The media is full of news about an outbreak of a Patagonian strain of hantavirus that caused three deaths on board a cruise ship, the MV Hondius, that had set sail from Ushuaia, Tierra del Fuego on April 1, 2026.
Apparently the cases zero and one, were a Dutch couple that had arrived in South America last November, and traveled extensively in Chile, Uruguay, and Argentina, where they visited Neuquen, Mendoza, Salta, Misiones, and Buenos Aires, before arriving in Tierra del Fuego on March 29, a couple of days before embarking on the MV Hondius (pictured below).
The strain of hantavirus that killed these two tourists is unique to the Patagonian Andean region, it is carried by a species of mouse that lives in the Andean forests which passes it on to humans, and then, and this is the worrying part, it can jump from human to human. A unique feature of this strain.
The latest epidemiological bulletin (online, in Spanish) issued by the Argentine Ministry of Health discloses that the frequency of infection is very low, 0.32 per 100,000 people. Furthermore, there were 101 cases during 2025-2026 ytd vs. 57 for 2024-2025. The highest prevalence has been in the Northwestern provinces with 0.60 per 100,000, with 36 cases, 83% of them in Salta. There have been 32 deaths with a lethality of 31.7%. The following map shows the hotspots (red yellow, highest, black lowest) in the NW and Buenos Aires regions.
Hantavirus strains are found around the world, originally detected in Korea in the 1950s it was later identified in other places, including the Southwestern USA. These virus cause a high level of mortality. In Argentina there are different strains, and can be found in Buenos Aires, the Northeast (Misiones), Northwest (Salta), Cuyo and Patagonia regions.
It hasn't been detected yet in Tierra del Fuego, though sampling is ongoing, to capture mice and check them for the virus.
Contagion takes place when a person is exposed to the feces or urine of mice, in the forests, or while entering or cleaning rooms that have been closed for a long time where mice may have nested or lived, the dust particles in the air can carry the virus.
Back in 2018-2019, there was an outbreak in Epuyen, the region around the lake and river where the Plesiosaur was reported back in 1922. It infected dozens and killed eleven people with a very high mortality rate.
In this latest outbreak, the Dutch man died at sea on April 11, his wife died in a South African hospital on April 26, and the third person on May 2. A high death toll of 3 out of 147 people on board between crew and passengers.
Before the 2018-2019 Epuyén outbreak, only 2.5% of the cases were due to human-to-human transmission of the virus. This time it seems higher, and strengthened by the closed quarters of a ship at sea.
The 2018 Epuyén outbreak began with a man who had gathered mushrooms in the forest and fell ill, he infected people who he met, and more died after getting infected at the wake of one of the deceased. The lag between contact and end of contagion was determined to be 45 days. This outbreak had a 20-30% mortality rate.
Furhter reading about the 2018 outbreak here, online (Spanish).
No cases have been reported in Tierra del Fuego, and the local rodent, of the Oligoryzomys longicaudatus magallanicus subspecies does not seem to be a carrier. Further studies should clarify the issue. So, when visiting Patagonia, stay on the trails when trekking, keep in the open, avoid places where mice live and stay out of old sheds, barns, closed areas. The CDC has some interesting tips for protection against hantavirus, which are valid for the Andean strain.
In Patagonia, there is a cycle of population growth among the mice that are the carriers of the virus. When food is abundant, mice proliferate and they can be found by the hundreds in the forests. Some make it into settled areas and the interaction of mouse and human can lead to contagion. However, as the figures show, the chances of infection are extremely low. These people seem to have had bad luck.
Personally, seing how cruise ships were hit by Covid-19 during the pandemic, and how this virus and others (like norovirus), I will stay away from them.
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2026 by Austin Whittall ©
