H5N1 outbreak: Cambodia reports 12th case this year; early symptoms to watch for

Cambodia’s health ministry just reported another human case of H5N1 bird flu this year—this time, it’s a 5-year-old boy from Kampot province, Center for Infectious Disease Research and Policy (CIDRAP), University of Minnesota said citing a Facebook post that has translated and posted the information.

This is the 12th case of H5N1 infection from Cambodia, this year.

H5N1, also known as avian influenza or bird flu is originally found in birds, it has occasionally crossed over to humans, usually through close contact with infected poultry. Though rare, human infections tend to be serious and sometimes even deadly.

Despite its severity, many people are still unaware of how it presents in humans.

Here’s what you should know.

It starts like any flu, but don’t be fooled
The early signs of H5N1 infection can look just like the seasonal flu. That’s why it often goes unnoticed in the beginning.

H5N1—also known as bird flu—isn’t your average flu. It usually spreads from infected birds to people (think chickens, ducks, even cows lately), and while human cases are rare, they can be serious. So what should you watch out for if you’ve been around birds or on a farm?

At first, H5N1 can look a lot like the regular flu. You might get:

• A high fever
• Chills
• Body aches
• Cough
• Runny nose
• Sore throat

Sounds familiar, right? But here’s where it gets intense:
For some people, symptoms ramp up quickly. That means:

• Shortness of breath or difficulty breathing
• Chest pain
• Fatigue that wipes you out
• Diarrhea, nausea, or even vomiting
• And in some serious cases—confusion, seizures, or coma

Unlike seasonal flu, H5N1 often goes straight for the lungs. It can cause pneumonia or even acute respiratory distress, which is why many people who get really sick end up in the ICU.

The tricky part? Symptoms can take 2 to 8 days to show up after exposure, so you might feel fine at first—then suddenly not.

H5N1 outbreak in the US
H5N1 bird flu has been spreading across U.S. farms since early 2024, with about 70 human cases—mostly from direct animal exposure—and a first fatality in Louisiana in January 2025. The virus, especially the new D1.1 strain, has jumped into dairy cows, sparking concern over potential mutations that could boost human-to-human spread. While the CDC still rates overall risk as low, it warns that reduced surveillance and ongoing mammal infections make the situation unpredictable.

When should you see a doctor?
If you’ve recently handled poultry, been in live bird markets, or live in an area where bird flu has been reported, you need to be cautious even if your symptoms seem mild at first.

Seek medical attention immediately if:

• Your fever doesn’t go down after 48 hours
• You’re short of breath, or breathing feels harder than normal
• You have chest pain or pressure
• Your cough gets worse and includes blood
• You feel confused, very sleepy, or unusually weak
• You’ve had direct contact with birds in the past 10 days

Even if it turns out to be another illness, it’s always better to rule out something serious early.

Treatment and why timing matters
It’s also worth noting that antibiotics won’t help, because H5N1 is caused by a virus, not bacteria. Only targeted antiviral treatment can assist, alongside rest, hydration, and hospital support in severe cases.

Pay attention to your body. If you feel worse than usual, if your symptoms escalate fast, or if you have any exposure to birds, don’t wait it out. Get checked. Most of all, take your health seriously. Your body often tells you when something’s wrong, you just have to listen closely.