90-Second Read: Americans from Hantavirus-hit cruise ship back in U.S.: What to know, where they will quarantine

One the 17 American passengers evacuated from the ship and flown to Nebraska also tested positive for the Hantavirus but is not showing any symptoms. State health officials said it's up to the local health department to decide whether to test the Arizona resident for Hantavirus, but noted that any test results would likely be negative since the person is asymptomatic. The strain of Hantavirus involved in the cruise ship outbreak, known as the Andes strain, is the only version known to be transmissible between humans. The Americans will be quarantined and monitored at a special unit at the University of Nebraska Medical Campus in Omaha. Arizona and Virginia are monitoring one each California's health department said Friday in a statement that at least one California resident remains on board.

I don't believe asymptomatic spread in the home is a concern." Arizona state health officials said Thursday at a press briefing that the resident there who returned from the cruise is being monitored for symptoms and having their temperature checked daily as well. Hantavirus was first identified as a cause of sickness of one of the cases on May 2. But the Andes virus detected in the cruise ship outbreak may be able to spread between people in rare cases. The 17 passengers will be received at the National Quarantine Unit, a secured facility on the University of Nebraska Medical Center campus in Omaha, said Dr. Georgia and Texas have each said they are monitoring two residents who were on the cruise ship.

Hantavirus usually spreads from rodent droppings and is not easily transmitted between people. People are typically exposed to Hantavirus around their homes, cabins or sheds, especially when cleaning enclosed spaces with little ventilation or exploring areas with mouse droppings. Symptoms of Hantavirus pulmonary syndrome usually show between one and eight weeks after contact with an infected rodent. Hantavirus pulmonary syndrome is fatal in about 35% of people infected, while the death rate for hemorrhagic fever with renal syndrome varies from 1% to 15% of patients, according to the CDC. According to Wadman, there are 20 available spaces in the quarantine unit and each individual will have their own room and get food delivered to them.

The agency has classified the Hantavirus outbreak as a "level 3," which is the lowest level of concern. The other syndrome caused by Hantavirus, known as hemorrhagic fever with renal syndrome, which can cause bleeding, high fever, and kidney failure, usually develops within a week or two after exposure. The Texas Department of State Health Services (DSHS) said Thursday in a statement that the two residents who were on board are monitoring themselves for symptoms with daily temperature checks and will contact public health officials at any sign of possible illness. If they develop any symptoms, they will contact public health and isolate. Death rates vary by which Hantavirus causes the illness.