Argentinian scientists have identified the Andes strain of hantavirus as the source of a recent outbreak on a cruise ship departing from Ushuaia.
This discovery is critical because the Andes strain is the only one of approximately 40 [1] known hantavirus variants capable of human-to-human transmission. Most other variants require contact with rodent excrement to infect humans, but this specific strain can spread between people and carries a very high mortality rate [2].
The outbreak was detected in early 2026 as the vessel left the port of Ushuaia [3]. Researchers traced the virus to the Andes region of Patagonia, noting that it traveled through northern Argentina before the cruise departed [3], [4].
While some scientific reports indicate the Andes strain has been confirmed as the origin, official government positions vary. Some authorities said they are still investigating and have not yet confirmed the strain as the definitive source [4].
Public health data shows a significant increase in hantavirus activity in the region. There have been 31 [5] new hantavirus cases reported in the recent period, compared to an average of 16 [5] cases during the previous five-year period.
The increase in cases has prompted health authorities to monitor the Patagonia region more closely. The ability of the Andes strain to move through a crowded environment, such as a cruise ship, increases the risk of rapid transmission compared to traditional rural exposures [2].
“The Andes hantavirus is the only one of approximately 40 known variants capable of human-to-human transmission.”
The identification of the Andes strain suggests that the cruise ship acted as a catalyst for a virus that typically remains isolated in rural Patagonia. Because this specific variant can spread between humans, it transforms a localized zoonotic risk into a potential public health emergency that can travel across international borders via tourism.
