GENEVA — The World Health Organization (World Health Organization) reported 11 confirmed cases of hantavirus linked to an outbreak aboard the cruise ship MV Hondius, including three deaths, with the Andes strain identified as the cause.
Health authorities said the outbreak is the only known cluster involving the Andes virus, a hantavirus strain that can spread between humans. The cases occurred among passengers and crew on the vessel.
Eighteen U.S. passengers have returned to the United States for monitoring and isolation. The U.S. Centers for Disease Control and Prevention (Centers for Disease Control and Prevention) has not announced the length of quarantine, though the virus has an incubation period of up to 42 days.
Health experts noted that hantaviruses have circulated in the United States for decades. Between 1993 and 2023, 35 deaths in Texas and nearly 900 cases nationwide were recorded, all linked to rodent exposure.
The Sin Nombre strain, found in western deer mice in the Southwest, does not spread between humans, according to public health data.
Experts said the Andes strain differs in its ability to transmit between people, raising questions about whether viral reassortment could occur if multiple hantavirus strains infect a single host. Reassortment is a process in which viruses exchange genetic material and form new variants.
Infectious disease specialist Dr. Máximo Brito said there is currently limited cause for alarm because hantaviruses mutate more slowly than viruses such as influenza and SARS-CoV-2, reducing the likelihood of reassortment.
He added that the risk is not zero and said environmental changes, including climate change, could increase human exposure to wildlife and raise the likelihood of future outbreaks.
