Twenty-three passengers from the MV Hondius cruise ship who were unknowingly exposed to hantavirus have returned home to various countries worldwide, including the United States. Among them is a man from Switzerland who is already sick with the virus, and a Frenchman who tested positive after contact with him on a plane.

Typically, hantavirus is transmitted through rodent droppings. However, this strain — known as the Andes virus — can also spread through human-to-human contact. Symptoms may take up to eight weeks to appear, making it difficult to determine how many passengers have been infected or how many have already spread the virus.

Authorities state that while hantavirus has a high fatality rate (up to 40%), it is not as contagious as COVID-19. Experts emphasize that transmission requires prolonged close contact, such as sharing meals, rather than casual conversations.

According to a passenger still aboard the ship, the travelers did not realize they had been exposed when leaving the vessel during its stop at Saint Helena on April 23. The passenger noted that “there are 23 people wandering around there, and until three days ago, no one had contacted them.” This passenger also reported that individuals returned to their home countries: the Swiss man with his wife went back to Switzerland, an Australian returned to Australia, a Taiwanese person returned to Taiwan, Americans across North America, an Englishman returned to England, and Dutch passengers returned to the Netherlands.

Investigations in Argentina suggest a Dutch couple brought the virus onboard after picking it up from rodents at a landfill during bird-watching tours days before the ship departed from Ushuaia on March 20. Both individuals have since died.

Health officials report that national governments are now conducting contact tracing, but experts warn that the response may be delayed because passengers were only informed of the outbreak days after symptoms began.