Gabriela Emanuel

That can be annoying because you have to watch for symptoms, but it gives medical experts time to get a handle on the outbreak.

It's serious.

It's serious.

In this outbreak, we have nine cases so far, three deaths, according to the World Health Organization.

Authorities say in general, between 30 and 40 percent of patients die.

Basically, what happens is their lungs fill up with fluid.

However, that fatality rate is likely significantly lower because many mild cases go undetected.

But it's still a big percentage and there's no vaccine or specific treatment.

And another thing that makes this virus serious is the early symptoms are very generic flu-like symptoms like a fever or muscle aches, meaning it can be hard to know when you need to isolate and get medical attention.

Yeah, so it starts spreading right around the onset of symptoms and in very close contact.

Yet scientists can't say definitively if it's droplets in the air or the virus lives on surfaces.

What we do know is this hantavirus does not attack the upper respiratory tract or even respiratory cells as much as it attacks the blood vessels, which impact the lungs in the lower respiratory tract.

That's likely part of why it does not transmit as easily as, say, the common cold.

But scientists still need to learn more.

Dr. Weaver actually had a grant from the federal government to study hantavirus, and the grant was terminated last May by the Trump administration.

That worries Weaver.

He says more investment, not less, is needed.

It happened in 2018, 2019, and one man spread the virus to 33 other people with 11 deaths total.

So deadly but not huge.

Researchers found that the genetic makeup of that virus was almost exactly the same as in an outbreak two decades earlier.