(FOX40.COM) — Health officials across the globe are racing to track down and prevent the spread of hantavirus after a deadly outbreak hit a luxury cruise and killed three people. Just this week, the California Department of Public Health confirmed California residents were aboard and have returned to the state.

As community members become increasingly riddled with questions and fear, Doctor Dean Blumberg with UC Davis Health shared a message to Californians.

“If you weren’t on that cruise ship, if you’re not in contact with somebody who was on that cruise ship, you’re safe,” Dr. Blumberg said.

The announcement that Californians aboard the boat have returned to the state has sparked waves of fear across social media with some people reflecting on 2020 and asking if this has the potential to evolve into another pandemic.

“This is so much different than covid,” Dr. Blumberg said. “In January of 2020, people in my field were really worried about COVID, even though it hadn’t hit the U.S. yet, we knew it was going to be something. I’m not aware that anybody is really thinking that in my field with hantavirus these days.”

He said hantavirus is far less easily spread than COVID-19.

“It’s by respiratory droplets and it’s by very close proximity,” Dr. Blumberg said.

The strain linked to this incident, a separate one from what is historically found in California, is generally transmitted from environments contaminated by rodent droppings. Dr. Blumberg said only about 5% to 8% of cases are spread person-to-person.

However, he said, when contracted, it is severe and symptoms escalate rapidly. He added that the fatality rate is reportedly nearly 40% and there is no antiviral treatment nor is there a vaccine.

“It causes an illness that starts off just like many other infections with fever, nausea, muscle aches, but then a couple of days in, it can have a really rapid progression to very severe pneumonia with leaky lungs that just can’t get any oxygen exchange going on,” Dr. Blumberg said.

To put things in perspective, the California Department of Public Health has a map available online that shows hantavirus cases in the state between 1980 and 2025. The map indicates that most areas had zero cases and the other most common shade on the map is just 1-5 cases.

Therefore, health experts said to be aware, but not afraid.

“The increased awareness is very useful, but I’m certainly not worried about seeing a lot more cases or an outbreak,” Dr. Blumberg assured.

A spokesperson for the California Department of Public Health said the agency cannot share information about where the California residents who were on the ship live, but the department said they are being monitored by medical professionals.

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