90-Second Read: Hantavirus outbreaks rare, but not unheard of in U.S.

Last month, the world's attention was gripped by an outbreak of the contagious "Andes strain" of Hantavirus aboard the M/V Hondius cruise ship. As of 2023, according to the most recent statistics from the Centers for Disease Control and Prevention, there have been 890 reported cases of Hantavirus in the United States since records began in 1993. Pennsylvania has reported only nine Hantavirus cases in a 30-year span, with the most recent occurring in late 2022. According to the most recent reports from the World Health Organization, 13 positive infections and three deaths have been reported so far, all suffered by either passengers or crew members of the ship.

In North America, cases of Hantavirus are attributed to the Sin Nombre Hantavirus. The Andes Hantavirus has not been previously reported in North America. Although there have been only nine known Hantavirus cases in Pennsylvania since 1993, there are other diseases that could be spread by rodent droppings, including lymphocytic choriomeningitis and the blood infection leptospirosis. New Mexico has the most cases with 129, followed by Colorado with 121.

In 2023, when the most recent Hantavirus data was recorded by the CDC, 26 individuals across the country tested positive. To date, the Andes Hantavirus is the only known Hantavirus that has demonstrated human-to-human transmission, though this occurs very inefficiently. Although there are key differences between both strains of Hantavirus, the main vector for human infection is the same for both Andes and Sin Nombre, rodent droppings. Consequently, any area where rodents are present carries a potential risk for acquiring Hantavirus infection.

All types of Hantavirus are acquired through inhaling aerosolized rodent excreta: saliva, feces and urine. Although Hantavirus is uncommon in the United States, it is also uncommonly deadly. In January 2018, a woman admitted to a Delaware hospital tested positive for the Andes strain shortly after returning from a two-week trip to Argentina and Chile, where the Andes strain is typically found.