Hantavirus Cases in Argentina Prompt Review After Cruise Ship Deaths

An outbreak of hantavirus in rural communities in Patagonia 30 years ago led scientists to document the first known instance of person-to-person transmission of the virus, which had previously been understood to spread only through contact with rodents.

Nearly a decade ago, another outbreak in the same region provided further evidence of inter-human spread. An infected 68-year-old rural worker attended a birthday party in a small village, after which the infection spread and resulted in 11 deaths. These earlier cases have been recalled following the deaths of three people from hantavirus on the Dutch cruise ship MV Hondius.

The vessel had departed from Argentina bound for Cape Verde. The World Health Organization has ruled out an epidemic on the ship and is investigating whether transmission occurred before boarding. Tests on surviving passengers confirmed infection with the Andes strain.

This is the only hantavirus strain in which human-to-human transmission has been documented. It is found mainly in parts of Argentina and Chile. Argentine scientists who have studied the virus for decades said the country is not facing anything significantly new.

They noted a slight recent increase in cases but said it remains consistent with patterns from previous decades. Since July last year, Argentina has recorded 101 hantavirus cases with 32 deaths. In the 2024-25 season, there were 64 cases and 14 deaths.

The 2023-24 season saw 82 cases and 13 deaths. One biologist attributed the recent rise to rodent population changes linked to weather patterns. A significant drought in 2023 and 2024 was followed by increased rainfall, which produced greater vegetation cover and more food for rodents.

The World Health Organization has stated that the risk of hantavirus to the general population is absolutely low. Person-to-person transmission does not occur easily. Argentina's annual total remains far below the thousands of cases reported each year in China and the Republic of Korea.

The Dutch couple who first developed symptoms had been in Argentina since 27 November. They made multiple car journeys, including trips to Chile and Uruguay, before boarding the ship on 1 April from the port of Ushuaia. Argentina's health ministry plans to capture rodents for analysis along the route they traveled.

The ministry has stated that it is not confirmed the infection occurred in Argentina. The province from which the ship departed, Tierra del Fuego, has not had a confirmed hantavirus case in the past 30 years.

Hantavirus infections occur in many regions, with up to 100,000 cases annually worldwide, most in Asia and Europe. Fatality rates differ by strain: up to 15 percent in those regions compared with rates that can reach 50 percent in the Americas. Scientists have linked Argentina's position as the Latin American country with the highest total to the climate crisis and ecological changes, including the loss of natural predators of rodents.

Reporting of hantavirus infections has been mandatory in Argentina since the 1996 outbreak.