MILWAUKEE (CBS 58) -- CDC teams continue to work with state and public health authorities as they monitor the deadly hantavirus outbreak that began on a cruise ship.

But Wisconsin officials say the threat of an outbreak here is extremely low. No passengers were from Wisconsin, and no one affected will be coming here for monitoring.

This strain of the hantavirus is the only one that is passed from person to person.

But other strains have already been in Wisconsin for years.

All but one of the roughly 25 hantaviruses are passed to humans by rodents. Some don't even infect humans.

The cruise ship virus is from south America. All the others are spread directly from rodents, when dried feces turns to dust and is inhaled.

Dr. Tony Goldberg is a professor of epidemiology at the UW Madison School of Veterinary Medicine. He told us, "We've known about hantaviruses for a long time."

Goldberg's level of concern is a two out of ten, the lowest he'll go.

He says hantavirus is a very different virus from coronavirus, and the chances of a pandemic are extremely low. "They don't transmit very efficiently among people and we don't expect them to cause a major epidemic."

There are several genuses within the family and each has several species that have different features and behaviors.

All rats and mice do not have hantavirus.

The very first hantavirus case in the US was in Wisconsin. In 2016, someone in Wisconsin contracted what's called the Seoul strain, believed to have come from the rats they bred to sell as pets.

The most common is the "sin nombre" virus, found in wild deer mice, including those in Wisconsin.

"We have had a couple of sporadic cases of hantavirus in Wisconsin. The most recent one being in 2025," said Dr. Angie Maxted, the state public health veterinarian at Wisconsin DHS.

She said hantavirus pulmonary syndrome causes difficulty breathing and shortness of breath. And it usually requires hospitalization. Symptoms include fever, chills, and gastrointestinal issues.

Milwaukee's Department of Neighborhood Services says rats "destroy thousands of dollars worth of property each year."

And Orkin ranked the city of Milwaukee the 16^th "rattiest" city in the us in 2025 based on service requests.

City code says property owners must make their buildings "reasonably ratproof" and are responsible for eliminating infestations. If they don't, the city will do it and then charge the owner.

Maxted told us, "Even though rodent encounters are incredibly common, it's a very, very rare disease."

As experts monitor the cruise ship outbreak, they're urging awareness but not concern.

Goldberg said, "For the average person who's dealing with the occasional mouse in a trap or a few cute little house mice just running around, it's not much of a concern."

The experts say common sense goes a long way: wear a mask and gloves when cleaning out a basement or garage that may have mouse or rat droppings. And the same goes for if you catch a rodent in a trap and need to dispose of it.