from the food supply and testing dairy cows before transporting them across state lines. This includes increasing the
And we have other encouraging news.
9. How worried should I be about bird flu?
There's a lot we don't know, but one thing seems certain. Avian influenza will continue to evolve, posing challenges for farmers and health professionals to stay ahead of it. So far, public health experts believe that bird flu poses little health risk to the general population.
So now is not the time to panic about bird flu. However, we recommend that you take common sense steps to avoid exposure and stay updated with relevant news.
For the latest information in the US, please visit
CDC website
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