90-Second Read: How long is Hantavirus contagious? What to know about quarantine

Americans aboard the cruise ship at the center of a deadly Hantavirus outbreak were headed to quarantine on Monday, May 11, after they were evacuated back to the United States. As international health authorities continue to contend with the outbreak that has sickened at least 9, including three deaths, the long incubation period of the virus poses a challenge for quarantine measures. Experts know less about Hantaviruses and associated illnesses, especially the Andes virus, and how it may spread in the U.S., than something like the flu, which they see often. Hantavirus is typically transmitted to people through contact with rodents' urine, feces or saliva. The current Hantavirus cases are a little more complex to track than more common diseases because it's rarer.

Hantaviruses have relatively long incubation periods, according to the Centers for Disease Control and Prevention (CDC), taking between 1 and 8 weeks for symptoms to appear. More specifically, the CDC estimates symptoms of Hantavirus pulmonary syndrome (HPS) appear between 1 and 8 weeks after exposure, and symptoms of hemorrhagic fever with renal syndrome (HFRS) appear within 1 to 2 weeks; however, symptoms can rarely take up to 8 weeks. It's important to remember that Hantaviruses do not spread like COVID-19 or the common cold and generally require very close, extended contact, such as being confined to a cruise ship. They boarded a repatriation flight back to the States, where they will pass through an Air Force base before entering the National Quarantine Unit at the University of Nebraska Medical Center..

Public health officials also use incubation periods to help determine how long to track someone for signs of infection. Olivier Le Polan, unit head of epidemiology and analytics for response at the World Health Organization, told reporters on Monday, May 11, that it is tracking a 3 to 6-week incubation period, with most people expected to show symptoms by three weeks post-exposure. People are only infectious for about two to three days before they develop symptoms and then while they have symptoms. Hantavirus is primarily spread when people come in contact with urine, droppings and saliva from rats, according to the CDC. Knowing the incubation period of a disease is important for doctors and scientists because it tells them how long it takes for someone to get sick after they.

The quarantine period for each passenger will vary and be based upon an assessment done upon arrival in Nebraska, USA TODAY previously reported. Passengers who go home will still be subject to a monitoring period, which states like New York have identified as 42 days, in line with WHO recommendations. Somebody without symptoms can test positive, and nobody has ever studied those patients and how contagious they could be." "Without symptoms, it's very, very unlikely to infect anybody unless you have an exchange of fluids with another person, like a close partner. So if contagiousness starts with symptoms, when does it end? Americans evacuated from the cruise ship are being held at a quarantine center in Nebraska, where they will be monitored for symptoms.