Hantavirus in the US: Where the rare, sometimes deadly disease has been found

Among passengers of the ship, which was traveling from Argentina across the Atlantic, there have been three deaths and at least eight reported cases, several of them laboratory-confirmed, according to the World Health Organization and subsequent health reports.

At least five states are now monitoring residents who returned from the MV Hondius, including Texas, Virginia, Georgia, Arizona and California, reports have noted.

CDC data supports this, showing that 890 cases of hantavirus disease have been reported in the U.S. from 1993 through the end of 2023.

"Most of these cases have been west of the Mississippi River, and classically the risk factors are being in contact with feces and urine from rodents," Marcos told Fox News Digital. 

The most common strain is called Sin Nombre, which is not transmitted from human to human, the doctor said.

Most strains of hantavirus spread from inhaling contaminated particles from rodent urine, droppings or saliva - or, less commonly, from touching contaminated surfaces and then touching the mouth, nose or eyes - and are not transmitted person-to-person.

"They were not symptomatic at all - the incubation period can be one, two, three or four weeks," Marcos said.

"Some people may have mild disease, so not everybody will be very, very sick," the doctor noted.

"It has to be really, really close contact," he said. "The transmission is not as efficient as other viruses."

While it's possible for the virus to be airborne via droplets, Marcos pointed out that those transmissions are "not as effective" as COVID, influenza or cold viruses. 

There are not currently any antiviral treatments for hantavirus. 

Although there is not currently a vaccine for hantavirus in the U.S., Marcos noted that several are in development.

The doctor said he believes the risk of hantavirus leading to a pandemic is "pretty much almost zero."

"I really think this is going to go away in the next two to three weeks, and we will know exactly the number of cases," he added.

To prevent hantavirus, Marcos recommends wearing gloves and a mask in environments where mice might be present, such as cleaning a basement. 

Proper ventilation and frequent hand-washing can also help curb spread.