90-Second Read: What do Argentine scientists know about Hantavirus so far?

The Andes strain of Hantavirus typically circulates via rodents, but human-to-human transmission such as the outbreak aboard the MV Hondius is not impossible either. AFP breaks down what Argentine scientists know so far about the rare respiratory disease and how it spreads. During the current epidemiological season, which runs from June to June each year, Argentina has recorded 102 Hantavirus cases, almost double the 57 reported in the same period the previous year. In the known cases of human-to-human Hantavirus transmission, the only rodent involved is the one that caused the first infection.

It requires close contact of less than one meter for 30 minutes, he said, adding that Hantavirus is "much less transmissible" than COVID-19 or the flu. Because there are so few Hantavirus cases, "you need a very long time to have a minimally decent number to draw conclusions," according to Lazaro. Bustamante has observed the same issue, there have only been between two and four Hantavirus cases a year at the hospital where he works in Bariloche. The South American country recorded transmission of the virus via humans during an outbreak in 1996, which was then confirmed in a second outbreak in 2018.

Three infected people died on the cruise ship that set sail from Ushuaia in the southern Argentine Tierra del Fuego province on April 1. Hantavirus typically spreads through the urine, feces and saliva of infected rodents, generally in closed environments. Scientists have rejected the idea that a recent mutation made the Andes virus transmissible between humans. Each Hantavirus has evolved since ancient times along with its rodent host without undergoing significant mutations.

How the virus spreads along "transmission chains with several links," and not just to one person, remains unknown, she added. Scientists from Argentina's leading epidemiological Malbran Institute will lead a fact-finding mission to Ushuaia next week to determine whether the virus is present in the area. Its heavy rains caused vegetation to grow more, which may in turn have increased Argentina's rodent population.